0001140361-23-009417 | 10-K | XBRL Viewer

Amount to be reclassified from AOCI as a reduction to interest expense during next twelve months

Derivatives Not Designated as Hedging Instruments [Member]

Netting adjustments, fair value

117,294

60,455

^[1]

24,109

(170)

Net derivatives in the balance sheet, fair value

93,185

60,625

Derivatives not offset on the balance sheet, fair value

352

5,455

Cash collateral, fair value

^[2]

Net derivative amounts, fair value

92,833

55,170

Netting adjustments, fair value

117,257

60,263

^[1]

5,482

Net derivatives in the balance sheet, fair value

117,257

54,781

Derivatives not offset on the balance sheet, fair value

352

5,455

Cash collateral, fair value

^[2]

43,420

Net derivative amounts, fair value

116,905

5,906

Derivatives Not Designated as Hedging Instruments [Member] | Other Income [Member]

Gain or loss recognized in income on derivatives not designating as a hedging relationship [Abstract]

(Decrease) increase in other income

$ (155)

$ (356)

$ 1

Derivatives Not Designated as Hedging Instruments [Member] | Interest Rate Swaps [Member]

Interest rate derivatives [Abstract]

Number of risk participation agreements held | Agreement

Derivatives Not Designated as Hedging Instruments [Member] | Interest Rate Swaps [Member] | Other Assets [Member]

$ 1,275,708

$ 1,342,187

Derivatives Not Designated as Hedging Instruments [Member] | Interest Rate Swaps [Member] | Other Liabilities [Member]

117,247

60,203

1,275,708

1,342,187

Derivatives Not Designated as Hedging Instruments [Member] | Risk Participation Agreements [Member] | Other Assets [Member]

117,247

60,203

88,963

90,938

Derivatives Not Designated as Hedging Instruments [Member] | Risk Participation Agreements [Member] | Other Liabilities [Member]

252

18,421

37,193

Commitments and Contingent Liabilities [Abstract]

$ 10

$ 60

[1]

Netting adjustments represents the amounts recorded to convert derivatives assets and liabilities from a gross basis to a net basis in accordance with the applicable accounting guidance on the settle-to-market rules for cleared derivatives. The CME legally characterizes the variation margin posted between counterparties as settlements of the outstanding derivative contracts instead of cash collateral. Company began to clear certain derivative transactions through the CME in 2021.

[2]

Cash collateral represents the amount that cannot be used to offset our derivative assets and liabilities from a gross basis to a net basis in accordance with the applicable accounting guidance. The other collateral consists of securities and is exchanged under bilateral collateral and master netting agreements that allow us to offset the net derivative position with the related collateral. The application of the other collateral cannot reduce the net derivative position below zero. Therefore, excess other collateral, if any, is not reflected above.

Acquisitions

12 Months Ended

Dec. 31, 2022

Acquisitions [Abstract]

Acquisitions

3.	Acquisitions

In 2020, the Company acquired Alliance Benefit Group of Illinois, Inc. for a total consideration of $9.1 million. As part of the acquisition, the Company recorded goodwill of $5.8 million and $5.1 million of contingent consideration recorded in other liabilities on the consolidated balance sheet as of December 31, 2020.

The operating results of acquired companies are included in the consolidated results after the dates of acquisition.

Pending Acquisition of Salisbury Bancorp, Inc.

On December 5, 2022, the Company entered into an Agreement and Plan of Merger (the “Merger Agreement”) with Salisbury Bancorp, Inc. (“Salisbury”), Salisbury Bank and Trust Company (“Salisbury Bank”), Salisbury’s subsidiary bank, and NBT Bank, the Company’s subsidiary bank, pursuant to which the Company will acquire Salisbury. Salisbury, with assets of approximately $1.54 billion at December 31, 2022, is headquartered in Lakeville, Connecticut. Its primary subsidiary, Salisbury Bank, is a Connecticut chartered commercial bank with 14 banking locations in northwestern Connecticut, the Hudson Valley region of New York and southwestern Massachusetts.

Subject to the terms and conditions of the Merger Agreement, which has been approved by the boards of directors of each party, Salisbury will merge with and into the Company, with the Company as the surviving entity, and immediately thereafter, Salisbury Bank will merge with and into NBT Bank, with NBT Bank as the surviving bank (the “Merger”).

Under the terms of the Merger Agreement, each outstanding share of Salisbury common stock will be converted into the right to receive 0.7450 shares of the Company’s common stock. The Merger is subject to customary closing conditions, including the receipt of regulatory approvals and approval by the stockholders of Salisbury, and is expected to close in the second quarter of 2023.

Securities, Gains and (Losses) on Equity Securities (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Gains (losses) on equity securities [Abstract]
Net (losses) and gains recognized on equity securities	$ (1,135)	$ 537
Less: Net (losses) and gains recognized on equity securities sold during the period	0	0
Unrealized (losses) and gains recognized on equity securities still held	(1,135)	537
Equity Securities without Readily Determinable Fair Value, Annual Amount [Abstract]
Carrying amount of equity securities without readily determinable fair values	1,000	1,000
Impairment adjustments of equity securities without readily determinable fair values	0	0
Downward adjustments of equity securities without readily determinable fair values	0	0
Upward adjustments of equity securities without readily determinable fair values	$ 0	$ 0

Reclassification Adjustments Out of Other Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Reclassification Adjustments out of AOCI [Abstract]
Net securities (gains) losses	$ 1,131	$ (566)	$ 388
Interest income (expense)	362,190	321,088	315,678
Other noninterest expense	19,795	20,339	24,863
Income tax (benefit) expense	44,161	44,973	28,699
Net Income	151,995	154,885	104,388
Reclassification out of Accumulated Other Comprehensive Income [Member]
Reclassification Adjustments out of AOCI [Abstract]
Total reclassifications, net of tax	938	1,478	1,923
Accumulated Net Unrealized Investment Gain (Loss) [Member] \| Reclassification out of Accumulated Other Comprehensive Income [Member]
Reclassification Adjustments out of AOCI [Abstract]
Income tax (benefit) expense	(128)	(145)	(160)
Net Income	385	432	481
(Gains) on AFS securities [Member] \| Reclassification out of Accumulated Other Comprehensive Income [Member]
Reclassification Adjustments out of AOCI [Abstract]
Net securities (gains) losses	0	0	(3)
Amortization of Unrealized Gains Related to Securities Transfer [Member] \| Reclassification out of Accumulated Other Comprehensive Income [Member]
Reclassification Adjustments out of AOCI [Abstract]
Interest income (expense)	513	577	644
Net Unrealized Losses on Cash Flow Hedges Reclassified to Interest Expense [Member] \| Reclassification out of Accumulated Other Comprehensive Income [Member]
Reclassification Adjustments out of AOCI [Abstract]
Interest income (expense)	0	21	296
Income tax (benefit) expense	0	(5)	(74)
Net Income	0	16	222
Accumulated Defined Benefit Plans Adjustment [Member] \| Reclassification out of Accumulated Other Comprehensive Income [Member]
Reclassification Adjustments out of AOCI [Abstract]
Income tax (benefit) expense	(184)	(343)	(407)
Net Income	553	1,030	1,220
Amortization of Net Losses [Member] \| Reclassification out of Accumulated Other Comprehensive Income [Member]
Reclassification Adjustments out of AOCI [Abstract]
Other noninterest expense	623	1,263	1,535
Amortization of Prior Service Costs [Member] \| Reclassification out of Accumulated Other Comprehensive Income [Member]
Reclassification Adjustments out of AOCI [Abstract]
Other noninterest expense	$ 114	$ 110	$ 92

Stock-Based Compensation (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Share-based compensation [Abstract]
Stock-based compensation expense	$ 4,530	$ 4,414	$ 4,581
Weighted Average Remaining Contractual Term and Aggregate Intrinsic Value [Abstract]
Number of shares available for future grant (in shares)	384,182
Stock Options [Member]
Share-based compensation [Abstract]
Stock awards termination period	10 years
Stock-based compensation expense	$ 0	$ 0	0
Number of Shares [Roll Forward]
Outstanding, beginning of period (in shares)	9,100
Exercised (in shares)	0
Expired (in shares)	0
Outstanding, end of period (in shares)	9,100	9,100
Exercisable, end of period (in shares)	9,100
Weighted Average Exercise Price [Abstract]
Outstanding, beginning of period (in dollars per share)	$ 29.89
Exercised (in dollars per share)	0
Expired (in dollars per share)	0
Outstanding, end of period (in dollars per share)	29.89	$ 29.89
Exercisable, end of period (in dollars per share)	$ 29.89
Weighted Average Remaining Contractual Term and Aggregate Intrinsic Value [Abstract]
Weighted average remaining contractual term, outstanding, end of period	3 years 25 days
Weighted average remaining contractual term, exercisable, end of period	3 years 25 days
Aggregate intrinsic value, outstanding, end of period	$ 123
Aggregate intrinsic value, exercisable, end of period	123
Proceeds from stock options exercised	0	$ 112	185
Tax benefits related to stock options exercised	0	13	41
Intrinsic value of stock options exercised	0	52	165
Restricted Stock [Member]
Share-based compensation [Abstract]
Stock-based compensation expense	$ 4,500	4,400	4,600
Restricted Stock [Member] \| Employees [Member] \| Minimum [Member]
Share-based compensation [Abstract]
Stock awards vesting period	3 years
Restricted Stock [Member] \| Employees [Member] \| Maximum [Member]
Share-based compensation [Abstract]
Stock awards vesting period	5 years
Restricted Stock [Member] \| Non-employee Directors [Member]
Share-based compensation [Abstract]
Stock awards vesting period	3 years
Restricted Stock Units (RSUs) [Member]
Share-based compensation [Abstract]
Tax benefit on restricted stock awards	$ 1,200	$ 1,900	$ 1,000
Unrecognized compensation cost	$ 5,700
Unrecognized compensation cost, weighted average period of recognition	1 year 6 months
Number of Shares [Roll Forward]
Unvested, beginning of period (in shares)	494,032
Forfeited (in shares)	(16,893)
Vested (in shares)	(114,745)
Granted (in shares)	169,978
Unvested, end of period (in shares)	532,372	494,032
Weighted Average Grant Date Fair Value [Abstract]
Unvested, beginning of period (in dollars per share)	$ 30.89
Forfeited (in dollars per share)	31.28
Vested (in dollars per share)	31.96
Granted (in dollars per share)	35.59
Unvested, end of period (in dollars per share)	$ 32.15	$ 30.89

Loans

12 Months Ended

Dec. 31, 2022

Loans [Abstract]

Loans

5. Loans

A summary of loans, net of deferred fees and origination costs, by category is as follows:

	At December 31,
(In thousands)	2022		2021
Commercial & industrial	$	1,265,082	$	1,155,240
Commercial real estate		2,807,941		2,655,367
Paycheck protection program		949		101,222
Residential real estate		1,649,870		1,571,232
Indirect auto		989,587		859,454
Residential solar		856,798		440,016
Home equity		314,124		330,357
Other consumer		265,796		385,571
Total loans	$	8,150,147	$	7,498,459

Included in the above loans are net deferred loan origination (fees) costs totaling $(109.1) million and $(23.7) million at December 31, 2022 and 2021, respectively. The Company had $0.6 million and $0.8 million of residential loans held for sale as of December 31, 2022 and 2021, respectively.

The total amount of loans serviced by the Company for unrelated third parties was $576.0 million and $575.9 million at December 31, 2022 and 2021, respectively. At December 31, 2022 and 2021, the Company had $0.6 million and $1.0 million, respectively, of mortgage servicing rights. In addition, as of December 31, 2022 and 2021, the Company serviced Springstone consumer loans of $6.2 million and $11.4 million, respectively.

At December 31, 2022 and 2021, the Company serviced $31.0 million and $25.6 million, respectively, of agricultural loans sold with recourse. Due to sufficient collateral on these loans and government guarantees, no reserve is considered necessary at December 31, 2022 and 2021.

FHLB advances are collateralized by a blanket lien on the Company’s residential real estate mortgages.

In the ordinary course of business, the Company has made loans at prevailing rates and terms to directors, officers and other related parties. Such loans, in management’s opinion, do not present more than the normal risk of collectability or incorporate other unfavorable features. The aggregate amount of loans outstanding to qualifying related parties and changes during the years are summarized as follows:

(In thousands)	2022			2021
Balance at January 1	$	3,292		$	5,936
New loans		576			182
Adjustment due to change in composition of related parties		(37	)		(683	)
Repayments		(1,315	)		(2,143	)
Balance at December 31	$	2,516		$	3,292

Summary of Significant Accounting Policies, Loans (Details)	12 Months Ended
	Dec. 31, 2022
Loans [Abstract]
Minimum number of days past due for loans to be considered nonperforming	90 days
Period of sustained repayment performance for nonperforming TDRs to be returned to performing status	6 months

Commitments and Contingent Liabilities

12 Months Ended

Dec. 31, 2022

Commitments and Contingent Liabilities

18. Commitments and Contingent Liabilities

The Company’s concentrations of credit risk are reflected in the consolidated balance sheets. The concentrations of credit risk with standby letters of credit, unused lines of credit, commitments to originate new loans and loans sold with recourse generally follow the loan classifications.

At December 31, 2022, approximately 59% of the Company’s loans were secured by real estate located in central and upstate New York, northeastern Pennsylvania, western Massachusetts, southern New Hampshire, Vermont, southern Maine and central Connecticut. Accordingly, the ultimate collectability of a substantial portion of the Company’s portfolio is susceptible to changes in market conditions of those areas. Management is not aware of any material concentrations of credit to any industry or individual borrowers.

The Company is a party to certain financial instruments with off-balance sheet risk in the normal course of business to meet the financing needs of its customers. These financial instruments include commitments to extend credit, unused lines of credit, standby letters of credit and certain agricultural real estate loans sold to investors with recourse, with the sold portion having a government guarantee that is assignable back to the Company upon repurchase of the loan in the event of default. The Company’s exposure to credit loss in the event of nonperformance by the other party to the commitments to extend credit, unused lines of credit, standby letters of credit and loans sold with recourse is represented by the contractual amount of those instruments. The credit risk associated with commitments to extend credit and standby and commercial letters of credit is essentially the same as that involved with extending loans to customers and is subject to normal credit policies. Collateral may be obtained based on management’s assessment of the customer’s creditworthiness.

	At December 31,
(In thousands)	2022		2021
Unused lines of credit	$	384,370	$	355,852
Commitments to extend credits, primarily variable rate		2,033,549		1,944,615
Standby letters of credit		53,307		55,133
Loans sold with recourse		31,021		25,593

Since many loan commitments, standby letters of credit and guarantees and indemnification contracts expire without being funded in whole or in part, the contract amounts are not necessarily indicative of future cash flows. The Company does not issue any guarantees that would require liability-recognition or disclosure, other than its standby letters of credit.

The Company guarantees the obligations or performance of customers by issuing standby letters of credit to third-parties. These standby letters of credit are generally issued in support of third-party debt, such as corporate debt issuances, industrial revenue bonds and municipal securities. The risk involved in issuing standby letters of credit is essentially the same as the credit risk involved in extending loan facilities to customers and letters of credit are subject to the same credit origination, portfolio maintenance and management procedures in effect to monitor other credit and off-balance sheet products. Typically, these instruments have one year expirations with an option to renew upon annual review; therefore, the total amounts do not necessarily represent future cash requirements. As of December 31, 2022 and 2021, the fair value of the Company’s standby letters of credit was not significant.

In the normal course of business there are various outstanding legal proceedings. If legal costs are deemed material by management, the Company accrues for the estimated loss from a loss contingency if the information available indicates that it is probable that a liability had been incurred at the date of the financial statements and the amount of loss can be reasonably estimated.

The Company is required to maintain reserve balances with the Federal Reserve Bank. The required average total reserve for NBT Bank for the 14-day maintenance period ending December 28, 2022 was $86.7 million.

Stock-Based Compensation (Tables)

12 Months Ended

Dec. 31, 2022

Stock-Based Compensation [Abstract]

Unvested Restricted Stock Units Activity

The Company has outstanding restricted stock granted from various plans at December 31, 2022. The Company recognized $4.5 million, $4.4 million and $4.6 million in stock-based compensation expense related to these stock awards for the years ended December 31, 2022, 2021 and 2020, respectively. Tax benefits recognized with respect to restricted stock units were $1.2 million, $1.9 million and $1.0 million for the years ended December 31, 2022, 2021 and 2020, respectively. Unrecognized compensation cost related to restricted stock units totaled $5.7 million at December 31, 2022 and will be recognized over 1.5 years on a weighted average basis. Shares issued are funded from the Company’s treasury stock. The following table summarizes information for unvested restricted stock units outstanding as of December 31, 2022:

	Number of Shares			Weighted- Average Grant Date Fair Value
Unvested at January 1, 2022		494,032		$	30.89
Forfeited		(16,893	)		31.28
Vested		(114,745	)		31.96
Granted		169,978			35.59
Unvested at December 31, 2022		532,372		$	32.15

Stock Option Activity

The following table summarizes information concerning stock options outstanding:

(In thousands, except share and per share data)	Number of Shares		Weighted Average Exercise Price		Weighted Average Remaining Contractual Term (in Years)		Aggregate Intrinsic Value
Outstanding at January 1, 2022		9,100	$	29.89
Exercised		-		-
Expired		-		-
Outstanding at December 31, 2022		9,100	$	29.89		3.07	$	123

Exercisable at December 31, 2022		9,100	$	29.89		3.07	$	123

Cash Proceeds, Tax Benefits and Intrinsic Value of Stock Options Exercised

There was no stock-based compensation expense for stock option awards for the years ended December 31, 2022, 2021 and 2020. Cash proceeds, tax benefits and intrinsic value related to total stock options exercised is as follows:

	Years Ended December 31,
(In thousands)	2022		2021		2020
Proceeds from stock options exercised	$	-	$	112	$	185
Tax benefits related to stock options exercised		-		13		41
Intrinsic value of stock options exercised		-		52		165

Stock-Based Compensation

12 Months Ended

Dec. 31, 2022

Stock-Based Compensation [Abstract]

Stock-Based Compensation

13. Stock-Based Compensation

In May 2018, the Company adopted the NBT Bancorp Inc. 2018 Omnibus Incentive Plan (the “Stock Plan”) replacing the 2008 Omnibus Incentive Plan which automatically expired in April 2018. Under the terms of the Stock Plan, equity-based awards are granted to directors and employees to increase their direct proprietary interest in the operations and success of the Company. The Stock Plan assumed all prior equity-based incentive plans and any new equity-based awards are granted under the terms of the Stock Plan. Restricted shares granted under the Plan typically vest after three or five years for employees and three years for non-employee directors. Restricted stock units granted under the Stock Plan may have different terms and conditions. Performance shares and units granted under the Stock Plan for executives may have different terms and conditions. Since 2011, the Company primarily grants restricted stock unit awards. Stock option grants since that time were reloads of existing grants which terminate ten years from the date of the grant. Under terms of the Stock Plan, stock options are granted to purchase shares of the Company’s common stock at a price equal to the fair market value of the common stock on the date of the grant. Shares issued as a result of vesting of restricted stock unit awards and stock option exercises are funded from the Company’s treasury stock.

	Number of Shares			Weighted- Average Grant Date Fair Value
Unvested at January 1, 2022		494,032		$	30.89
Forfeited		(16,893	)		31.28
Vested		(114,745	)		31.96
Granted		169,978			35.59
Unvested at December 31, 2022		532,372		$	32.15

The following table summarizes information concerning stock options outstanding:

(In thousands, except share and per share data)	Number of Shares		Weighted Average Exercise Price		Weighted Average Remaining Contractual Term (in Years)		Aggregate Intrinsic Value
Outstanding at January 1, 2022		9,100	$	29.89
Exercised		-		-
Expired		-		-
Outstanding at December 31, 2022		9,100	$	29.89		3.07	$	123

Exercisable at December 31, 2022		9,100	$	29.89		3.07	$	123

	Years Ended December 31,
(In thousands)	2022		2021		2020
Proceeds from stock options exercised	$	-	$	112	$	185
Tax benefits related to stock options exercised		-		13		41
Intrinsic value of stock options exercised		-		52		165

The Company has 384,182 securities remaining available to be granted as part of the Plan at December 31, 2022.

Consolidated Statements of Changes in Stockholders' Equity - USD ($) $ in Thousands	Common Stock [Member]	Additional Paid-in-Capital [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive (Loss) Income [Member]	Common Stock in Treasury [Member]	Total	Cumulative Effect Adjustment for ASU Implementation [Member] Common Stock [Member]	Cumulative Effect Adjustment for ASU Implementation [Member] Additional Paid-in-Capital [Member]	Cumulative Effect Adjustment for ASU Implementation [Member] Retained Earnings [Member]	Cumulative Effect Adjustment for ASU Implementation [Member] Accumulated Other Comprehensive (Loss) Income [Member]	Cumulative Effect Adjustment for ASU Implementation [Member] Common Stock in Treasury [Member]	Cumulative Effect Adjustment for ASU Implementation [Member]
Balance at Dec. 31, 2019	$ 497	$ 576,708	$ 696,214	$ (19,026)	$ (133,996)	$ 1,120,397
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	0	0	104,388	0	0	104,388
Cash dividends	0	0	(47,207)	0	0	(47,207)
Purchase of treasury shares	0	0	0	0	(7,980)	(7,980)
Net issuance of shares to employee and other stock plans	0	(3,207)	0	0	1,542	(1,665)
Stock-based compensation	0	4,581	0	0	0	4,581
Other comprehensive income (loss)	0	0	0	19,443	0	19,443
Balance at Dec. 31, 2020	497	578,082	749,056	417	(140,434)	1,187,618
Balance (ASU 2016-13 [Member]) at Dec. 31, 2020							$ 0	$ 0	$ (4,339)	$ 0	$ 0	$ (4,339)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	0	0	154,885	0	0	154,885
Cash dividends	0	0	(47,738)	0	0	(47,738)
Purchase of treasury shares	0	0	0	0	(21,714)	(21,714)
Net issuance of shares to employee and other stock plans	0	(5,520)	0	0	2,269	(3,251)
Stock-based compensation	0	4,414	0	0	0	4,414
Other comprehensive income (loss)	0	0	0	(23,761)	0	(23,761)
Balance at Dec. 31, 2021	497	576,976	856,203	(23,344)	(159,879)	1,250,453
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	0	0	151,995	0	0	151,995
Cash dividends	0	0	(49,765)	0	0	(49,765)
Purchase of treasury shares	0	0	0	0	(14,713)	(14,713)
Net issuance of shares to employee and other stock plans	0	(3,653)	0	0	1,397	(2,256)
Stock-based compensation	0	4,530	0	0	0	4,530
Other comprehensive income (loss)	0	0	0	(166,690)	0	(166,690)
Balance at Dec. 31, 2022	$ 497	$ 577,853	$ 958,433	$ (190,034)	$ (173,195)	$ 1,173,554

The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 220
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-04(22))
-URI https://asc.fasb.org/extlink&oid=120399700&loc=SL114874048-224260

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 32
-Subparagraph (f)
-URI https://asc.fasb.org/extlink&oid=126901519&loc=d3e8933-108599

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 250
-SubTopic 10
-Section 50
-Paragraph 4
-URI https://asc.fasb.org/extlink&oid=124431687&loc=d3e22595-107794

Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 220
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-04(18))
-URI https://asc.fasb.org/extlink&oid=120400993&loc=SL114874131-224263

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 40
-Section 65
-Paragraph 1
-Subparagraph (f)
-URI https://asc.fasb.org/extlink&oid=126732423&loc=SL123482106-238011

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 50
-Paragraph 6
-URI https://asc.fasb.org/extlink&oid=124431353&loc=SL124452729-227067

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 10
-Section S99
-Paragraph 1B
-Subparagraph (SX 210.13-02(a)(5))
-URI https://asc.fasb.org/extlink&oid=126975872&loc=SL124442552-122756

Reference 8: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03(20))
-URI https://asc.fasb.org/extlink&oid=126953954&loc=SL114868664-224227

Reference 9: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-URI https://asc.fasb.org/extlink&oid=126954810&loc=d3e3602-108585

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 250
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (b)(2)
-URI https://asc.fasb.org/extlink&oid=124431687&loc=d3e22499-107794

Reference 11: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 10
-Section S99
-Paragraph 1A
-Subparagraph (SX 210.13-01(a)(4)(iv))
-URI https://asc.fasb.org/extlink&oid=126975872&loc=SL124442526-122756

Reference 12: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 10
-Section S99
-Paragraph 1A
-Subparagraph (SX 210.13-01(a)(4)(iii)(A))
-URI https://asc.fasb.org/extlink&oid=126975872&loc=SL124442526-122756

Reference 13: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 10
-Section S99
-Paragraph 1B
-Subparagraph (SX 210.13-02(a)(4)(i))
-URI https://asc.fasb.org/extlink&oid=126975872&loc=SL124442552-122756

Reference 14: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 10
-Section S99
-Paragraph 1A
-Subparagraph (SX 210.13-01(a)(4)(i))
-URI https://asc.fasb.org/extlink&oid=126975872&loc=SL124442526-122756

Reference 15: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 250
-SubTopic 10
-Section 50
-Paragraph 9
-URI https://asc.fasb.org/extlink&oid=124431687&loc=d3e22663-107794

Reference 16: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 10
-Section S99
-Paragraph 1B
-Subparagraph (SX 210.13-02(a)(4)(iv))
-URI https://asc.fasb.org/extlink&oid=126975872&loc=SL124442552-122756

Reference 17: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 10
-Section S99
-Paragraph 1A
-Subparagraph (SX 210.13-01(a)(4)(ii))
-URI https://asc.fasb.org/extlink&oid=126975872&loc=SL124442526-122756

Reference 18: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 28
-Subparagraph (f)
-URI https://asc.fasb.org/extlink&oid=123596393&loc=d3e14064-108612

Reference 19: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 250
-SubTopic 10
-Section 50
-Paragraph 3
-URI https://asc.fasb.org/extlink&oid=124431687&loc=d3e22583-107794

Reference 20: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08(g)(1)(ii))
-URI https://asc.fasb.org/extlink&oid=120395691&loc=d3e23780-122690

Reference 21: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 260
-SubTopic 10
-Section 45
-Paragraph 60B
-Subparagraph (a)
-URI https://asc.fasb.org/extlink&oid=126958026&loc=SL5780133-109256

Reference 22: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 323
-SubTopic 10
-Section 50
-Paragraph 3
-Subparagraph (c)
-URI https://asc.fasb.org/extlink&oid=114001798&loc=d3e33918-111571

Reference 23: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 250
-SubTopic 10
-Section 50
-Paragraph 8
-URI https://asc.fasb.org/extlink&oid=124431687&loc=d3e22658-107794

Reference 24: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 45
-Paragraph 1A
-Subparagraph (a)
-URI https://asc.fasb.org/extlink&oid=126968391&loc=SL7669619-108580

Reference 25: http://www.xbrl.org/2003/role/exampleRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 31
-URI https://asc.fasb.org/extlink&oid=126901519&loc=d3e8924-108599

Reference 26: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 250
-SubTopic 10
-Section 50
-Paragraph 11
-Subparagraph (b)
-URI https://asc.fasb.org/extlink&oid=124431687&loc=d3e22694-107794

Reference 27: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 250
-SubTopic 10
-Section 50
-Paragraph 11
-Subparagraph (a)
-URI https://asc.fasb.org/extlink&oid=124431687&loc=d3e22694-107794

Reference 28: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 205
-SubTopic 20
-Section 50
-Paragraph 7
-URI https://asc.fasb.org/extlink&oid=109222650&loc=SL51721683-107760

Reference 29: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 45
-Paragraph 1B
-Subparagraph (a)
-URI https://asc.fasb.org/extlink&oid=126968391&loc=SL7669625-108580

Reference 30: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 22
-URI https://asc.fasb.org/extlink&oid=126901519&loc=d3e8736-108599

Reference 31: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 10
-Section S99
-Paragraph 1A
-Subparagraph (SX 210.13-01(a)(5))
-URI https://asc.fasb.org/extlink&oid=126975872&loc=SL124442526-122756

Reference 32: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 10
-Section S99
-Paragraph 1B
-Subparagraph (SX 210.13-02(a)(4)(iii)(B))
-URI https://asc.fasb.org/extlink&oid=126975872&loc=SL124442552-122756

Reference 33: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 10
-Section S99
-Paragraph 1B
-Subparagraph (SX 210.13-02(a)(4)(iii)(A))
-URI https://asc.fasb.org/extlink&oid=126975872&loc=SL124442552-122756

Reference 34: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 30
-Subparagraph (b)
-URI https://asc.fasb.org/extlink&oid=126901519&loc=d3e8906-108599

Reference 35: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 32
-Subparagraph (c)
-URI https://asc.fasb.org/extlink&oid=126901519&loc=d3e8933-108599

Total of all stockholders' equity (deficit) items, net of receivables from officers, directors, owners, and affiliates of the entity which are attributable to the parent. The amount of the economic entity's stockholders' equity attributable to the parent excludes the amount of stockholders' equity which is allocable to that ownership interest in subsidiary equity which is not attributable to the parent (noncontrolling interest, minority interest). This excludes temporary equity and is sometimes called permanent equity.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08(g)(1)(ii))
-URI https://asc.fasb.org/extlink&oid=120395691&loc=d3e23780-122690

Reference 2: http://www.xbrl.org/2003/role/exampleRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 852
-SubTopic 10
-Section 55
-Paragraph 10
-URI https://asc.fasb.org/extlink&oid=84165509&loc=d3e56426-112766

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SAB Topic 4.E)
-URI https://asc.fasb.org/extlink&oid=122038336&loc=d3e74512-122707

Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(31))
-URI https://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

Reference 5: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(29))
-URI https://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

Reference 6: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(30))
-URI https://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

Reference 7: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 28
-Subparagraph (f)
-URI https://asc.fasb.org/extlink&oid=123596393&loc=d3e14064-108612

Reference 8: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 323
-SubTopic 10
-Section 50
-Paragraph 3
-Subparagraph (c)
-URI https://asc.fasb.org/extlink&oid=114001798&loc=d3e33918-111571

Regulatory Capital Requirements [Abstract]

Premises, Equipment and Leases (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Premises and Equipment [Abstract]
Premises and equipment before accumulated depreciation	$ 189,809	$ 184,361
Accumulated depreciation	120,762	112,268
Total premises and equipment	69,047	72,093
Operating lease ROU assets	$ 23,900	$ 23,300
Operating Lease, Right-of-Use Asset, Statement of Financial Position [Extensible List]	Other Assets	Other Assets
Net Lease Cost [Abstract]
Operating lease cost	$ 6,643	$ 7,176
Variable lease cost	2,041	2,090
Short-term lease cost	297	369
Sublease income	(266)	(466)
Total premises and equipment	8,715	9,169
Future Minimum Rental Commitments Related to Non-cancelable Operating Leases [Abstract]
2023	6,446
2024	5,427
2025	4,195
2026	3,298
2027	2,681
Thereafter	6,327
Total lease payments	28,374
Less: interest	(2,822)
Present value of lease liabilities	$ 25,552	$ 27,600
Operating Lease, Liability, Statement of Financial Position [Extensible List]	Other Liabilities	Other Liabilities
Additional Information Related to Operating Leases [Abstract]
Weighted average remaining lease term, in years	6 years 5 months 1 day	6 years 10 months 28 days
Weighted average discount rate	3.10%	2.97%
Cash paid for amounts included in the measurement of lease liabilities [Abstract]
Operating cash flows from operating leases	$ 8,371	$ 7,373
ROU assets obtained in exchange for lease liabilities	7,377	1,843
Rental expense	7,200	7,200	$ 8,000
Land, Buildings and Improvements [Member]
Premises and Equipment [Abstract]
Premises and equipment before accumulated depreciation	123,574	125,320
Furniture and Equipment [Member]
Premises and Equipment [Abstract]
Premises and equipment before accumulated depreciation	$ 66,235	$ 59,041
Furniture and Equipment [Member] \| Minimum [Member]
Premises and Equipment [Abstract]
Property, plant and equipment, useful life	3 years
Furniture and Equipment [Member] \| Maximum [Member]
Premises and Equipment [Abstract]
Property, plant and equipment, useful life	10 years
Building and Improvements [Member] \| Minimum [Member]
Premises and Equipment [Abstract]
Property, plant and equipment, useful life	5 years
Building and Improvements [Member] \| Maximum [Member]
Premises and Equipment [Abstract]
Property, plant and equipment, useful life	20 years

Allowance for Credit Losses and Credit Quality of Loans, Troubled Debt Restructuring (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2022 USD ($) Contract	Dec. 31, 2021 USD ($) Contract	Dec. 31, 2020 USD ($) Contract
Recorded Investment and Number of Modifications Designated as TDRs [Abstract]
Number of contracts \| Contract	10	12
Pre-modification outstanding recorded investment	$ 829	$ 1,159
Post-modification outstanding recorded investment	$ 928	$ 1,274
Recorded Investment and Number of Modifications for TDRs Where a Concession Has Been Made and Subsequently Defaulted [Abstract]
Number of contracts \| Contract	53	52	64
Recorded Investment	$ 3,727	$ 2,866	$ 3,774
Commercial Loans [Member]
Recorded Investment and Number of Modifications for TDRs Where a Concession Has Been Made and Subsequently Defaulted [Abstract]
Number of contracts \| Contract	1	0	2
Recorded Investment	$ 320	$ 0	$ 555
Commercial Loans [Member] \| C&I [Member]
Recorded Investment and Number of Modifications for TDRs Where a Concession Has Been Made and Subsequently Defaulted [Abstract]
Number of contracts \| Contract	1	0	1
Recorded Investment	$ 320	$ 0	$ 387
Commercial Loans [Member] \| CRE [Member]
Recorded Investment and Number of Modifications for TDRs Where a Concession Has Been Made and Subsequently Defaulted [Abstract]
Number of contracts \| Contract	0	0	1
Recorded Investment	$ 0	$ 0	$ 168
Consumer Loans [Member]
Recorded Investment and Number of Modifications Designated as TDRs [Abstract]
Number of contracts \| Contract	0	2
Pre-modification outstanding recorded investment	$ 0	$ 38
Post-modification outstanding recorded investment	$ 0	$ 38
Recorded Investment and Number of Modifications for TDRs Where a Concession Has Been Made and Subsequently Defaulted [Abstract]
Number of contracts \| Contract	2	3	1
Recorded Investment	$ 20	$ 36	$ 6
Consumer Loans [Member] \| Auto [Member]
Recorded Investment and Number of Modifications Designated as TDRs [Abstract]
Number of contracts \| Contract	0	2
Pre-modification outstanding recorded investment	$ 0	$ 38
Post-modification outstanding recorded investment	$ 0	$ 38
Recorded Investment and Number of Modifications for TDRs Where a Concession Has Been Made and Subsequently Defaulted [Abstract]
Number of contracts \| Contract	2	3	1
Recorded Investment	$ 20	$ 36	$ 6
Residential [Member]
Recorded Investment and Number of Modifications Designated as TDRs [Abstract]
Number of contracts \| Contract	10	10
Pre-modification outstanding recorded investment	$ 829	$ 1,121
Post-modification outstanding recorded investment	$ 928	$ 1,236
Recorded Investment and Number of Modifications for TDRs Where a Concession Has Been Made and Subsequently Defaulted [Abstract]
Number of contracts \| Contract	50	49	61
Recorded Investment	$ 3,387	$ 2,830	$ 3,213

Regulatory Capital Requirements

12 Months Ended

Dec. 31, 2022

Regulatory Capital Requirements

15. Regulatory Capital Requirements

The Company and the Bank are subject to various regulatory capital requirements administered by the federal banking agencies. Failure to meet minimum capital requirements can initiate certain mandatory and possibly additional discretionary actions by regulators that, if undertaken, could have a direct material effect on the consolidated financial statements. Under capital adequacy guidelines and the regulatory framework for prompt corrective action, the Bank must meet specific capital guidelines that involve quantitative measures of NBT Bank’s assets, liabilities and certain off-balance sheet items as calculated under regulatory accounting practices. The capital amounts and classifications are also subject to qualitative judgments by the regulators about components, risk weightings and other factors.

Quantitative measures established by regulation to ensure capital adequacy require the Company and the Bank to maintain minimum amounts and ratios (set forth in the table below) of total and Tier 1 Capital to risk-weighted assets and of Tier 1 capital to average assets. In addition to maintaining minimum capital ratios, the Company is subject to a capital conservation buffer (“Buffer”) of 2.50% above the minimum to avoid restriction on capital distributions and discretionary bonus paychecks to officers. At December 31, 2022 and 2021, the Company and the Bank meet all capital adequacy requirements to which they were subject.

Under their prompt corrective action regulations, regulatory authorities are required to take certain supervisory actions (and may take additional discretionary actions) with respect to an undercapitalized institution. Such actions could have a direct material effect on an institution’s financial statements. The regulations establish a framework for the classification of banks into five categories: well-capitalized, adequately capitalized, undercapitalized, significantly undercapitalized and critically undercapitalized. As of December 31, 2022 and 2021, the most recent notifications from the Bank’s regulators categorized the Bank as well-capitalized under the regulatory framework for prompt corrective action. To be categorized as well-capitalized the Bank must maintain minimum total risk-based, Tier 1 risk-based and Tier 1 Capital to Average Asset ratios as set forth in the table below. There are no conditions or events since that notification that management believes have changed the Bank’s category.

In March 2020, the OCC, the Board of Governors of the Federal Reserve System and the Federal Deposit Insurance Corporation (“FDIC”) announced an interim final rule to delay the estimated impact on regulatory capital stemming from the implementation of CECL. Under the modified CECL transition provision, the regulatory capital impact of the January 1, 2020 CECL adoption date adjustment to the allowance for credit losses (after-tax) has been deferred and will phase into regulatory capital at 25% per year commencing January 1, 2022. For the ongoing impact of CECL, the Company is allowed to defer the regulatory capital impact of the allowance for credit losses in an amount equal to 25% of the change in the allowance for credit losses (pre-tax) recognized through earnings for each period between January 1, 2020 and December 31, 2021. The cumulative adjustment to the allowance for credit losses between January 1, 2020 and December 31, 2021, will also phase into regulatory capital at 25% per year commencing January 1, 2022. The Company adopted the capital transition relief over the permissible five-year period. The Company and NBT Bank’s actual capital amounts and ratios are presented as follows:

	Actual					Regulatory Ratio Requirements
(Dollars in thousands)	Amount		Ratio			Minimum Capital Adequacy			Minimum plus Buffer			For Classification as Well- Capitalized
As of December 31, 2022
Tier I Capital (to average assets)
Company	$	1,193,336		10.32	%		4.00	%					5.00	%
NBT Bank		1,133,481		9.86	%		4.00	%					5.00	%
Common Equity Tier 1 Capital
Company		1,096,336		12.12	%		4.50	%		7.00	%		6.50	%
NBT Bank		1,133,481		12.63	%		4.50	%		7.00	%		6.50	%
Tier I Capital (to risk-weighted assets)
Company		1,193,336		13.19	%		6.00	%		8.50	%		8.00	%
NBT Bank		1,133,481		12.63	%		6.00	%		8.50	%		8.00	%
Total Capital (to risk-weighted assets)
Company		1,391,182		15.38	%		8.00	%		10.50	%		10.00	%
NBT Bank		1,233,327		13.74	%		8.00	%		10.50	%		10.00	%

As of December 31, 2021
Tier I Capital (to average assets)
Company	$	1,103,661		9.41	%		4.00	%					5.00	%
NBT Bank		1,087,990		9.32	%		4.00	%					5.00	%
Common Equity Tier 1 Capital
Company		1,006,661		12.25	%		4.50	%		7.00	%		6.50	%
NBT Bank		1,087,990		13.36	%		4.50	%		7.00	%		6.50	%
Tier I Capital (to risk-weighted assets)
Company		1,103,661		13.43	%		6.00	%		8.50	%		8.00	%
NBT Bank		1,087,990		13.36	%		6.00	%		8.50	%		8.00	%
Total Capital (to risk-weighted assets)
Company		1,292,669		15.73	%		8.00	%		10.50	%		10.00	%
NBT Bank		1,176,998		14.45	%		8.00	%		10.50	%		10.00	%

The entire disclosure for regulatory capital requirement for depository and lending institutions. Institutions include, but not are not limited to, finance company, insured depository institution, bank holding company, savings and loan association holding company, bank and savings institution not federally insured, mortgage company, foreign financial institution and credit union.

Components of Accumulated Other Comprehensive Income (Loss), Net Periodic Benefit Cost

Employee Benefit Plans (Tables)

12 Months Ended

Dec. 31, 2022

Employee Benefit Plans [Abstract]

The components of AOCI, which have not yet been recognized as components of net periodic benefit cost, related to pensions and other post-retirement benefits are summarized below:

	Pension Benefits						Other Benefits
(In thousands)	2022			2021			2022				2021
Net actuarial loss (gain)		$	35,971		$	21,608		$	(921	)		$	(226	)
Prior service cost (credit)			211			320			(14	)			(8	)
Total amounts recognized in AOCI (pre-tax)		$	36,182		$	21,928		$	(935	)		$	(234	)

Changes in Benefit Obligations, Changes in Plan Assets, and the Funded Status of the Pension Plans and Other Postretirement Benefits

A December 31 measurement date is used for the pension, supplemental pension and post-retirement benefit plans. The following table sets forth changes in benefit obligations, changes in plan assets and the funded status of the pension plans and other post-retirement benefits:

	Pension Benefits						Other Benefits
(In thousands)	2022			2021			2022			2021
Change in benefit obligation:
Benefit obligation at beginning of year	$	88,919		$	90,194		$	5,152		$	5,999
Service cost		2,024			2,069			7			8
Interest cost		2,765			2,717			170			163
Plan participants’ contributions		-			-			147			160
Actuarial (gain) loss		(11,158	)		499			(695	)		(543	)
Benefits paid		(6,610	)		(6,560	)		(598	)		(635	)
Projected benefit obligation at end of year	$	75,940		$	88,919		$	4,183		$	5,152
Change in plan assets:
Fair value of plan assets at beginning of year	$	135,867		$	128,563		$	-		$	-
(Loss) gain on plan assets		(17,260	)		12,523			-			-
Employer contributions		1,319			1,341			451			475
Plan participants’ contributions		-			-			147			160
Benefits paid		(6,610	)		(6,560	)		(598	)		(635	)
Fair value of plan assets at end of year	$	113,316		$	135,867		$	-		$	-

Funded (unfunded) status at year end	$	37,376		$	46,948		$	(4,183	)	$	(5,152	)

Amounts Recognized in Balance Sheet

An asset is recognized for an overfunded plan and a liability is recognized for an underfunded plan. The accumulated benefit obligation for pension benefits was $75.9 million and $88.9 million at December 31, 2022 and 2021, respectively. The accumulated benefit obligation for other post-retirement benefits was $4.2 million and $5.2 million at December 31, 2022 and 2021, respectively. The funded status of the pension and other post-retirement benefit plans has been recognized as follows in the consolidated balance sheets at December 31, 2022 and 2021.

	Pension Benefits						Other Benefits
(In thousands)	2022			2021			2022			2021
Other assets	$	53,031		$	65,638		$	-		$	-
Other liabilities		(15,655	)		(18,690	)		(4,183	)		(5,152	)
Funded status	$	37,376		$	46,948		$	(4,183	)	$	(5,152	)

Assumptions used to Determine Benefit Obligations and Net Periodic Pension Cost

The following assumptions were used to determine the benefit obligation and the net periodic pension cost for the years indicated:

	Years Ended December 31,
	2022	2021	2020
Weighted average assumptions:
The following assumptions were used to determine benefit obligations:
Discount rate	5.54% - 5.66%	3.23% - 3.35%	3.08% - 3.25%
Expected long-term return on plan assets	6.70%	6.70%	7.00%
Rate of compensation increase	3.00%	3.00%	3.00%
Interest rate of credit for cash balance plan	3.99%	1.94%	1.62%

The following assumptions were used to determine net periodic pension cost:
Discount rate	3.23% - 3.35%	3.08% - 3.25%	3.69% - 3.73%
Expected long-term return on plan assets	6.70%	7.00%	7.00%
Rate of compensation increase	3.00%	3.00%	3.00%
Interest rate of credit for cash balance plan	1.94%	1.62%	2.28%

Net Periodic Pension Benefits and Other Benefit Costs

Net periodic benefit cost and other amounts recognized in OCI for the years ended December 31 included the following components:

	Pension Benefits									Other Benefits
(In thousands)	2022			2021			2020			2022			2021			2020
Components of net periodic (benefit) cost:
Service cost	$	2,024		$	2,069		$	1,840		$	7		$	8		$	8
Interest cost		2,765			2,717			3,237			170			163			213
Expected return on plan assets		(8,884	)		(8,786	)		(8,410	)		-			-			-
Additional gain due to curtailment		-			-			(74	)		-			-			-
Amortization of prior service cost		108			59			41			6			51			51
Amortization of unrecognized net loss		623			1,263			1,535			-			-			-
Net periodic pension (benefit) cost	$	(3,364	)	$	(2,678	)	$	(1,831	)	$	183		$	222		$	272

Other changes in plan assets and benefit obligations recognized in OCI (pre-tax):
Net loss (gain)	$	14,987		$	(3,237	)	$	(628	)	$	(695	)	$	(543	)	$	192
Additional gain due to curtailment		-			-			7			-			-			-
Amortization of prior service cost		(108	)		(59	)		(41	)		(6	)		(51	)		(51	)
Amortization of unrecognized net loss		(623	)		(1,263	)		(1,535	)		-			-			-
Total recognized in OCI	$	14,256		$	(4,559	)	$	(2,197	)	$	(701	)	$	(594	)	$	141

Total recognized in net periodic cost (benefit) and OCI, pre-tax	$	10,892		$	(7,237	)	$	(4,028	)	$	(518	)	$	(372	)	$	413

Estimated Future Benefit Payments for the Pension Plans and Other Postretirement Benefit Plans

The following table sets forth estimated future benefit payments for the pension plans and other post-retirement benefit plans as of December 31, 2022:

(In thousands)	Pension Benefits		Other Benefits
2023	$	6,824	$	415
2024		7,218		410
2025		7,467		405
2026		7,003		398
2027		7,595		374
2028 - 2032		33,279		1,688

Target and Actual Allocations of Defined Benefit Pension Plan's Assets

The target and actual allocations expressed as a percentage of the defined benefit pension plan’s assets are as follows:

	Target 2022	2022	2021
Cash and cash equivalents	0 - 15%	3%	2%
Fixed income securities	30 - 60%	38%	37%
Equities	40 - 70%	59%	61%
Total		100%	100%

Financial Instruments Recorded at Fair Value on a Recurring Basis by the Plan

The following table presents the financial instruments recorded at fair value on a recurring basis by the Plan:

(In thousands)	Level 1		Level 2		December 31, 2022
Cash and cash equivalents	$	3,401	$	-	$	3,401
Foreign equity mutual funds		36,111		-		36,111
Equity mutual funds		30,859		-		30,859
U.S. government bonds		-		20		20
Corporate bonds		-		42,925		42,925
Total	$	70,371	$	42,945	$	113,316

	Level 1		Level 2		December 31, 2021
Cash and cash equivalents	$	3,298	$	-	$	3,298
Foreign equity mutual funds		46,385		-		46,385
Equity mutual funds		36,034		-		36,034
U.S. government bonds		-		33		33
Corporate bonds		-		50,117		50,117
Total	$	85,717	$	50,150	$	135,867

Securities, HTM Securities in Continuous Unrealized Loss Position (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2022 USD ($) Position	Dec. 31, 2021 USD ($) Position
Unrealized Loss Position, Fair Value [Abstract]
Less than 12 months	$ 393,788	$ 211,184
12 months or longer	349,496	104,585
Total	743,284	315,769
Unrealized Loss Position, Unrealized Losses [Abstract]
Less than 12 months	(27,889)	(3,311)
12 months or longer	(79,190)	(4,679)
Total	$ (107,079)	$ (7,990)
Unrealized Loss Position, Number of Positions [Abstract]
Less than 12 months \| Position	217	56
12 months or longer \| Position	101	14
Total \| Position	318	70
Accrued interest reversed against interest income	$ 0	$ 0
Collateral-dependent HTM debt securities	0	0
AIR on HTM debt securities	$ 3,800	$ 2,700
Debt Securities, Held-to-Maturity, Accrued Interest, after Allowance for Credit Loss, Statement of Financial Position [Extensible Enumeration]	Other Assets	Other Assets
Past Due [Member]
Unrealized Loss Position, Number of Positions [Abstract]
HTM debt securities	$ 0	$ 0
Federal Agency [Member]
Unrealized Loss Position, Fair Value [Abstract]
Less than 12 months	0	0
12 months or longer	79,322	95,635
Total	79,322	95,635
Unrealized Loss Position, Unrealized Losses [Abstract]
Less than 12 months	0	0
12 months or longer	(20,678)	(4,365)
Total	$ (20,678)	$ (4,365)
Unrealized Loss Position, Number of Positions [Abstract]
Less than 12 months \| Position	0	0
12 months or longer \| Position	4	4
Total \| Position	4	4
Mortgage-Backed [Member]
Unrealized Loss Position, Fair Value [Abstract]
Less than 12 months	$ 91,417	$ 103,789
12 months or longer	138,936	0
Total	230,353	103,789
Unrealized Loss Position, Unrealized Losses [Abstract]
Less than 12 months	(9,096)	(1,319)
12 months or longer	(28,342)	0
Total	$ (37,438)	$ (1,319)
Unrealized Loss Position, Number of Positions [Abstract]
Less than 12 months \| Position	21	10
12 months or longer \| Position	13	0
Total \| Position	34	10
Collateralized Mortgage Obligations [Member]
Unrealized Loss Position, Fair Value [Abstract]
Less than 12 months	$ 191,644	$ 54,612
12 months or longer	48,289	0
Total	239,933	54,612
Unrealized Loss Position, Unrealized Losses [Abstract]
Less than 12 months	(13,863)	(803)
12 months or longer	(10,855)	0
Total	$ (24,718)	$ (803)
Unrealized Loss Position, Number of Positions [Abstract]
Less than 12 months \| Position	47	6
12 months or longer \| Position	8	0
Total \| Position	55	6
State & Municipal [Member]
Unrealized Loss Position, Fair Value [Abstract]
Less than 12 months	$ 110,727	$ 52,783
12 months or longer	82,949	8,950
Total	193,676	61,733
Unrealized Loss Position, Unrealized Losses [Abstract]
Less than 12 months	(4,930)	(1,189)
12 months or longer	(19,315)	(314)
Total	$ (24,245)	$ (1,503)
Unrealized Loss Position, Number of Positions [Abstract]
Less than 12 months \| Position	149	40
12 months or longer \| Position	76	10
Total \| Position	225	50
US Government Agencies Debt Securities and US Government-sponsored Enterprises Debt Securities [Member]
Unrealized Loss Position, Number of Positions [Abstract]
Held-to-maturity debt securities, percentage	70.00%	56.00%

Allowance for Credit Losses and Credit Quality of Loans (Policies)	12 Months Ended
	Dec. 31, 2022
Allowance for Credit Losses and Credit Quality of Loans [Abstract]
Allowance for Credit Losses	The January 1, 2020 (“Day 1”) increase in the allowance for credit loss on loans relating to the adoption of ASU 2016-13, Financial Instruments - Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments was $3.0 million, which decreased retained earnings by $2.3 million and increased the deferred tax asset by $0.7 million. The allowance for credit losses calculation incorporated a 6-quarter forecast period to account for forecast economic conditions under each scenario utilized in the measurement. For periods beyond the 6-quarter forecast, the model reverts to long-term economic conditions over a 4-quarter reversion period on a straight-line basis. The Company considers a baseline, upside and downside economic forecast in measuring the allowance. The quantitative model as of December 31, 2022 incorporates a baseline economic outlook along with an alternative downside scenario sourced from a reputable third-party to accommodate other potential economic conditions in the model. The baseline outlook reflected an unemployment rate environment initially around pre-COVID-19 levels at 3.9% that increases slightly during the forecast period to 4.0%. Northeast GDP’s annualized growth (on a quarterly basis) is expected to start the first quarter of 2023 at approximately 3.9% and hovering around 4.6% by the end of the forecast period. Other utilized economic variables have generally deteriorated in their respective forecasts, with retail sales and housing starts forecasts declining from the prior year. Key assumptions in the baseline economic outlook included a full employment economy being realized in the near future, continued tapering of the Federal Reserve balance sheet, an increasing yield on ten-year treasury securities, and a gradual decline in global oil prices. The alternative downside scenario assumed deteriorated economic and pandemic related conditions from the baseline outlook. Under this scenario, northeast unemployment rises from 3.9% in the fourth quarter of 2022 to a peak of 6.9% in the first quarter of 2024. These scenarios and their respective weightings are evaluated at each measurement date and reflect management’s expectations as of December 31, 2022. Additional adjustments were made for factors not incorporated in the forecasts or the model, such as loss rate expectations for certain loan pools, considerations for inflation, and recent trends in asset value indices. Additional monitoring for industry concentrations, loan growth, and policy exceptions was also conducted. All these factors were considered through separate quantitative processes and incorporated when applicable into the estimate of current expected credit losses at December 31, 2022. The quantitative model as of December 31, 2021 incorporates a baseline economic outlook along with alternative upside and downside scenarios sourced from a reputable third-party to accommodate other potential economic conditions in the model. The baseline outlook reflected an unemployment rate environment initially above pre-COVID-19 levels at 4.8% but falling below pre-COVID-19 levels by the end of the forecast period to 3.5%. Northeast GDP’s annualized growth (on a quarterly basis) was expected to start the first quarter of 2022 at approximately 9% and hover around 5% by the middle and end of the forecast period. The alternative downside scenario assumed deteriorated economic and pandemic related conditions from the baseline outlook. Under this scenario, northeast unemployment rose from 5.7% in the fourth quarter of 2021 to a peak of 8% in the first quarter of 2023, remaining around or above 7% for the entire forecast period. The alternative upside scenario incorporated a more optimistic outlook than the baseline scenario, with a swift return to full employment by the second quarter of 2022 and with northeast unemployment moving down to 3.1% by the end of the forecast period. These scenarios and their respective weightings are evaluated at each measurement date and reflect management’s expectations as of December 31, 2021. At December 31, 2021, the weightings were 60%, 10% and 30% for the baseline, upside and downside economic forecasts, respectively. Additional adjustments were made for COVID-19 related factors not incorporated in the forecasts, such as the mitigating impact of unprecedented stimulus in the second and third quarters of 2020, including direct payments to individuals, increased unemployment benefits, the Company’s loan deferral and modification initiatives and various government sponsored loan programs. The Company also continued to monitor the level of criticized and classified loans in the fourth quarter of 2021 compared to the level contemplated by the model during similar, historical economic conditions, and an adjustment was made to estimate potential additional losses above modeled losses. Additionally, qualitative adjustments were made for Moody’s baseline economic forecast to include impacts of the Build Back Better Act not passing by December 31, 2021 and to address potential economic deterioration due to Omicron, as well as isolated model limitations related to modeled outputs given abnormally high retail sales and business output growth rates in historical periods. These factors were considered through separate quantitative processes and incorporated into the estimate of current expected credit losses at December 31, 2021. The quantitative model as of December 31, 2020 incorporated a baseline economic outlook, along with alternative upside and downside scenarios sourced from a reputable third-party to accommodate other potential economic conditions in the model. The baseline outlook reflected an unemployment rate environment above pre-COVID-19 levels for the entire forecast period, though steadily improving, before returning to low single digits by the end of 2023. Northeast GDP’s annual growth (on a quarterly basis) was expected to start 2021 in the low to mid-single digits, with a peak growth rate of 8% in the fourth quarter of 2021 and steadily falling back down to normalized levels through 2023 and 2024. Other utilized economic variables show improvement in their respective forecasts, namely business output. Key assumptions in the baseline economic outlook included an additional stimulus package passed at the same timing and a comparable level to that of the actual $900 billion COVID-19 relief package passed in December 2020 along with no significant secondary surge in COVID-19 cases or pandemic-related business closures. The alternative downside scenario assumed deteriorated economic and pandemic related conditions from the baseline outlook. In the same way, the alternative upside scenario assumed a faster economic recovery and more effective management of the COVID-19 virus from the baseline outlook. These scenarios and their respective weightings are evaluated at each measurement date and reflect management’s expectations as of December 31, 2020. Additional adjustments were made for COVID-19 related factors not incorporated in the forecasts, such as the mitigating impact of unprecedented stimulus in 2020, including direct payments to individuals, increased unemployment benefits, the Company’s loan deferral and modification initiatives and various government-sponsored loan programs. The commercial & industrial and consumer segment models were based upon percent change in unemployment with modeled values as of December 31, 2020 well outside the observed historical experience. Therefore, adjustments were required to produce outputs more aligned with default expectations given the forecast economic environment. Additionally, the Company identified a slightly higher level of criticized and classified loans during 2020 than those contemplated by the model during similar economic conditions in the past for which an adjustment was made for estimated expected additional losses above modeled output. These factors were considered through a separate quantitative process and incorporated into the estimate for allowance for credit losses at December 31, 2020. There were no loans purchased with credit deterioration during the years ended December 31, 2022 and 2021. During 2022, the Company purchased $11.5 million of residential loans at a 1.53% premium and $50.1 million in consumer loans at par. The allowance for credit losses recorded for these loans on the purchase date was $3.2 million. During 2021, the Company purchased $58.9 million of residential loans at premiums ranging from 2% to 5% and $92.5 million of consumer loans at a par. The allowance for credit losses recorded for these loans on the purchase date was $6.8 million. The Company made a policy election to report AIR in the other assets line item on the balance sheet. AIR on loans totaled $25.0 million at December 31, 2022 and $19.5 million at December 31, 2021 and there was no estimated allowance for credit losses related to AIR at December 31, 2022 and 2021.
Troubled Debt Restructuring	Troubled Debt Restructuring When the Company modifies a loan in a troubled debt restructuring (“TDR”), such modifications generally include one or a combination of the following: an extension of the maturity date at a stated rate of interest lower than the current market rate for new debt with similar risk; temporary reduction in the interest rate; or change in scheduled payment amount. Residential and Consumer TDRs occurring during 2022 and 2021 were due to reductions in the interest rate and/or extension of the term. On August 3, 2020, the Federal Financial Institutions Examination Council issued a joint statement on additional loan accommodations related to COVID-19. The joint statement clarifies that for loan modifications in which Section 4013 of the CARES Act (“Section 4013”) is being applied, subsequent modifications could also be eligible under Section 4013. Accordingly, the Company offered modifications made in response to COVID-19 to borrowers who were current and otherwise not past due in accordance with the criteria stated in Section 4013. These include short-term, 180 days or less, modifications in the form of payment deferrals, fee waivers, extensions of repayment terms, or other delays in payment. The Company evaluated the modification programs provided to its borrowers and has concluded the modifications were generally made in accordance with the CARES Act guidance to borrowers who were in good standing prior to the COVID-19 pandemic and are not required to be designated as TDRs.

Describes an entity's accounting policy and methodology for estimating its allowance for loan and lease losses, and its accounting policy for nonperforming loans. The description identifies the factors that influenced management of the entity in establishing the level of the allowance (for example, historical losses and existing economic conditions) and also may include discussion of the risk elements relevant to particular categories of receivables. The disclosure also may describe any liability the entity has recorded for off-balance sheet credit losses and may include the basis for determining each element of the allowance for loan and lease losses. The disclosure also could discuss the entity's policy for (1) placing loans on nonaccrual status (or discontinuing accrual of interest) and recording payments received on nonaccrual loans, and the policy for resuming accrual of interest, (2) charging-off uncollectible loans, and (3) determining past due or delinquency status (that is, whether past due status is based on how recently payments have been received or contractual terms).

Summary of Significant Accounting Policies [Abstract]

Summary of Significant Accounting Policies (Tables)

12 Months Ended

Dec. 31, 2022

Portfolio and Class Segments

The following table illustrates the portfolio and class segments for the Company’s loan portfolio:

Portfolio Segment	Class
Commercial Loans	Commercial & Industrial Paycheck Protection Program Commercial Real Estate
Consumer Loans	Auto Other Consumer
Residential Loans

Noninterest Income, Segregated by Revenue Streams in-Scope and Out-of-Scope of ASC 606

The following table presents noninterest income, segregated by revenue streams in-scope and out-of-scope of ASC 606:

	Years Ended December 31,
(In thousands)	2022		2021		2020
Noninterest income
In-Scope of ASC 606:
Service charges on deposit accounts	$	14,630	$	13,348	$	13,201
Card services income		29,058		34,682		28,611
Retirement plan administration fees		48,112		42,188		35,851
Wealth management		33,311		33,718		29,247
Insurance services		14,696		14,083		14,757
Other		10,858		12,992		19,254
Total noninterest income in-scope of ASC 606	$	150,665	$	151,011	$	140,921
Total noninterest income out-of-scope of ASC 606	$	4,913	$	6,783	$	5,355
Total noninterest income	$	155,578	$	157,794	$	146,276

Employee Benefit Plans, Financial Instruments Recorded At Fair Value On A Recurring Basis By The Plan (Details) - Pension Benefits [Member] - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Defined Benefit Plan, Information about Plan Assets [Abstract]
Fair value of plan assets	$ 113,316	$ 135,867	$ 128,563
Recurring Basis [Member]
Defined Benefit Plan, Information about Plan Assets [Abstract]
Fair value of plan assets	113,316	135,867
Recurring Basis [Member] \| Level 1 [Member]
Defined Benefit Plan, Information about Plan Assets [Abstract]
Fair value of plan assets	70,371	85,717
Recurring Basis [Member] \| Level 2 [Member]
Defined Benefit Plan, Information about Plan Assets [Abstract]
Fair value of plan assets	42,945	50,150
Recurring Basis [Member] \| Cash and Cash Equivalents [Member]
Defined Benefit Plan, Information about Plan Assets [Abstract]
Fair value of plan assets	3,401	3,298
Recurring Basis [Member] \| Cash and Cash Equivalents [Member] \| Level 1 [Member]
Defined Benefit Plan, Information about Plan Assets [Abstract]
Fair value of plan assets	3,401	3,298
Recurring Basis [Member] \| Cash and Cash Equivalents [Member] \| Level 2 [Member]
Defined Benefit Plan, Information about Plan Assets [Abstract]
Fair value of plan assets	0	0
Recurring Basis [Member] \| Foreign Equity Mutual Funds [Member]
Defined Benefit Plan, Information about Plan Assets [Abstract]
Fair value of plan assets	36,111	46,385
Recurring Basis [Member] \| Foreign Equity Mutual Funds [Member] \| Level 1 [Member]
Defined Benefit Plan, Information about Plan Assets [Abstract]
Fair value of plan assets	36,111	46,385
Recurring Basis [Member] \| Foreign Equity Mutual Funds [Member] \| Level 2 [Member]
Defined Benefit Plan, Information about Plan Assets [Abstract]
Fair value of plan assets	0	0
Recurring Basis [Member] \| Equity Mutual Funds [Member]
Defined Benefit Plan, Information about Plan Assets [Abstract]
Fair value of plan assets	30,859	36,034
Recurring Basis [Member] \| Equity Mutual Funds [Member] \| Level 1 [Member]
Defined Benefit Plan, Information about Plan Assets [Abstract]
Fair value of plan assets	30,859	36,034
Recurring Basis [Member] \| Equity Mutual Funds [Member] \| Level 2 [Member]
Defined Benefit Plan, Information about Plan Assets [Abstract]
Fair value of plan assets	0	0
Recurring Basis [Member] \| US Government Bonds [Member]
Defined Benefit Plan, Information about Plan Assets [Abstract]
Fair value of plan assets	20	33
Recurring Basis [Member] \| US Government Bonds [Member] \| Level 1 [Member]
Defined Benefit Plan, Information about Plan Assets [Abstract]
Fair value of plan assets	0	0
Recurring Basis [Member] \| US Government Bonds [Member] \| Level 2 [Member]
Defined Benefit Plan, Information about Plan Assets [Abstract]
Fair value of plan assets	20	33
Recurring Basis [Member] \| Corporate Bonds [Member]
Defined Benefit Plan, Information about Plan Assets [Abstract]
Fair value of plan assets	42,925	50,117
Recurring Basis [Member] \| Corporate Bonds [Member] \| Level 1 [Member]
Defined Benefit Plan, Information about Plan Assets [Abstract]
Fair value of plan assets	0	0
Recurring Basis [Member] \| Corporate Bonds [Member] \| Level 2 [Member]
Defined Benefit Plan, Information about Plan Assets [Abstract]
Fair value of plan assets	$ 42,925	$ 50,117

Loans (Tables)

12 Months Ended

Dec. 31, 2022

Loans [Abstract]

Loans, Net of Deferred Fees and Origination Costs

A summary of loans, net of deferred fees and origination costs, by category is as follows:

	At December 31,
(In thousands)	2022		2021
Commercial & industrial	$	1,265,082	$	1,155,240
Commercial real estate		2,807,941		2,655,367
Paycheck protection program		949		101,222
Residential real estate		1,649,870		1,571,232
Indirect auto		989,587		859,454
Residential solar		856,798		440,016
Home equity		314,124		330,357
Other consumer		265,796		385,571
Total loans	$	8,150,147	$	7,498,459

Related Party Loans

(In thousands)	2022			2021
Balance at January 1	$	3,292		$	5,936
New loans		576			182
Adjustment due to change in composition of related parties		(37	)		(683	)
Repayments		(1,315	)		(2,143	)
Balance at December 31	$	2,516		$	3,292

Borrowings

12 Months Ended

Dec. 31, 2022

Borrowings [Abstract]

Borrowings

10. Borrowings

Short-Term Borrowings

In addition to the liquidity provided by balance sheet cash flows, liquidity must also be supplemented with additional sources such as credit lines from correspondent banks as well as borrowings from the FHLB and the Federal Reserve Bank. Other funding alternatives may also be appropriate from time to time, including wholesale and retail repurchase agreements and brokered certificate of deposit (“CD”) accounts.

Short-term borrowings totaled $585.0 million and $97.8 million at December 31, 2022 and 2021, respectively, and consist of Federal funds purchased and securities sold under repurchase agreements, which generally represent overnight borrowing transactions and other short-term borrowings, primarily FHLB advances, with original maturities of one year or less.

The Company has unused lines of credit with the FHLB and access to brokered deposits available for short-term financing. Those sources totaled approximately $2.90 billion and $3.45 billion at December 31, 2022 and 2021, respectively. Borrowings on the FHLB lines are secured by FHLB stock, certain securities and one-to-four family first lien mortgage loans. Securities collateralizing repurchase agreements are held in safekeeping by nonaffiliated financial institutions and are under the Company’s control.

Information related to short-term borrowings is summarized as follows:

	December 31,
(Dollars in thousands)	2022			2021			2020
Federal funds purchased:
Balance at year-end	$	60,000		$	-		$	-
Average during the year		14,644			17			14,727
Maximum month end balance		80,000			-			40,000
Weighted average rate during the year		4.02	%		0.11	%		2.05	%
Weighted average rate at year-end		4.28	%		-			-

Securities sold under repurchase agreements:
Balance at year-end	$	86,012		$	97,795		$	143,386
Average during the year		69,561			100,519			154,383
Maximum month end balance		88,637			135,623			176,840
Weighted average rate during the year		0.10	%		0.13	%		0.17	%
Weighted average rate at year-end		0.11	%		0.11	%		0.20	%

Other short-term borrowings:
Balance at year-end	$	439,000		$	-		$	25,000
Average during the year		46,371			1,302			183,699
Maximum month end balance		439,000			-			366,500
Weighted average rate during the year		4.24	%		2.02	%		1.55	%
Weighted average rate at year-end		4.45	%		-			1.99	%

See Note 4 for additional information regarding securities pledged as collateral for securities sold under the repurchase agreements.

Long-Term Debt

Long-term debt consists of obligations having an original maturity at issuance of more than one year. A majority of the Company’s long-term debt is comprised of FHLB advances collateralized by the FHLB stock owned by the Company, and a blanket lien on its residential real estate mortgage loans. As of December 31, 2022 the Company had no callable long-term debt. A summary is as follows:

(Dollars in thousands)	December 31, 2022					December 31, 2021
Maturity	Amount		Weighted Average Rate			Amount		Weighted Average Rate
2022	$	-		-		$	10,598		2.53	%
2025		1,519		4.39	%		-		-
2031		3,296		2.45	%		3,397		2.45	%
Total	$	4,815				$	13,995

Subordinated Debt

On June 23, 2020, the Company issued $100.0 million aggregate principal amount of 5.00% fixed-to-floating rate subordinated notes due 2030. The subordinated notes, which qualify as Tier 2 capital, bear interest at an annual rate of 5.00%, payable semi-annually in arrears commencing on January 1, 2021, and a floating rate of interest equivalent to the three-month Secured Overnight Financing Rate (“SOFR”) plus a spread of 4.85%, payable quarterly in arrears commencing on October 1, 2025. The subordinated notes issuance costs of $2.2 million are being amortized on a straight-line basis into interest expense over five years.

The Company may redeem the subordinated notes (1) in whole or in part beginning with the interest payment date of July 1, 2025, and on any interest payment date thereafter or (2) in whole but not in part upon the occurrence of a “Tax Event”, a “Tier 2 Capital Event” or in the event the Company is required to register as an investment company pursuant to the Investment Company Act of 1940, as amended. The redemption price for any redemption is 100% of the principal amount of the subordinated notes being redeemed, plus accrued and unpaid interest thereon to, but excluding, the date of redemption. Any redemption of the subordinated notes will be subject to the receipt of the approval of the Board of Governors of the Federal Reserve System to the extent then required under applicable laws or regulations, including capital regulations.

The Company repurchased $2.0 million of the subordinated notes during the year ended December 31, 2022 at a discount of $0.1 million.

The following table summarizes the Company’s subordinated debt:

(Dollars in thousands)	December 31, 2022			December 31, 2021
Subordinated notes issued June 2020 – fixed interest rate of 5.00% through June 2025 and a variable interest rate equivalent to three-month SOFR plus 4.85% thereafter, maturing July 1, 2030	$	98,000		$	100,000
Unamortized debt issuance costs		(1,073	)		(1,510	)
Total subordinated debt, net	$	96,927		$	98,490

Junior Subordinated Debt

The Company sponsors five business trusts, CNBF Capital Trust I, NBT Statutory Trust I, NBT Statutory Trust II, Alliance Financial Capital Trust I and Alliance Financial Capital Trust II (collectively, the “Trusts”). The Company’s junior subordinated debentures include amounts related to the Company’s NBT Statutory Trust I and II as well as junior subordinated debentures associated with one statutory trust affiliate that was acquired from our merger with CNB Financial Corp. and two statutory trusts that were acquired from our acquisition of Alliance Financial Corporation (“Alliance”). The Trusts were formed for the purpose of issuing company-obligated mandatorily redeemable trust preferred securities to third-party investors and investing in the proceeds from the sale of such preferred securities solely in junior subordinated debt securities of the Company for general corporate purposes. The Company guarantees, on a limited basis, payments of distributions on the trust preferred securities and payments on redemption of the trust preferred securities. The Trusts are VIEs for which the Company is not the primary beneficiary, as defined by GAAP. In accordance with GAAP, the accounts of the Trusts are not included in the Company’s consolidated financial statements. See Note 1 for additional information about the Company’s consolidation policy.

The debentures held by each trust are the sole assets of that trust. The Trusts hold, as their sole assets, junior subordinated debentures of the Company with face amounts totaling $98.0 million at December 31, 2022. The Company owns all of the common securities of the Trusts and has accordingly recorded $3.2 million in equity method investments classified as other assets in our consolidated balance sheets at December 31, 2022. The Company owns all of the common stock of the Trusts, which have issued trust preferred securities in conjunction with the Company issuing trust preferred debentures to the Trusts. The terms of the trust preferred debentures are substantially the same as the terms of the trust preferred securities.

As of December 31, 2022, the Trusts had the following trust preferred securities outstanding and held the following junior subordinated debentures of the Company (dollars in thousands):

Description	Issuance Date	Trust Preferred Securities Outstanding		Interest Rate	Trust Preferred Debt Owed To Trust		Final Maturity Date
CNBF Capital Trust I	August 1999	$	18,000	3-month LIBOR plus 2.75%	$	18,720	August 2029
NBT Statutory Trust I	November 2005		5,000	3-month LIBOR plus 1.40%		5,155	December 2035
NBT Statutory Trust II	February 2006		50,000	3-month LIBOR plus 1.40%		51,547	March 2036
Alliance Financial Capital Trust I	December 2003		10,000	3-month LIBOR plus 2.85%		10,310	January 2034
Alliance Financial Capital Trust II	September 2006		15,000	3-month LIBOR plus 1.65%		15,464	September 2036

The Company’s junior subordinated debentures are redeemable prior to the maturity date at our option upon each trust’s stated option repurchase dates and from time to time thereafter. These debentures are also redeemable in whole at any time upon the occurrence of specific events defined within the trust indenture. Our obligations under the debentures and related documents, taken together, constitute a full and unconditional guarantee by the Company of the issuers’ obligations under the trust preferred securities. The Company owns all of the common stock of the Trusts, which have issued trust preferred securities in conjunction with the Company issuing trust preferred debentures to the Trusts. The terms of the trust preferred debentures are substantially the same as the terms of the trust preferred securities.

With respect to the Trusts, the Company has the right to defer payments of interest on the debentures issued to the Trusts at any time or from time to time for a period of up to ten consecutive semi-annual periods with respect to each deferral period. Under the terms of the debentures, if in certain circumstances there is an event of default under the debentures or the Company elects to defer interest on the debentures, the Company may not, with certain exceptions, declare or pay any dividends or distributions on its capital stock or purchase or acquire any of its capital stock.

Despite the fact that the Trusts are not included in the Company’s consolidated financial statements, $97 million of the $101 million in trust preferred securities issued by these subsidiary trusts is included in the Tier 1 capital of the Company for regulatory capital purposes as allowed by the Federal Reserve Board (NBT Bank owns $1.0 million of CNBF Trust I securities). The Dodd-Frank Wall Street Reform and Consumer Protection Act of 2010 requires bank holding companies with assets greater than $500 million to be subject to the same capital requirements as insured depository institutions, meaning, for instance, that such bank holding companies will not be able to count trust preferred securities issued after May 19, 2010 as Tier 1 capital. The aforementioned Trusts are grandfathered with respect to this enactment based on their date of issuance.

The entire disclosure for information about short-term and long-term debt arrangements, which includes amounts of borrowings under each line of credit, note payable, commercial paper issue, bonds indenture, debenture issue, own-share lending arrangements and any other contractual agreement to repay funds, and about the underlying arrangements, rationale for a classification as long-term, including repayment terms, interest rates, collateral provided, restrictions on use of assets and activities, whether or not in compliance with debt covenants, and other matters important to users of the financial statements, such as the effects of refinancing and noncompliance with debt covenants.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-URI https://asc.fasb.org/topic&trid=2208564

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 50
-Paragraph 1B
-Subparagraph (h)
-URI https://asc.fasb.org/extlink&oid=123466505&loc=SL123495323-112611

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 50
-Paragraph 1C
-Subparagraph (c)
-URI https://asc.fasb.org/extlink&oid=123466505&loc=SL123495334-112611

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 50
-Paragraph 1I
-Subparagraph (a)
-URI https://asc.fasb.org/extlink&oid=123466505&loc=SL123495371-112611

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 50
-Paragraph 1I
-Subparagraph (d)
-URI https://asc.fasb.org/extlink&oid=123466505&loc=SL123495371-112611

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08(c))
-URI https://asc.fasb.org/extlink&oid=120395691&loc=d3e23780-122690

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 50
-Paragraph 1B
-Subparagraph (g)
-URI https://asc.fasb.org/extlink&oid=123466505&loc=SL123495323-112611

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 50
-Paragraph 1C
-Subparagraph (b)
-URI https://asc.fasb.org/extlink&oid=123466505&loc=SL123495334-112611

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 50
-Paragraph 1C
-Subparagraph (a)
-URI https://asc.fasb.org/extlink&oid=123466505&loc=SL123495334-112611

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 50
-Paragraph 1E
-Subparagraph (b)
-URI https://asc.fasb.org/extlink&oid=123466505&loc=SL123495348-112611

Reference 11: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 50
-Paragraph 1B
-URI https://asc.fasb.org/extlink&oid=123466505&loc=SL123495323-112611

Reference 12: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 50
-Paragraph 1I
-Subparagraph (b)
-URI https://asc.fasb.org/extlink&oid=123466505&loc=SL123495371-112611

Reference 13: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 50
-Paragraph 1B
-Subparagraph (i)
-URI https://asc.fasb.org/extlink&oid=123466505&loc=SL123495323-112611

Recent Accounting Pronouncements [Abstract]

Recent Accounting Pronouncements

12 Months Ended

Dec. 31, 2022

Recent Accounting Pronouncements

2.	Recent Accounting Pronouncements

Recently Adopted Accounting Standards

In March 2020, the FASB issued ASU 2020-04, Reference Rate Reform (Topic 848): Facilitation of the Effects of Reference Rate Reform on Financial Reporting. On January 7, 2021, the FASB issued ASU 2021-01, which refines the scope of Topic 848 and clarifies some of its guidance. ASU 2020-04 and related amendments provide temporary optional expedients and exceptions to the existing guidance for applying GAAP to affected contract modifications and hedge accounting relationships in the transition away from the London Interbank Offered Rate (“LIBOR”) or other interbank offered rates on financial reporting. The guidance also allows a one-time election to sell and/or reclassify to AFS or trading HTM debt securities that reference an interest rate affected by reference rate reform. The amendments in this ASU are effective March 12, 2020 through December 31, 2022 and permits relief solely for reference rate reform actions and permits different elections over the effective date for legacy and new activity.

In December 2020, the FASB issued ASU 2022-06, Reference Rate Reform (Topic 848): Deferral of the Sunset Date of Topic 848. The ASU extends the period of time companies can utilize the reference rate reform relief guidance provided by ASU 2020-04 and ASU 2021-01. The guidance which was effective upon issuance, defers the sunset date from December 31, 2022 to December 31, 2024, after which companies will no longer be permitted to apply the relief guidance in Topic 848. The adoption did not have a material impact on the consolidated financial statements and related disclosures.

Accounting Standards Issued Not Yet Adopted

In March 2022, the FASB issued ASU 2022-02, Financial Instruments - CECL Losses (Topic 326): Troubled Debt Restructurings and Vintage Disclosures. The ASU eliminates the guidance on Troubled Debt Restructurings (“TDRs”) and requires an evaluation on all loan modifications to determine if they result in a new loan or a continuation of the existing loan. The ASU also requires that entities disclose current-period gross charge-offs by year of origination. The elimination of the TDR guidance may be adopted prospectively for loan modifications after adoption or on a modified retrospective basis, which would also apply to loans previously modified, resulting in a cumulative effect adjustment to retained earnings in the period of adoption for changes in the allowance for credit losses. The amendments in this ASU are effective for the Company on January 1, 2023, with early adoption permitted. The adoption is not expected to have a material impact on the consolidated financial statements and related disclosures.

The entire disclosure for change in accounting principle. Includes, but is not limited to, nature, reason, and method of adopting amendment to accounting standards or other change in accounting principle.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 250
-URI https://asc.fasb.org/topic&trid=2122394

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 105
-SubTopic 10
-Section 65
-Paragraph 6
-Subparagraph (f)
-URI https://asc.fasb.org/extlink&oid=126987489&loc=SL124442142-165695

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 20
-Section 65
-Paragraph 2
-Subparagraph (d)(1)
-URI https://asc.fasb.org/extlink&oid=126986314&loc=SL124402458-218513

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 40
-Section 65
-Paragraph 2
-Subparagraph (g)(2)(iii)
-URI https://asc.fasb.org/extlink&oid=124501264&loc=SL117420844-207641

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 250
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (b)(4)
-URI https://asc.fasb.org/extlink&oid=124431687&loc=d3e22499-107794

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 40
-Section 65
-Paragraph 2
-Subparagraph (g)(2)(ii)
-URI https://asc.fasb.org/extlink&oid=124501264&loc=SL117420844-207641

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 40
-Section 65
-Paragraph 2
-Subparagraph (g)(2)(i)
-URI https://asc.fasb.org/extlink&oid=124501264&loc=SL117420844-207641

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 40
-Section 65
-Paragraph 1
-Subparagraph (e)(1)
-URI https://asc.fasb.org/extlink&oid=126732423&loc=SL123482106-238011

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 20
-Section 65
-Paragraph 2
-Subparagraph (d)(2)
-URI https://asc.fasb.org/extlink&oid=126986314&loc=SL124402458-218513

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 40
-Section 65
-Paragraph 2
-Subparagraph (g)(2)(iv)
-URI https://asc.fasb.org/extlink&oid=124501264&loc=SL117420844-207641

Reference 11: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 250
-SubTopic 10
-Section S99
-Paragraph 5
-Subparagraph (SAB Topic 11.M.Q2)
-URI https://asc.fasb.org/extlink&oid=122038215&loc=d3e31137-122693

Reference 12: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 10
-Section 65
-Paragraph 4
-Subparagraph (e)(1)
-URI https://asc.fasb.org/extlink&oid=122640432&loc=SL121648383-210437

Reference 13: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 40
-Section 65
-Paragraph 2
-Subparagraph (h)(2)
-URI https://asc.fasb.org/extlink&oid=124501264&loc=SL117420844-207641

Reference 14: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 10
-Section 65
-Paragraph 4
-Subparagraph (e)(2)
-URI https://asc.fasb.org/extlink&oid=122640432&loc=SL121648383-210437

Reference 15: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 848
-SubTopic 10
-Section 65
-Paragraph 1
-Subparagraph (e)(1)
-URI https://asc.fasb.org/extlink&oid=125980421&loc=SL122150809-237846

Reference 16: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 65
-Paragraph 8
-Subparagraph (e)(2)
-URI https://asc.fasb.org/extlink&oid=126983759&loc=SL121830611-158277

Reference 17: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 250
-SubTopic 10
-Section S99
-Paragraph 6
-URI https://asc.fasb.org/extlink&oid=122038215&loc=SL108384541-122693

Reference 18: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 842
-SubTopic 10
-Section 65
-Paragraph 5
-Subparagraph (f)(1)
-URI https://asc.fasb.org/extlink&oid=128293352&loc=SL126838806-209984

Reference 19: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 65
-Paragraph 6
-Subparagraph (e)(2)
-URI https://asc.fasb.org/extlink&oid=126983955&loc=SL121967933-165497

Reference 20: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 40
-Section 65
-Paragraph 2
-Subparagraph (c)(2)
-URI https://asc.fasb.org/extlink&oid=126732423&loc=SL126732908-238011

Reference 21: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 842
-SubTopic 10
-Section 65
-Paragraph 5
-Subparagraph (f)(3)
-URI https://asc.fasb.org/extlink&oid=128293352&loc=SL126838806-209984

Reference 22: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 40
-Section 65
-Paragraph 2
-Subparagraph (c)(1)
-URI https://asc.fasb.org/extlink&oid=126732423&loc=SL126732908-238011

Reference 23: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 65
-Paragraph 6
-Subparagraph (e)(1)
-URI https://asc.fasb.org/extlink&oid=126983955&loc=SL121967933-165497

Reference 24: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 65
-Paragraph 8
-Subparagraph (e)(1)
-URI https://asc.fasb.org/extlink&oid=126983759&loc=SL121830611-158277

Reference 25: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 40
-Section 65
-Paragraph 2
-Subparagraph (c)(3)
-URI https://asc.fasb.org/extlink&oid=126732423&loc=SL126732908-238011

Reference 26: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 926
-SubTopic 20
-Section 65
-Paragraph 2
-Subparagraph (f)(1)
-URI https://asc.fasb.org/extlink&oid=120154821&loc=SL120154904-197079

Reference 27: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 926
-SubTopic 20
-Section 65
-Paragraph 2
-Subparagraph (f)(2)
-URI https://asc.fasb.org/extlink&oid=120154821&loc=SL120154904-197079

Reference 28: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 250
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (a)
-URI https://asc.fasb.org/extlink&oid=124431687&loc=d3e22499-107794

Reference 29: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 926
-SubTopic 20
-Section 65
-Paragraph 2
-Subparagraph (f)(3)
-URI https://asc.fasb.org/extlink&oid=120154821&loc=SL120154904-197079

Reference 30: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 65
-Paragraph 6
-Subparagraph (e)(3)
-URI https://asc.fasb.org/extlink&oid=126983955&loc=SL121967933-165497

Reference 31: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 848
-SubTopic 10
-Section 65
-Paragraph 2
-Subparagraph (c)
-URI https://asc.fasb.org/extlink&oid=125980421&loc=SL125981372-237846

Reference 32: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 250
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (c)(1)
-URI https://asc.fasb.org/extlink&oid=124431687&loc=d3e22499-107794

Reference 33: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 250
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (b)(1)
-URI https://asc.fasb.org/extlink&oid=124431687&loc=d3e22499-107794

Reference 34: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 65
-Paragraph 8
-Subparagraph (e)(3)
-URI https://asc.fasb.org/extlink&oid=126983759&loc=SL121830611-158277

Summary of Significant Accounting Policies [Abstract]

Parent Company Financial Information, Condensed Statements of Income (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Consolidated Statements of Income [Abstract]
Net securities (losses) gains	$ (1,131)	$ 566	$ (388)
Interest, dividends and other income	384,070	339,876	348,282
Income before income tax expense	196,156	199,858	133,087
Income tax benefit	44,161	44,973	28,699
Net income	151,995	154,885	104,388
NBT Bancorp Inc [Member]
Consolidated Statements of Income [Abstract]
Dividends from subsidiaries	119,000	118,900	77,000
Management fee from subsidiaries	2,005	2,653	4,151
Net securities (losses) gains	(618)	543	(483)
Interest, dividends and other income	638	564	824
Total revenue	121,025	122,660	81,492
Operating expenses	14,035	11,956	11,825
Income before income tax expense	106,990	110,704	69,667
Income tax benefit	(3,027)	(2,250)	(2,653)
Equity in undistributed income of subsidiaries	41,978	41,931	32,068
Net income	$ 151,995	$ 154,885	$ 104,388

Deposits

12 Months Ended

Dec. 31, 2022

Deposits [Abstract]

Deposits

9. Deposits

The following table sets forth the maturity distribution of time deposits:

(In thousands)	December 31, 2022
Within one year	$	280,996
After one but within two years		92,492
After two but within three years		24,033
After three but within four years		21,483
After four but within five years		14,332
After five years		436
Total	$	433,772

Time deposits of $250,000 or more aggregated $48.4 million and $72.3 million December 31, 2022 and 2021, respectively.

Commitments and Contingent Liabilities (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Commitments and Contingent Liabilities [Abstract]
Percentage of the Company's loans secured by real estate	59.00%
Guarantor Obligations [Abstract]
Obligation instrument term	1 year
Federal Reserve Bank Requirement [Abstract]
Federal Reserve Bank maintenance period	14 days
Average reserve at Federal Reserve Bank for maintenance period	$ 86,700
Unused Lines of Credit [Member]
Guarantor Obligations [Abstract]
Commitments - maximum potential obligation	384,370	$ 355,852
Commitments to Extend Credits, Primarily Variable Rate [Member]
Guarantor Obligations [Abstract]
Commitments - maximum potential obligation	2,033,549	1,944,615
Standby Letters of Credit [Member]
Guarantor Obligations [Abstract]
Commitments - maximum potential obligation	53,307	55,133
Loans Sold with Recourse [Member]
Guarantor Obligations [Abstract]
Commitments - maximum potential obligation	$ 31,021	$ 25,593

Summary of Significant Accounting Policies, Revenue from Contracts with Customers (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Noninterest Income [Abstract]
Total noninterest income in-scope of ASC 606	$ 150,665	$ 151,011	$ 140,921
Total noninterest income out-of-scope of ASC 606	4,913	6,783	5,355
Total noninterest income	155,578	157,794	146,276
Service Charges on Deposit Accounts [Member]
Noninterest Income [Abstract]
Total noninterest income in-scope of ASC 606	14,630	13,348	13,201
Card Services Income [Member]
Noninterest Income [Abstract]
Total noninterest income in-scope of ASC 606	29,058	34,682	28,611
Retirement Plan Administration Fees [Member]
Noninterest Income [Abstract]
Total noninterest income in-scope of ASC 606	48,112	42,188	35,851
Wealth Management [Member]
Noninterest Income [Abstract]
Total noninterest income in-scope of ASC 606	33,311	33,718	29,247
Insurance Services [Member]
Noninterest Income [Abstract]
Total noninterest income in-scope of ASC 606	14,696	14,083	14,757
Other [Member]
Noninterest Income [Abstract]
Total noninterest income in-scope of ASC 606	$ 10,858	$ 12,992	$ 19,254

Premises, Equipment and Leases (Policies)	12 Months Ended
Premises, Equipment and Leases (Policies)	Dec. 31, 2022
Premises, Equipment and Leases [Abstract]
Estimated Useful Lives	Buildings and improvements are depreciated based on useful lives of five to twenty years. Furniture and equipment is depreciated based on useful lives of three to ten years.
Operating Leases	Operating leases in which the Company is the lessee are recorded as operating lease ROU assets and operating lease liabilities, included in other assets and other liabilities, respectively, on the consolidated balance sheets. The Company does not have any significant finance leases in which we are the lessee as of December 31, 2022 and December 31, 2021. Operating lease ROU assets represent the Company’s right to use an underlying asset during the lease term and operating lease liabilities represent our obligation to make lease payments arising from the lease. ROU assets and operating lease liabilities are recognized at lease commencement based on the present value of the remaining lease payments using a discount rate that represents the Company’s incremental borrowing rate at the lease commencement date. ROU assets are further adjusted for lease incentives. Operating lease expense, which is comprised of amortization of the ROU asset and the implicit interest accreted on the operating lease liability, is recognized on a straight-line basis over the lease term and is recorded in occupancy expense in the consolidated statements of income. The Company made a policy election to exclude the recognition requirements to all classes of leases with original terms of 12 months or less. Instead, the short-term lease payments are recognized in profit or loss on a straight-line basis over the lease term. The Company has lease agreements with lease and non-lease components, which are generally accounted for separately. For real estate leases, non-lease components and other non-components, such as common area maintenance charges, real estate taxes and insurance are not included in the measurement of the lease liability since they are generally able to be segregated. Our leases relate primarily to office space and bank branches, and some contain options to renew the lease. These options to renew are generally not considered reasonably certain to exercise, and are therefore not included in the lease term until such time that the option to renew is reasonably certain. As of December 31, 2022, operating lease ROU assets and liabilities were $23.9 million and $25.6 million, respectively. As of December 31, 2021, operating lease ROU assets and liabilities were $23.3 million and $27.6 million, respectively.

Borrowings, Subordinated Debt (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Subordinated Debt [Abstract]
Repurchase of subordinated debt	$ 2,000	$ 0	$ 0
Discount on repurchase of subordinated debt	(106)	0	$ 0
Summary of Subordinated Notes [Abstract]
Total subordinated debt, net	$ 96,927	98,490
Subordinated Notes [Member]
Subordinated Debt [Abstract]
Debt instrument, rate on fixed portion	5.00%
Debt issuance cost	$ 2,200
Debt instrument, redemption price percentage of principal amount	100.00%
Repurchase of subordinated debt	$ 2,000
Discount on repurchase of subordinated debt	(100)
Summary of Subordinated Notes [Abstract]
Subordinated notes issued June 2020 - fixed interest rate of 5.00% through June 2025 and a variable interest rate equivalent to three-month SOFR plus 4.85% thereafter, maturing July 1, 2030	98,000	100,000
Unamortized debt issuance costs	(1,073)	(1,510)
Total subordinated debt, net	$ 96,927	$ 98,490
Subordinated Notes [Member] \| Minimum [Member]
Subordinated Debt [Abstract]
Debt issuance cost amortization period	5 years
Subordinated Notes [Member] \| SOFR [Member]
Subordinated Debt [Abstract]
Term of variable rate basis	3 months
Basis spread on variable rate	4.85%

Employee Benefit Plans, Defined Benefit Post-Retirement Plans (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Defined benefit plan disclosure [Abstract]
Transition obligation period of recognition	20 years
Assumptions used to determine benefit obligations [Abstract]
Expected long-term return on plan assets	6.70%	6.70%	7.00%
Rate of compensation increase	3.00%	3.00%	3.00%
Interest rate of credit for cash balance plan	3.99%	1.94%	1.62%
Assumptions used to determine net periodic pension cost [Abstract]
Expected long-term return on plan assets	6.70%	7.00%	7.00%
Rate of compensation increase	3.00%	3.00%	3.00%
Interest rate of credit for cash balance plan	1.94%	1.62%	2.28%
Other changes in plan assets and benefit obligation recognized in OCI (pre-tax) [Abstract]
Net loss (gain)	$ 14,292	$ (3,780)	$ (429)
Amortization of unrecognized net loss	$ (3,573)	$ 945	$ 107
Estimate future benefit payments [Abstract]
Ultimate health care cost trend rate	4.00%
Actual plan asset allocations [Abstract]
Actual plan asset allocations	100.00%	100.00%
Minimum [Member]
Assumptions used to determine benefit obligations [Abstract]
Discount rate	5.54%	3.23%	3.08%
Assumptions used to determine net periodic pension cost [Abstract]
Discount rate	3.23%	3.08%	3.69%
Estimate future benefit payments [Abstract]
Annual rates of increase in the per capita cost of covered medical and prescription drug benefits,	4.50%
Maximum [Member]
Assumptions used to determine benefit obligations [Abstract]
Discount rate	5.66%	3.35%	3.25%
Assumptions used to determine net periodic pension cost [Abstract]
Discount rate	3.35%	3.25%	3.73%
Estimate future benefit payments [Abstract]
Annual rates of increase in the per capita cost of covered medical and prescription drug benefits,	6.50%
Pension Benefits [Member]
Accumulated other comprehensive income (loss), before tax [Abstract]
Net actuarial loss (gain)	$ 35,971	$ 21,608
Prior service cost (credit)	211	320
Total amounts recognized in AOCI (pre-tax)	36,182	21,928
Change in benefit obligation [Roll Forward]
Benefit obligation at beginning of year	88,919	90,194
Service cost	2,024	2,069	$ 1,840
Interest cost	2,765	2,717	3,237
Plan participants' contributions	0	0
Actuarial (gain) loss	(11,158)	499
Benefits paid	(6,610)	(6,560)
Projected benefit obligation at end of year	75,940	88,919	90,194
Change in plan assets [Roll Forward]
Fair value of plan assets at beginning of year	135,867	128,563
(Loss) gain on plan assets	(17,260)	12,523
Employer contributions	1,319	1,341
Plan participants' contributions	0	0
Benefits paid	(6,610)	(6,560)
Fair value of plan assets at end of year	113,316	135,867	128,563
Funded (unfunded) status at year end	37,376	46,948
Accumulated benefit obligation	75,900	88,900
Amounts recognized in Balance Sheet [Abstract]
Funded (unfunded) status at year end	37,376	46,948
Components of net periodic (benefit) cost [Abstract]
Service cost	2,024	2,069	1,840
Interest cost	2,765	2,717	3,237
Expected return on plan assets	(8,884)	(8,786)	(8,410)
Additional gain due to curtailment	0	0	(74)
Amortization of prior service cost	108	59	41
Amortization of unrecognized net loss	623	1,263	1,535
Net periodic pension (benefit) cost	(3,364)	(2,678)	(1,831)
Other changes in plan assets and benefit obligation recognized in OCI (pre-tax) [Abstract]
Net loss (gain)	14,987	(3,237)	(628)
Additional gain due to curtailment	0	0	7
Amortization of prior service cost	(108)	(59)	(41)
Amortization of unrecognized net loss	(623)	(1,263)	(1,535)
Total recognized in OCI	14,256	(4,559)	(2,197)
Total recognized in net periodic cost (benefit) and OCI, pre-tax	10,892	(7,237)	(4,028)
Estimate future benefit payments [Abstract]
2023	6,824
2024	7,218
2025	7,467
2026	7,003
2027	7,595
2028 - 2032	33,279
Employer voluntary contribution to plan	0	0
Pension Benefits [Member] \| Other Assets [Member]
Amounts recognized in Balance Sheet [Abstract]
Assets recognized	53,031	65,638
Pension Benefits [Member] \| Other Liabilities [Member]
Amounts recognized in Balance Sheet [Abstract]
Liabilities recognized	$ (15,655)	$ (18,690)
Pension Benefits [Member] \| Cash and Cash Equivalents [Member]
Actual plan asset allocations [Abstract]
Actual plan asset allocations	3.00%	2.00%
Pension Benefits [Member] \| Cash and Cash Equivalents [Member] \| Minimum [Member]
Target asset allocations [Abstract]
Target allocation percentage of assets	0.00%
Pension Benefits [Member] \| Cash and Cash Equivalents [Member] \| Maximum [Member]
Target asset allocations [Abstract]
Target allocation percentage of assets	15.00%
Pension Benefits [Member] \| Fixed Income Securities [Member]
Actual plan asset allocations [Abstract]
Actual plan asset allocations	38.00%	37.00%
Pension Benefits [Member] \| Fixed Income Securities [Member] \| Minimum [Member]
Target asset allocations [Abstract]
Target allocation percentage of assets	30.00%
Pension Benefits [Member] \| Fixed Income Securities [Member] \| Maximum [Member]
Target asset allocations [Abstract]
Target allocation percentage of assets	60.00%
Pension Benefits [Member] \| Equities [Member]
Actual plan asset allocations [Abstract]
Actual plan asset allocations	59.00%	61.00%
Pension Benefits [Member] \| Equities [Member] \| Minimum [Member]
Target asset allocations [Abstract]
Target allocation percentage of assets	40.00%
Pension Benefits [Member] \| Equities [Member] \| Maximum [Member]
Target asset allocations [Abstract]
Target allocation percentage of assets	70.00%
Other Benefits [Member]
Accumulated other comprehensive income (loss), before tax [Abstract]
Net actuarial loss (gain)	$ (921)	$ (226)
Prior service cost (credit)	(14)	(8)
Total amounts recognized in AOCI (pre-tax)	(935)	(234)
Change in benefit obligation [Roll Forward]
Benefit obligation at beginning of year	5,152	5,999
Service cost	7	8	8
Interest cost	170	163	213
Plan participants' contributions	147	160
Actuarial (gain) loss	(695)	(543)
Benefits paid	(598)	(635)
Projected benefit obligation at end of year	4,183	5,152	5,999
Change in plan assets [Roll Forward]
Fair value of plan assets at beginning of year	0	0
(Loss) gain on plan assets	0	0
Employer contributions	451	475
Plan participants' contributions	147	160
Benefits paid	(598)	(635)
Fair value of plan assets at end of year	0	0	0
Funded (unfunded) status at year end	(4,183)	(5,152)
Accumulated benefit obligation	4,200	5,200
Amounts recognized in Balance Sheet [Abstract]
Funded (unfunded) status at year end	(4,183)	(5,152)
Components of net periodic (benefit) cost [Abstract]
Service cost	7	8	8
Interest cost	170	163	213
Expected return on plan assets	0	0	0
Additional gain due to curtailment	0	0	0
Amortization of prior service cost	6	51	51
Amortization of unrecognized net loss	0	0	0
Net periodic pension (benefit) cost	183	222	272
Other changes in plan assets and benefit obligation recognized in OCI (pre-tax) [Abstract]
Net loss (gain)	(695)	(543)	192
Additional gain due to curtailment	0	0	0
Amortization of prior service cost	(6)	(51)	(51)
Amortization of unrecognized net loss	0	0	0
Total recognized in OCI	(701)	(594)	141
Total recognized in net periodic cost (benefit) and OCI, pre-tax	(518)	(372)	$ 413
Estimate future benefit payments [Abstract]
2023	415
2024	410
2025	405
2026	398
2027	374
2028 - 2032	1,688
Employer voluntary contribution to plan	0	0
Other Benefits [Member] \| Other Assets [Member]
Amounts recognized in Balance Sheet [Abstract]
Assets recognized	0	0
Other Benefits [Member] \| Other Liabilities [Member]
Amounts recognized in Balance Sheet [Abstract]
Liabilities recognized	$ (4,183)	$ (5,152)

Income Taxes (Details) - USD ($) $ in Thousands	12 Months Ended
Income Taxes (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Current [Abstract]
Federal	$ 51,077	$ 35,483	$ 36,358
State	12,934	8,626	9,768
Total Current	64,011	44,109	46,126
Deferred [Abstract]
Federal	(15,862)	507	(14,021)
State	(3,988)	357	(3,406)
Total Deferred	(19,850)	864	(17,427)
Total income tax expense	44,161	44,973	28,699
Deferred tax assets [Abstract]
Allowance for loan losses	24,792	22,479
Lease liability	6,273	6,744
Deferred compensation	9,181	9,584
Loan fees	33,389	12,936
Stock-based compensation expense	2,822	2,679
Unrealized losses on securities	53,663	1,482
Other	6,027	7,109
Total deferred tax assets	136,147	63,013
Deferred tax liabilities [Abstract]
Pension benefits	13,103	16,137
Lease right-of-use asset	5,877	5,681
Amortization of intangible assets	14,112	13,187
Premises and equipment, primarily due to accelerated depreciation	4,889	4,962
Other	846	1,008
Total deferred tax liabilities	38,827	40,975
Net deferred tax asset at year-end	97,320	22,038	15,117
Net deferred tax asset at beginning of year	22,038	15,117
Increase in net deferred tax asset	75,282	6,921
Income tax reconciliation [Abstract]
Federal income tax at statutory rate	41,193	41,971	27,948
Tax exempt income	(984)	(1,014)	(981)
Net increase in cash surrender value of life insurance	(1,215)	(1,230)	(1,135)
Federal tax credits	(2,417)	(1,884)	(1,705)
State taxes, net of federal tax benefit	7,067	7,097	5,026
Other, net	517	33	(454)
Total income tax expense	44,161	44,973	28,699
Reconciliation of gross unrecognized tax benefits [Roll Forward]
Beginning balance	1,545	1,178
Additions for tax positions of prior years	3	80
Current period tax positions	394	287
Ending balance	1,942	1,545	$ 1,178
Amount that would affect the effective tax rate if recognized, gross of tax	$ 1,535	$ 1,221
State and Local Jurisdiction [Member]
Income Tax Examination [Abstract]
Tax years under examination	2015 2016 2017 2018 2019

Fair Value Measurements and Fair Values of Financial Instruments (Policies)	12 Months Ended
	Dec. 31, 2022
Fair Value Measurements and Fair Values of Financial Instruments [Abstract]
Fair Value of Financial Instruments, Policy	GAAP states that fair value is an exit price, representing the amount that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants. Fair value measurements are not adjusted for transaction costs. A fair value hierarchy exists within GAAP that prioritizes the inputs to valuation techniques used to measure fair value. The hierarchy gives the highest priority to unadjusted quoted prices in active markets for identical assets or liabilities (Level 1 measurements) and the lowest priority to unobservable inputs (Level 3 measurements). The three levels of the fair value hierarchy are described below: Level 1 - Unadjusted quoted prices in active markets that are accessible at the measurement date for identical, unrestricted assets or liabilities; Level 2 - Quoted prices for similar assets or liabilities in active markets, quoted prices in markets that are not active or inputs that are observable, either directly or indirectly, for substantially the full term of the asset or liability; and Level 3 - Prices or valuation techniques that require inputs that are both significant to the fair value measurement and unobservable (i.e., supported by little or no market activity). A financial instrument’s level within the fair value hierarchy is based on the lowest level of input that is significant to the fair value measurement. The types of instruments valued based on quoted market prices in active markets include most U.S. government and agency securities, many other sovereign government obligations, liquid mortgage products, active listed equities and most money market securities. Such instruments are generally classified within Level 1 or Level 2 of the fair value hierarchy. The Company does not adjust the quoted prices for such instruments. The types of instruments valued based on quoted prices in markets that are not active, broker or dealer quotations or quote from alternative pricing sources with reasonable levels of price transparency include most investment-grade and high-yield corporate bonds, less liquid mortgage products, less liquid agency securities, less liquid listed equities, state, municipal and provincial obligations and certain physical commodities. Such instruments are generally classified within Level 2 of the fair value hierarchy. Certain common equity securities are reported at fair value utilizing Level 1 inputs (exchange quoted prices). Other investment securities are reported at fair value utilizing Level 1 and Level 2 inputs. The prices for Level 2 instruments are obtained through an independent pricing service or dealer market participants with whom the Company has historically transacted both purchases and sales of investment securities. Prices obtained from these sources include prices derived from market quotations and matrix pricing. The fair value measurements consider observable data that may include dealer quotes, market spreads, cash flows, the U.S. Treasury yield curve, live trading levels, trade execution data, market consensus prepayment speeds, credit information and the bond’s terms and conditions, among other things. Management reviews the methodologies used by its third-party providers in pricing the securities. Level 3 is for positions that are not traded in active markets or are subject to transfer restrictions. Valuations are adjusted to reflect illiquidity and/or non-transferability and such adjustments are generally based on available market evidence. In the absence of such evidence, management’s best estimate will be used. Management’s best estimate consists of both internal and external support on certain Level 3 investments. Subsequent to inception, management only changes Level 3 inputs and assumptions when corroborated by evidence such as transactions in similar instruments, completed or pending third-party transactions in the underlying investment or comparable entities, subsequent rounds of financing, recapitalizations and other transactions across the capital structure, offerings in the equity or debt markets and changes in financial ratios or cash flows. GAAP requires disclosure of assets and liabilities measured and recorded at fair value on a non-recurring basis such as goodwill, loans held for sale, other real estate owned, collateral-dependent loans individually evaluated for expected credit losses and HTM securities. The non-recurring fair value measurements recorded during the years ended December 31, 2022 and 2021 were related to loans individually evaluated for expected credit losses with fair value of $1.1 million and $7.4 million as of December 31, 2022 and 2021, respectively. The Company uses the fair value of underlying collateral, less costs to sell, to estimate the allowance for credit losses for individually evaluated collateral dependent loans. The appraisals may be adjusted by management for qualitative factors such as economic conditions and estimated liquidation expenses ranging from 10% to 50%. Based on the valuation techniques used, the fair value measurements for collateral dependent individually evaluated loans are classified as Level 3. Fair value estimates are made at a specific point in time, based on relevant market information and information about the financial instrument. These estimates do not reflect any premium or discount that could result from offering for sale at one time the Company’s entire holdings of a particular financial instrument. Because no market exists for a significant portion of the Company’s financial instruments, fair value estimates are based on judgments regarding future expected loss experience, current economic conditions, risk characteristics of various financial instruments and other factors. These estimates are subjective in nature and involve uncertainties and matters of significant judgment and therefore cannot be determined with precision. Changes in assumptions could significantly affect the estimates. Fair value estimates are based on existing on and off-balance sheet financial instruments without attempting to estimate the value of anticipated future business and the value of assets and liabilities that are not considered financial instruments. For example, the Company has a substantial wealth operation that contributes net fee income annually. The wealth management operation is not considered a financial instrument and its value has not been incorporated into the fair value estimates. Other significant assets and liabilities include the benefits resulting from the low-cost funding of deposit liabilities as compared to the cost of borrowing funds in the market and premises and equipment. In addition, the tax ramifications related to the realization of the unrealized gains and losses can have a significant effect on fair value estimates and have not been considered in the estimate of fair value. HTM Securities The fair value of the Company’s HTM securities is primarily measured using information from a third-party pricing service. The fair value measurements consider observable data that may include dealer quotes, market spreads, cash flows, the U.S. Treasury yield curve, live trading levels, trade execution data, market consensus prepayment speeds, credit information and the bond’s terms and conditions, among other things. Net Loans Net loans include portfolio loans and loans held for sale. Loans were first segregated by type and then further segmented into fixed and variable rate and loan quality categories. Expected future cash flows were projected based on contractual cash flows, adjusted for estimated prepayments, and those expected future cash flows also include credit risk, illiquidity risk and other market factors to calculate the exit price fair value in accordance with ASC 820. Time Deposits The fair value of time deposits was estimated using a discounted cash flow approach that applies prevailing market interest rates for similar maturity instruments. The fair values of the Company’s time deposit liabilities do not take into consideration the value of the Company’s long-term relationships with depositors, which may have significant value. Long-Term Debt The fair value of long-term debt was estimated using a discounted cash flow approach that applies prevailing market interest rates for similar maturity instruments. Subordinated Debt The fair value of subordinated debt has been measured using the observable market price as of the period reported. Junior Subordinated Debt The fair value of junior subordinated debt has been estimated using a discounted cash flow analysis.

Allowance for Credit Losses and Credit Quality of Loans, Past Due Loans (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2022 USD ($) Relationship	Dec. 31, 2021 USD ($) Relationship
Allowance for Credit Losses and Credit Quality of Loans [Abstract]
Individually evaluated loans, number of relationships \| Relationship	2	5
Individually evaluated loans, amortized cost	$ 2,400	$ 10,200
Individually evaluated loans, allowance for credit losses	$ 0	0
Individually evaluated loans, number of relationships resolved \| Relationship	1
Individually evaluated loans, allowance for credit losses reversed	$ 800
Past Due and Nonperforming Loans [Abstract]
Nonaccrual	17,233	30,285
Recorded total loans	8,150,147	7,498,459
Loans in non-accrual without an allowance for credit losses	1,100	8,800
Past Due [Member]
Past Due and Nonperforming Loans [Abstract]
Recorded total loans	26,690	21,395
31-60 Days Past Due Accruing [Member]
Past Due and Nonperforming Loans [Abstract]
Recorded total loans	18,155	15,022
61-90 Days Past Due Accruing [Member]
Past Due and Nonperforming Loans [Abstract]
Recorded total loans	4,712	3,915
Greater Than 90 Days Past Due Accruing [Member]
Past Due and Nonperforming Loans [Abstract]
Recorded total loans	3,823	2,458
Current [Member]
Past Due and Nonperforming Loans [Abstract]
Recorded total loans	8,106,224	7,446,779
C&I [Member]
Past Due and Nonperforming Loans [Abstract]
Recorded total loans	1,240,208	1,130,670
CRE [Member]
Past Due and Nonperforming Loans [Abstract]
Recorded total loans	2,695,408	2,564,987
PPP [Member]
Past Due and Nonperforming Loans [Abstract]
Recorded total loans	949	101,222
Auto [Member]
Past Due and Nonperforming Loans [Abstract]
Recorded total loans	962,701	826,508
Other Consumer [Member]
Past Due and Nonperforming Loans [Abstract]
Recorded total loans	1,136,386	839,390
Commercial Loans [Member]
Past Due and Nonperforming Loans [Abstract]
Nonaccrual	8,024	16,344
Recorded total loans	3,936,565	3,796,879
Commercial Loans [Member] \| Past Due [Member]
Past Due and Nonperforming Loans [Abstract]
Recorded total loans	877	1,973
Commercial Loans [Member] \| 31-60 Days Past Due Accruing [Member]
Past Due and Nonperforming Loans [Abstract]
Recorded total loans	678	1,841
Commercial Loans [Member] \| 61-90 Days Past Due Accruing [Member]
Past Due and Nonperforming Loans [Abstract]
Recorded total loans	195	132
Commercial Loans [Member] \| Greater Than 90 Days Past Due Accruing [Member]
Past Due and Nonperforming Loans [Abstract]
Recorded total loans	4	0
Commercial Loans [Member] \| Current [Member]
Past Due and Nonperforming Loans [Abstract]
Recorded total loans	3,927,664	3,778,562
Commercial Loans [Member] \| C&I [Member]
Past Due and Nonperforming Loans [Abstract]
Nonaccrual	2,244	3,618
Recorded total loans	1,240,208	1,130,670
Commercial Loans [Member] \| C&I [Member] \| Past Due [Member]
Past Due and Nonperforming Loans [Abstract]
Recorded total loans	434	622
Commercial Loans [Member] \| C&I [Member] \| 31-60 Days Past Due Accruing [Member]
Past Due and Nonperforming Loans [Abstract]
Recorded total loans	342	622
Commercial Loans [Member] \| C&I [Member] \| 61-90 Days Past Due Accruing [Member]
Past Due and Nonperforming Loans [Abstract]
Recorded total loans	88	0
Commercial Loans [Member] \| C&I [Member] \| Greater Than 90 Days Past Due Accruing [Member]
Past Due and Nonperforming Loans [Abstract]
Recorded total loans	4	0
Commercial Loans [Member] \| C&I [Member] \| Current [Member]
Past Due and Nonperforming Loans [Abstract]
Recorded total loans	1,237,530	1,126,430
Commercial Loans [Member] \| CRE [Member]
Past Due and Nonperforming Loans [Abstract]
Nonaccrual	5,780	12,726
Recorded total loans	2,695,408	2,564,987
Commercial Loans [Member] \| CRE [Member] \| Past Due [Member]
Past Due and Nonperforming Loans [Abstract]
Recorded total loans	432	1,351
Commercial Loans [Member] \| CRE [Member] \| 31-60 Days Past Due Accruing [Member]
Past Due and Nonperforming Loans [Abstract]
Recorded total loans	336	1,219
Commercial Loans [Member] \| CRE [Member] \| 61-90 Days Past Due Accruing [Member]
Past Due and Nonperforming Loans [Abstract]
Recorded total loans	96	132
Commercial Loans [Member] \| CRE [Member] \| Greater Than 90 Days Past Due Accruing [Member]
Past Due and Nonperforming Loans [Abstract]
Recorded total loans	0	0
Commercial Loans [Member] \| CRE [Member] \| Current [Member]
Past Due and Nonperforming Loans [Abstract]
Recorded total loans	2,689,196	2,550,910
Commercial Loans [Member] \| PPP [Member]
Past Due and Nonperforming Loans [Abstract]
Nonaccrual	0	0
Recorded total loans	949	101,222
Commercial Loans [Member] \| PPP [Member] \| Past Due [Member]
Past Due and Nonperforming Loans [Abstract]
Recorded total loans	11	0
Commercial Loans [Member] \| PPP [Member] \| 31-60 Days Past Due Accruing [Member]
Past Due and Nonperforming Loans [Abstract]
Recorded total loans	0	0
Commercial Loans [Member] \| PPP [Member] \| 61-90 Days Past Due Accruing [Member]
Past Due and Nonperforming Loans [Abstract]
Recorded total loans	11	0
Commercial Loans [Member] \| PPP [Member] \| Greater Than 90 Days Past Due Accruing [Member]
Past Due and Nonperforming Loans [Abstract]
Recorded total loans	0	0
Commercial Loans [Member] \| PPP [Member] \| Current [Member]
Past Due and Nonperforming Loans [Abstract]
Recorded total loans	938	101,222
Consumer Loans [Member]
Past Due and Nonperforming Loans [Abstract]
Nonaccrual	1,667	1,528
Recorded total loans	2,099,087	1,665,898
Consumer Loans [Member] \| Past Due [Member]
Past Due and Nonperforming Loans [Abstract]
Recorded total loans	21,991	15,713
Consumer Loans [Member] \| 31-60 Days Past Due Accruing [Member]
Past Due and Nonperforming Loans [Abstract]
Recorded total loans	14,981	10,700
Consumer Loans [Member] \| 61-90 Days Past Due Accruing [Member]
Past Due and Nonperforming Loans [Abstract]
Recorded total loans	3,962	3,363
Consumer Loans [Member] \| Greater Than 90 Days Past Due Accruing [Member]
Past Due and Nonperforming Loans [Abstract]
Recorded total loans	3,048	1,650
Consumer Loans [Member] \| Current [Member]
Past Due and Nonperforming Loans [Abstract]
Recorded total loans	2,075,429	1,648,657
Consumer Loans [Member] \| Auto [Member]
Past Due and Nonperforming Loans [Abstract]
Nonaccrual	1,494	1,295
Recorded total loans	962,701	826,508
Consumer Loans [Member] \| Auto [Member] \| Past Due [Member]
Past Due and Nonperforming Loans [Abstract]
Recorded total loans	10,818	9,003
Consumer Loans [Member] \| Auto [Member] \| 31-60 Days Past Due Accruing [Member]
Past Due and Nonperforming Loans [Abstract]
Recorded total loans	8,640	6,911
Consumer Loans [Member] \| Auto [Member] \| 61-90 Days Past Due Accruing [Member]
Past Due and Nonperforming Loans [Abstract]
Recorded total loans	1,393	1,547
Consumer Loans [Member] \| Auto [Member] \| Greater Than 90 Days Past Due Accruing [Member]
Past Due and Nonperforming Loans [Abstract]
Recorded total loans	785	545
Consumer Loans [Member] \| Auto [Member] \| Current [Member]
Past Due and Nonperforming Loans [Abstract]
Recorded total loans	950,389	816,210
Consumer Loans [Member] \| Other Consumer [Member]
Past Due and Nonperforming Loans [Abstract]
Nonaccrual	173	233
Recorded total loans	1,136,386	839,390
Consumer Loans [Member] \| Other Consumer [Member] \| Past Due [Member]
Past Due and Nonperforming Loans [Abstract]
Recorded total loans	11,173	6,710
Consumer Loans [Member] \| Other Consumer [Member] \| 31-60 Days Past Due Accruing [Member]
Past Due and Nonperforming Loans [Abstract]
Recorded total loans	6,341	3,789
Consumer Loans [Member] \| Other Consumer [Member] \| 61-90 Days Past Due Accruing [Member]
Past Due and Nonperforming Loans [Abstract]
Recorded total loans	2,569	1,816
Consumer Loans [Member] \| Other Consumer [Member] \| Greater Than 90 Days Past Due Accruing [Member]
Past Due and Nonperforming Loans [Abstract]
Recorded total loans	2,263	1,105
Consumer Loans [Member] \| Other Consumer [Member] \| Current [Member]
Past Due and Nonperforming Loans [Abstract]
Recorded total loans	1,125,040	832,447
Residential [Member]
Past Due and Nonperforming Loans [Abstract]
Nonaccrual	7,542	12,413
Recorded total loans	2,114,495	2,035,682
Residential [Member] \| Past Due [Member]
Past Due and Nonperforming Loans [Abstract]
Recorded total loans	3,822	3,709
Residential [Member] \| 31-60 Days Past Due Accruing [Member]
Past Due and Nonperforming Loans [Abstract]
Recorded total loans	2,496	2,481
Residential [Member] \| 61-90 Days Past Due Accruing [Member]
Past Due and Nonperforming Loans [Abstract]
Recorded total loans	555	420
Residential [Member] \| Greater Than 90 Days Past Due Accruing [Member]
Past Due and Nonperforming Loans [Abstract]
Recorded total loans	771	808
Residential [Member] \| Current [Member]
Past Due and Nonperforming Loans [Abstract]
Recorded total loans	$ 2,103,131	$ 2,019,560

Allowance for Credit Losses and Credit Quality of Loans, Credit Quality Indicators (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Financing Receivable, Credit Quality Indicator [Line Items]
Minimum number of days past due for loans to be considered nonperforming	90 days
Credit Quality by Loan Class [Abstract]
2022/2021	$ 1,952,599	$ 2,045,326
2021/2020	1,615,395	1,179,768
2020/2019	1,012,149	993,265
2019/2018	774,792	680,836
2018/2017	518,993	528,706
Prior	1,414,638	1,294,841
Revolving Loans Amortized Cost Basis	800,156	703,846
Revolving Loans Converted to Term	61,425	71,871
Total	8,150,147	7,498,459
C&I [Member]
Credit Quality by Loan Class [Abstract]
2022/2021	297,682	337,315
2021/2020	252,534	226,060
2020/2019	169,738	126,268
2019/2018	94,817	66,928
2018/2017	40,593	25,460
Prior	36,800	36,529
Revolving Loans Amortized Cost Basis	344,748	295,823
Revolving Loans Converted to Term	3,296	16,287
Total	1,240,208	1,130,670
C&I [Member] \| Pass [Member]
Credit Quality by Loan Class [Abstract]
2022/2021	296,562	335,685
2021/2020	251,531	219,931
2020/2019	164,976	114,617
2019/2018	91,497	64,310
2018/2017	39,394	20,137
Prior	32,413	32,146
Revolving Loans Amortized Cost Basis	327,166	280,476
Revolving Loans Converted to Term	3,133	15,731
Total	1,206,672	1,083,033
C&I [Member] \| Special Mention [Member]
Credit Quality by Loan Class [Abstract]
2022/2021	1,044	148
2021/2020	524	5,255
2020/2019	4,531	4,641
2019/2018	194	2,430
2018/2017	1,108	2,699
Prior	417	1,111
Revolving Loans Amortized Cost Basis	5,234	11,835
Revolving Loans Converted to Term	0	522
Total	13,052	28,641
C&I [Member] \| Substandard [Member]
Credit Quality by Loan Class [Abstract]
2022/2021	76	1,482
2021/2020	459	874
2020/2019	231	7,010
2019/2018	3,098	187
2018/2017	91	2,582
Prior	3,969	3,272
Revolving Loans Amortized Cost Basis	12,348	3,512
Revolving Loans Converted to Term	163	34
Total	20,435	18,953
C&I [Member] \| Doubtful [Member]
Credit Quality by Loan Class [Abstract]
2022/2021	0	0
2021/2020	20	0
2020/2019	0	0
2019/2018	28	1
2018/2017	0	42
Prior	1	0
Revolving Loans Amortized Cost Basis	0	0
Revolving Loans Converted to Term	0	0
Total	49	43
CRE [Member]
Credit Quality by Loan Class [Abstract]
2022/2021	375,227	490,089
2021/2020	466,754	435,769
2020/2019	442,196	386,151
2019/2018	340,146	252,752
2018/2017	223,612	278,885
Prior	614,625	534,088
Revolving Loans Amortized Cost Basis	203,126	142,891
Revolving Loans Converted to Term	29,722	44,362
Total	2,695,408	2,564,987
CRE [Member] \| Pass [Member]
Credit Quality by Loan Class [Abstract]
2022/2021	374,313	489,300
2021/2020	465,990	434,866
2020/2019	439,012	370,377
2019/2018	333,568	236,274
2018/2017	217,141	251,082
Prior	566,783	441,310
Revolving Loans Amortized Cost Basis	201,563	141,367
Revolving Loans Converted to Term	24,735	43,942
Total	2,623,105	2,408,518
CRE [Member] \| Special Mention [Member]
Credit Quality by Loan Class [Abstract]
2022/2021	605	789
2021/2020	764	826
2020/2019	868	11,235
2019/2018	2,641	3,544
2018/2017	4,649	15,379
Prior	24,023	53,372
Revolving Loans Amortized Cost Basis	850	780
Revolving Loans Converted to Term	0	420
Total	34,400	86,345
CRE [Member] \| Substandard [Member]
Credit Quality by Loan Class [Abstract]
2022/2021	309	0
2021/2020	0	77
2020/2019	2,316	4,539
2019/2018	3,937	12,934
2018/2017	1,822	12,424
Prior	23,819	34,563
Revolving Loans Amortized Cost Basis	713	744
Revolving Loans Converted to Term	4,987	0
Total	37,903	65,281
CRE [Member] \| Doubtful [Member]
Credit Quality by Loan Class [Abstract]
2022/2021		0
2021/2020		0
2020/2019		0
2019/2018		0
2018/2017		0
Prior		4,843
Revolving Loans Amortized Cost Basis		0
Revolving Loans Converted to Term		0
Total		4,843
PPP [Member]
Credit Quality by Loan Class [Abstract]
2022/2021	0	92,884
2021/2020	949	8,338
2020/2019	0	0
2019/2018	0	0
2018/2017	0	0
Prior	0	0
Revolving Loans Amortized Cost Basis	0	0
Revolving Loans Converted to Term	0	0
Total	949	101,222
PPP [Member] \| Pass [Member]
Credit Quality by Loan Class [Abstract]
2022/2021	0	92,884
2021/2020	949	8,338
2020/2019	0	0
2019/2018	0	0
2018/2017	0	0
Prior	0	0
Revolving Loans Amortized Cost Basis	0	0
Revolving Loans Converted to Term	0	0
Total	949	101,222
Auto [Member]
Credit Quality by Loan Class [Abstract]
2022/2021	489,366	352,083
2021/2020	239,745	129,738
2020/2019	76,257	184,416
2019/2018	100,000	101,852
2018/2017	44,277	46,273
Prior	13,056	12,146
Revolving Loans Amortized Cost Basis	0	0
Revolving Loans Converted to Term	0	0
Total	962,701	826,508
Auto [Member] \| Performing [Member]
Credit Quality by Loan Class [Abstract]
2022/2021	488,776	351,778
2021/2020	239,090	129,419
2020/2019	75,853	183,959
2019/2018	99,615	101,441
2018/2017	44,061	46,007
Prior	13,027	12,064
Revolving Loans Amortized Cost Basis	0	0
Revolving Loans Converted to Term	0	0
Total	960,422	824,668
Auto [Member] \| Nonperforming [Member]
Credit Quality by Loan Class [Abstract]
2022/2021	590	305
2021/2020	655	319
2020/2019	404	457
2019/2018	385	411
2018/2017	216	266
Prior	29	82
Revolving Loans Amortized Cost Basis	0	0
Revolving Loans Converted to Term	0	0
Total	2,279	1,840
Other Consumer [Member]
Credit Quality by Loan Class [Abstract]
2022/2021	539,045	427,617
2021/2020	305,531	151,729
2020/2019	111,389	116,700
2019/2018	82,317	78,657
2018/2017	51,728	29,943
Prior	26,885	15,693
Revolving Loans Amortized Cost Basis	19,226	19,029
Revolving Loans Converted to Term	265	22
Total	1,136,386	839,390
Other Consumer [Member] \| Performing [Member]
Credit Quality by Loan Class [Abstract]
2022/2021	538,488	427,401
2021/2020	304,595	151,300
2020/2019	110,944	116,451
2019/2018	82,045	78,523
2018/2017	51,655	29,705
Prior	26,755	15,660
Revolving Loans Amortized Cost Basis	19,218	19,011
Revolving Loans Converted to Term	250	1
Total	1,133,950	838,052
Other Consumer [Member] \| Nonperforming [Member]
Credit Quality by Loan Class [Abstract]
2022/2021	557	216
2021/2020	936	429
2020/2019	445	249
2019/2018	272	134
2018/2017	73	238
Prior	130	33
Revolving Loans Amortized Cost Basis	8	18
Revolving Loans Converted to Term	15	21
Total	2,436	1,338
Residential [Member]
Credit Quality by Loan Class [Abstract]
2022/2021	251,279	345,338
2021/2020	349,882	228,134
2020/2019	212,569	179,730
2019/2018	157,512	180,647
2018/2017	158,783	148,145
Prior	723,272	696,385
Revolving Loans Amortized Cost Basis	233,056	246,103
Revolving Loans Converted to Term	28,142	11,200
Total	2,114,495	2,035,682
Residential [Member] \| Performing [Member]
Credit Quality by Loan Class [Abstract]
2022/2021	251,012	345,338
2021/2020	349,498	226,723
2020/2019	212,161	179,087
2019/2018	156,957	179,575
2018/2017	157,755	146,611
Prior	717,621	687,863
Revolving Loans Amortized Cost Basis	233,056	246,103
Revolving Loans Converted to Term	28,122	11,161
Total	2,106,182	2,022,461
Residential [Member] \| Nonperforming [Member]
Credit Quality by Loan Class [Abstract]
2022/2021	267	0
2021/2020	384	1,411
2020/2019	408	643
2019/2018	555	1,072
2018/2017	1,028	1,534
Prior	5,651	8,522
Revolving Loans Amortized Cost Basis	0	0
Revolving Loans Converted to Term	20	39
Total	$ 8,313	$ 13,221

Summary of Significant Accounting Policies (Policies)

12 Months Ended

Dec. 31, 2022

Basis of Presentation

The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts in the financial statements and accompanying notes. Actual results could differ from these estimates and such differences could be material to the financial statements.

Use of Estimates

Estimates associated with the allowance for credit losses, pension accounting, provision for income taxes, fair values of financial instruments and status of contingencies are particularly susceptible to material change in the near term.

Consolidation

The accompanying consolidated financial statements include the accounts of NBT Bancorp and its wholly-owned subsidiaries mentioned above. All material intercompany transactions have been eliminated in consolidation. Amounts previously reported in the consolidated financial statements are reclassified whenever necessary to conform to the current year’s presentation. The Company combined ATM and debit card fees with card related income previously reported in Other noninterest income which is now disclosed as Card services income. The Company reclassified Data processing and communications expense into Technology and data services expense. The Company reclassified Equipment expense into Occupancy expense and Technology and data services expense. In the “Parent Company Financial Information,” the investment in subsidiaries is recorded using the equity method of accounting.

The Company determines whether it has a controlling financial interest in an entity by first evaluating whether the entity is a voting interest entity or a variable interest entity under GAAP. Voting interest entities are entities in which the total equity investment at risk is sufficient to enable the entity to finance itself independently and provides the equity holders with the obligation to absorb losses, the right to receive residual returns and the right to make decisions about the entity’s activities. The Company consolidates voting interest entities in which it has all, or at least a majority of, the voting interest. As defined in applicable accounting standards, variable interest entities (“VIEs”) are entities that lack one or more of the characteristics of a voting interest entity. A controlling financial interest in a VIE is present when the Company has both the power and ability to direct the activities of the VIE that most significantly impact the VIE’s economic performance and an obligation to absorb losses or the right to receive benefits that could potentially be significant to the VIE. The Company’s wholly-owned subsidiaries CNBF Capital Trust I, NBT Statutory Trust I, NBT Statutory Trust II, Alliance Financial Capital Trust I and Alliance Financial Capital Trust II are VIEs for which the Company is not the primary beneficiary. Accordingly, the accounts of these entities are not included in the Company’s consolidated financial statements.

Segment Reporting

The Company’s operations are primarily in the community banking industry and include the provision of traditional banking services. The Company also provides other services through its subsidiaries such as insurance, retirement plan administration and trust administration. The Company operates in the geographical regions of central and upstate New York, northeastern Pennsylvania, southern New Hampshire, western Massachusetts, Vermont, southern Maine and central Connecticut. The Company has no reportable operating segments.

Cash Equivalents

The Company considers amounts due from correspondent banks, cash items in process of collection and institutional money market mutual funds to be cash equivalents for purposes of the consolidated statements of cash flows.

Securities

The Company classifies its securities at date of purchase as either held to maturity (“HTM”), available for sale (“AFS”) or equity. HTM debt securities are those that the Company has the ability and intent to hold until maturity. AFS debt securities are securities that are not classified as HTM. AFS securities are recorded at fair value. Unrealized holding gains and losses, net of the related tax effect, on AFS securities are excluded from earnings and are reported in the consolidated statements of changes in stockholders’ equity and the consolidated statements of comprehensive income as a component of accumulated other comprehensive income or loss (“AOCI”). HTM securities are recorded at amortized cost. Equity securities are recorded at fair value, with net unrealized gains and losses recognized in income. Transfers of securities between categories are recorded at fair value at the date of transfer. Non-marketable equity securities are carried at cost. Equity securities without readily determinable fair values are carried at cost. The Company performs a qualitative assessment on equity securities to determine whether the investments are impaired and downward or upward adjustments are recognized through the income statement.

Premiums and discounts are amortized or accreted over the life of the related security as an adjustment to yield using the interest method. Dividend and interest income are recognized when earned. Realized gains and losses on securities sold are derived using the specific identification method for determining the cost of securities sold.

Allowance for Credit Losses –HTM Debt Securities

With respect to its HTM debt securities, the Company is required to utilize the Accounting Standards Update (“ASU”) 2016-13, Financial Instruments - Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments (“CECL”) approach to estimate expected credit losses. Management measures expected credit losses on HTM debt securities on a collective basis by major security types that share similar risk characteristics, such as (as applicable): internal or external (third-party) credit score or credit ratings, risk ratings or classification, financial asset type, collateral type, size, effective interest rate, term, geographical location, industry of the borrower, vintage, historical or expected credit loss patterns, and reasonable and supportable forecast periods. Management classifies the HTM portfolio into the following major security types: U.S. government agency or U.S. government-sponsored mortgage-backed and collateralized mortgage obligations securities, and state and municipal debt securities.

The mortgage-backed and collateralized mortgage obligations HTM securities are issued by U.S. government entities and agencies. These securities are either explicitly and/or implicitly guaranteed by the U.S. government as to timely repayment of principal and interest, are highly rated by major rating agencies, and have a long history of zero credit losses. Therefore, the Company did not record an allowance for credit loss for these securities.

State and municipal bonds generally carry a Moody’s rating of A to AAA. In addition, the Company has a limited amount of New York state local municipal bonds that are not rated. The estimate of expected credit losses on the HTM portfolio is based on the expected cash flows of each individual bond over its contractual life and considers historical credit loss information, current conditions and reasonable and supportable forecasts. Given the rarity of municipal defaults and losses, the Company utilized Moody’s Municipal Loss Forecast Model as the sole source of municipal default and loss rates which provides decades of data across all municipal sectors and geographies. As with the loan portfolio, cash flows are forecast over a 6-quarter period under various weighted economic conditions, with a reversion to long-term average economic conditions over a 4-quarter period on a straight-line basis. Management may exercise discretion to make adjustments based on environmental factors. The Company determined that the expected credit loss on its HTM municipal bond portfolio was immaterial and therefore no allowance for credit losses was recorded.

Allowance for Credit Losses –AFS Debt Securities

The impairment model for AFS debt securities differs from the CECL approach utilized for HTM debt securities because AFS debt securities are measured at fair value rather than amortized cost. For AFS debt securities in an unrealized loss position, the Bank first assesses whether it intends to sell, or it is more likely than not that it will be required to sell the security before recovery of its amortized cost basis. If either of the criteria regarding intent or requirement to sell is met, the security’s amortized cost basis is written down to fair value through income. For AFS debt securities that do not meet the aforementioned criteria, in making this assessment, management considers the extent to which fair value is less than amortized cost, any changes to the rating of the security by a rating agency, adverse conditions specifically related to the security, failure of the issuer of the debt security to make scheduled interest or principal payments, among other factors. If this assessment indicates that a credit loss exists, the present value of cash flows expected to be collected from the security are compared to the amortized cost basis of the security. The cash flows should be estimated using information relevant to the collectability of the security, including information about past events, current conditions and reasonable and supportable forecasts. If the present value of cash flows expected to be collected is less than the amortized cost basis, a credit loss exists and an allowance for credit losses is recorded for the credit loss, limited by the amount that the fair value is less than the amortized cost basis. Any impairment that has not been recorded through an allowance for credit losses is recognized in other comprehensive income.

Investments in Federal Reserve Bank and Federal Home Loan Bank (“FHLB”) stock are required for membership in those organizations and are carried at cost since there is no market value available. The FHLB New York continues to pay dividends and repurchase stock. As such, the Company has not recognized any impairment on its holdings of Federal Reserve Bank and FHLB stock.

Loan Held for Sale and Loan Servicing

Loans held for sale are recorded at the lower of cost or fair value on an individual basis. Loan sales are recorded when the sales are funded. Gains and losses on sales of loans held for sale are included in other noninterest income in the Consolidated Statements of Income. Mortgage loans held for sale are generally sold with servicing rights retained. Mortgage servicing rights are recorded at fair value upon sale of the loan, and are amortized in proportion to and over the period of estimated net servicing income.

Loans

Loans are recorded at their current unpaid principal balance, net of unearned income and unamortized loan fees and expenses, which are amortized under the effective interest method over the estimated lives of the loans. Interest income on loans is accrued based on the principal amount outstanding.

For all loan classes within the Company’s loan portfolio, loans are placed on nonaccrual status when timely collection of principal and/or interest in accordance with contractual terms is in doubt. Loans are transferred to nonaccrual status generally when principal or interest payments become over ninety days delinquent, unless the loan is well secured and in the process of collection or sooner when management concludes circumstances indicate that borrowers may be unable to meet contractual principal or interest payments. When a loan is transferred to a nonaccrual status, all interest previously accrued in the current period but not collected is reversed against interest income in that period. Interest accrued in a prior period and not collected is charged-off against the allowance for credit losses.

If ultimate repayment of a nonaccrual loan is expected, any payments received are applied in accordance with contractual terms. If ultimate repayment of principal is not expected, any payment received on a nonaccrual loan is applied to principal until ultimate repayment becomes expected. For all loan classes within the Company’s loan portfolio, nonaccrual loans are returned to accrual status when they become current as to principal and interest and demonstrate a period of performance under the contractual terms and, in the opinion of management, are fully collectible as to principal and interest. For loans in all portfolios, the principal amount is charged off in full or in part as soon as management determines, based on available facts, that the collection of principal in full or in part is improbable. For Commercial loans, management considers specific facts and circumstances relative to individual credits in making such a determination. For Consumer and Residential loan classes, management uses specific guidance and thresholds from the Federal Financial Institutions Examination Council’s Uniform Retail Credit Classification and Account Management Policy.

A loan is considered to be a troubled debt restructuring (“TDR”) when the Company grants a concession to the borrower because of the borrower’s financial condition that the Company would not otherwise consider. Such concessions generally include one or a combination of the following: an extension of the maturity date at a stated rate of interest lower than the current market rate for new debt with similar risk; a temporary reduction in the interest rate; or a change in scheduled payment amount. TDR loans are nonaccrual loans; however, they can be returned to accrual status after a period of performance, generally evidenced by six months of compliance with their modified terms.

Allowance for Credit Losses - Loans

The CECL approach requires an estimate of the credit losses expected over the life of a loan (or pool of loans). The allowance for credit losses is a valuation account that is deducted from, or added to, the loans’ amortized cost basis to present the net, lifetime amount expected to be collected on the loans. Loan losses are charged off against the allowance when management believes a loan balance is confirmed to be uncollectible. Expected recoveries do not exceed the aggregate of amounts previously charged-off and expected to be charged-off.

Management estimates the allowance balance using relevant information, from internal and external sources, related to past events, current conditions, and reasonable and supportable forecasts that affect the collectability of the reported amounts. Historical loss experience is generally the starting point for estimating expected credit losses. The Company then considers whether the historical loss experience should be adjusted for asset-specific risk characteristics or current conditions at the reporting date that did not exist over the period from which historical experience is used. Adjustments to historical loss information is made for differences in current loan-specific risk characteristics such as differences in underwriting standards, portfolio mix, delinquency level or term as well as changes in environmental conditions, such as changes in unemployment rates, production metrics, property values, or other relevant factors. Company historical loss experience is supplemented with peer information when there is insufficient loss data for the Company. Peer selection is based on a review of institutions with comparable loss experience as well as loan yield, bank size, portfolio concentration and geography. Finally, the Company considers forecasts about future economic conditions that are reasonable and supportable. Significant management judgment is required at various points in the measurement process.

Portfolio segment is defined as the level at which an entity develops and documents a systematic methodology to determine its allowance for credit losses. Management developed segments for estimating loss based on type of borrower and collateral which is generally based upon federal call report segmentation and have been combined or subsegmented as needed to ensure loans of similar risk profiles are appropriately pooled.

The following table illustrates the portfolio and class segments for the Company’s loan portfolio:

Portfolio Segment	Class
Commercial Loans	Commercial & Industrial Paycheck Protection Program Commercial Real Estate
Consumer Loans	Auto Other Consumer
Residential Loans

Commercial Loans

The Company offers a variety of commercial loan products. The Company’s underwriting analysis for commercial loans typically includes credit verification, independent appraisals, a review of the borrower’s financial condition and a detailed analysis of the borrower’s underlying cash flows.

Commercial and Industrial (“C&I”) – The Company offers a variety of loan options to meet the specific needs of our C&I customers including term loans, time notes and lines of credit. Such loans are made available to businesses for working capital needs and are typically collateralized by business assets such as equipment, accounts receivable and perishable agricultural products, which are exposed to industry price volatility. To reduce these risks, management also attempts to obtain personal guarantees of the owners or to obtain government loan guarantees to provide further support.

Paycheck Protection Program (“PPP”) – Section 1102 of the Coronavirus Aid, Relief and Economic Security Act (“CARES Act”) created the Paycheck Protection Program, a program administered by the Small Business Administration (the “SBA”) to provide loans to small businesses for payroll and other basic expenses during the coronavirus (“COVID-19”) pandemic. The Company has been a participant in the PPP as a lender. Loans made under the PPP are fully guaranteed by the SBA, whose guarantee is backed by the full faith and credit of the United States government. PPP covered loans also afford borrowers forgiveness up to the principal amount of the PPP covered loan, plus accrued interest, if the loan proceeds are used to retain workers and maintain payroll or to make certain mortgage interest, lease and utility payments, and certain other criteria are satisfied. The SBA will reimburse PPP lenders for any amount of a PPP covered loan that is forgiven, and PPP lenders will not be held liable for any representations made by PPP borrowers in connection with their requests for loan forgiveness. Lenders receive pre-determined fees for processing and servicing PPP loans. In addition, PPP loans are risk-weighted at zero percent under the generally applicable Standardized Approach used to calculate risk-weighted assets for regulatory capital purposes. The Company processed approximately 6,100 loans totaling $835 million in relief. As of December 31, 2022 total forgiveness and paydown is equal to 99% of the original balance.

Commercial Real Estate (“CRE”) – The Company offers CRE loans to finance real estate purchases, refinancing’s, expansions and improvements to commercial and agricultural properties. CRE loans are loans that are secured by liens on real estate, which may include both owner-occupied and nonowner-occupied properties, such as apartments, commercial structures, health care facilities and other facilities. The Company’s underwriting analysis includes credit verification, independent appraisals, a review of the borrower’s financial condition and a detailed analysis of the borrower’s underlying cash flows. These loans are typically originated in amounts of no more than 80% of the appraised value of the property. Government loan guarantees may be obtained to provide further support for agricultural property.

Consumer Loans

The Company offers a variety of Consumer loan products including Auto and Other Consumer loans.

Auto – The Company provides both direct and indirect financing of automobiles (“Auto”). The Company maintains relationships with many dealers primarily in the communities that we serve. Through these relationships, the Company primarily finances the purchases of automobiles indirectly through dealer relationships. Most of these loans carry a fixed rate of interest with principal repayment terms typically ranging from three to six years, based upon the nature of the collateral and the size of the loan.

Other Consumer – The Other Consumer loan segment consists primarily of unsecured consumer loans, residential solar loans and direct consumer loans. The Company offers unsecured consumer loans across a national footprint originated through our relationships with national technology-driven consumer lending companies to finance such things as dental and medical procedures, K-12 tuition, solar energy installations and other consumer purpose loans. Advances of credit through this business line are subject to the Company’s underwriting standards including criteria such as FICO score and debt to income thresholds. In 2017, the Company partnered with Sungage Financial, Inc. to offer financing to consumers for solar ownership with the program tailored for delivery through solar installers. Advances of credit through this business line are to prime borrowers and are subject to the Company’s underwriting standards. Typically, the Company collects origination fees that are deferred and recognized into interest income over the estimated life of the loan. The Company offers a variety of direct consumer installment loans to finance various personal expenditures. In addition to installment loans, the Company also offers personal lines of credit, overdraft protection, debt consolidation, education and other uses. Direct consumer installment loans carry a fixed rate of interest with principal repayment terms typically ranging from one to fifteen years, based upon the nature of the collateral and the size of the loan. Consumer installment loans are often secured with collateral consisting of a perfected lien on the asset being purchased or a perfected lien on a consumer’s deposit account. Risk is reduced through underwriting criteria, which include credit verification, appraisals, a review of the borrower’s financial condition and personal cash flows. A security interest, with title insurance when necessary, is taken in the underlying real estate.

Residential

Residential loans consist primarily of loans secured by a first or second mortgage on primary residences, home equity loans and lines of credit in first and second lien positions and residential construction loans. We originate adjustable-rate and fixed rate, one-to-four-family residential loans for the construction or purchase of a residential property or the refinancing of a mortgage. These loans are collateralized by properties located in the Company’s market area. Loans on one-to-four-family residential are generally originated in amounts of no more than 85% of the purchase price or appraised value (whichever is lower) or have private mortgage insurance. Mortgage title insurance and hazard insurance are normally required. Construction loans have a unique risk because they are secured by an incomplete dwelling. This risk is reduced through periodic site inspections, including one at each loan draw period. For home equity loans, consumers are able to borrow up to 85% of the equity in their homes and are generally tied to Prime with a ten-year draw followed by a fifteen-year amortization. These loans carry a higher risk than first mortgage residential loans as they are often in a second position with respect to collateral.

Historical credit loss experience for both the Company and segment-specific peers provides the basis for the estimation of expected credit losses, where observed credit losses are converted to probability of default rate (“PD”) curves through the use of segment-specific loss given default (“LGD”) risk factors that convert default rates to loss severity based on industry-level, observed relationships between the two variables for each asset class, primarily due to the nature of the underlying collateral. These risk factors were assessed for reasonableness against the Company’s own loss experience and adjusted in certain cases when the relationship between the Company’s historical default and loss severity deviate from that of the wider industry. The historical PD curves, together with corresponding economic conditions, establish a quantitative relationship between economic conditions and loan performance through an economic cycle.

Using the historical relationship between economic conditions and loan performance, management’s expectation of future loan performance is incorporated using externally developed economic forecasts which are probabilistically weighted to reflect potential forecast inaccuracy and model limitations. These forecasts are applied over a period that management has determined to be reasonable and supportable. Beyond the period over which management can develop or source a reasonable and supportable forecast, the model will revert to long-term average economic conditions using a straight-line, time-based methodology.

The allowance for credit losses is measured on a collective (pool) basis, with both a quantitative and qualitative analysis that is applied on a quarterly basis, when similar risk characteristics exist. The respective quantitative allowance for each segment is measured using an econometric, PD/LGD modeling methodology in which distinct, segment-specific multi-variate regression models are applied to multiple, probabilistically weighted external economic forecasts. Under the discounted cash flows methodology, expected credit losses are estimated over the effective life of the loans by measuring the difference between the net present value of modeled cash flows and amortized cost basis. Contractual cash flows over the contractual life of the loans are the basis for modeled cash flows, adjusted for modeled defaults and expected prepayments and discounted at the loan-level stated interest rate. The contractual term excludes expected extensions, renewals, and modifications unless either of the following applies: management has a reasonable expectation at the reporting date that a TDR will be executed with an individual borrower or the extension or renewal options are included in the original or modified contract at the reporting date and are not unconditionally cancellable by the Company.

After quantitative considerations, management applies additional qualitative adjustments so that the allowance for credit losses is reflective of the estimate of lifetime losses that exist in the loan portfolio at the balance sheet date. Qualitative considerations include limitations inherent in the quantitative model; trends experienced in nonperforming and delinquent loans; changes in value of underlying collateral; changes in lending policies and procedures; nature and composition of loans; portfolio concentrations that may affect loss experience across one or more components of the portfolio; the experience, ability and depth of lending management and staff; the Company’s credit review system; and the effect of external factors; such as competition, legal and regulatory requirements.

Loans that do not share risk characteristics and meet materiality criteria are evaluated on an individual basis and are excluded from the pooled evaluation. When management determines that foreclosure is probable, expected credit losses are based on the fair value of the collateral at the reporting date, adjusted for selling costs as appropriate. If the loan is not collateral dependent, the allowance for credit losses related to individually assessed loans is based on discounted expected cash flows using the loan’s initial effective interest rate. Generally, individually assessed loans are collateral dependent.

A loan for which the terms have been modified resulting in a concession, and for which the borrower is experiencing financial difficulties is considered to be a TDR. The allowance for credit losses on a TDR is measured using the same method as all other loans held for investment, except that the original interest rate is used to discount the expected cash flows, not the rate specified within the restructuring. If the sole (remaining) source of repayment for the loan is the operation or liquidation of the collateral, then management uses the current fair value of the collateral, less selling costs. If management determines that the value of the modified loan is less than the recorded investment in the loan, a write-down would be recorded.

Allowance for Credit Losses on Off-Balance Sheet Credit Exposures

The Company estimates expected credit losses over the contractual period in which the Company has exposure to credit risk via a contractual obligation to extend credit, unless that obligation is unconditionally cancellable by the Company. The allowance for credit losses on off-balance sheet credit exposures is adjusted as an expense in other noninterest expense. The estimate includes consideration of the likelihood that funding will occur and an estimate of expected credit losses on commitments expected to be funded over their estimated lives. Estimating credit losses on unfunded commitments requires the Bank to consider the following categories of off-balance sheet credit exposure: unfunded commitments to extend credit, unfunded lines of credit, and standby letters of credit. Each of these unfunded commitments is then analyzed for a probability of funding to calculate a probable funding amount. The life of loan loss factor by related portfolio segment from the loan allowance for credit loss calculation is then applied to the probable funding amount to calculate a reserve on unfunded commitments.

Accrued Interest Receivable

Accrued interest receivable balances are presented separately within other assets balance sheet line item. The Company has excluded interest receivable that is included in amortized cost of financing receivables from related disclosures requirements and accrued interest receivable is written off by reversing interest income. For loans, write off typically occurs upon becoming over 90 to 120 days past due and therefore the amount of such write offs are immaterial. Historically, the Company has not experienced uncollectible accrued interest receivable on investment securities.

Premises and Equipment

Premises and equipment are stated at cost, less accumulated depreciation. Depreciation of premises and equipment is determined using the straight-line method over the estimated useful lives of the respective assets. Expenditures for maintenance, repairs and minor replacements are charged to expense as incurred.

Leases

The Company determines if a lease is present at the inception of an agreement. Right-of-use (“ROU”) assets and lease liabilities are recognized at lease commencement based on the present value of the remaining lease payments using a discount rate that represents the Company’s incremental borrowing rate at the lease commencement date. ROU assets and operating lease liabilities, are included in other assets and other liabilities, respectively, on the consolidated balance sheets. Leases with original terms of 12 months or less are recognized in profit or loss on a straight-line basis over the lease term.

Operating lease ROU assets represent the Company’s right to use an underlying asset during the lease term and operating lease liabilities represent our obligation to make lease payments arising from the lease. ROU assets are further adjusted for lease incentives. Operating lease expense, which is comprised of amortization of the ROU asset and the implicit interest accreted on the operating lease liability, is recognized on a straight-line basis over the lease term, and is recorded in occupancy expense in the consolidated statements of income.

The Company has lease agreements with lease and non-lease components, which are generally accounted for separately. For real estate leases, non-lease components and other non-components, such as common area maintenance charges, real estate taxes and insurance are not included in the measurement of the lease liability since they are generally able to be segregated. Our leases relate primarily to office space and bank branches, and some contain options to renew the lease. These options to renew are generally not considered reasonably certain to exercise, and are therefore not included in the lease term until such time that the option to renew is reasonably certain.

Other Real Estate Owned

Other real estate owned (“OREO”) consists of properties acquired through foreclosure or by acceptance of a deed in lieu of foreclosure. These assets are recorded at the lower of fair value of the asset acquired less estimated costs to sell or “cost” (defined as the fair value at initial foreclosure). At the time of foreclosure, or when foreclosure occurs in-substance, the excess, if any, of the loan over the fair market value of the assets received, less estimated selling costs, is charged to the allowance for loan losses and any subsequent valuation write-downs are charged to other expense. In connection with the determination of the allowance for loan losses and the valuation of OREO, management obtains appraisals for properties. Operating costs associated with the properties are charged to expense as incurred. Gains on the sale of OREO are included in income when title has passed and the sale has met the minimum down payment requirements prescribed by GAAP. The balance of OREO is recorded in other assets on the consolidated balance sheets.

Goodwill and Other Intangible Assets

Goodwill represents the cost of acquired business in excess of the fair value of the related net assets acquired. Goodwill is not amortized but tested at the reporting unit level for impairment on an annual basis and on an interim basis or when events or circumstances dictate. The Company has elected June 30 as the annual impairment testing date for the insurance and retirement services reporting units and December 31 for the Bank reporting unit.

The Company has the option to first assess qualitative factors, by performing a qualitative analysis, to determine whether the existence of events or circumstances leads to a determination that it is more likely than not that the fair value of a reporting unit is less than its carrying amount. If, after assessing the events or circumstances, the Company determines it is more likely than not that the fair value of a reporting unit is greater than its carrying amount, the impairment test is not required. If the Company concludes otherwise, the Company is required to perform a quantitative impairment test. In the quantitative impairment test, the estimated fair value of a reporting unit is compared to the carrying amount in order to determine if impairment is indicated. If the estimated fair value exceeds the carrying amount, the reporting unit is not deemed to be impaired. If the estimated fair value is below the carrying value of the reporting unit, the difference is the amount of impairment.

Intangible assets that have indefinite useful lives are not amortized, but are tested at least annually for impairment. Intangible assets that have finite useful lives are amortized over their useful lives. Core deposit intangibles and trust intangibles at the Company are amortized using the sum-of-the-years’-digits method. Covenants not to compete are amortized on a straight-line basis. Customer lists are amortized using an accelerated method. When facts and circumstances indicate potential impairment of amortizable intangible assets, the Company evaluates the recoverability of the asset carrying value, using estimates of undiscounted future cash flows over the remaining asset life. Any impairment loss is measured by the excess of carrying value over fair value.

Determining the fair value of a reporting unit under the goodwill impairment tests and determining the fair value of other intangible assets are judgmental and often involve the use of significant estimates and assumptions. Estimates of fair value are primarily determined using the discounted cash flows method, which uses significant estimates and assumptions including projected future cash flows, discount rates reflecting the market rate of return and projected growth rates. Future events may impact such estimates and assumptions and could cause the Company to conclude that our goodwill or intangible assets have become impaired, which would result in recording an impairment loss.

Bank-Owned Life Insurance

The Bank has purchased life insurance policies on certain employees, key executives and directors. Bank-owned life insurance is recorded at the amount that can be realized under the insurance contract at the balance sheet date, which is the cash surrender value adjusted for other charges or other amounts due that are probable at settlement.

Treasury Stock

Treasury stock acquisitions are recorded at cost. Subsequent sales of treasury stock are recorded on an average cost basis. Gains on the sale of treasury stock are credited to additional paid-in-capital. Losses on the sale of treasury stock are charged to additional paid-in-capital to the extent of previous gains, otherwise charged to retained earnings.

Income Taxes

Income taxes are accounted for under the asset and liability method. Deferred income taxes are recognized for the future tax consequences attributable to differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax bases. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in the years in which those temporary differences are expected to be recovered or settled. The effect on deferred taxes of a change in tax rates is recognized in income in the period that includes the enactment date. The Company recognizes interest accrued and penalties related to unrecognized tax benefits in income tax expense.

Tax positions are recognized as a benefit only if it is “more likely than not” that the tax position would be sustained in a tax examination, with a tax examination being presumed to occur. The amount recognized is the largest amount of tax benefit that is greater than 50 percent likely of being realized on examination. For tax positions not meeting the “more likely than not” test, no tax benefit is recorded.

Pension Costs

The Company has a qualified, noncontributory, defined benefit pension plan covering substantially all of its employees, as well as supplemental employee retirement plans to certain current and former executives and a defined benefit postretirement healthcare plan that covers certain employees. Costs associated with these plans, based on actuarial computations of current and future benefits for employees, are charged to current operating expenses.

Stock-Based Compensation

The Company maintains various long-term incentive stock benefit plans under which restricted stock units are granted to certain directors and key employees. Compensation expense is recognized in the consolidated statements of income over the requisite service period, based on the grant-date fair value of the award. For restricted stock units, compensation expense is recognized ratably over the vesting period for the fair value of the award, measured at the grant date.

Earnings Per Share

Basic earnings per share (“EPS”) excludes dilution and is computed by dividing income available to common stockholders by the weighted average number of common shares outstanding for the period. Diluted EPS reflects the potential dilution that could occur if securities or other contracts to issue common stock were exercised or converted into common stock or resulted in the issuance of common stock that then shared in the earnings of the entity (such as the Company’s dilutive stock options and restricted stock units).

Comprehensive Income (Loss)

At the Company, comprehensive income (loss) represents net income plus OCI, which consists primarily of the net change in unrealized gains (losses) on AFS debt securities for the period, changes in the funded status of employee benefit plans and unrealized gains (losses) on derivatives designated as hedging instruments. AOCI represents the net unrealized gains (losses) on AFS debt securities, the previously unrecognized portion of the funded status of employee benefit plans and the fair value of instruments designated as hedging instruments, net of income taxes, as of the consolidated balance sheet dates.

Derivative Instruments and Hedging Activities

The Company records all derivatives on the balance sheet at fair value. The accounting for changes in the fair value of derivatives depends on the intended use of the derivative, whether the Company has elected to designate a derivative in a hedging relationship and apply hedge accounting and whether the hedging relationship has satisfied the criteria necessary to apply hedge accounting. Derivatives designated and qualifying as a hedge of the exposure to changes in the fair value of an asset, liability or firm commitment attributable to a particular risk, such as interest rate risk, are considered fair value hedges. Derivatives designated and qualifying as a hedge of the exposure to variability in expected future cash flows, or other types of forecasted transactions, are considered cash flow hedges. Hedge accounting generally provides for the matching of the timing of gain or loss recognition on the hedging instrument with the recognition of the changes in the fair value of the hedged asset or liability that are attributable to the hedged risk in a fair value hedge or the earnings effect of the hedged forecasted transactions in a cash flow hedge. The Company may enter into derivative contracts that are intended to economically hedge certain of its risks, even though hedge accounting does not apply or the Company elects not to apply hedge accounting.

For derivatives designated as fair value hedges, changes in the fair value of the derivative and the hedged item related to the hedged risk are recognized in earnings. For derivatives designated as cash flow hedges, changes in fair value of the cash flow hedges are reported in OCI. When the cash flows associated with the hedged item are realized, the gain or loss included in OCI is recognized in the consolidated statements of income.

When the Company purchases or sells a portion of a commercial loan that has an existing interest rate swap, it may enter into a risk participation agreement to provide credit protection to the financial institution that originated the swap transaction should the borrower fail to perform on its obligation. The Company enters into both risk participation agreements in which it purchases credit protection from other financial institutions and those in which it provides credit protection to other financial institutions. Any fee paid to the Company under a risk participation agreement is in consideration of the credit risk of the counterparties and is recognized in the income statement. Credit risk on the risk participation agreements is determined after considering the risk rating, probability of default and loss given default of the counterparties.

Fair Value Measurements

GAAP states that fair value is an exit price, representing the amount that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants. Fair value measurements are not adjusted for transaction costs. A fair value hierarchy exists within GAAP that prioritizes the inputs to valuation techniques used to measure fair value. The hierarchy gives the highest priority to unadjusted quoted prices in active markets for identical assets or liabilities (Level 1 measurements) and the lowest priority to unobservable inputs (Level 3 measurements). The three levels of the fair value hierarchy are described below:

Level 1 - Unadjusted quoted prices in active markets that are accessible at the measurement date for identical, unrestricted assets or liabilities;

Level 2 - Quoted prices for similar assets or liabilities in active markets, quoted prices in markets that are not active or inputs that are observable, either directly or indirectly, for substantially the full term of the asset or liability; and

Level 3 - Prices or valuation techniques that require inputs that are both significant to the fair value measurement and unobservable (i.e., supported by little or no market activity).

A financial instrument’s level within the fair value hierarchy is based on the lowest level of input that is significant to the fair value measurement.

The types of instruments valued based on quoted market prices in active markets include most U.S. government and agency securities, many other sovereign government obligations, liquid mortgage products, active listed equities and most money market securities. Such instruments are generally classified within Level 1 or Level 2 of the fair value hierarchy. The Company does not adjust the quoted price for such instruments.

The types of instruments valued based on quoted prices in markets that are not active, broker or dealer quotations or quote from alternative pricing sources with reasonable levels of price transparency include most investment-grade and high-yield corporate bonds, less liquid mortgage products, less liquid agency securities, less liquid listed equities, state, municipal and provincial obligations and certain physical commodities. Such instruments are generally classified within Level 2 of the fair value hierarchy. Certain common equity securities are reported at fair value utilizing Level 1 inputs (exchange quoted prices). Other investment securities are reported at fair value utilizing Level 1 and Level 2 inputs. The prices for Level 2 instruments are obtained through an independent pricing service or dealer market participants with whom the Company has historically transacted both purchases and sales of investment securities. Prices obtained from these sources include prices derived from market quotations and matrix pricing. The fair value measurements consider observable data that may include dealer quotes, market spreads, cash flows, the U.S. Treasury yield curve, live trading levels, trade execution data, market consensus prepayment speeds, credit information and the bond’s terms and conditions, among other things. Management reviews the methodologies used in pricing the securities by its third-party providers in pricing the securities.

Level 3 is for positions that are not traded in active markets or are subject to transfer restrictions. Valuations are adjusted to reflect illiquidity and/or non-transferability and such adjustments are generally based on available market evidence. In the absence of such evidence, management’s best estimate will be used. Management’s best estimate consists of both internal and external support on certain Level 3 investments. Subsequent to inception, management only changes Level 3 inputs and assumptions when corroborated by evidence such as transactions in similar instruments, completed or pending third-party transactions in the underlying investment or comparable entities, subsequent rounds of financing, recapitalizations and other transactions across the capital structure, offerings in the equity or debt markets and changes in financial ratios or cash flows.

Other Financial Instruments

The Company is a party to certain instruments with off-balance-sheet risk such as commitments to extend credit, unused lines of credit, standby letter of credit and certain agricultural real estate loans sold to investors with recourse. The Company’s policy is to record such instruments when funded.

Standby letters of credit are conditional commitments issued to guarantee the performance of a customer to a third-party. The risk involved in issuing standby letters of credit is essentially the same as the credit risk involved in extending loan facilities to customers. Under the standby letters of credit, the Company is required to make payments to the beneficiary of the letters of credit upon request by the beneficiary contingent upon the customer’s failure to perform under the terms of the underlying contract with the beneficiary. Standby letters of credit typically have one year expirations with an option to renew upon annual review. The Company typically receives a fee for these transactions. The fair value of standby letters of credit is recorded upon inception.

Repurchase Agreements

Repurchase agreements are accounted for as secured financing transactions since the Company maintains effective control over the transferred securities and the transfer meets the other criteria for such accounting. Obligations to repurchase securities sold are reflected as a liability in the consolidated balance sheets. The securities underlying the agreements are delivered to a custodial account for the benefit of the counterparties with whom each transaction is executed. The counterparties, who may sell, loan or otherwise dispose of such securities to other parties in the normal course of their operations, agree to resell to the Company the same securities at the maturities of the agreements.

Revenue from Contracts with Customers

Effective January 1, 2018, the Company adopted Financial Accounting Standards Board (“FASB”) Accounting Standards Update (“ASU”) 2014-09, Revenue from Contracts with Customers (Accounting Standards Codification (“ASC”) Topic 606) (“ASC 606” and “ASU 2014-09”), and all subsequent ASUs that modified ASC 606. The implementation of ASC 606 did not have a material impact on the measurement or recognition of revenue; as such, a cumulative effect adjustment to opening retained earnings was not deemed necessary. ASC 606 does not apply to revenue associated with financial instruments, including revenue from loans and securities and certain noninterest income streams such as fees associated with mortgage servicing rights, financial guarantees, derivatives and certain credit card fees are also not in scope. ASC 606 is applicable to noninterest revenue streams such as retirement plan administration fees, trust and asset management income, deposit related fees and annuity and insurance commissions; however, the recognition of these revenue streams did not change significantly upon adoption of ASC 606.

Service Charges on Deposit Accounts

Service charges on deposit accounts consist of overdraft fees, monthly service fees, check orders and other deposit account related fees. Overdraft, monthly service, check orders and other deposit account related fees are transactional based, and therefore, the Company’s performance obligation is satisfied, and related revenue recognized, at a point in time. Payment for service charges on deposit accounts is primarily received immediately or in the following month through a direct charge to customers’ accounts.

Card Services Income

ATM fees are primarily generated when a Company cardholder uses a non-Company ATM or a non-Company cardholder uses a Company ATM. Debit card income is primarily comprised of interchange fees earned whenever the Company’s debit cards are processed through card payment networks. The Company’s performance obligations for these revenue streams are satisfied, and related revenue recognized, when the services are rendered or upon completion. Payment is typically received immediately or in the following month.

Retirement Plan Administration Fees

Retirement plan administration fees are primarily generated for services related to the recordkeeping, administration and plan design solutions of defined benefit, defined contribution and revenue sharing plans. Revenue is recognized in arrears for services already provided in accordance with fees established in contracts with customers or based on rates agreed to with investment trade platforms based on ending investment balances held. The Company’s performance obligation is satisfied, and related revenue recognized based on services completed or ending investment balances, for which receivables are recorded at the time of revenue recognition.

Wealth Management

Wealth Management revenue primarily is comprised of trust and other financial services revenue. Trust and asset management income is primarily comprised of fees earned from the management and administration of trusts, pensions and other customer assets. The Company’s performance obligation is generally satisfied with the resulting fees recognized monthly, based upon services completed or the month-end market value of the assets under management and the applicable fee rate. Payment is generally received shortly after services are rendered or a few days after month end through a direct charge to customers’ accounts. The Company does not earn performance-based incentives. Financial services revenue primarily consists of commissions received on brokered investment product sales. For other financial services revenue, the Company’s performance obligation is generally satisfied upon the issuance of the annuity policy. Shortly after the policy is issued, the carrier remits the commission payment to the Company, and the Company recognizes the revenue. The Company does not earn a significant amount of trailing commission fees on brokered investment product sales. The majority of the trailing commission fees are calculated based on a percentage of market value of a period end and revenue is recognized when an investment product’s market value can be determined.

Insurance Revenue

Insurance and other financial services revenue primarily consists of commissions received on insurance. The Company acts as an intermediary between the Company’s customer and the insurance carrier. The Company’s performance obligation related to insurance sales for both property and casualty insurance and employee benefit plans is generally satisfied upon the later of the issuance or effective date of the policy. The Company earns performance based incentives, commonly known as contingency payments, which usually are based on certain criteria established by the insurance carrier such as premium volume, growth and insured loss ratios. Contingent payments are accrued for based upon management’s expectations for the year. Commission expense associated with sales of insurance products is expensed as incurred. The Company does not earn a significant amount of trailing commission fees on insurance product sales. The majority of the trailing commission fees are calculated based on a percentage of market value of a period end and revenue is recognized when an investment product’s market value can be determined.

Other

Other noninterest income consists of other recurring revenue streams such as account and loan fees, interest rate swap fees, safe deposit box rental fees and other miscellaneous revenue streams. These revenue streams are primarily transactional based and payment is received immediately or in the following month, and therefore, the Company’s performance obligation is satisfied, and the related revenue is recognized, at a point in time.

The following table presents noninterest income, segregated by revenue streams in-scope and out-of-scope of ASC 606:

	Years Ended December 31,
(In thousands)	2022		2021		2020
Noninterest income
In-Scope of ASC 606:
Service charges on deposit accounts	$	14,630	$	13,348	$	13,201
Card services income		29,058		34,682		28,611
Retirement plan administration fees		48,112		42,188		35,851
Wealth management		33,311		33,718		29,247
Insurance services		14,696		14,083		14,757
Other		10,858		12,992		19,254
Total noninterest income in-scope of ASC 606	$	150,665	$	151,011	$	140,921
Total noninterest income out-of-scope of ASC 606	$	4,913	$	6,783	$	5,355
Total noninterest income	$	155,578	$	157,794	$	146,276

Contract Balances

A contract asset balance occurs when an entity performs a service for a customer before the customer pays consideration or before payment is due, which would result in contract receivables or assets, respectively. A contract liability balance is an entity’s obligation to transfer a service to a customer for which the entity has already received payment or for which payment is due from the customer. The Company’s noninterest revenue streams are largely based on transactional activity, or standard month-end revenue accruals such as asset management fees based on month-end market values. Consideration is often received immediately or shortly after the Company satisfies its performance obligation and revenue is recognized. The Company does not typically enter into long-term revenue contracts with customers, and therefore, does not experience significant contract balances.

Contract Acquisition Costs

ASC 606 requires the capitalization, and subsequently amortization into expense, of certain incremental costs of obtaining a contract with a customer if these costs are expected to be recovered. The incremental costs of obtaining a contract are those costs that an entity incurs to obtain a contract with a customer that it would not have incurred if the contract had not been obtained. The Company elected the practical expedient, which allows immediate expensing of contract acquisition costs when the asset that would have resulted from capitalizing these costs would have been amortized in one year or less, and did not capitalize any contract acquisition costs upon adoption of ASC 606 as of or during the year ended December 31, 2022, 2021 and 2020.

Trust Operations

Assets held by the Company in a fiduciary or agency capacity for its customers are not included in the accompanying consolidated balance sheets, since such assets are not assets of the Company.

Subsequent Events

The Company has evaluated subsequent events for potential recognition and/or disclosure and there were none identified.

Deposits (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Maturities of Time Deposits [Abstract]
Within one year	$ 280,996
After one but within two years	92,492
After two but within three years	24,033
After three but within four years	21,483
After four but within five years	14,332
After five years	436
Total	433,772	$ 501,472
Time Deposits, $250,000 or More [Abstract]
Time deposits of $250,000 or more	$ 48,400	$ 72,300

Fair Value Measurements and Fair Values of Financial Instruments (Tables)

12 Months Ended

Dec. 31, 2022

Fair Value Measurements and Fair Values of Financial Instruments [Abstract]

Fair Value of Financial Assets and Liabilities Measured on a Recurring Basis

The following tables set forth the Company’s financial assets and liabilities measured on a recurring basis that were accounted for at fair value. Assets and liabilities are classified in their entirety based on the lowest level of input that is significant to the fair value measurement:

(In thousands)	Level 1		Level 2		Level 3		December 31, 2022
Assets:
AFS securities
U.S. treasury	$	121,658	$	-	$	-	$	121,658
Federal agency		-		206,419		-		206,419
State & municipal		-		82,851		-		82,851
Mortgage-backed		-		473,694		-		473,694
Collateralized mortgage obligations		-		588,363		-		588,363
Corporate		-		54,240		-		54,240
Total AFS securities	$	121,658	$	1,405,567	$	-	$	1,527,225
Equity securities		29,784		1,000		-		30,784
Derivatives		-		93,185		-		93,185
Total	$	151,442	$	1,499,752	$	-	$	1,651,194

Liabilities:
Derivatives	$	-	$	117,257	$	-	$	117,257
Total	$	-	$	117,257	$	-	$	117,257

(In thousands)	Level 1		Level 2		Level 3		December 31, 2021
Assets:
AFS securities
U.S. treasury	$	73,069	$	-	$	-	$	73,069
Federal agency		-		239,931		-		239,931
State & municipal		-		94,088		-		94,088
Mortgage-backed		-		606,675		-		606,675
Collateralized mortgage obligations		-		621,595		-		621,595
Corporate		-		52,003		-		52,003
Total AFS securities	$	73,069	$	1,614,292	$	-	$	1,687,361
Equity securities		32,550		1,000		-		33,550
Derivatives		-		60,625		-		60,625
Total	$	105,619	$	1,675,917	$	-	$	1,781,536

Liabilities:
Derivatives	$	-	$	60,263	$	-	$	60,263
Total	$	-	$	60,263	$	-	$	60,263

Information with Regard to Estimated Fair Values of Financial Instruments

The following table sets forth information with regard to estimated fair values of financial instruments. This table excludes financial instruments for which the carrying amount approximates fair value. Financial instruments for which the fair value approximates carrying value include cash and cash equivalents, AFS securities, equity securities, accrued interest receivable, non-maturity deposits, short-term borrowings, accrued interest payable and derivatives.

			December 31, 2022				December 31, 2021
(In thousands)	Fair Value Hierarchy		Carrying Amount		Estimated Fair Value		Carrying Amount		Estimated Fair Value
Financial assets:
HTM securities		2	$	919,517	$	812,647	$	733,210	$	735,260
Net loans		3		8,049,909		7,840,350		7,407,289		7,530,768
Financial liabilities:
Time deposits		2	$	433,772	$	413,868	$	501,472	$	500,717
Long-term debt		2		4,815		4,539		13,995		14,260
Subordinated debt		1		98,000		92,883		100,000		107,402
Junior subordinated debt		2		101,196		98,372		101,196		107,569

Securities

12 Months Ended

Dec. 31, 2022

Securities [Abstract]

Securities

4.	Securities

The amortized cost, estimated fair value and unrealized gains (losses) of AFS securities are as follows:

(In thousands)	Amortized Cost		Unrealized Gains		Unrealized Losses			Estimated Fair Value
As of December 31, 2022
U.S. treasury	$	132,891	$	-	$	(11,233	)	$	121,658
Federal agency		248,419		-		(42,000	)		206,419
State & municipal		97,036		5		(14,190	)		82,851
Mortgage-backed:
Government-sponsored enterprises		454,177		9		(54,675	)		399,511
U.S. government agency securities		81,844		15		(7,676	)		74,183
Collateralized mortgage obligations:
Government-sponsored enterprises		498,021		9		(59,473	)		438,557
U.S. government agency securities		171,090		-		(21,284	)		149,806
Corporate		60,404		-		(6,164	)		54,240
Total AFS securities	$	1,743,882	$	38	$	(216,695	)	$	1,527,225
As of December 31, 2021
U.S. treasury	$	73,016	$	59	$	(6	)	$	73,069
Federal agency		248,454		-		(8,523	)		239,931
State & municipal		95,531		116		(1,559	)		94,088
Mortgage-backed:
Government-sponsored enterprises		538,036		8,036		(5,589	)		540,483
U.S. government securities		65,339		1,108		(255	)		66,192
Collateralized mortgage obligations:
Government-sponsored enterprises		484,550		2,723		(5,113	)		482,160
U.S. government securities		139,380		939		(884	)		139,435
Corporate		50,500		1,516		(13	)		52,003
Total AFS securities	$	1,694,806	$	14,497	$	(21,942	)	$	1,687,361

There was no allowance for credit losses on AFS securities as of December 31, 2022 and 2021.

The components of net realized gains (losses) on AFS securities are as follows.

	Years Ended December 31,
(In thousands)	2022			2021			2020
Gross realized gains		$	-		$	-		$	3
Gross realized (losses)			-			-			-
Net AFS realized gains (losses)		$	-		$	-		$	3

The Company had no net realized gains (losses) on AFS securities for the years ended December 31, 2022 and 2021. Included in net realized gains (losses) on AFS securities, the Company recorded gains from calls of approximately $3 thousand for the year ended December 31, 2020, which were reclassified out of AOCI and into earnings.

The amortized cost, estimated fair value and unrealized gains (losses) of HTM securities are as follows:

(In thousands)	Amortized Cost		Unrealized Gains		Unrealized Losses			Estimated Fair Value
As of December 31, 2022
Federal agency	$	100,000	$	-	$	(20,678	)	$	79,322
Mortgage-backed:
Government-sponsored enterprises		249,511		-		(36,819	)		212,692
U.S. government agency securities		18,396		4		(619	)		17,781
Collateralized mortgage obligations:
Government-sponsored enterprises		207,738		200		(14,876	)		193,062
U.S. government agency securities		66,628		-		(9,842	)		56,786
State & municipal		277,244		5		(24,245	)		253,004
Total HTM securities	$	919,517	$	209	$	(107,079	)	$	812,647
As of December 31, 2021
Federal agency	$	100,000	$	-	$	(4,365	)	$	95,635
Mortgage-backed:
Government-sponsored enterprises		161,462		2,232		(1,319	)		162,375
U.S. government agency securities		9,112		514		-			9,626
Collateralized mortgage obligations:
Government-sponsored enterprises		94,342		1,932		(129	)		96,145
U.S. government agency securities		44,473		336		(674	)		44,135
State & municipal		323,821		5,026		(1,503	)		327,344
Total HTM securities	$	733,210	$	10,040	$	(7,990	)	$	735,260

At December 31, 2022 and 2021, all of the mortgaged-backed HTM securities were comprised of U.S. government agency and government-sponsored enterprises securities. There was no allowance for credit losses on HTM securities as of December 31, 2022 and 2021 because the expectation of nonrepayment of the amortized cost is zero, except for state & municipal securities, which such expected losses from nonrepayment are immaterial.

Included in net realized gains (losses), the Company recorded gains from calls on HTM securities of approximately $4 thousand for the year ended December 31, 2022, approximately $29 thousand for the year ended December 31, 2021 and approximately $24 thousand for the year ended December 31, 2020.

During the year ended December 31, 2020, the Company sold HTM securities with an amortized cost of $1.0 million and resulted in a realized loss of $1 thousand. Due to significant deterioration in the creditworthiness of the issuer of the HTM securities, the circumstances caused the Company to change its intent to hold the HTM securities sold to maturity, which did not affect the Company’s intent to hold the remainder of the HTM portfolio to maturity. There were no sales of HTM securities in the years ended December 31, 2022 and 2021.

AFS and HTM securities with amortized costs totaling $1.73 billion at December 31, 2022 and $1.63 billion at December 31, 2021 were pledged to secure public deposits and for other purposes required or permitted by law. Additionally, at December 31, 2022 and 2021, AFS and HTM securities with an amortized cost of $149.5 million and $162.1 million, respectively, were pledged as collateral for securities sold under repurchase agreements.

The following table set forth information with regard to gains and (losses) on equity securities:

	Years Ended December 31,
(In thousands)	2022			2021
Net (losses) and gains recognized on equity securities	$	(1,135	)	$	537
Less: Net (losses) and gains recognized on equity securities sold during the period		-			-
Unrealized (losses) and gains recognized on equity securities still held	$	(1,135	)	$	537

As of December 31, 2022 and 2021 the carrying value of equity securities without readily determinable fair values was $1.0 million. The Company performed a qualitative assessment to determine whether the investments were impaired and identified no areas of concern as of December 31, 2022 and 2021. There were no impairments, downward or upward adjustments recognized for equity securities without readily determinable fair values during the years ended December 31, 2022 and 2021.

The following table set forth information with regard to contractual maturities of debt securities at December 31, 2022:

(In thousands)	Amortized Cost		Estimated Fair Value
AFS debt securities:
Within one year	$	682	$	675
From one to five years		402,807		361,295
From five to ten years		582,736		506,036
After ten years		757,657		659,219
Total AFS debt securities	$	1,743,882	$	1,527,225
HTM debt securities:
Within one year	$	49,986	$	49,979
From one to five years		92,443		89,979
From five to ten years		278,664		241,294
After ten years		498,424		431,395
Total HTM debt securities	$	919,517	$	812,647

Maturities of mortgage-backed, collateralized mortgage obligations and asset-backed securities are stated based on their estimated average lives. Actual maturities may differ from estimated average lives or contractual maturities because, in certain cases, borrowers have the right to call or prepay obligations with or without call or prepayment penalties.

Except for U.S. government securities and government-sponsored enterprises securities, there were no holdings, when taken in the aggregate, of any single issuer that exceeded 10% of consolidated stockholders’ equity at December 31, 2022, 2021 and 2020.

The following table sets forth information with regard to investment securities with unrealized losses, for which an allowance for credit losses has not been recorded, segregated according to the length of time the securities had been in a continuous unrealized loss position:

	Less Than 12 Months							12 Months or Longer							Total
(In thousands)	Fair Value		Unrealized Losses			Number of Positions		Fair Value		Unrealized Losses			Number of Positions		Fair Value		Unrealized Losses			Number of Positions
As of December 31, 2022
AFS securities:
U.S. treasury	$	55,616	$	(3,864	)		5	$	66,042	$	(7,369	)		3	$	121,658	$	(11,233	)		8
Federal agency		-		-			-		206,419		(42,000	)		16		206,419		(42,000	)		16
State & municipal		3,679		(341	)		2		78,395		(13,849	)		64		82,074		(14,190	)		66
Mortgage-backed		204,447		(15,048	)		149		267,926		(47,303	)		32		472,373		(62,351	)		181
Collateralized mortgage obligations		211,612		(14,458	)		77		374,376		(66,299	)		49		585,988		(80,757	)		126
Corporate		34,434		(2,970	)		12		19,806		(3,194	)		6		54,240		(6,164	)		18
Total securities with unrealized losses	$	509,788	$	(36,681	)		245	$	1,012,964	$	(180,014	)		170	$	1,522,752	$	(216,695	)		415

HTM securities:
Federal agency	$	-	$	-			-	$	79,322	$	(20,678	)		4	$	79,322	$	(20,678	)		4
Mortgage-backed		91,417		(9,096	)		21		138,936		(28,342	)		13		230,353		(37,438	)		34
Collateralized mortgage obligations		191,644		(13,863	)		47		48,289		(10,855	)		8		239,933		(24,718	)		55
State & municipal		110,727		(4,930	)		149		82,949		(19,315	)		76		193,676		(24,245	)		225
Total securities with unrealized losses	$	393,788	$	(27,889	)		217	$	349,496	$	(79,190	)		101	$	743,284	$	(107,079	)		318

As of December 31, 2021
AFS securities:
U.S. treasury	$	49,105	$	(6	)		2	$	-	$	-			-	$	49,105	$	(6	)		2
Federal agency		41,618		(1,846	)		4		198,313		(6,677	)		12		239,931		(8,523	)		16
State & municipal		87,515		(1,559	)		61		-		-			-		87,515		(1,559	)		61
Mortgage-backed		281,217		(4,319	)		24		39,491		(1,525	)		6		320,708		(5,844	)		30
Collateralized mortgage obligations		341,673		(5,495	)		34		15,774		(502	)		4		357,447		(5,997	)		38
Corporate		9,987		(13	)		2		-		-			-		9,987		(13	)		2
Total securities with unrealized losses	$	811,115	$	(13,238	)		127	$	253,578	$	(8,704	)		22	$	1,064,693	$	(21,942	)		149

HTM securities:
Federal agency	$	-	$	-			-	$	95,635	$	(4,365	)		4	$	95,635	$	(4,365	)		4
Mortgage-backed		103,789		(1,319	)		10		-		-			-		103,789		(1,319	)		10
Collateralized mortgage obligations		54,612		(803	)		6		-		-			-		54,612		(803	)		6
State & municipal		52,783		(1,189	)		40		8,950		(314	)		10		61,733		(1,503	)		50
Total securities with unrealized losses	$	211,184	$	(3,311	)		56	$	104,585	$	(4,679	)		14	$	315,769	$	(7,990	)		70

The Company does not believe the AFS securities that were in an unrealized loss position as of December 31, 2022 and 2021, which consisted of 415 and 149 individual securities, respectively, represented a credit loss impairment. AFS debt securities in unrealized loss positions are evaluated for impairment related to credit losses at least quarterly. As of December 31, 2022 and 2021, the majority of the AFS securities in an unrealized loss position consisted of debt securities issued by U.S. government agencies or U.S. government-sponsored enterprises that carry the explicit and/or implicit guarantee of the U.S. government, which are widely recognized as “risk-free” and have a long history of zero credit losses. Total gross unrealized losses were primarily attributable to changes in interest rates, relative to when the investment securities were purchased, and not due to the credit quality of the investment securities. The Company does not intend to sell, nor is it more likely than not that the Company will be required to sell the security before recovery of its amortized cost basis, which may be at maturity. The Company elected to exclude accrued interest receivable (“AIR”) from the amortized cost basis of debt securities. AIR on AFS debt securities totaled $4.2 million at December 31, 2022 and $3.9 million at December 31, 2021 and is excluded from the estimate of credit losses and reported in the other assets financial statement line.

None of the bank’s HTM debt securities were past due or on nonaccrual status as of December 31, 2022 and 2021. There was no accrued interest reversed against interest income for the years ended December 31, 2022 and 2021 as all securities remained on accrual status. In addition, there were no collateral-dependent HTM debt securities as of December 31, 2022 and 2021. As of December 31, 2022 and 2021, 70% and 56%, respectively, of the Company’s HTM debt securities were issued by U.S. government agencies or U.S. government-sponsored enterprises. These securities carry the explicit and/or implicit guarantee of the U.S. government, are widely recognized as “risk free,” and have a long history of zero credit loss. Therefore, the Company did not record an allowance for credit losses for these securities as of December 31, 2022 and 2021. The remaining HTM debt securities at December 31, 2022 and 2021 were comprised of state and municipal obligations generally with bond ratings of A to AAA. Utilizing the CECL approach, the Company determined that the expected credit loss on its HTM municipal bond portfolio was immaterial and therefore no allowance for credit loss was recorded as of December 31, 2022 and 2021. AIR on HTM debt securities totaled $3.8 million at December 31, 2022 and $2.7 million at December 31, 2021 and is excluded from the estimate of credit losses and reported in the other assets financial statement line.

Consolidated Statements of Changes in Stockholders' Equity (Parenthetical) - $ / shares	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Consolidated Statements of Changes in Stockholders' Equity [Abstract]
Cash dividends - per share (in dollars per share)	$ 1.16	$ 1.1	$ 1.08
Purchase of treasury shares (in shares)	400,000	604,637	263,507
Net issuance of shares to employee benefit plans and other stock plans (in shares)	89,811	143,555	95,990

Securities (Tables)

12 Months Ended

Dec. 31, 2022

Securities [Abstract]

Amortized Cost, Estimated Fair Value and Unrealized Gains (Losses) of Available for Sale ("AFS") Securities

The amortized cost, estimated fair value and unrealized gains (losses) of AFS securities are as follows:

(In thousands)	Amortized Cost		Unrealized Gains		Unrealized Losses			Estimated Fair Value
As of December 31, 2022
U.S. treasury	$	132,891	$	-	$	(11,233	)	$	121,658
Federal agency		248,419		-		(42,000	)		206,419
State & municipal		97,036		5		(14,190	)		82,851
Mortgage-backed:
Government-sponsored enterprises		454,177		9		(54,675	)		399,511
U.S. government agency securities		81,844		15		(7,676	)		74,183
Collateralized mortgage obligations:
Government-sponsored enterprises		498,021		9		(59,473	)		438,557
U.S. government agency securities		171,090		-		(21,284	)		149,806
Corporate		60,404		-		(6,164	)		54,240
Total AFS securities	$	1,743,882	$	38	$	(216,695	)	$	1,527,225
As of December 31, 2021
U.S. treasury	$	73,016	$	59	$	(6	)	$	73,069
Federal agency		248,454		-		(8,523	)		239,931
State & municipal		95,531		116		(1,559	)		94,088
Mortgage-backed:
Government-sponsored enterprises		538,036		8,036		(5,589	)		540,483
U.S. government securities		65,339		1,108		(255	)		66,192
Collateralized mortgage obligations:
Government-sponsored enterprises		484,550		2,723		(5,113	)		482,160
U.S. government securities		139,380		939		(884	)		139,435
Corporate		50,500		1,516		(13	)		52,003
Total AFS securities	$	1,694,806	$	14,497	$	(21,942	)	$	1,687,361

Components of Net Realized Gains (Losses) on Sale of AFS Securities

The components of net realized gains (losses) on AFS securities are as follows.

	Years Ended December 31,
(In thousands)	2022			2021			2020
Gross realized gains		$	-		$	-		$	3
Gross realized (losses)			-			-			-
Net AFS realized gains (losses)		$	-		$	-		$	3

Amortized Cost, Estimated Fair Value and Unrealized Gains (Losses) of Held to Maturity ("HTM") Securities

The amortized cost, estimated fair value and unrealized gains (losses) of HTM securities are as follows:

(In thousands)	Amortized Cost		Unrealized Gains		Unrealized Losses			Estimated Fair Value
As of December 31, 2022
Federal agency	$	100,000	$	-	$	(20,678	)	$	79,322
Mortgage-backed:
Government-sponsored enterprises		249,511		-		(36,819	)		212,692
U.S. government agency securities		18,396		4		(619	)		17,781
Collateralized mortgage obligations:
Government-sponsored enterprises		207,738		200		(14,876	)		193,062
U.S. government agency securities		66,628		-		(9,842	)		56,786
State & municipal		277,244		5		(24,245	)		253,004
Total HTM securities	$	919,517	$	209	$	(107,079	)	$	812,647
As of December 31, 2021
Federal agency	$	100,000	$	-	$	(4,365	)	$	95,635
Mortgage-backed:
Government-sponsored enterprises		161,462		2,232		(1,319	)		162,375
U.S. government agency securities		9,112		514		-			9,626
Collateralized mortgage obligations:
Government-sponsored enterprises		94,342		1,932		(129	)		96,145
U.S. government agency securities		44,473		336		(674	)		44,135
State & municipal		323,821		5,026		(1,503	)		327,344
Total HTM securities	$	733,210	$	10,040	$	(7,990	)	$	735,260

Gains and (Losses) on Equity Securities

The following table set forth information with regard to gains and (losses) on equity securities:

	Years Ended December 31,
(In thousands)	2022			2021
Net (losses) and gains recognized on equity securities	$	(1,135	)	$	537
Less: Net (losses) and gains recognized on equity securities sold during the period		-			-
Unrealized (losses) and gains recognized on equity securities still held	$	(1,135	)	$	537

Contractual Maturities of Debt Securities

The following table set forth information with regard to contractual maturities of debt securities at December 31, 2022:

(In thousands)	Amortized Cost		Estimated Fair Value
AFS debt securities:
Within one year	$	682	$	675
From one to five years		402,807		361,295
From five to ten years		582,736		506,036
After ten years		757,657		659,219
Total AFS debt securities	$	1,743,882	$	1,527,225
HTM debt securities:
Within one year	$	49,986	$	49,979
From one to five years		92,443		89,979
From five to ten years		278,664		241,294
After ten years		498,424		431,395
Total HTM debt securities	$	919,517	$	812,647

Investment Securities with Unrealized Losses

	Less Than 12 Months							12 Months or Longer							Total
(In thousands)	Fair Value		Unrealized Losses			Number of Positions		Fair Value		Unrealized Losses			Number of Positions		Fair Value		Unrealized Losses			Number of Positions
As of December 31, 2022
AFS securities:
U.S. treasury	$	55,616	$	(3,864	)		5	$	66,042	$	(7,369	)		3	$	121,658	$	(11,233	)		8
Federal agency		-		-			-		206,419		(42,000	)		16		206,419		(42,000	)		16
State & municipal		3,679		(341	)		2		78,395		(13,849	)		64		82,074		(14,190	)		66
Mortgage-backed		204,447		(15,048	)		149		267,926		(47,303	)		32		472,373		(62,351	)		181
Collateralized mortgage obligations		211,612		(14,458	)		77		374,376		(66,299	)		49		585,988		(80,757	)		126
Corporate		34,434		(2,970	)		12		19,806		(3,194	)		6		54,240		(6,164	)		18
Total securities with unrealized losses	$	509,788	$	(36,681	)		245	$	1,012,964	$	(180,014	)		170	$	1,522,752	$	(216,695	)		415

HTM securities:
Federal agency	$	-	$	-			-	$	79,322	$	(20,678	)		4	$	79,322	$	(20,678	)		4
Mortgage-backed		91,417		(9,096	)		21		138,936		(28,342	)		13		230,353		(37,438	)		34
Collateralized mortgage obligations		191,644		(13,863	)		47		48,289		(10,855	)		8		239,933		(24,718	)		55
State & municipal		110,727		(4,930	)		149		82,949		(19,315	)		76		193,676		(24,245	)		225
Total securities with unrealized losses	$	393,788	$	(27,889	)		217	$	349,496	$	(79,190	)		101	$	743,284	$	(107,079	)		318

As of December 31, 2021
AFS securities:
U.S. treasury	$	49,105	$	(6	)		2	$	-	$	-			-	$	49,105	$	(6	)		2
Federal agency		41,618		(1,846	)		4		198,313		(6,677	)		12		239,931		(8,523	)		16
State & municipal		87,515		(1,559	)		61		-		-			-		87,515		(1,559	)		61
Mortgage-backed		281,217		(4,319	)		24		39,491		(1,525	)		6		320,708		(5,844	)		30
Collateralized mortgage obligations		341,673		(5,495	)		34		15,774		(502	)		4		357,447		(5,997	)		38
Corporate		9,987		(13	)		2		-		-			-		9,987		(13	)		2
Total securities with unrealized losses	$	811,115	$	(13,238	)		127	$	253,578	$	(8,704	)		22	$	1,064,693	$	(21,942	)		149

HTM securities:
Federal agency	$	-	$	-			-	$	95,635	$	(4,365	)		4	$	95,635	$	(4,365	)		4
Mortgage-backed		103,789		(1,319	)		10		-		-			-		103,789		(1,319	)		10
Collateralized mortgage obligations		54,612		(803	)		6		-		-			-		54,612		(803	)		6
State & municipal		52,783		(1,189	)		40		8,950		(314	)		10		61,733		(1,503	)		50
Total securities with unrealized losses	$	211,184	$	(3,311	)		56	$	104,585	$	(4,679	)		14	$	315,769	$	(7,990	)		70

Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Assets
Securities held to maturity fair value	$ 812,647	$ 735,260
Stockholders' equity
Preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01
Preferred stock, shares authorized (in shares)	2,500,000	2,500,000
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)	100,000,000	100,000,000
Common stock, shares issued (in shares)	49,651,493	49,651,493
Common stock in treasury, at cost (in shares)	6,793,670	6,483,481

Parent Company Financial Information, Condensed Statements of Cash Flows (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Operating activities [Abstract]
Net income	$ 151,995	$ 154,885	$ 104,388
Adjustments to reconcile net income to net cash provided by operating activities [Abstract]
Depreciation and amortization of premises and equipment	10,155	9,896	9,772
Excess tax benefit on stock-based compensation	(288)	(385)	(181)
Stock-based compensation expense	4,530	4,414	4,581
Net security losses (gains)	1,131	(566)	388
Bank owned life insurance income	(6,044)	(6,217)	(5,743)
Amortization of subordinated debt issuance costs	437	438	230
Discount on repurchase of subordinated debt	(106)	0	0
Net change in other assets and other liabilities	(7,918)	(11,117)	(47,069)
Net cash provided by operating activities	183,223	159,185	145,273
Investing activities [Abstract]
Net cash provided by (used in) investing activities	(926,216)	(547,608)	(712,586)
Financing activities [Abstract]
Proceeds from issuance of subordinated debt	0	0	100,000
Payment of subordinated debt issuance costs	0	0	(2,178)
Repurchase of subordinated debt	(2,000)	0	0
Proceeds from the issuance of shares to employee and other stock plans	0	112	184
Cash paid by employer for tax-withholding on stock issuance	(1,751)	(2,931)	(1,537)
Purchases of treasury shares	(14,713)	(21,714)	(7,980)
Cash dividends	(49,765)	(47,738)	(47,207)
Net cash (used in) provided by financing activities	(328,728)	984,813	1,023,151
Net (decrease) increase in cash and cash equivalents	(1,071,721)	596,390	455,838
NBT Bancorp Inc [Member]
Operating activities [Abstract]
Net income	151,995	154,885	104,388
Adjustments to reconcile net income to net cash provided by operating activities [Abstract]
Depreciation and amortization of premises and equipment	582	1,113	1,739
Excess tax benefit on stock-based compensation	(288)	(385)	(181)
Stock-based compensation expense	4,530	4,414	4,581
Net security losses (gains)	618	(543)	483
Equity in undistributed income of subsidiaries	(41,978)	(41,931)	(32,068)
Bank owned life insurance income	(238)	(326)	(391)
Amortization of subordinated debt issuance costs	437	438	230
Discount on repurchase of subordinated debt	(106)	0	0
Net change in other assets and other liabilities	(8,376)	(7,127)	(3,535)
Net cash provided by operating activities	107,176	110,538	75,246
Investing activities [Abstract]
Investment in the Bank	0	0	(90,000)
Proceeds from calls of equity securities	0	1,000	2,000
Net cash provided by (used in) investing activities	0	1,000	(88,000)
Financing activities [Abstract]
Proceeds from issuance of subordinated debt	0	0	100,000
Payment of subordinated debt issuance costs	0	0	(2,178)
Repurchase of subordinated debt	(2,000)	0	0
Proceeds from the issuance of shares to employee and other stock plans	0	112	184
Cash paid by employer for tax-withholding on stock issuance	(1,751)	(2,931)	(1,537)
Purchases of treasury shares	(14,713)	(21,714)	(7,980)
Cash dividends	(49,765)	(47,738)	(47,207)
Net cash (used in) provided by financing activities	(68,229)	(72,271)	41,282
Net (decrease) increase in cash and cash equivalents	38,947	39,267	28,528
Cash and cash equivalents at beginning of year	77,182	37,915	9,387
Cash and cash equivalents at end of year	$ 116,129	$ 77,182	$ 37,915

Stockholders' Equity

12 Months Ended

Dec. 31, 2022

Stockholders' Equity [Abstract]

Stockholders' Equity

14. Stockholders’ Equity

In accordance with GAAP, unrecognized prior service costs and net actuarial gains or losses associated with the Company’s pension and postretirement benefit plans and unrealized gains on derivatives and on AFS securities are included in AOCI, net of tax. For the years ended December 31, components of AOCI are:

(In thousands)	2022			2021			2020
Unrecognized prior service cost and net actuarial (losses) on pension plans	$	(26,435	)	$	(16,269	)	$	(20,134	)
Unrealized (losses) on derivatives (cash flow hedges)		-			-			(16	)
Unrealized net holding (losses) gains on AFS securities		(163,599	)		(7,075	)		20,567
AOCI	$	(190,034	)	$	(23,344	)	$	417

Certain restrictions exist regarding the ability of the subsidiary bank to transfer funds to the Company in the form of cash dividends. The approval of the Office of the Comptroller of the Currency (“OCC”) is required to pay dividends when a bank fails to meet certain minimum regulatory capital standards or when such dividends are in excess of a subsidiary bank’s earnings retained in the current year plus retained net profits for the preceding two years as specified in applicable OCC regulations. At December 31, 2022, approximately $145.3 million of the total stockholders’ equity of the Bank was available for payment of dividends to the Company without approval by the OCC. The Bank’s ability to pay dividends also is subject to the Bank’s continued compliance with regulatory capital requirements. The Bank is currently in compliance with these requirements. Under the State of Delaware General Corporation Law, the Company may declare and pay dividends either out of accumulated net retained earnings or capital surplus.

The Company purchased 400,000 shares of its common stock during the year ended December 31, 2022, for a total of $14.7 million at an average price of $36.78 per share under its previously announced share repurchase program. On December 20, 2021, the Board of Directors authorized a repurchase program for the Company to repurchase up to 2,000,000 shares of its outstanding common stock. As of December 31, 2022, there were 1,600,000 shares available for repurchase under this plan which is set to expire on December 31, 2023.

The entire disclosure for shareholders' equity comprised of portions attributable to the parent entity and noncontrolling interest, including other comprehensive income. Includes, but is not limited to, balances of common stock, preferred stock, additional paid-in capital, other capital and retained earnings, accumulated balance for each classification of other comprehensive income and amount of comprehensive income.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-URI https://asc.fasb.org/topic&trid=2208762

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 13
-Subparagraph (b)
-URI https://asc.fasb.org/extlink&oid=126973232&loc=SL123496158-112644

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 13
-URI https://asc.fasb.org/extlink&oid=126973232&loc=SL123496158-112644

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 14
-Subparagraph (c)
-URI https://asc.fasb.org/extlink&oid=126973232&loc=SL123496171-112644

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 14
-Subparagraph (b)
-URI https://asc.fasb.org/extlink&oid=126973232&loc=SL123496171-112644

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.3-04)
-URI https://asc.fasb.org/extlink&oid=120397183&loc=d3e187085-122770

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 18
-Subparagraph (d)
-URI https://asc.fasb.org/extlink&oid=126973232&loc=SL123496189-112644

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 13
-Subparagraph (g)
-URI https://asc.fasb.org/extlink&oid=126973232&loc=SL123496158-112644

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 18
-Subparagraph (a)
-URI https://asc.fasb.org/extlink&oid=126973232&loc=SL123496189-112644

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 13
-Subparagraph (h)
-URI https://asc.fasb.org/extlink&oid=126973232&loc=SL123496158-112644

Reference 11: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 14
-Subparagraph (a)
-URI https://asc.fasb.org/extlink&oid=126973232&loc=SL123496171-112644

Reference 12: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 18
-Subparagraph (b)
-URI https://asc.fasb.org/extlink&oid=126973232&loc=SL123496189-112644

Reference 13: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 16
-Subparagraph (b)
-URI https://asc.fasb.org/extlink&oid=126973232&loc=SL123496180-112644

Reference 14: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 13
-Subparagraph (i)
-URI https://asc.fasb.org/extlink&oid=126973232&loc=SL123496158-112644

Reference 15: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08(e)(1))
-URI https://asc.fasb.org/extlink&oid=120395691&loc=d3e23780-122690

Reference 16: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 40
-Section 50
-Paragraph 6
-Subparagraph (a)
-URI https://asc.fasb.org/extlink&oid=126731327&loc=SL126733271-114008

Goodwill and Other Intangible Assets [Abstract]

Goodwill and Other Intangible Assets (Tables)

12 Months Ended

Dec. 31, 2022

Summary of Goodwill

A summary of goodwill is as follows:

(In thousands)
January 1, 2022	$	280,541
Goodwill acquired		663
December 31, 2022	$	281,204

January 1, 2021	$	280,541
Goodwill acquired		-
December 31, 2021	$	280,541

Summary of Core Deposit and Other Intangible Assets

A summary of core deposit and other intangible assets follows:

	December 31,
(In thousands)	2022		2021
Core deposit intangibles:
Gross carrying amount	$	6,161	$	7,435
Less: accumulated amortization		6,133		7,258
Net carrying amount	$	28	$	177

Identified intangible assets:
Gross carrying amount	$	25,179	$	25,025
Less: accumulated amortization		17,866		16,275
Net carrying amount	$	7,313	$	8,750

Total intangibles:
Gross carrying amount	$	31,340	$	32,460
Less: accumulated amortization		23,999		23,533
Net carrying amount	$	7,341	$	8,927

Tabular disclosure of goodwill by reportable segment and in total which includes a rollforward schedule.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (h)
-URI https://asc.fasb.org/extlink&oid=121556970&loc=d3e13816-109267

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (c)
-URI https://asc.fasb.org/extlink&oid=121556970&loc=d3e13816-109267

Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (g)
-URI https://asc.fasb.org/extlink&oid=121556970&loc=d3e13816-109267

Reference 4: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 20
-Section 50
-Paragraph 1
-URI https://asc.fasb.org/extlink&oid=121556970&loc=d3e13816-109267

Reference 5: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (e)
-URI https://asc.fasb.org/extlink&oid=121556970&loc=d3e13816-109267

Reference 6: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (d)
-URI https://asc.fasb.org/extlink&oid=121556970&loc=d3e13816-109267

Reference 7: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 20
-Section 50
-Paragraph 1A
-URI https://asc.fasb.org/extlink&oid=121556970&loc=SL108378252-109267

Reference 8: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (f)
-URI https://asc.fasb.org/extlink&oid=121556970&loc=d3e13816-109267

Reference 9: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (a)
-URI https://asc.fasb.org/extlink&oid=121556970&loc=d3e13816-109267

Reference 10: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 20
-Section 50
-Paragraph 2
-Subparagraph (b)
-URI https://asc.fasb.org/extlink&oid=121556970&loc=d3e13854-109267

Reference 11: http://www.xbrl.org/2003/role/exampleRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 20
-Section 55
-Paragraph 24
-URI https://asc.fasb.org/extlink&oid=122137925&loc=d3e14258-109268

Reference 12: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (b)
-URI https://asc.fasb.org/extlink&oid=121556970&loc=d3e13816-109267

Summary of Significant Accounting Policies [Abstract]

Summary of Significant Accounting Policies

12 Months Ended

Dec. 31, 2022

Summary of Significant Accounting Policies

1. Summary of Significant Accounting Policies

The accounting and reporting policies of NBT Bancorp Inc. (“NBT Bancorp”) and its subsidiaries, NBT Bank, National Association (“NBT Bank” or the “Bank”), NBT Financial Services, Inc. and NBT Holdings, Inc., conform, in all material respects, with generally accepted accounting principles in the United States of America (“GAAP”) and to general practices within the banking industry. Collectively, NBT Bancorp and its subsidiaries are referred to herein as (“the Company”).

The following is a description of significant policies and practices:

Consolidation

Segment Reporting

Cash Equivalents

Securities

Allowance for Credit Losses –HTM Debt Securities

Allowance for Credit Losses –AFS Debt Securities

Loan Held for Sale and Loan Servicing

Loans

Allowance for Credit Losses - Loans

The following table illustrates the portfolio and class segments for the Company’s loan portfolio:

Portfolio Segment	Class
Commercial Loans	Commercial & Industrial Paycheck Protection Program Commercial Real Estate
Consumer Loans	Auto Other Consumer
Residential Loans

Commercial Loans

Consumer Loans

The Company offers a variety of Consumer loan products including Auto and Other Consumer loans.

Residential

Allowance for Credit Losses on Off-Balance Sheet Credit Exposures

Accrued Interest Receivable

Premises and Equipment

Leases

Operating lease ROU assets represent the Company’s right to use an underlying asset during the lease term and operating lease liabilities represent our obligation to make lease payments arising from the lease. ROU assets are further adjusted for lease incentives. Operating lease expense, which is comprised of amortization of the ROU asset and the implicit interest accreted on the operating lease liability, is recognized on a straight-line basis over the lease term, and is recorded in occupancy expense in the consolidated statements of income.

Other Real Estate Owned

Goodwill and Other Intangible Assets

Bank-Owned Life Insurance

Treasury Stock

Income Taxes

Pension Costs

Stock-Based Compensation

Earnings Per Share

Comprehensive Income (Loss)

Derivative Instruments and Hedging Activities

Fair Value Measurements

Level 1 - Unadjusted quoted prices in active markets that are accessible at the measurement date for identical, unrestricted assets or liabilities;

Level 3 - Prices or valuation techniques that require inputs that are both significant to the fair value measurement and unobservable (i.e., supported by little or no market activity).

A financial instrument’s level within the fair value hierarchy is based on the lowest level of input that is significant to the fair value measurement.

Other Financial Instruments

Repurchase Agreements

Revenue from Contracts with Customers

Service Charges on Deposit Accounts

Card Services Income

Retirement Plan Administration Fees

Wealth Management

Insurance Revenue

Other

The following table presents noninterest income, segregated by revenue streams in-scope and out-of-scope of ASC 606:

	Years Ended December 31,
(In thousands)	2022		2021		2020
Noninterest income
In-Scope of ASC 606:
Service charges on deposit accounts	$	14,630	$	13,348	$	13,201
Card services income		29,058		34,682		28,611
Retirement plan administration fees		48,112		42,188		35,851
Wealth management		33,311		33,718		29,247
Insurance services		14,696		14,083		14,757
Other		10,858		12,992		19,254
Total noninterest income in-scope of ASC 606	$	150,665	$	151,011	$	140,921
Total noninterest income out-of-scope of ASC 606	$	4,913	$	6,783	$	5,355
Total noninterest income	$	155,578	$	157,794	$	146,276

Contract Balances

Contract Acquisition Costs

Trust Operations

Assets held by the Company in a fiduciary or agency capacity for its customers are not included in the accompanying consolidated balance sheets, since such assets are not assets of the Company.

Subsequent Events

The Company has evaluated subsequent events for potential recognition and/or disclosure and there were none identified.

Reclassification Adjustments Out of Other Comprehensive Income (Loss) (Tables)

12 Months Ended

Dec. 31, 2022

Reclassification Adjustments Out of Other Comprehensive Income (Loss) [Abstract]

Reclassification Adjustments out of AOCI

The following table summarizes the reclassification adjustments out of AOCI:

Detail About AOCI Components	Amount Reclassified From AOCI									Affected Line Item in the Consolidated Statements of Comprehensive Income (Loss)
(In thousands)	Years Ended December 31,
(In thousands)	2022			2021			2020
AFS securities:
(Gains) on AFS securities	$	-		$	-		$	(3	)	Net securities (gains) losses
Amortization of unrealized gains related to securities transfer		513			577			644		Interest income
Tax effect	$	(128	)	$	(145	)	$	(160	)	Income tax (benefit)
Net of tax	$	385		$	432		$	481

Cash flow hedges:
Net unrealized losses on cash flow hedges reclassified to interest expense	$	-		$	21		$	296		Interest expense
Tax effect	$	-		$	(5	)	$	(74	)	Income tax (benefit)
Net of tax	$	-		$	16		$	222

Pension and other benefits:
Amortization of net losses	$	623		$	1,263		$	1,535		Other noninterest expense
Amortization of prior service costs		114			110			92		Other noninterest expense
Tax effect	$	(184	)	$	(343	)	$	(407	)	Income tax (benefit)
Net of tax	$	553		$	1,030		$	1,220

Total reclassifications, net of tax	$	938		$	1,478		$	1,923

Document and Entity Information - USD ($)	12 Months Ended
Document and Entity Information - USD ($)	Dec. 31, 2022	Feb. 03, 2023	Jun. 30, 2022
Cover [Abstract]
Document Type	10-K
Amendment Flag	false
Document Annual Report	true
Document Period End Date	Dec. 31, 2022
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2022
Document Fiscal Period Focus	FY
Document Transition Report	false
Entity File Number	0-14703
Entity Registrant Name	NBT BANCORP INC
Entity Central Index Key	0000790359
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	16-1268674
Entity Address, Address Line One	52 South Broad Street
Entity Address, City or Town	Norwich
Entity Address, State or Province	NY
Entity Address, Postal Zip Code	13815
City Area Code	607
Local Phone Number	337-2265
Title of 12(b) Security	Common Stock, par value $0.01 per share
Trading Symbol	NBTB
Security Exchange Name	NASDAQ
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
ICFR Auditor Attestation Flag	true
Entity Shell Company	false
Entity Public Float			$ 1,558,025,644
Entity Common Stock, Shares Outstanding		42,901,522
Auditor Firm ID	185
Auditor Name	KPMG LLP
Auditor Location	Albany, New York

Summary of Significant Accounting Policies, Securities (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2022 USD ($)
Securities [Abstract]
Allowance for credit losses - HTM debt securities	$ 0

Consolidated Statements of Comprehensive Income (Loss) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Consolidated Statements of Comprehensive Income (Loss) [Abstract]
Net income	$ 151,995	$ 154,885	$ 104,388
Securities available for sale:
Unrealized net holding (losses) gains arising during the period, gross	(209,212)	(37,432)	23,204
Tax effect	52,303	9,358	(5,800)
Unrealized net holding (losses) gains arising during the period, net	(156,909)	(28,074)	17,404
Reclassification adjustment for net (gains) in net income, gross	0	0	(3)
Tax effect	0	0	1
Reclassification adjustment for net (gains) in net income, net	0	0	(2)
Amortization of unrealized net gains for the reclassification of available for sale securities to held to maturity, gross	513	577	644
Tax effect	(128)	(145)	(161)
Amortization of unrealized net gains for the reclassification of available for sale securities to held to maturity, net	385	432	483
Total securities available for sale, net	(156,524)	(27,642)	17,885
Cash flow hedges:
Unrealized losses on derivatives (cash flow hedges), gross	0	0	(275)
Tax effect	0	0	69
Unrealized losses on derivatives (cash flow hedges), net	0	0	(206)
Reclassification of net unrealized losses on cash flow hedges to interest expense, gross	0	21	296
Tax effect	0	(5)	(74)
Reclassification of net unrealized losses on cash flow hedges to interest expense, net	0	16	222
Total cash flow hedges, net	0	16	16
Pension and other benefits:
Amortization of prior service cost and actuarial losses, gross	737	1,373	1,627
Tax effect	(184)	(343)	(407)
Amortization of prior service cost and actuarial losses, net	553	1,030	1,220
(Increase) decrease in unrecognized actuarial loss, gross	(14,292)	3,780	429
Tax effect	3,573	(945)	(107)
(Increase) decrease in unrecognized actuarial loss, net	(10,719)	2,835	322
Total pension and other benefits, net	(10,166)	3,865	1,542
Total other comprehensive (loss) income	(166,690)	(23,761)	19,443
Comprehensive (loss) income	$ (14,695)	$ 131,124	$ 123,831

Income Taxes (Tables)

12 Months Ended

Dec. 31, 2022

Income Taxes [Abstract]

Components of Income Tax Expense Attributable to Operations

The significant components of income tax expense attributable to operations are as follows:

	Years Ended December 31,
(In thousands)	2022			2021		2020
Current
Federal	$	51,077		$	35,483	$	36,358
State		12,934			8,626		9,768
Total Current	$	64,011		$	44,109	$	46,126

Deferred
Federal	$	(15,862	)	$	507	$	(14,021	)
State		(3,988	)		357		(3,406	)
Total Deferred	$	(19,850	)	$	864	$	(17,427	)
Total income tax expense	$	44,161		$	44,973	$	28,699

Components of Deferred Tax Assets and Liabilities

The tax effects of temporary differences that give rise to significant portions of the deferred tax assets and deferred tax liabilities are as follows:

	December 31,
(In thousands)	2022		2021
Deferred tax assets:
Allowance for loan losses	$	24,792	$	22,479
Lease liability		6,273		6,744
Deferred compensation		9,181		9,584
Loan fees		33,389		12,936
Stock-based compensation expense		2,822		2,679
Unrealized losses on securities		53,663		1,482
Other		6,027		7,109
Total deferred tax assets	$	136,147	$	63,013
Deferred tax liabilities:
Pension benefits	$	13,103	$	16,137
Lease right-of-use asset		5,877		5,681
Amortization of intangible assets		14,112		13,187
Premises and equipment, primarily due to accelerated depreciation		4,889		4,962
Other		846		1,008
Total deferred tax liabilities	$	38,827	$	40,975
Net deferred tax asset at year-end	$	97,320	$	22,038
Net deferred tax asset at beginning of year		22,038		15,117
Increase in net deferred tax asset	$	75,282	$	6,921

Reconciliation of the Provision for Income taxes to the Amount Computed by Applying the Federal Statutory Rate

The following is a reconciliation of the provision for income taxes to the amount computed by applying the applicable Federal statutory rate to income before taxes:

	Years Ended December 31,
(In thousands)	2022			2021			2020
Federal income tax at statutory rate	$	41,193		$	41,971		$	27,948
Tax exempt income		(984	)		(1,014	)		(981	)
Net increase in cash surrender value of life insurance		(1,215	)		(1,230	)		(1,135	)
Federal tax credits		(2,417	)		(1,884	)		(1,705	)
State taxes, net of federal tax benefit		7,067			7,097			5,026
Other, net		517			33			(454	)
Income tax expense	$	44,161		$	44,973		$	28,699

Reconciliation of Gross Unrecognized Tax Benefits

A reconciliation of the beginning and ending balance of Federal and State gross unrecognized tax benefits (“UTBs”) is as follows:

(In thousands)	2022		2021
Balance at January 1	$	1,545	$	1,178
Additions for tax positions of prior years		3		80
Current period tax positions		394		287
Balance at December 31	$	1,942	$	1,545
Amount that would affect the effective tax rate if recognized, gross of tax	$	1,535	$	1,221

Earnings Per Share

12 Months Ended

Dec. 31, 2022

Earnings Per Share [Abstract]

Earnings Per Share

16. Earnings Per Share

The following is a reconciliation of basic and diluted EPS for the years presented in the consolidated statements of income:

	Years Ended December 31,
	2022						2021						2020
(In thousands except per share data)	Net Income		Weighted Average Shares		Per Share Amount		Net Income		Weighted Average Shares		Per Share Amount		Net Income		Weighted Average Shares		Per Share Amount
Basic EPS	$	151,995		42,917	$	3.54	$	154,885		43,421	$	3.57	$	104,388		43,693	$	2.39
Effect of dilutive securities:
Stock-based compensation				264						298						296
Diluted EPS	$	151,995		43,181	$	3.52	$	154,885		43,719	$	3.54	$	104,388		43,989	$	2.37

There was a nominal number of weighted average stock options outstanding for the years ended December 31, 2022, 2021 and 2020, that were not considered in the calculation of diluted EPS since the stock options’ exercise prices were greater than the average market price during these periods.

Parent Company Financial Information (Tables)

12 Months Ended

Dec. 31, 2022

Parent Company Financial Information [Abstract]

Parent Company Financial Information

Condensed Balance Sheets

	December 31,
(In thousands)	2022		2021
Assets
Cash and cash equivalents	$	116,129	$	77,182
Equity securities, at estimated fair value		24,499		27,622
Investment in subsidiaries, on equity basis		1,245,459		1,359,613
Other assets		39,339		36,216
Total assets	$	1,425,426	$	1,500,633
Liabilities and Stockholders’ Equity
Total liabilities	$	251,872	$	250,180
Stockholders’ equity		1,173,554		1,250,453
Total liabilities and stockholders’ equity	$	1,425,426	$	1,500,633

Condensed Statements of Income

	Years Ended December 31,
(In thousands)	2022			2021			2020
Dividends from subsidiaries	$	119,000		$	118,900		$	77,000
Management fee from subsidiaries		2,005			2,653			4,151
Net securities (losses) gains		(618	)		543			(483	)
Interest, dividends and other income		638			564			824
Total revenue	$	121,025		$	122,660		$	81,492
Operating expenses		14,035			11,956			11,825
Income before income tax benefit and equity in undistributed income of subsidiaries	$	106,990		$	110,704		$	69,667
Income tax benefit		(3,027	)		(2,250	)		(2,653	)
Equity in undistributed income of subsidiaries		41,978			41,931			32,068
Net income	$	151,995		$	154,885		$	104,388

Condensed Statements of Cash Flows

	Years Ended December 31,
(In thousands)	2022			2021			2020
Operating activities
Net income	$	151,995		$	154,885		$	104,388
Adjustments to reconcile net income to net cash provided by operating activities
Depreciation and amortization of premises and equipment		582			1,113			1,739
Excess tax benefit on stock-based compensation		(288	)		(385	)		(181	)
Stock-based compensation expense		4,530			4,414			4,581
Net securities losses (gains)		618			(543	)		483
Equity in undistributed income of subsidiaries		(41,978	)		(41,931	)		(32,068	)
Bank owned life insurance income		(238	)		(326	)		(391	)
Amortization of subordinated debt issuance costs		437			438			230
Discount on repurchase of subordinated debt		(106	)		-			-
Net change in other assets and other liabilities		(8,376	)		(7,127	)		(3,535	)
Net cash provided by operating activities	$	107,176		$	110,538		$	75,246
Investing activities
Investment in the Bank	$	-		$	-		$	(90,000	)
Proceeds from calls of equity securities		-			1,000			2,000
Net cash provided by (used in) investing activities	$	-		$	1,000		$	(88,000	)
Financing activities
Proceeds from issuance of subordinated debt	$	-		$	-		$	100,000
Payment of subordinated debt issuance costs		-			-			(2,178	)
Repurchase of subordinated debt		(2,000	)		-			-
Proceeds from the issuance of shares to employee and other stock plans		-			112			184
Cash paid by employer for tax-withholding on stock issuance		(1,751	)		(2,931	)		(1,537	)
Purchases of treasury shares		(14,713	)		(21,714	)		(7,980	)
Cash dividends		(49,765	)		(47,738	)		(47,207	)
Net cash (used in) provided by financing activities	$	(68,229	)	$	(72,271	)	$	41,282
Net increase in cash and cash equivalents	$	38,947		$	39,267		$	28,528
Cash and cash equivalents at beginning of year		77,182			37,915			9,387
Cash and cash equivalents at end of year	$	116,129		$	77,182		$	37,915

Loans (Details) - USD ($) $ in Thousands	12 Months Ended
Loans (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Summary of Loans [Abstract]
Loans	$ 8,150,147	$ 7,498,459
Deferred loan origination (fees) costs, net	(109,100)	(23,700)
Residential loans held for sale	562	830
Loans serviced for unrelated third parties	576,000	575,900
Mortgage servicing rights	600	1,000
Loans and Leases Receivable, Related Parties [Roll Forward]
Balance at January 1	3,292	5,936
New loans	576	182
Adjustment due to change in composition of related parties	(37)	(683)
Repayments	(1,315)	(2,143)
Balance at December 31	2,516	3,292
Commercial and Industrial [Member]
Summary of Loans [Abstract]
Loans	1,265,082	1,155,240
Commercial Real Estate [Member]
Summary of Loans [Abstract]
Loans	2,807,941	2,655,367
Paycheck Protection Program [Member]
Summary of Loans [Abstract]
Loans	949	101,222
Residential Real Estate [Member]
Summary of Loans [Abstract]
Loans	1,649,870	1,571,232
Indirect Auto [Member]
Summary of Loans [Abstract]
Loans	989,587	859,454
Residential Solar [Member]
Summary of Loans [Abstract]
Loans	856,798	440,016
Home Equity [Member]
Summary of Loans [Abstract]
Loans	314,124	330,357
Other Consumer [Member]
Summary of Loans [Abstract]
Loans	265,796	385,571
Agricultural and Agricultural Real Estate Mortgages [Member]
Summary of Loans [Abstract]
Loans serviced for unrelated third parties	31,000	25,600
Springstone Consumer Loans [Member]
Summary of Loans [Abstract]
Loans serviced for unrelated third parties	$ 6,200	$ 11,400

Parent Company Financial Information, Condensed Balance Sheets (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Assets [Abstract]
Equity securities, at estimated fair value	$ 30,784	$ 33,550
Other assets	379,797	266,733
Total assets	11,739,296	12,012,111
Liabilities and Stockholders' Equity [Abstract]
Total liabilities	10,565,742	10,761,658
Stockholders' equity	1,173,554	1,250,453	$ 1,187,618	$ 1,120,397
Total liabilities and stockholders' equity	11,739,296	12,012,111
NBT Bancorp Inc [Member]
Assets [Abstract]
Cash and cash equivalents	116,129	77,182	$ 37,915	$ 9,387
Equity securities, at estimated fair value	24,499	27,622
Investment in subsidiaries, on equity basis	1,245,459	1,359,613
Other assets	39,339	36,216
Total assets	1,425,426	1,500,633
Liabilities and Stockholders' Equity [Abstract]
Total liabilities	251,872	250,180
Stockholders' equity	1,173,554	1,250,453
Total liabilities and stockholders' equity	$ 1,425,426	$ 1,500,633

Summary of Significant Accounting Policies, Other Financial Instruments (Details)	12 Months Ended
	Dec. 31, 2022
Other Financial Instruments [Abstract]
Standby letters of credit expiration period	1 year

Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Basic EPS [Abstract]
Net income	$ 151,995	$ 154,885	$ 104,388
Weighted average shares, basic (in shares)	42,917	43,421	43,693
Basic EPS (in dollars per share)	$ 3.54	$ 3.57	$ 2.39
Diluted earnings per share [Abstract]
Net income	$ 151,995	$ 154,885	$ 104,388
Dilutive effect of stock-based compensation (in shares)	264	298	296
Weighted average shares, diluted (in shares)	43,181	43,719	43,989
Diluted EPS (in dollars per share)	$ 3.52	$ 3.54	$ 2.37

The amount of net income (loss) for the period per each share of common stock or unit outstanding during the reporting period.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 40
-Section 65
-Paragraph 1
-Subparagraph (e)(4)
-URI https://asc.fasb.org/extlink&oid=126732423&loc=SL123482106-238011

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 250
-SubTopic 10
-Section 50
-Paragraph 3
-URI https://asc.fasb.org/extlink&oid=124431687&loc=d3e22583-107794

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 250
-SubTopic 10
-Section 50
-Paragraph 11
-Subparagraph (b)
-URI https://asc.fasb.org/extlink&oid=124431687&loc=d3e22694-107794

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 260
-SubTopic 10
-Section 45
-Paragraph 10
-URI https://asc.fasb.org/extlink&oid=126958026&loc=d3e1448-109256

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 250
-SubTopic 10
-Section 50
-Paragraph 4
-URI https://asc.fasb.org/extlink&oid=124431687&loc=d3e22595-107794

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 250
-SubTopic 10
-Section 50
-Paragraph 11
-Subparagraph (a)
-URI https://asc.fasb.org/extlink&oid=124431687&loc=d3e22694-107794

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 260
-SubTopic 10
-Section 45
-Paragraph 7
-URI https://asc.fasb.org/extlink&oid=126958026&loc=d3e1337-109256

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 40
-Section 65
-Paragraph 1
-Subparagraph (f)
-URI https://asc.fasb.org/extlink&oid=126732423&loc=SL123482106-238011

Reference 9: http://www.xbrl.org/2003/role/exampleRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 260
-SubTopic 10
-Section 55
-Paragraph 52
-URI https://asc.fasb.org/extlink&oid=128363288&loc=d3e4984-109258

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 220
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-04(23))
-URI https://asc.fasb.org/extlink&oid=120400993&loc=SL114874131-224263

Reference 11: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 260
-SubTopic 10
-Section 55
-Paragraph 15
-URI https://asc.fasb.org/extlink&oid=128363288&loc=d3e3842-109258

Reference 12: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 250
-SubTopic 10
-Section 50
-Paragraph 7
-Subparagraph (a)
-URI https://asc.fasb.org/extlink&oid=124431687&loc=d3e22644-107794

Reference 13: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 260
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (a)
-URI https://asc.fasb.org/extlink&oid=124432515&loc=d3e3550-109257

Reference 14: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03(25))
-URI https://asc.fasb.org/extlink&oid=126953954&loc=SL114868664-224227

Reference 15: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 260
-SubTopic 10
-Section 45
-Paragraph 2
-URI https://asc.fasb.org/extlink&oid=126958026&loc=d3e1252-109256

Reference 16: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 260
-SubTopic 10
-Section 45
-Paragraph 60B
-Subparagraph (d)
-URI https://asc.fasb.org/extlink&oid=126958026&loc=SL5780133-109256

Reference 17: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 220
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-04(27))
-URI https://asc.fasb.org/extlink&oid=120399700&loc=SL114874048-224260

The amount of net income (loss) for the period available to each share of common stock or common unit outstanding during the reporting period and to each share or unit that would have been outstanding assuming the issuance of common shares or units for all dilutive potential common shares or units outstanding during the reporting period.

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 260
-SubTopic 10
-Section 55
-Paragraph 52
-URI https://asc.fasb.org/extlink&oid=128363288&loc=d3e4984-109258

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 250
-SubTopic 10
-Section 50
-Paragraph 7
-Subparagraph (a)
-URI https://asc.fasb.org/extlink&oid=124431687&loc=d3e22644-107794

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 260
-SubTopic 10
-Section 55
-Paragraph 15
-URI https://asc.fasb.org/extlink&oid=128363288&loc=d3e3842-109258

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 260
-SubTopic 10
-Section 45
-Paragraph 2
-URI https://asc.fasb.org/extlink&oid=126958026&loc=d3e1252-109256

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 250
-SubTopic 10
-Section 50
-Paragraph 11
-Subparagraph (b)
-URI https://asc.fasb.org/extlink&oid=124431687&loc=d3e22694-107794

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 250
-SubTopic 10
-Section 50
-Paragraph 4
-URI https://asc.fasb.org/extlink&oid=124431687&loc=d3e22595-107794

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 250
-SubTopic 10
-Section 50
-Paragraph 3
-URI https://asc.fasb.org/extlink&oid=124431687&loc=d3e22583-107794

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 260
-SubTopic 10
-Section 45
-Paragraph 60B
-Subparagraph (d)
-URI https://asc.fasb.org/extlink&oid=126958026&loc=SL5780133-109256

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 40
-Section 65
-Paragraph 1
-Subparagraph (f)
-URI https://asc.fasb.org/extlink&oid=126732423&loc=SL123482106-238011

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 220
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-04(27))
-URI https://asc.fasb.org/extlink&oid=120399700&loc=SL114874048-224260

Reference 11: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 260
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (a)
-URI https://asc.fasb.org/extlink&oid=124432515&loc=d3e3550-109257

Reference 12: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 220
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-04(23))
-URI https://asc.fasb.org/extlink&oid=120400993&loc=SL114874131-224263

Reference 13: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 250
-SubTopic 10
-Section 50
-Paragraph 11
-Subparagraph (a)
-URI https://asc.fasb.org/extlink&oid=124431687&loc=d3e22694-107794

Reference 14: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 260
-SubTopic 10
-Section 45
-Paragraph 7
-URI https://asc.fasb.org/extlink&oid=126958026&loc=d3e1337-109256

Reference 15: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 40
-Section 65
-Paragraph 1
-Subparagraph (e)(4)
-URI https://asc.fasb.org/extlink&oid=126732423&loc=SL123482106-238011

Reference 16: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03(25))
-URI https://asc.fasb.org/extlink&oid=126953954&loc=SL114868664-224227

The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

Summary of Long-term Debt

Borrowings, Long-Term Debt (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Long-term debt by maturity, amount [Abstract]
Due in next 12 months		$ 10,598
Due in year three	$ 1,519
Due in year four		0
Due in year nine	3,296
Due in year ten		3,397
Total	$ 4,815	$ 13,995
Long-term debt by maturity, weighted average rate [Abstract]
Due in next 12 months		2.53%
Due in year three	4.39%
Due in year four		0.00%
Due in year nine	2.45%
Due in year ten		2.45%

Securities, Available for Sale (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Debt securities, available-for-sale [Abstract]
Amortized cost	$ 1,743,882	$ 1,694,806
Unrealized gains	38	14,497
Unrealized losses	(216,695)	(21,942)
Estimated fair value	1,527,225	1,687,361
Allowance for credit losses on AFS securities	0	0
Components of net realized gains (losses) on sale of AFS securities [Abstract]
Gross realized gains	0	0	$ 3
Gross realized (losses)	0	0	0
Net AFS realized gains (losses)	0	0	3
Gains from calls on securities available for sale			$ 3
U.S. Treasury [Member]
Debt securities, available-for-sale [Abstract]
Amortized cost	132,891	73,016
Unrealized gains	0	59
Unrealized losses	(11,233)	(6)
Estimated fair value	121,658	73,069
Federal Agency [Member]
Debt securities, available-for-sale [Abstract]
Amortized cost	248,419	248,454
Unrealized gains	0	0
Unrealized losses	(42,000)	(8,523)
Estimated fair value	206,419	239,931
State & Municipal [Member]
Debt securities, available-for-sale [Abstract]
Amortized cost	97,036	95,531
Unrealized gains	5	116
Unrealized losses	(14,190)	(1,559)
Estimated fair value	82,851	94,088
Mortgage-Backed, Government Sponsored Enterprises [Member]
Debt securities, available-for-sale [Abstract]
Amortized cost	454,177	538,036
Unrealized gains	9	8,036
Unrealized losses	(54,675)	(5,589)
Estimated fair value	399,511	540,483
Mortgage-backed Securities, U.S. Government Agency Securities [Member]
Debt securities, available-for-sale [Abstract]
Amortized cost	81,844	65,339
Unrealized gains	15	1,108
Unrealized losses	(7,676)	(255)
Estimated fair value	74,183	66,192
Collateralized Mortgage Obligations, Government-Sponsored Enterprises [Member]
Debt securities, available-for-sale [Abstract]
Amortized cost	498,021	484,550
Unrealized gains	9	2,723
Unrealized losses	(59,473)	(5,113)
Estimated fair value	438,557	482,160
Collateralized Mortgage Obligations, U.S. Government Agency Securities [Member]
Debt securities, available-for-sale [Abstract]
Amortized cost	171,090	139,380
Unrealized gains	0	939
Unrealized losses	(21,284)	(884)
Estimated fair value	149,806	139,435
Corporate [Member]
Debt securities, available-for-sale [Abstract]
Amortized cost	60,404	50,500
Unrealized gains	0	1,516
Unrealized losses	(6,164)	(13)
Estimated fair value	$ 54,240	$ 52,003

Summary of Significant Accounting Policies, Allowance for Credit Losses - Loans (Details) $ in Millions	12 Months Ended
	Dec. 31, 2022 USD ($) Loan
Minimum [Member]
Allowance for Credit Losses [Abstract]
Threshold period past due for loans to be written off	90 days
Maximum [Member]
Allowance for Credit Losses [Abstract]
Threshold period past due for loans to be written off	120 days
Paycheck Protection Program [Member]
Allowance for Credit Losses [Abstract]
Number of loans processed \| Loan	6,100
Amount of loans processed \| $	$ 835
Percentage of forgiveness and paydown	99.00%
Commercial Loans [Member] \| Commercial Real Estate [Member] \| Maximum [Member]
Allowance for Credit Losses [Abstract]
Loan amount, percentage of appraised value or purchase price of the property	80.00%
Consumer Loans [Member] \| Auto [Member] \| Minimum [Member]
Allowance for Credit Losses [Abstract]
Principal repayment term of loan	3 years
Consumer Loans [Member] \| Auto [Member] \| Maximum [Member]
Allowance for Credit Losses [Abstract]
Principal repayment term of loan	6 years
Consumer Loans [Member] \| Installment Loans [Member] \| Minimum [Member]
Allowance for Credit Losses [Abstract]
Principal repayment term of loan	1 year
Consumer Loans [Member] \| Installment Loans [Member] \| Maximum [Member]
Allowance for Credit Losses [Abstract]
Principal repayment term of loan	15 years
Residential [Member] \| Maximum [Member]
Allowance for Credit Losses [Abstract]
Loan amount, percentage of appraised value or purchase price of the property	85.00%
Residential [Member] \| Home Equity [Member] \| Maximum [Member]
Allowance for Credit Losses [Abstract]
Loan amount, percentage of equity in property	85.00%
Term of draw	10 years
Term of amortization	15 years

Borrowings (Tables)

12 Months Ended

Dec. 31, 2022

Borrowings [Abstract]

Information related to short-term borrowings is summarized as follows:

	December 31,
(Dollars in thousands)	2022			2021			2020
Federal funds purchased:
Balance at year-end	$	60,000		$	-		$	-
Average during the year		14,644			17			14,727
Maximum month end balance		80,000			-			40,000
Weighted average rate during the year		4.02	%		0.11	%		2.05	%
Weighted average rate at year-end		4.28	%		-			-

Securities sold under repurchase agreements:
Balance at year-end	$	86,012		$	97,795		$	143,386
Average during the year		69,561			100,519			154,383
Maximum month end balance		88,637			135,623			176,840
Weighted average rate during the year		0.10	%		0.13	%		0.17	%
Weighted average rate at year-end		0.11	%		0.11	%		0.20	%

Other short-term borrowings:
Balance at year-end	$	439,000		$	-		$	25,000
Average during the year		46,371			1,302			183,699
Maximum month end balance		439,000			-			366,500
Weighted average rate during the year		4.24	%		2.02	%		1.55	%
Weighted average rate at year-end		4.45	%		-			1.99	%

(Dollars in thousands)	December 31, 2022					December 31, 2021
Maturity	Amount		Weighted Average Rate			Amount		Weighted Average Rate
2022	$	-		-		$	10,598		2.53	%
2025		1,519		4.39	%		-		-
2031		3,296		2.45	%		3,397		2.45	%
Total	$	4,815				$	13,995

Subordinated Debt

The following table summarizes the Company’s subordinated debt:

(Dollars in thousands)	December 31, 2022			December 31, 2021
Subordinated notes issued June 2020 – fixed interest rate of 5.00% through June 2025 and a variable interest rate equivalent to three-month SOFR plus 4.85% thereafter, maturing July 1, 2030	$	98,000		$	100,000
Unamortized debt issuance costs		(1,073	)		(1,510	)
Total subordinated debt, net	$	96,927		$	98,490

Schedule of Debt of VIE where Entity is not Primary Beneficiary

As of December 31, 2022, the Trusts had the following trust preferred securities outstanding and held the following junior subordinated debentures of the Company (dollars in thousands):

Description	Issuance Date	Trust Preferred Securities Outstanding		Interest Rate	Trust Preferred Debt Owed To Trust		Final Maturity Date
CNBF Capital Trust I	August 1999	$	18,000	3-month LIBOR plus 2.75%	$	18,720	August 2029
NBT Statutory Trust I	November 2005		5,000	3-month LIBOR plus 1.40%		5,155	December 2035
NBT Statutory Trust II	February 2006		50,000	3-month LIBOR plus 1.40%		51,547	March 2036
Alliance Financial Capital Trust I	December 2003		10,000	3-month LIBOR plus 2.85%		10,310	January 2034
Alliance Financial Capital Trust II	September 2006		15,000	3-month LIBOR plus 1.65%		15,464	September 2036

Tabular disclosure of long-debt instruments or arrangements, including identification, terms, features, collateral requirements and other information necessary to a fair presentation. These are debt arrangements that originally required repayment more than twelve months after issuance or greater than the normal operating cycle of the entity, if longer.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.22)
-URI https://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 3
-Subparagraph (SX 210.12-04(a))
-URI https://asc.fasb.org/extlink&oid=120395691&loc=d3e24072-122690

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 1A
-URI https://asc.fasb.org/extlink&oid=124435984&loc=d3e28541-108399

Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 6
-URI https://asc.fasb.org/extlink&oid=126973232&loc=d3e21506-112644

Reference 5: http://www.xbrl.org/2003/role/exampleRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 55
-Paragraph 69B
-URI https://asc.fasb.org/extlink&oid=123466577&loc=SL123495735-112612

Reference 6: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 2
-URI https://asc.fasb.org/extlink&oid=124435984&loc=d3e28551-108399

Reference 7: http://www.xbrl.org/2003/role/exampleRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 55
-Paragraph 69E
-URI https://asc.fasb.org/extlink&oid=123466577&loc=SL123495743-112612

Reference 8: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 7
-URI https://asc.fasb.org/extlink&oid=126973232&loc=d3e21521-112644

Reference 9: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 8
-URI https://asc.fasb.org/extlink&oid=126973232&loc=d3e21538-112644

Reference 10: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 470
-Section 50
-Paragraph 3
-URI https://asc.fasb.org/extlink&oid=123599511&loc=d3e64711-112823

Reference 11: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 55
-Paragraph 8
-URI https://asc.fasb.org/extlink&oid=114775985&loc=d3e28878-108400

Reference 12: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 3
-URI https://asc.fasb.org/extlink&oid=126973232&loc=d3e21475-112644

Allowance for Credit Losses and Credit Quality of Loans [Abstract]

Employee Benefit Plans (Policies)	12 Months Ended
Employee Benefit Plans (Policies)	Dec. 31, 2022
Employee Benefit Plans [Abstract]
Postemployment Benefit Plans, Policy	Defined Benefit Post-Retirement Plans The Company has a qualified, noncontributory, defined benefit pension plan (“the Plan”) covering substantially all of its employees at December 31, 2022. Benefits paid from the Plan are based on age, years of service, compensation and social security benefits and are determined in accordance with defined formulas. The Company’s policy is to fund the Plan in accordance with Employee Retirement Income Security Act of 1974 standards. Assets of the Plan are invested in publicly traded stocks, bonds and mutual funds. Prior to January 1, 2000, the Plan was a traditional defined benefit plan based on final average compensation. On January 1, 2000, the Plan was converted to a cash balance plan with grandfathering provisions for existing participants. Effective March 1, 2013, the Plan was amended. Benefit accruals for participants who, as of January 1, 2000, elected to continue participating in the traditional defined benefit plan design were frozen as of March 1, 2013. In May 2013, the noncontributory, frozen, defined benefit pension plan assumed from Alliance in the acquisition was merged into the Plan. In addition to the Plan, the Company provides supplemental employee retirement plans to certain current and former executives. The Company also assumed supplemental retirement plans for former executives in the Alliance acquisition. These supplemental employee retirement plans and the Plan are collectively referred to herein as “Pension Benefits.” In addition, the Company provides certain health care benefits for retired employees. Benefits were accrued over the employees’ active service period. Only employees that were employed by the Company on or before January 1, 2000 are eligible to receive post-retirement health care benefits. The Plan is contributory for participating retirees, requiring participants to absorb certain deductibles and coinsurance amounts with contributions adjusted annually to reflect cost sharing provisions and benefit limitations called for in the Plan. Employees become eligible for these benefits if they reach normal retirement age while working for the Company. For eligible employees described above, the Company funds the cost of post-retirement health care as benefits are paid. The Company elected to recognize the transition obligation on a delayed basis over twenty years. In addition, the Company assumed post-retirement medical life insurance benefits for certain Alliance employees, retirees and their spouses, if applicable, in the Alliance acquisition. These post-retirement benefits are referred to herein as “Other Benefits.” Accounting standards require an employer to: (1) recognize the overfunded or underfunded status of defined benefit post-retirement plans, which is measured as the difference between plan assets at fair value and the benefit obligation, as an asset or liability in its balance sheet; (2) recognize changes in that funded status in the year in which the changes occur through comprehensive income; and (3) measure the defined benefit plan assets and obligations as of the date of its year-end balance sheet. Plan Investment Policy The Company’s key investment objectives in managing its defined benefit plan assets are to ensure that present and future benefit obligations to all participants and beneficiaries are met as they become due; to provide a total return that, over the long-term, maximizes the ratio of the plan assets to liabilities, while minimizing the present value of required Company contributions, at the appropriate levels of risk; to meet statutory requirements and regulatory agencies’ requirements; and to satisfy applicable accounting standards. The Company periodically evaluates the asset allocations, funded status, rate of return assumption and contribution strategy for satisfaction of our investment objectives. Determination of Assumed Rate of Return The expected long-term rate-of-return on assets was 6.7% at December 31, 2022 and 2021, respectively. This assumption represents the rate of return on plan assets reflecting the average rate of earnings expected on the funds invested or to be invested to provide for the benefits included in the projected benefit obligation. The assumption has been determined by reflecting expectations regarding future rates of return for the portfolio considering the asset distribution and related historical rates of return. The appropriateness of the assumption is reviewed annually. Employee 401(k) and Employee Stock Ownership Plans The Company maintains a 401(k) and employee stock ownership plan (the “401(k) Plan”). The Company contributes to the 401(k) Plan based on employees’ contributions out of their annual salaries. In addition, the Company may also make discretionary contributions to the 401(k) Plan based on profitability. Participation in the 401(k) Plan is contingent upon certain age and service requirements. The employer contributions associated with the 401(k) Plan were $4.0 million in 2022, $3.9 million in 2021 and $3.6 million in 2020.

Allowance for Credit Losses and Credit Quality of Loans

12 Months Ended

Dec. 31, 2022

Allowance for Credit Losses and Credit Quality of Loans

6. Allowance for Credit Losses and Credit Quality of Loans

The allowance for credit losses totaled $100.8 million at December 31, 2022, compared to $92.0 million at December 31, 2021. The allowance for credit losses as a percentage of loans was 1.24% at December 31, 2022, compared to 1.23% at December 31, 2021.

The January 1, 2020 (“Day 1”) increase in the allowance for credit loss on loans relating to the adoption of ASU 2016-13, Financial Instruments - Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments was $3.0 million, which decreased retained earnings by $2.3 million and increased the deferred tax asset by $0.7 million.

The allowance for credit losses calculation incorporated a 6-quarter forecast period to account for forecast economic conditions under each scenario utilized in the measurement. For periods beyond the 6-quarter forecast, the model reverts to long-term economic conditions over a 4-quarter reversion period on a straight-line basis. The Company considers a baseline, upside and downside economic forecast in measuring the allowance.

The quantitative model as of December 31, 2022 incorporates a baseline economic outlook along with an alternative downside scenario sourced from a reputable third-party to accommodate other potential economic conditions in the model. The baseline outlook reflected an unemployment rate environment initially around pre-COVID-19 levels at 3.9% that increases slightly during the forecast period to 4.0%. Northeast GDP’s annualized growth (on a quarterly basis) is expected to start the first quarter of 2023 at approximately 3.9% and hovering around 4.6% by the end of the forecast period. Other utilized economic variables have generally deteriorated in their respective forecasts, with retail sales and housing starts forecasts declining from the prior year. Key assumptions in the baseline economic outlook included a full employment economy being realized in the near future, continued tapering of the Federal Reserve balance sheet, an increasing yield on ten-year treasury securities, and a gradual decline in global oil prices. The alternative downside scenario assumed deteriorated economic and pandemic related conditions from the baseline outlook. Under this scenario, northeast unemployment rises from 3.9% in the fourth quarter of 2022 to a peak of 6.9% in the first quarter of 2024. These scenarios and their respective weightings are evaluated at each measurement date and reflect management’s expectations as of December 31, 2022. Additional adjustments were made for factors not incorporated in the forecasts or the model, such as loss rate expectations for certain loan pools, considerations for inflation, and recent trends in asset value indices. Additional monitoring for industry concentrations, loan growth, and policy exceptions was also conducted. All these factors were considered through separate quantitative processes and incorporated when applicable into the estimate of current expected credit losses at December 31, 2022.

The quantitative model as of December 31, 2021 incorporates a baseline economic outlook along with alternative upside and downside scenarios sourced from a reputable third-party to accommodate other potential economic conditions in the model. The baseline outlook reflected an unemployment rate environment initially above pre-COVID-19 levels at 4.8% but falling below pre-COVID-19 levels by the end of the forecast period to 3.5%. Northeast GDP’s annualized growth (on a quarterly basis) was expected to start the first quarter of 2022 at approximately 9% and hover around 5% by the middle and end of the forecast period. The alternative downside scenario assumed deteriorated economic and pandemic related conditions from the baseline outlook. Under this scenario, northeast unemployment rose from 5.7% in the fourth quarter of 2021 to a peak of 8% in the first quarter of 2023, remaining around or above 7% for the entire forecast period. The alternative upside scenario incorporated a more optimistic outlook than the baseline scenario, with a swift return to full employment by the second quarter of 2022 and with northeast unemployment moving down to 3.1% by the end of the forecast period. These scenarios and their respective weightings are evaluated at each measurement date and reflect management’s expectations as of December 31, 2021. At December 31, 2021, the weightings were 60%, 10% and 30% for the baseline, upside and downside economic forecasts, respectively. Additional adjustments were made for COVID-19 related factors not incorporated in the forecasts, such as the mitigating impact of unprecedented stimulus in the second and third quarters of 2020, including direct payments to individuals, increased unemployment benefits, the Company’s loan deferral and modification initiatives and various government sponsored loan programs. The Company also continued to monitor the level of criticized and classified loans in the fourth quarter of 2021 compared to the level contemplated by the model during similar, historical economic conditions, and an adjustment was made to estimate potential additional losses above modeled losses. Additionally, qualitative adjustments were made for Moody’s baseline economic forecast to include impacts of the Build Back Better Act not passing by December 31, 2021 and to address potential economic deterioration due to Omicron, as well as isolated model limitations related to modeled outputs given abnormally high retail sales and business output growth rates in historical periods. These factors were considered through separate quantitative processes and incorporated into the estimate of current expected credit losses at December 31, 2021.

The quantitative model as of December 31, 2020 incorporated a baseline economic outlook, along with alternative upside and downside scenarios sourced from a reputable third-party to accommodate other potential economic conditions in the model. The baseline outlook reflected an unemployment rate environment above pre-COVID-19 levels for the entire forecast period, though steadily improving, before returning to low single digits by the end of 2023. Northeast GDP’s annual growth (on a quarterly basis) was expected to start 2021 in the low to mid-single digits, with a peak growth rate of 8% in the fourth quarter of 2021 and steadily falling back down to normalized levels through 2023 and 2024. Other utilized economic variables show improvement in their respective forecasts, namely business output. Key assumptions in the baseline economic outlook included an additional stimulus package passed at the same timing and a comparable level to that of the actual $900 billion COVID-19 relief package passed in December 2020 along with no significant secondary surge in COVID-19 cases or pandemic-related business closures. The alternative downside scenario assumed deteriorated economic and pandemic related conditions from the baseline outlook. In the same way, the alternative upside scenario assumed a faster economic recovery and more effective management of the COVID-19 virus from the baseline outlook. These scenarios and their respective weightings are evaluated at each measurement date and reflect management’s expectations as of December 31, 2020. Additional adjustments were made for COVID-19 related factors not incorporated in the forecasts, such as the mitigating impact of unprecedented stimulus in 2020, including direct payments to individuals, increased unemployment benefits, the Company’s loan deferral and modification initiatives and various government-sponsored loan programs. The commercial & industrial and consumer segment models were based upon percent change in unemployment with modeled values as of December 31, 2020 well outside the observed historical experience. Therefore, adjustments were required to produce outputs more aligned with default expectations given the forecast economic environment. Additionally, the Company identified a slightly higher level of criticized and classified loans during 2020 than those contemplated by the model during similar economic conditions in the past for which an adjustment was made for estimated expected additional losses above modeled output. These factors were considered through a separate quantitative process and incorporated into the estimate for allowance for credit losses at December 31, 2020.

There were no loans purchased with credit deterioration during the years ended December 31, 2022 and 2021. During 2022, the Company purchased $11.5 million of residential loans at a 1.53% premium and $50.1 million in consumer loans at par. The allowance for credit losses recorded for these loans on the purchase date was $3.2 million. During 2021, the Company purchased $58.9 million of residential loans at premiums ranging from 2% to 5% and $92.5 million of consumer loans at a par. The allowance for credit losses recorded for these loans on the purchase date was $6.8 million. The Company made a policy election to report AIR in the other assets line item on the balance sheet. AIR on loans totaled $25.0 million at December 31, 2022 and $19.5 million at December 31, 2021 and there was no estimated allowance for credit losses related to AIR at December 31, 2022 and 2021.

The following tables present the activity in the allowance for credit losses by our portfolio segment:

(In thousands)	Commercial Loans			Consumer Loans			Residential			Total
Balance as of December 31, 2021	$	28,941		$	44,253		$	18,806		$	92,000
Charge-offs		(1,870	)		(16,140	)		(633	)		(18,643	)
Recoveries		2,430			7,014			852			10,296
Provision		5,221			15,824			(3,898	)		17,147
Ending Balance as of December 31, 2022	$	34,722		$	50,951		$	15,127		$	100,800

Balance as of December 31, 2020	$	50,942		$	37,803		$	21,255		$	110,000
Charge-offs		(4,638	)		(14,489	)		(979	)		(20,106	)
Recoveries		723			8,571			1,069			10,363
Provision		(18,086	)		12,368			(2,539	)		(8,257	)
Ending Balance as of December 31, 2021	$	28,941		$	44,253		$	18,806		$	92,000

Balance as of January 1, 2020 (after adoption of ASC 326)	$	27,156		$	32,122		$	16,721		$	75,999
Charge-offs		(4,005	)		(21,938	)		(1,135	)		(27,078	)
Recoveries		786			8,541			618			9,945
Provision		27,005			19,078			5,051			51,134
Ending Balance as of December 31, 2020	$	50,942		$	37,803		$	21,255		$	110,000

The increase in the allowance for credit losses from December 31, 2021 to December 31, 2022 was primarily due to an increase in loan balances and a modest deterioration in the economic forecast. The decrease in the allowance for credit losses from December 31, 2020 to December 31, 2021 was primarily due to the improvement in the economic forecast, partly offset by providing for the increase in loan balances. The increase in the allowance for credit losses from Day 1 to December 31, 2020 was primarily due to the deterioration of macroeconomic factors surrounding the COVID-19 pandemic.

Individually Evaluated Loans

As of December 31, 2022, there were two relationships identified to be evaluated for loss on an individual basis which, in aggregate, had an amortized cost basis of $2.4 million, with no allowance for credit loss. As of December 31, 2021, there were five relationships identified to be evaluated for loss on an individual basis with an aggregate amortized cost basis of $10.2 million and no allowance for credit loss. The decrease in the amortized cost basis on an individual basis from December 31, 2021 to December 31, 2022 was primarily due to principal payments and resolution of one relationship in which the cost basis was substantially collected and the related $0.8 million allowance for credit losses was reversed.

The following table sets forth information with regard to past due and nonperforming loans by loan segment:

(In thousands)	31-60 Days Past Due Accruing		61-90 Days Past Due Accruing		Greater Than 90 Days Past Due Accruing		Total Past Due Accruing		Nonaccrual		Current		Recorded Total Loans
As of December 31, 2022
Commercial loans:
C&I	$	342	$	88	$	4	$	434	$	2,244	$	1,237,530	$	1,240,208
CRE		336		96		-		432		5,780		2,689,196		2,695,408
PPP		-		11		-		11		-		938		949
Total commercial loans	$	678	$	195	$	4	$	877	$	8,024	$	3,927,664	$	3,936,565
Consumer loans:
Auto	$	8,640	$	1,393	$	785	$	10,818	$	1,494	$	950,389	$	962,701
Other consumer		6,341		2,569		2,263		11,173		173		1,125,040		1,136,386
Total consumer loans	$	14,981	$	3,962	$	3,048	$	21,991	$	1,667	$	2,075,429	$	2,099,087
Residential	$	2,496	$	555	$	771	$	3,822	$	7,542	$	2,103,131	$	2,114,495
Total loans	$	18,155	$	4,712	$	3,823	$	26,690	$	17,233	$	8,106,224	$	8,150,147

(In thousands)	31-60 Days Past Due Accruing		61-90 Days Past Due Accruing		Greater Than 90 Days Past Due Accruing		Total Past Due Accruing		Nonaccrual		Current		Recorded Total Loans
As of December 31, 2021
Commercial loans:
C&I	$	622	$	-	$	-	$	622	$	3,618	$	1,126,430	$	1,130,670
CRE		1,219		132		-		1,351		12,726		2,550,910		2,564,987
PPP		-		-		-		-		-		101,222		101,222
Total commercial loans	$	1,841	$	132	$	-	$	1,973	$	16,344	$	3,778,562	$	3,796,879
Consumer loans:
Auto	$	6,911	$	1,547	$	545	$	9,003	$	1,295	$	816,210	$	826,508
Other consumer		3,789		1,816		1,105		6,710		233		832,447		839,390
Total consumer loans	$	10,700	$	3,363	$	1,650	$	15,713	$	1,528	$	1,648,657	$	1,665,898
Residential	$	2,481	$	420	$	808	$	3,709	$	12,413	$	2,019,560	$	2,035,682
Total loans	$	15,022	$	3,915	$	2,458	$	21,395	$	30,285	$	7,446,779	$	7,498,459

As of December 31, 2022 and 2021, there were $1.1 million and $8.8 million, respectively, of loans in nonaccrual that were specifically evaluated for individual expected credit loss without an allowance for credit losses.

Credit Quality Indicators

The Company has developed an internal loan grading system to evaluate and quantify the Company’s loan portfolio with respect to quality and risk. The system focuses on, among other things, financial strength of borrowers, experience and depth of borrower’s management, primary and secondary sources of repayment, payment history, nature of the business and outlook on particular industries. The internal grading system enables the Company to monitor the quality of the entire loan portfolio on a consistent basis and provide management with an early warning system, which facilitates recognition and response to problem loans and potential problem loans.

Commercial Grading System

For Commercial and Industrial (“C&I”), Paycheck Protection Program (“PPP”) and Commercial Real Estate (“CRE”) loans, the Company uses a grading system that relies on quantifiable and measurable characteristics when available. This includes comparison of financial strength to available industry averages, comparison of transaction factors (loan terms and conditions) to loan policy and comparison of credit history to stated repayment terms and industry averages. Some grading factors are necessarily more subjective such as economic and industry factors, regulatory environment and management. C&I and CRE loans are graded Doubtful, Substandard, Special Mention and Pass.

Doubtful

A Doubtful loan has a high probability of total or substantial loss, but because of specific pending events that may strengthen the asset, its classification as a loss is deferred. Doubtful borrowers are usually in default, lack adequate liquidity or capital and lack the resources necessary to remain an operating entity. Pending events can include mergers, acquisitions, liquidations, capital injections, the perfection of liens on additional collateral, the valuation of collateral and refinancing. Generally, pending events should be resolved within a relatively short period and the ratings will be adjusted based on the new information. Nonaccrual treatment is required for Doubtful assets because of the high probability of loss.

Substandard

Substandard loans have a high probability of payment default or they have other well-defined weaknesses. They require more intensive supervision by bank management. Substandard loans are generally characterized by current or expected unprofitable operations, inadequate debt service coverage, inadequate liquidity or marginal capitalization. Repayment may depend on collateral or other credit risk mitigants. For some Substandard loans, the likelihood of full collection of interest and principal may be in doubt and those loans should be placed on nonaccrual. Although Substandard assets, in the aggregate, will have a distinct potential for loss, an individual asset’s loss potential does not have to be distinct for the asset to be rated Substandard.

Special Mention

Special Mention loans have potential weaknesses that may, if not checked or corrected, weaken the asset or inadequately protect the Company’s position at some future date. These loans pose elevated risk, but their weakness does not yet justify a Substandard classification. Borrowers may be experiencing adverse operating trends (i.e., declining revenues or margins) or may be struggling with an ill-proportioned balance sheet (i.e., increasing inventory without an increase in sales, high leverage and/or tight liquidity). Adverse economic or market conditions, such as interest rate increases or the entry of a new competitor, may also support a Special Mention rating. Although a Special Mention loan has a higher probability of default than a Pass asset, its default is not imminent.

Pass

Loans graded as Pass encompass all loans not graded as Doubtful, Substandard or Special Mention. Pass loans are in compliance with loan covenants and payments are generally made as agreed. Pass loans range from superior quality to fair quality. Pass loans also include any portion of a government guaranteed loan, including PPP loans.

Consumer and Residential Grading System

Consumer and Residential loans are graded as either Nonperforming or Performing.

Nonperforming

Nonperforming loans are loans that are (1) over 90 days past due and interest is still accruing or (2) on nonaccrual status.

Performing

All loans not meeting any of the above criteria are considered Performing.

The following tables illustrate the Company’s credit quality by loan class by year of origination (vintage):

(In thousands)	2022		2021		2020		2019		2018		Prior		Revolving Loans Amortized Cost Basis		Revolving Loans Converted to Term		Total
As of December 31, 2022
C&I
By internally assigned grade:
Pass	$	296,562	$	251,531	$	164,976	$	91,497	$	39,394	$	32,413	$	327,166	$	3,133	$	1,206,672
Special mention		1,044		524		4,531		194		1,108		417		5,234		-		13,052
Substandard		76		459		231		3,098		91		3,969		12,348		163		20,435
Doubtful		-		20		-		28		-		1		-		-		49
Total C&I	$	297,682	$	252,534	$	169,738	$	94,817	$	40,593	$	36,800	$	344,748	$	3,296	$	1,240,208

CRE
By internally assigned grade:
Pass	$	374,313	$	465,990	$	439,012	$	333,568	$	217,141	$	566,783	$	201,563	$	24,735	$	2,623,105
Special mention		605		764		868		2,641		4,649		24,023		850		-		34,400
Substandard		309		-		2,316		3,937		1,822		23,819		713		4,987		37,903
Total CRE	$	375,227	$	466,754	$	442,196	$	340,146	$	223,612	$	614,625	$	203,126	$	29,722	$	2,695,408

PPP
By internally assigned grade:
Pass	$	-	$	949	$	-	$	-	$	-	$	-	$	-	$	-	$	949
Total PPP	$	-	$	949	$	-	$	-	$	-	$	-	$	-	$	-	$	949

Auto
By payment activity:
Performing	$	488,776	$	239,090	$	75,853	$	99,615	$	44,061	$	13,027	$	-	$	-	$	960,422
Nonperforming		590		655		404		385		216		29		-		-		2,279
Total auto	$	489,366	$	239,745	$	76,257	$	100,000	$	44,277	$	13,056	$	-	$	-	$	962,701

Other consumer
By payment activity:
Performing	$	538,488	$	304,595	$	110,944	$	82,045	$	51,655	$	26,755	$	19,218	$	250	$	1,133,950
Nonperforming		557		936		445		272		73		130		8		15		2,436
Total other consumer	$	539,045	$	305,531	$	111,389	$	82,317	$	51,728	$	26,885	$	19,226	$	265	$	1,136,386

Residential
By payment activity:
Performing	$	251,012	$	349,498	$	212,161	$	156,957	$	157,755	$	717,621	$	233,056	$	28,122	$	2,106,182
Nonperforming		267		384		408		555		1,028		5,651		-		20		8,313
Total residential	$	251,279	$	349,882	$	212,569	$	157,512	$	158,783	$	723,272	$	233,056	$	28,142	$	2,114,495

Total loans	$	1,952,599	$	1,615,395	$	1,012,149	$	774,792	$	518,993	$	1,414,638	$	800,156	$	61,425	$	8,150,147

(In thousands)	2021		2020		2019		2018		2017		Prior		Revolving Loans Amortized Cost Basis		Revolving Loans Converted to Term		Total
As of December 31, 2021
C&I
By internally assigned grade:
Pass	$	335,685	$	219,931	$	114,617	$	64,310	$	20,137	$	32,146	$	280,476	$	15,731	$	1,083,033
Special mention		148		5,255		4,641		2,430		2,699		1,111		11,835		522		28,641
Substandard		1,482		874		7,010		187		2,582		3,272		3,512		34		18,953
Doubtful		-		-		-		1		42		-		-		-		43
Total C&I	$	337,315	$	226,060	$	126,268	$	66,928	$	25,460	$	36,529	$	295,823	$	16,287	$	1,130,670

CRE
By internally assigned grade:
Pass	$	489,300	$	434,866	$	370,377	$	236,274	$	251,082	$	441,310	$	141,367	$	43,942	$	2,408,518
Special mention		789		826		11,235		3,544		15,379		53,372		780		420		86,345
Substandard		-		77		4,539		12,934		12,424		34,563		744		-		65,281
Doubtful		-		-		-		-		-		4,843		-		-		4,843
Total CRE	$	490,089	$	435,769	$	386,151	$	252,752	$	278,885	$	534,088	$	142,891	$	44,362	$	2,564,987

PPP
By internally assigned grade:
Pass	$	92,884	$	8,338	$	-	$	-	$	-	$	-	$	-	$	-	$	101,222
Total PPP	$	92,884	$	8,338	$	-	$	-	$	-	$	-	$	-	$	-	$	101,222

Auto
By payment activity:
Performing	$	351,778	$	129,419	$	183,959	$	101,441	$	46,007	$	12,064	$	-	$	-	$	824,668
Nonperforming		305		319		457		411		266		82		-		-		1,840
Total auto	$	352,083	$	129,738	$	184,416	$	101,852	$	46,273	$	12,146	$	-	$	-	$	826,508

Other consumer
By payment activity:
Performing	$	427,401	$	151,300	$	116,451	$	78,523	$	29,705	$	15,660	$	19,011	$	1	$	838,052
Nonperforming		216		429		249		134		238		33		18		21		1,338
Total other consumer	$	427,617	$	151,729	$	116,700	$	78,657	$	29,943	$	15,693	$	19,029	$	22	$	839,390

Residential
By payment activity:
Performing	$	345,338	$	226,723	$	179,087	$	179,575	$	146,611	$	687,863	$	246,103	$	11,161	$	2,022,461
Nonperforming		-		1,411		643		1,072		1,534		8,522		-		39		13,221
Total residential	$	345,338	$	228,134	$	179,730	$	180,647	$	148,145	$	696,385	$	246,103	$	11,200	$	2,035,682

Total loans	$	2,045,326	$	1,179,768	$	993,265	$	680,836	$	528,706	$	1,294,841	$	703,846	$	71,871	$	7,498,459

Allowance for Credit Losses on Off-Balance Sheet Credit Exposures

The allowance for losses on unfunded commitments totaled $5.1 million as of December 31, 2022 and 2021.

Troubled Debt Restructuring

When the Company modifies a loan in a troubled debt restructuring (“TDR”), such modifications generally include one or a combination of the following: an extension of the maturity date at a stated rate of interest lower than the current market rate for new debt with similar risk; temporary reduction in the interest rate; or change in scheduled payment amount. Residential and Consumer TDRs occurring during 2022 and 2021 were due to reductions in the interest rate and/or extension of the term.

On August 3, 2020, the Federal Financial Institutions Examination Council issued a joint statement on additional loan accommodations related to COVID-19. The joint statement clarifies that for loan modifications in which Section 4013 of the CARES Act (“Section 4013”) is being applied, subsequent modifications could also be eligible under Section 4013. Accordingly, the Company offered modifications made in response to COVID-19 to borrowers who were current and otherwise not past due in accordance with the criteria stated in Section 4013. These include short-term, 180 days or less, modifications in the form of payment deferrals, fee waivers, extensions of repayment terms, or other delays in payment. The Company evaluated the modification programs provided to its borrowers and has concluded the modifications were generally made in accordance with the CARES Act guidance to borrowers who were in good standing prior to the COVID-19 pandemic and are not required to be designated as TDRs.

The following tables illustrate the recorded investment and number of modifications designated as TDRs, including the recorded investment in the loans prior to a modification and the recorded investment in the loans after restructuring:

	Year Ended December 31, 2022						Year Ended December 31, 2021
(Dollars in thousands)	Number of Contracts		Pre-Modification Outstanding Recorded Investment		Post-Modification Outstanding Recorded Investment			Number of Contracts		Pre-Modification Outstanding Recorded Investment		Post-Modification Outstanding Recorded Investment
Consumer loans:
Auto		-	$	-	$	-			2	$	38	$	38
Total consumer loans		-	$	-	$	-			2	$	38	$	38
Residential		10	$	829	$	928			10	$	1,121	$	1,236
Total TDRs		10	$	829	$	928			12	$	1,159	$	1,274

The following table illustrates the recorded investment and number of modifications for TDRs where a concession has been made and subsequently defaulted during the year:

	Year Ended December 31, 2022				Year Ended December 31, 2021				Year Ended December 31, 2020
(Dollars in thousands)	Number of Contracts		Recorded Investment		Number of Contracts		Recorded Investment		Number of Contracts		Recorded Investment
Commercial loans:
C&I		1	$	320		-	$	-		1	$	387
CRE		-		-		-		-		1		168
Total commercial loans		1	$	320		-	$	-		2	$	555
Consumer loans:
Auto		2	$	20		3	$	36		1	$	6
Total consumer loans		2	$	20		3	$	36		1	$	6
Residential		50	$	3,387		49	$	2,830		61	$	3,213
Total TDRs		53	$	3,727		52	$	2,866		64	$	3,774

Acquisitions (Details) $ in Thousands	12 Months Ended
Acquisitions (Details) $ in Thousands	Dec. 31, 2022 USD ($) Location shares	Dec. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)
Business Acquisitions [Abstract]
Goodwill acquired	$ 663	$ 0
Alliance Benefit Group of Illinois, Inc. [Member]
Business Acquisitions [Abstract]
Total consideration paid			$ 9,100
Goodwill acquired			5,800
Contingent consideration, liability			$ 5,100
Salisbury Bank [Member]
Business Acquisitions [Abstract]
Total consideration to be paid	$ 1,540,000
Number of banking locations operated by acquiree \| Location	14
Business acquisition shares to be converted to receive entity's common stock (in shares) \| shares	0.745

Borrowings, Junior Subordinated Debt (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2022 USD ($) Trust Period
Junior Subordinated Debt [Abstract]
Number of statutory business trusts included in the Trusts \| Trust	5
Minimum assets for bank holding companies to be subject to the same capital requirements as insured depository institutions	$ 500,000
CNBF Capital Trust I [Member]
Junior Subordinated Debt [Abstract]
Number of wholly owned Delaware statutory business trusts \| Trust	1
Issuance date	Aug. 01, 1999
Trust preferred securities outstanding	$ 18,000
Trust preferred debt owed to trust	$ 18,720
Final maturity date	Aug. 01, 2029
CNBF Capital Trust I [Member] \| LIBOR [Member]
Junior Subordinated Debt [Abstract]
Variable rate basis	3-month LIBOR
Basis spread on variable rate	2.75%
NBT Statutory Trust I [Member]
Junior Subordinated Debt [Abstract]
Issuance date	Nov. 01, 2005
Trust preferred securities outstanding	$ 5,000
Trust preferred debt owed to trust	$ 5,155
Final maturity date	Dec. 01, 2035
NBT Statutory Trust I [Member] \| LIBOR [Member]
Junior Subordinated Debt [Abstract]
Variable rate basis	3-month LIBOR
Basis spread on variable rate	1.40%
NBT Statutory Trust II [Member]
Junior Subordinated Debt [Abstract]
Issuance date	Feb. 01, 2006
Trust preferred securities outstanding	$ 50,000
Trust preferred debt owed to trust	$ 51,547
Final maturity date	Mar. 01, 2036
NBT Statutory Trust II [Member] \| LIBOR [Member]
Junior Subordinated Debt [Abstract]
Variable rate basis	3-month LIBOR
Basis spread on variable rate	1.40%
Alliance Financial Capital Trust I [Member]
Junior Subordinated Debt [Abstract]
Issuance date	Dec. 01, 2003
Trust preferred securities outstanding	$ 10,000
Trust preferred debt owed to trust	$ 10,310
Final maturity date	Jan. 01, 2034
Alliance Financial Capital Trust I [Member] \| LIBOR [Member]
Junior Subordinated Debt [Abstract]
Variable rate basis	3-month LIBOR
Basis spread on variable rate	2.85%
Alliance Financial Capital Trust II [Member]
Junior Subordinated Debt [Abstract]
Issuance date	Sep. 01, 2006
Trust preferred securities outstanding	$ 15,000
Trust preferred debt owed to trust	$ 15,464
Final maturity date	Sep. 01, 2036
Alliance Financial Capital Trust II [Member] \| LIBOR [Member]
Junior Subordinated Debt [Abstract]
Variable rate basis	3-month LIBOR
Basis spread on variable rate	1.65%
Alliance Financial Capital [Member]
Junior Subordinated Debt [Abstract]
Number of wholly owned Delaware statutory business trusts \| Trust	2
Trusts [Member]
Junior Subordinated Debt [Abstract]
Trust preferred securities outstanding	$ 98,000
Trust preferred debt owed to trust	101,000
Trust equity method investment	$ 3,200
Debentures period semi-annual deferral periods \| Period	10
Trust preferred securities included in Tier I capital	$ 97,000
NBT Bancorp Inc [Member]
Junior Subordinated Debt [Abstract]
Trust equity method investment	$ 1,000

Fair Value Measurements and Fair Values of Financial Instruments, Fair Value of Financial Assets and Liabilities Measured on a Recurring Basis (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
AFS securities [Abstract]
AFS securities	$ 1,527,225	$ 1,687,361
Equity securities	$ 30,784	33,550
Minimum [Member]
Fair Value Measurements [Abstract]
Liquidation expense ratio on impaired collateral	10.00%
Maximum [Member]
Fair Value Measurements [Abstract]
Liquidation expense ratio on impaired collateral	50.00%
U.S. Treasury [Member]
AFS securities [Abstract]
AFS securities	$ 121,658	73,069
Federal Agency [Member]
AFS securities [Abstract]
AFS securities	206,419	239,931
State & Municipal [Member]
AFS securities [Abstract]
AFS securities	82,851	94,088
Corporate [Member]
AFS securities [Abstract]
AFS securities	54,240	52,003
Recurring Basis [Member]
AFS securities [Abstract]
AFS securities	1,527,225	1,687,361
Equity securities	30,784	33,550
Derivatives	$ 93,185	$ 60,625
Derivative Asset, Statement of Financial Position [Extensible Enumeration]	Other Assets	Other Assets
Total	$ 1,651,194	$ 1,781,536
Liabilities [Abstract]
Derivatives	$ 117,257	$ 60,263
Derivative Liability, Statement of Financial Position [Extensible Enumeration]	Other Liabilities	Other Liabilities
Total	$ 117,257	$ 60,263
Recurring Basis [Member] \| Level 1 [Member]
AFS securities [Abstract]
AFS securities	121,658	73,069
Equity securities	29,784	32,550
Derivatives	0	0
Total	151,442	105,619
Liabilities [Abstract]
Derivatives	0	0
Total	0	0
Recurring Basis [Member] \| Level 2 [Member]
AFS securities [Abstract]
AFS securities	1,405,567	1,614,292
Equity securities	1,000	1,000
Derivatives	93,185	60,625
Total	1,499,752	1,675,917
Liabilities [Abstract]
Derivatives	117,257	60,263
Total	117,257	60,263
Recurring Basis [Member] \| Level 3 [Member]
AFS securities [Abstract]
AFS securities	0	0
Equity securities	0	0
Derivatives	0	0
Total	0	0
Liabilities [Abstract]
Derivatives	0	0
Total	0	0
Recurring Basis [Member] \| U.S. Treasury [Member]
AFS securities [Abstract]
AFS securities	121,658	73,069
Recurring Basis [Member] \| U.S. Treasury [Member] \| Level 1 [Member]
AFS securities [Abstract]
AFS securities	121,658	73,069
Recurring Basis [Member] \| U.S. Treasury [Member] \| Level 2 [Member]
AFS securities [Abstract]
AFS securities	0	0
Recurring Basis [Member] \| U.S. Treasury [Member] \| Level 3 [Member]
AFS securities [Abstract]
AFS securities	0	0
Recurring Basis [Member] \| Federal Agency [Member]
AFS securities [Abstract]
AFS securities	206,419	239,931
Recurring Basis [Member] \| Federal Agency [Member] \| Level 1 [Member]
AFS securities [Abstract]
AFS securities	0	0
Recurring Basis [Member] \| Federal Agency [Member] \| Level 2 [Member]
AFS securities [Abstract]
AFS securities	206,419	239,931
Recurring Basis [Member] \| Federal Agency [Member] \| Level 3 [Member]
AFS securities [Abstract]
AFS securities	0	0
Recurring Basis [Member] \| State & Municipal [Member]
AFS securities [Abstract]
AFS securities	82,851	94,088
Recurring Basis [Member] \| State & Municipal [Member] \| Level 1 [Member]
AFS securities [Abstract]
AFS securities	0	0
Recurring Basis [Member] \| State & Municipal [Member] \| Level 2 [Member]
AFS securities [Abstract]
AFS securities	82,851	94,088
Recurring Basis [Member] \| State & Municipal [Member] \| Level 3 [Member]
AFS securities [Abstract]
AFS securities	0	0
Recurring Basis [Member] \| Mortgage-Backed [Member]
AFS securities [Abstract]
AFS securities	473,694	606,675
Recurring Basis [Member] \| Mortgage-Backed [Member] \| Level 1 [Member]
AFS securities [Abstract]
AFS securities	0	0
Recurring Basis [Member] \| Mortgage-Backed [Member] \| Level 2 [Member]
AFS securities [Abstract]
AFS securities	473,694	606,675
Recurring Basis [Member] \| Mortgage-Backed [Member] \| Level 3 [Member]
AFS securities [Abstract]
AFS securities	0	0
Recurring Basis [Member] \| Collateralized Mortgage Obligations [Member]
AFS securities [Abstract]
AFS securities	588,363	621,595
Recurring Basis [Member] \| Collateralized Mortgage Obligations [Member] \| Level 1 [Member]
AFS securities [Abstract]
AFS securities	0	0
Recurring Basis [Member] \| Collateralized Mortgage Obligations [Member] \| Level 2 [Member]
AFS securities [Abstract]
AFS securities	588,363	621,595
Recurring Basis [Member] \| Collateralized Mortgage Obligations [Member] \| Level 3 [Member]
AFS securities [Abstract]
AFS securities	0	0
Recurring Basis [Member] \| Corporate [Member]
AFS securities [Abstract]
AFS securities	54,240	52,003
Recurring Basis [Member] \| Corporate [Member] \| Level 1 [Member]
AFS securities [Abstract]
AFS securities	0	0
Recurring Basis [Member] \| Corporate [Member] \| Level 2 [Member]
AFS securities [Abstract]
AFS securities	54,240	52,003
Recurring Basis [Member] \| Corporate [Member] \| Level 3 [Member]
AFS securities [Abstract]
AFS securities	0	0
Non-Recurring Basis [Member]
Fair Value Measurements [Abstract]
Loans individually evaluated for expected credit losses, fair value	$ 1,100	$ 7,400

Allowance for Credit Losses and Credit Quality of Loans, Allowance for Loan Losses by Portfolio Segments (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Activity in allowance for credit losses by portfolio segment [Roll Forward]
Balance, beginning of period	$ 92,000	$ 110,000	$ 75,999
Charge-offs	(18,643)	(20,106)	(27,078)
Recoveries	10,296	10,363	9,945
Provision	17,147	(8,257)	51,134
Balance, end of period	100,800	92,000	110,000
Commercial Loans [Member]
Activity in allowance for credit losses by portfolio segment [Roll Forward]
Balance, beginning of period	28,941	50,942	27,156
Charge-offs	(1,870)	(4,638)	(4,005)
Recoveries	2,430	723	786
Provision	5,221	(18,086)	27,005
Balance, end of period	34,722	28,941	50,942
Consumer Loans [Member]
Activity in allowance for credit losses by portfolio segment [Roll Forward]
Balance, beginning of period	44,253	37,803	32,122
Charge-offs	(16,140)	(14,489)	(21,938)
Recoveries	7,014	8,571	8,541
Provision	15,824	12,368	19,078
Balance, end of period	50,951	44,253	37,803
Residential [Member]
Activity in allowance for credit losses by portfolio segment [Roll Forward]
Balance, beginning of period	18,806	21,255	16,721
Charge-offs	(633)	(979)	(1,135)
Recoveries	852	1,069	618
Provision	(3,898)	(2,539)	5,051
Balance, end of period	$ 15,127	$ 18,806	$ 21,255

Amount of allowance for credit loss on financing receivable. Excludes allowance for financing receivable covered under loss sharing agreement.

Parent Company Financial Information [Abstract]

Employee Benefit Plans, 401(k) Plan and Other Retirement Benefits (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Other Retirement Benefits [Abstract]
Supplemental retirement benefits for retired executives under other retirement benefits plan	$ 1.1	$ 1.3
Expense related to other retirement benefits plan	0.2	0.2	$ 0.2
401(K) Plan [Member]
Defined benefit plan disclosure [Abstract]
Employer contribution to plan	$ 4.0	$ 3.9	$ 3.6

Parent Company Financial Information

12 Months Ended

Dec. 31, 2022

Parent Company Financial Information

21. Parent Company Financial Information

Condensed Balance Sheets

	December 31,
(In thousands)	2022		2021
Assets
Cash and cash equivalents	$	116,129	$	77,182
Equity securities, at estimated fair value		24,499		27,622
Investment in subsidiaries, on equity basis		1,245,459		1,359,613
Other assets		39,339		36,216
Total assets	$	1,425,426	$	1,500,633
Liabilities and Stockholders’ Equity
Total liabilities	$	251,872	$	250,180
Stockholders’ equity		1,173,554		1,250,453
Total liabilities and stockholders’ equity	$	1,425,426	$	1,500,633

Condensed Statements of Income

	Years Ended December 31,
(In thousands)	2022			2021			2020
Dividends from subsidiaries	$	119,000		$	118,900		$	77,000
Management fee from subsidiaries		2,005			2,653			4,151
Net securities (losses) gains		(618	)		543			(483	)
Interest, dividends and other income		638			564			824
Total revenue	$	121,025		$	122,660		$	81,492
Operating expenses		14,035			11,956			11,825
Income before income tax benefit and equity in undistributed income of subsidiaries	$	106,990		$	110,704		$	69,667
Income tax benefit		(3,027	)		(2,250	)		(2,653	)
Equity in undistributed income of subsidiaries		41,978			41,931			32,068
Net income	$	151,995		$	154,885		$	104,388

Condensed Statements of Cash Flows

	Years Ended December 31,
(In thousands)	2022			2021			2020
Operating activities
Net income	$	151,995		$	154,885		$	104,388
Adjustments to reconcile net income to net cash provided by operating activities
Depreciation and amortization of premises and equipment		582			1,113			1,739
Excess tax benefit on stock-based compensation		(288	)		(385	)		(181	)
Stock-based compensation expense		4,530			4,414			4,581
Net securities losses (gains)		618			(543	)		483
Equity in undistributed income of subsidiaries		(41,978	)		(41,931	)		(32,068	)
Bank owned life insurance income		(238	)		(326	)		(391	)
Amortization of subordinated debt issuance costs		437			438			230
Discount on repurchase of subordinated debt		(106	)		-			-
Net change in other assets and other liabilities		(8,376	)		(7,127	)		(3,535	)
Net cash provided by operating activities	$	107,176		$	110,538		$	75,246
Investing activities
Investment in the Bank	$	-		$	-		$	(90,000	)
Proceeds from calls of equity securities		-			1,000			2,000
Net cash provided by (used in) investing activities	$	-		$	1,000		$	(88,000	)
Financing activities
Proceeds from issuance of subordinated debt	$	-		$	-		$	100,000
Payment of subordinated debt issuance costs		-			-			(2,178	)
Repurchase of subordinated debt		(2,000	)		-			-
Proceeds from the issuance of shares to employee and other stock plans		-			112			184
Cash paid by employer for tax-withholding on stock issuance		(1,751	)		(2,931	)		(1,537	)
Purchases of treasury shares		(14,713	)		(21,714	)		(7,980	)
Cash dividends		(49,765	)		(47,738	)		(47,207	)
Net cash (used in) provided by financing activities	$	(68,229	)	$	(72,271	)	$	41,282
Net increase in cash and cash equivalents	$	38,947		$	39,267		$	28,528
Cash and cash equivalents at beginning of year		77,182			37,915			9,387
Cash and cash equivalents at end of year	$	116,129		$	77,182		$	37,915

A statement of changes in stockholders’ equity has not been presented since it is the same as the consolidated statement of changes in stockholders’ equity previously presented.

Allowance for Credit Losses and Credit Quality of Loans (Tables)

12 Months Ended

Dec. 31, 2022

Allowance for Credit Losses and Credit Quality of Loans [Abstract]

Allowance for Loan Losses by Portfolio

The following tables present the activity in the allowance for credit losses by our portfolio segment:

(In thousands)	Commercial Loans			Consumer Loans			Residential			Total
Balance as of December 31, 2021	$	28,941		$	44,253		$	18,806		$	92,000
Charge-offs		(1,870	)		(16,140	)		(633	)		(18,643	)
Recoveries		2,430			7,014			852			10,296
Provision		5,221			15,824			(3,898	)		17,147
Ending Balance as of December 31, 2022	$	34,722		$	50,951		$	15,127		$	100,800

Balance as of December 31, 2020	$	50,942		$	37,803		$	21,255		$	110,000
Charge-offs		(4,638	)		(14,489	)		(979	)		(20,106	)
Recoveries		723			8,571			1,069			10,363
Provision		(18,086	)		12,368			(2,539	)		(8,257	)
Ending Balance as of December 31, 2021	$	28,941		$	44,253		$	18,806		$	92,000

Balance as of January 1, 2020 (after adoption of ASC 326)	$	27,156		$	32,122		$	16,721		$	75,999
Charge-offs		(4,005	)		(21,938	)		(1,135	)		(27,078	)
Recoveries		786			8,541			618			9,945
Provision		27,005			19,078			5,051			51,134
Ending Balance as of December 31, 2020	$	50,942		$	37,803		$	21,255		$	110,000

Past due and Nonperforming Loans by Loan Class

The following table sets forth information with regard to past due and nonperforming loans by loan segment:

(In thousands)	31-60 Days Past Due Accruing		61-90 Days Past Due Accruing		Greater Than 90 Days Past Due Accruing		Total Past Due Accruing		Nonaccrual		Current		Recorded Total Loans
As of December 31, 2022
Commercial loans:
C&I	$	342	$	88	$	4	$	434	$	2,244	$	1,237,530	$	1,240,208
CRE		336		96		-		432		5,780		2,689,196		2,695,408
PPP		-		11		-		11		-		938		949
Total commercial loans	$	678	$	195	$	4	$	877	$	8,024	$	3,927,664	$	3,936,565
Consumer loans:
Auto	$	8,640	$	1,393	$	785	$	10,818	$	1,494	$	950,389	$	962,701
Other consumer		6,341		2,569		2,263		11,173		173		1,125,040		1,136,386
Total consumer loans	$	14,981	$	3,962	$	3,048	$	21,991	$	1,667	$	2,075,429	$	2,099,087
Residential	$	2,496	$	555	$	771	$	3,822	$	7,542	$	2,103,131	$	2,114,495
Total loans	$	18,155	$	4,712	$	3,823	$	26,690	$	17,233	$	8,106,224	$	8,150,147

(In thousands)	31-60 Days Past Due Accruing		61-90 Days Past Due Accruing		Greater Than 90 Days Past Due Accruing		Total Past Due Accruing		Nonaccrual		Current		Recorded Total Loans
As of December 31, 2021
Commercial loans:
C&I	$	622	$	-	$	-	$	622	$	3,618	$	1,126,430	$	1,130,670
CRE		1,219		132		-		1,351		12,726		2,550,910		2,564,987
PPP		-		-		-		-		-		101,222		101,222
Total commercial loans	$	1,841	$	132	$	-	$	1,973	$	16,344	$	3,778,562	$	3,796,879
Consumer loans:
Auto	$	6,911	$	1,547	$	545	$	9,003	$	1,295	$	816,210	$	826,508
Other consumer		3,789		1,816		1,105		6,710		233		832,447		839,390
Total consumer loans	$	10,700	$	3,363	$	1,650	$	15,713	$	1,528	$	1,648,657	$	1,665,898
Residential	$	2,481	$	420	$	808	$	3,709	$	12,413	$	2,019,560	$	2,035,682
Total loans	$	15,022	$	3,915	$	2,458	$	21,395	$	30,285	$	7,446,779	$	7,498,459

Credit Quality by Loan Class by Year of Origination (Vintage)

The following tables illustrate the Company’s credit quality by loan class by year of origination (vintage):

(In thousands)	2022		2021		2020		2019		2018		Prior		Revolving Loans Amortized Cost Basis		Revolving Loans Converted to Term		Total
As of December 31, 2022
C&I
By internally assigned grade:
Pass	$	296,562	$	251,531	$	164,976	$	91,497	$	39,394	$	32,413	$	327,166	$	3,133	$	1,206,672
Special mention		1,044		524		4,531		194		1,108		417		5,234		-		13,052
Substandard		76		459		231		3,098		91		3,969		12,348		163		20,435
Doubtful		-		20		-		28		-		1		-		-		49
Total C&I	$	297,682	$	252,534	$	169,738	$	94,817	$	40,593	$	36,800	$	344,748	$	3,296	$	1,240,208

CRE
By internally assigned grade:
Pass	$	374,313	$	465,990	$	439,012	$	333,568	$	217,141	$	566,783	$	201,563	$	24,735	$	2,623,105
Special mention		605		764		868		2,641		4,649		24,023		850		-		34,400
Substandard		309		-		2,316		3,937		1,822		23,819		713		4,987		37,903
Total CRE	$	375,227	$	466,754	$	442,196	$	340,146	$	223,612	$	614,625	$	203,126	$	29,722	$	2,695,408

PPP
By internally assigned grade:
Pass	$	-	$	949	$	-	$	-	$	-	$	-	$	-	$	-	$	949
Total PPP	$	-	$	949	$	-	$	-	$	-	$	-	$	-	$	-	$	949

Auto
By payment activity:
Performing	$	488,776	$	239,090	$	75,853	$	99,615	$	44,061	$	13,027	$	-	$	-	$	960,422
Nonperforming		590		655		404		385		216		29		-		-		2,279
Total auto	$	489,366	$	239,745	$	76,257	$	100,000	$	44,277	$	13,056	$	-	$	-	$	962,701

Other consumer
By payment activity:
Performing	$	538,488	$	304,595	$	110,944	$	82,045	$	51,655	$	26,755	$	19,218	$	250	$	1,133,950
Nonperforming		557		936		445		272		73		130		8		15		2,436
Total other consumer	$	539,045	$	305,531	$	111,389	$	82,317	$	51,728	$	26,885	$	19,226	$	265	$	1,136,386

Residential
By payment activity:
Performing	$	251,012	$	349,498	$	212,161	$	156,957	$	157,755	$	717,621	$	233,056	$	28,122	$	2,106,182
Nonperforming		267		384		408		555		1,028		5,651		-		20		8,313
Total residential	$	251,279	$	349,882	$	212,569	$	157,512	$	158,783	$	723,272	$	233,056	$	28,142	$	2,114,495

Total loans	$	1,952,599	$	1,615,395	$	1,012,149	$	774,792	$	518,993	$	1,414,638	$	800,156	$	61,425	$	8,150,147

(In thousands)	2021		2020		2019		2018		2017		Prior		Revolving Loans Amortized Cost Basis		Revolving Loans Converted to Term		Total
As of December 31, 2021
C&I
By internally assigned grade:
Pass	$	335,685	$	219,931	$	114,617	$	64,310	$	20,137	$	32,146	$	280,476	$	15,731	$	1,083,033
Special mention		148		5,255		4,641		2,430		2,699		1,111		11,835		522		28,641
Substandard		1,482		874		7,010		187		2,582		3,272		3,512		34		18,953
Doubtful		-		-		-		1		42		-		-		-		43
Total C&I	$	337,315	$	226,060	$	126,268	$	66,928	$	25,460	$	36,529	$	295,823	$	16,287	$	1,130,670

CRE
By internally assigned grade:
Pass	$	489,300	$	434,866	$	370,377	$	236,274	$	251,082	$	441,310	$	141,367	$	43,942	$	2,408,518
Special mention		789		826		11,235		3,544		15,379		53,372		780		420		86,345
Substandard		-		77		4,539		12,934		12,424		34,563		744		-		65,281
Doubtful		-		-		-		-		-		4,843		-		-		4,843
Total CRE	$	490,089	$	435,769	$	386,151	$	252,752	$	278,885	$	534,088	$	142,891	$	44,362	$	2,564,987

PPP
By internally assigned grade:
Pass	$	92,884	$	8,338	$	-	$	-	$	-	$	-	$	-	$	-	$	101,222
Total PPP	$	92,884	$	8,338	$	-	$	-	$	-	$	-	$	-	$	-	$	101,222

Auto
By payment activity:
Performing	$	351,778	$	129,419	$	183,959	$	101,441	$	46,007	$	12,064	$	-	$	-	$	824,668
Nonperforming		305		319		457		411		266		82		-		-		1,840
Total auto	$	352,083	$	129,738	$	184,416	$	101,852	$	46,273	$	12,146	$	-	$	-	$	826,508

Other consumer
By payment activity:
Performing	$	427,401	$	151,300	$	116,451	$	78,523	$	29,705	$	15,660	$	19,011	$	1	$	838,052
Nonperforming		216		429		249		134		238		33		18		21		1,338
Total other consumer	$	427,617	$	151,729	$	116,700	$	78,657	$	29,943	$	15,693	$	19,029	$	22	$	839,390

Residential
By payment activity:
Performing	$	345,338	$	226,723	$	179,087	$	179,575	$	146,611	$	687,863	$	246,103	$	11,161	$	2,022,461
Nonperforming		-		1,411		643		1,072		1,534		8,522		-		39		13,221
Total residential	$	345,338	$	228,134	$	179,730	$	180,647	$	148,145	$	696,385	$	246,103	$	11,200	$	2,035,682

Total loans	$	2,045,326	$	1,179,768	$	993,265	$	680,836	$	528,706	$	1,294,841	$	703,846	$	71,871	$	7,498,459

Troubled Debt Restructurings on Financing Receivables

	Year Ended December 31, 2022						Year Ended December 31, 2021
(Dollars in thousands)	Number of Contracts		Pre-Modification Outstanding Recorded Investment		Post-Modification Outstanding Recorded Investment			Number of Contracts		Pre-Modification Outstanding Recorded Investment		Post-Modification Outstanding Recorded Investment
Consumer loans:
Auto		-	$	-	$	-			2	$	38	$	38
Total consumer loans		-	$	-	$	-			2	$	38	$	38
Residential		10	$	829	$	928			10	$	1,121	$	1,236
Total TDRs		10	$	829	$	928			12	$	1,159	$	1,274

The following table illustrates the recorded investment and number of modifications for TDRs where a concession has been made and subsequently defaulted during the year:

	Year Ended December 31, 2022				Year Ended December 31, 2021				Year Ended December 31, 2020
(Dollars in thousands)	Number of Contracts		Recorded Investment		Number of Contracts		Recorded Investment		Number of Contracts		Recorded Investment
Commercial loans:
C&I		1	$	320		-	$	-		1	$	387
CRE		-		-		-		-		1		168
Total commercial loans		1	$	320		-	$	-		2	$	555
Consumer loans:
Auto		2	$	20		3	$	36		1	$	6
Total consumer loans		2	$	20		3	$	36		1	$	6
Residential		50	$	3,387		49	$	2,830		61	$	3,213
Total TDRs		53	$	3,727		52	$	2,866		64	$	3,774

Derivative Instruments and Hedging Activities (Tables)

12 Months Ended

Dec. 31, 2022

Derivative Instruments and Hedging Activities Disclosures [Line Items]

Summary of Derivatives Outstanding

The following table summarizes the derivatives outstanding:

(In thousands)	Notional Amount		Balance Sheet Location	Fair Value			Notional Amount		Balance Sheet Location	Fair Value
As of December 31, 2022
Derivatives not designated as hedging instruments
Interest rate derivatives	$	1,275,708	Other assets	$	117,247		$	1,275,708	Other liabilities	$	117,247
Risk participation agreements		88,963	Other assets		47			18,421	Other liabilities		10
Total derivatives not designated as hedging instruments				$	117,294					$	117,257
Netting adjustments⁽¹⁾					24,109						-
Net derivatives in the balance sheet				$	93,185					$	117,257
Derivatives not offset on the balance sheet				$	352					$	352
Cash collateral⁽²⁾					-						-
Net derivative amounts				$	92,833					$	116,905
As of December 31, 2021
Derivatives not designated as hedging instruments
Interest rate derivatives	$	1,342,187	Other assets	$	60,203		$	1,342,187	Other liabilities	$	60,203
Risk participation agreements		90,938	Other assets		252			37,193	Other liabilities		60
Total derivatives not designated as hedging instruments				$	60,455					$	60,263
Netting adjustments⁽¹⁾					(170	)					5,482
Net derivatives in the balance sheet				$	60,625					$	54,781
Derivatives not offset on the balance sheet				$	5,455					$	5,455
Cash collateral⁽²⁾					-						43,420
Net derivative amounts				$	55,170					$	5,906

(1)

(2)

Designated as Hedging Instrument [Member] | Cash Flow Hedging [Member]

Derivative Instruments and Hedging Activities Disclosures [Line Items]

Effect of Derivatives on AOCI and on Consolidated Statement of Income

The following table indicates the effect of cash flow hedge accounting on AOCI and on the consolidated statement of income:

	Years Ended December 31,
(In thousands)	2022		2021		2020
Derivatives designated as hedging instruments:
Interest rate derivatives - included component
Amount of loss recognized in OCI	$	-	$	-	$	(275	)
Amount of loss reclassified from AOCI into interest expense		-		21		296

Not Designated as Hedging Instrument [Member]

Derivative Instruments and Hedging Activities Disclosures [Line Items]

Effect of Derivatives on AOCI and on Consolidated Statement of Income

The following table indicates the gain or loss recognized in income on derivatives not designated as a hedging relationship:

	Years Ended December 31,
(In thousands)	2022			2021			2020
Derivatives not designated as hedging instruments:
(Decrease) increase in other income	$	(155	)	$	(356	)	$	1

Tabular disclosure of pertinent information about a derivative or group of derivatives on a disaggregated basis, such as for individual instruments, or small groups of similar instruments. May include a combination of the type of instrument, risks being hedged, notional amount, hedge designation, related hedged item, inception date, maturity date, or other relevant item.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 4B
-URI https://asc.fasb.org/extlink&oid=125515794&loc=SL5624163-113959

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 1B
-URI https://asc.fasb.org/extlink&oid=125515794&loc=SL5580258-113959

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 2
-URI https://asc.fasb.org/extlink&oid=125515794&loc=d3e41620-113959

Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 1A
-URI https://asc.fasb.org/extlink&oid=125515794&loc=SL5579245-113959

Reference 5: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 4
-URI https://asc.fasb.org/extlink&oid=125515794&loc=d3e41638-113959

Reference 6: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 8
-URI https://asc.fasb.org/extlink&oid=125515794&loc=d3e41678-113959

Reference 7: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 5
-URI https://asc.fasb.org/extlink&oid=125515794&loc=d3e41641-113959

Reference 8: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 4C
-URI https://asc.fasb.org/extlink&oid=125515794&loc=SL5624171-113959

Reference 9: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 1
-URI https://asc.fasb.org/extlink&oid=125515794&loc=SL5579240-113959

Fair Value Measurements and Fair Values of Financial Instruments [Abstract]

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Operating activities
Net income	$ 151,995	$ 154,885	$ 104,388
Adjustments to reconcile net income to net cash provided by operating activities
Provision for loan losses	17,147	(8,257)	51,134
Depreciation and amortization of premises and equipment	10,155	9,896	9,772
Net amortization on securities	3,460	5,832	4,369
Amortization of intangible assets	2,263	2,808	3,395
Amortization of operating lease right-of-use assets	6,643	7,176	7,382
Excess tax benefit on stock-based compensation	(288)	(385)	(181)
Stock-based compensation expense	4,530	4,414	4,581
Bank owned life insurance income	(6,044)	(6,217)	(5,743)
Amortization of subordinated debt issuance costs	437	438	230
Discount on repurchase of subordinated debt	(106)	0	0
Proceeds from sale of loans held for sale	5,674	55,065	168,707
Originations of loans held for sale	(5,475)	(54,608)	(158,279)
Net gains on sale of loans held for sale	(122)	(361)	(1,989)
Net security losses (gains)	1,131	(566)	388
Net (gains) losses on sale of other real estate owned	(259)	182	(96)
Lease termination losses	0	0	4,284
Net change in other assets and other liabilities	(7,918)	(11,117)	(47,069)
Net cash provided by operating activities	183,223	159,185	145,273
Investing activities
Net cash used in acquisitions	(2,616)	(1,550)	(6,760)
Securities available for sale:
Proceeds from maturities, calls and principal paydowns	213,722	395,386	336,410
Purchases	(264,569)	(775,963)	(689,932)
Securities held to maturity:
Proceeds from maturities, calls and principal paydowns	177,554	181,620	243,136
Proceeds from sales	0	0	996
Purchases	(365,033)	(299,014)	(230,951)
Equity securities:
Proceeds from calls	0	1,000	2,000
Purchases	(1,000)	0	0
Other:
Net increase in loans	(659,949)	(9,305)	(378,765)
Proceeds from Federal Home Loan Bank stock redemption	36,125	2,422	63,305
Purchases of Federal Reserve Bank and Federal Home Loan Bank stock	(55,740)	(167)	(46,038)
Proceeds from settlement of bank owned life insurance	1,873	4,413	1,057
Purchases of bank owned life insurance	0	(40,000)	0
Purchases of premises and equipment, net	(7,009)	(7,740)	(8,157)
Proceeds from sales of other real estate owned	426	1,290	1,113
Net cash provided by (used in) investing activities	(926,216)	(547,608)	(712,586)
Financing activities
Net (decrease) increase in deposits	(738,536)	1,152,777	1,493,872
Net increase (decrease) in short-term borrowings	487,217	(70,592)	(486,889)
Proceeds from issuance of subordinated debt	0	0	100,000
Payment of subordinated debt issuance costs	0	0	(2,178)
Repurchase of subordinated debt	(2,000)	0	0
Proceeds from issuance of long-term debt	1,519	0	0
Repayments of long-term debt	(10,699)	(25,101)	(25,114)
Proceeds from the issuance of shares to employee and other stock plans	0	112	184
Cash paid by employer for tax-withholding on stock issuance	(1,751)	(2,931)	(1,537)
Purchase of treasury stock	(14,713)	(21,714)	(7,980)
Cash dividends	(49,765)	(47,738)	(47,207)
Net cash (used in) provided by financing activities	(328,728)	984,813	1,023,151
Net (decrease) increase in cash and cash equivalents	(1,071,721)	596,390	455,838
Cash and cash equivalents at beginning of year	1,269,071	672,681	216,843
Cash and cash equivalents at end of year	197,350	1,269,071	672,681
Cash paid during the period for:
Interest expense	20,608	20,285	31,692
Income taxes paid, net of refund	62,795	46,097	45,790
Noncash investing activities:
Loans transferred to other real estate owned	105	181	1,017
Acquisitions:
Fair value of assets acquired	$ 705	$ 0	$ 3,328

Stockholders' Equity (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020	Dec. 20, 2021
Stockholders' Equity [Abstract]
Unrecognized prior service cost and net actuarial (losses) on pension plans	$ (26,435)	$ (16,269)	$ (20,134)
Unrealized (losses) on derivatives (cash flow hedges)	0	0	(16)
Unrealized net holding (losses) gains on AFS securities	(163,599)	(7,075)	20,567
AOCI	$ (190,034)	$ (23,344)	$ 417
Preceding period of retained net profits for approval of Office of Comptroller of the Currency	2 years
Statutory amount available for dividend payments	$ 145,300
Stock Repurchase Program [Abstract]
Purchase of common stock (in shares)	400,000	604,637	263,507
Purchase of common stock value	$ 14,713	$ 21,714	$ 7,980
Average price per share (in dollars per share)	$ 36.78
Number of shares authorized under stock repurchase program (in shares)				2,000,000
Number of shares available for repurchase under stock repurchase program (in shares)	1,600,000

Fair Value Measurements and Fair Values of Financial Instruments, Estimated Fair Values of Financial Instruments (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Financial assets [Abstract]
HTM securities	$ 812,647	$ 735,260
Carrying Amount [Member] \| Level 1 [Member]
Financial liabilities [Abstract]
Subordinated debt	98,000	100,000
Carrying Amount [Member] \| Level 2 [Member]
Financial assets [Abstract]
HTM securities	919,517	733,210
Financial liabilities [Abstract]
Time deposits	433,772	501,472
Long-term debt	4,815	13,995
Junior subordinated debt	101,196	101,196
Carrying Amount [Member] \| Level 3 [Member]
Financial assets [Abstract]
Net loans	8,049,909	7,407,289
Estimated Fair Value [Member] \| Level 1 [Member]
Financial liabilities [Abstract]
Subordinated debt	92,883	107,402
Estimated Fair Value [Member] \| Level 2 [Member]
Financial assets [Abstract]
HTM securities	812,647	735,260
Financial liabilities [Abstract]
Time deposits	413,868	500,717
Long-term debt	4,539	14,260
Junior subordinated debt	98,372	107,569
Estimated Fair Value [Member] \| Level 3 [Member]
Financial assets [Abstract]
Net loans	$ 7,840,350	$ 7,530,768

Allowance for Credit Losses and Credit Quality of Loans, Summary (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Allowance for Credit Losses [Abstract]
Allowance for credit losses	$ 100,800	$ 92,000	$ 110,000	$ 75,999
Percentage of allowance of credit losses	1.24%	1.23%
Retained earnings	$ 958,433	$ 856,203
Loans purchased with credit deterioration	0	0
Allowance for credit losses on loans purchased	$ 3,200	$ 6,800
Financing Receivable, Accrued Interest, after Allowance for Credit Loss, Statement of Financial Position [Extensible Enumeration]	Other Assets	Other Assets
Accrued Interest Receivable [Member]
Allowance for Credit Losses [Abstract]
Allowance for credit losses	$ 0	$ 0
AIR on loans	25,000	19,500
ASU 2016-13 [Member] \| Loans [Member]
Allowance for Credit Losses [Abstract]
Allowance for credit losses			3,000
Retained earnings			(2,300)
Deferred tax asset			700
Consumer Loans [Member]
Allowance for Credit Losses [Abstract]
Allowance for credit losses	50,951	44,253	37,803	32,122
Amount of loans purchased	50,100	92,500
Residential [Member]
Allowance for Credit Losses [Abstract]
Allowance for credit losses	15,127	18,806	$ 21,255	$ 16,721
Amount of loans purchased	$ 11,500	$ 58,900
Premium on loans purchased	1.53%
Residential [Member] \| Minimum [Member]
Allowance for Credit Losses [Abstract]
Premium on loans purchased		2.00%
Residential [Member] \| Maximum [Member]
Allowance for Credit Losses [Abstract]
Premium on loans purchased		5.00%

Fair Value Measurements and Fair Values of Financial Instruments

12 Months Ended

Dec. 31, 2022

Fair Value Measurements and Fair Values of Financial Instruments

20. Fair Value Measurements and Fair Values of Financial Instruments

Level 1 - Unadjusted quoted prices in active markets that are accessible at the measurement date for identical, unrestricted assets or liabilities;

Level 3 - Prices or valuation techniques that require inputs that are both significant to the fair value measurement and unobservable (i.e., supported by little or no market activity).

A financial instrument’s level within the fair value hierarchy is based on the lowest level of input that is significant to the fair value measurement.

The types of instruments valued based on quoted prices in markets that are not active, broker or dealer quotations or quote from alternative pricing sources with reasonable levels of price transparency include most investment-grade and high-yield corporate bonds, less liquid mortgage products, less liquid agency securities, less liquid listed equities, state, municipal and provincial obligations and certain physical commodities. Such instruments are generally classified within Level 2 of the fair value hierarchy. Certain common equity securities are reported at fair value utilizing Level 1 inputs (exchange quoted prices). Other investment securities are reported at fair value utilizing Level 1 and Level 2 inputs. The prices for Level 2 instruments are obtained through an independent pricing service or dealer market participants with whom the Company has historically transacted both purchases and sales of investment securities. Prices obtained from these sources include prices derived from market quotations and matrix pricing. The fair value measurements consider observable data that may include dealer quotes, market spreads, cash flows, the U.S. Treasury yield curve, live trading levels, trade execution data, market consensus prepayment speeds, credit information and the bond’s terms and conditions, among other things. Management reviews the methodologies used by its third-party providers in pricing the securities.

(In thousands)	Level 1		Level 2		Level 3		December 31, 2022
Assets:
AFS securities
U.S. treasury	$	121,658	$	-	$	-	$	121,658
Federal agency		-		206,419		-		206,419
State & municipal		-		82,851		-		82,851
Mortgage-backed		-		473,694		-		473,694
Collateralized mortgage obligations		-		588,363		-		588,363
Corporate		-		54,240		-		54,240
Total AFS securities	$	121,658	$	1,405,567	$	-	$	1,527,225
Equity securities		29,784		1,000		-		30,784
Derivatives		-		93,185		-		93,185
Total	$	151,442	$	1,499,752	$	-	$	1,651,194

Liabilities:
Derivatives	$	-	$	117,257	$	-	$	117,257
Total	$	-	$	117,257	$	-	$	117,257

(In thousands)	Level 1		Level 2		Level 3		December 31, 2021
Assets:
AFS securities
U.S. treasury	$	73,069	$	-	$	-	$	73,069
Federal agency		-		239,931		-		239,931
State & municipal		-		94,088		-		94,088
Mortgage-backed		-		606,675		-		606,675
Collateralized mortgage obligations		-		621,595		-		621,595
Corporate		-		52,003		-		52,003
Total AFS securities	$	73,069	$	1,614,292	$	-	$	1,687,361
Equity securities		32,550		1,000		-		33,550
Derivatives		-		60,625		-		60,625
Total	$	105,619	$	1,675,917	$	-	$	1,781,536

Liabilities:
Derivatives	$	-	$	60,263	$	-	$	60,263
Total	$	-	$	60,263	$	-	$	60,263

GAAP requires disclosure of assets and liabilities measured and recorded at fair value on a non-recurring basis such as goodwill, loans held for sale, other real estate owned, collateral-dependent loans individually evaluated for expected credit losses and HTM securities. The non-recurring fair value measurements recorded during the years ended December 31, 2022 and 2021 were related to loans individually evaluated for expected credit losses with fair value of $1.1 million and $7.4 million as of December 31, 2022 and 2021, respectively. The Company uses the fair value of underlying collateral, less costs to sell, to estimate the allowance for credit losses for individually evaluated collateral dependent loans. The appraisals may be adjusted by management for qualitative factors such as economic conditions and estimated liquidation expenses ranging from 10% to 50%. Based on the valuation techniques used, the fair value measurements for collateral dependent individually evaluated loans are classified as Level 3.

			December 31, 2022				December 31, 2021
(In thousands)	Fair Value Hierarchy		Carrying Amount		Estimated Fair Value		Carrying Amount		Estimated Fair Value
Financial assets:
HTM securities		2	$	919,517	$	812,647	$	733,210	$	735,260
Net loans		3		8,049,909		7,840,350		7,407,289		7,530,768
Financial liabilities:
Time deposits		2	$	433,772	$	413,868	$	501,472	$	500,717
Long-term debt		2		4,815		4,539		13,995		14,260
Subordinated debt		1		98,000		92,883		100,000		107,402
Junior subordinated debt		2		101,196		98,372		101,196		107,569

Fair value estimates are made at a specific point in time, based on relevant market information and information about the financial instrument. These estimates do not reflect any premium or discount that could result from offering for sale at one time the Company’s entire holdings of a particular financial instrument. Because no market exists for a significant portion of the Company’s financial instruments, fair value estimates are based on judgments regarding future expected loss experience, current economic conditions, risk characteristics of various financial instruments and other factors. These estimates are subjective in nature and involve uncertainties and matters of significant judgment and therefore cannot be determined with precision. Changes in assumptions could significantly affect the estimates.

Fair value estimates are based on existing on and off-balance sheet financial instruments without attempting to estimate the value of anticipated future business and the value of assets and liabilities that are not considered financial instruments. For example, the Company has a substantial wealth operation that contributes net fee income annually. The wealth management operation is not considered a financial instrument and its value has not been incorporated into the fair value estimates. Other significant assets and liabilities include the benefits resulting from the low-cost funding of deposit liabilities as compared to the cost of borrowing funds in the market and premises and equipment. In addition, the tax ramifications related to the realization of the unrealized gains and losses can have a significant effect on fair value estimates and have not been considered in the estimate of fair value.

HTM Securities

The fair value of the Company’s HTM securities is primarily measured using information from a third-party pricing service. The fair value measurements consider observable data that may include dealer quotes, market spreads, cash flows, the U.S. Treasury yield curve, live trading levels, trade execution data, market consensus prepayment speeds, credit information and the bond’s terms and conditions, among other things.

Net Loans

Net loans include portfolio loans and loans held for sale. Loans were first segregated by type and then further segmented into fixed and variable rate and loan quality categories. Expected future cash flows were projected based on contractual cash flows, adjusted for estimated prepayments, and those expected future cash flows also include credit risk, illiquidity risk and other market factors to calculate the exit price fair value in accordance with ASC 820.

Time Deposits

The fair value of time deposits was estimated using a discounted cash flow approach that applies prevailing market interest rates for similar maturity instruments. The fair values of the Company’s time deposit liabilities do not take into consideration the value of the Company’s long-term relationships with depositors, which may have significant value.

Long-Term Debt

The fair value of long-term debt was estimated using a discounted cash flow approach that applies prevailing market interest rates for similar maturity instruments.

Subordinated Debt

The fair value of subordinated debt has been measured using the observable market price as of the period reported.

Junior Subordinated Debt

The fair value of junior subordinated debt has been estimated using a discounted cash flow analysis.

The entire disclosure for the fair value of financial instruments (as defined), including financial assets and financial liabilities (collectively, as defined), and the measurements of those instruments as well as disclosures related to the fair value of non-financial assets and liabilities. Such disclosures about the financial instruments, assets, and liabilities would include: (1) the fair value of the required items together with their carrying amounts (as appropriate); (2) for items for which it is not practicable to estimate fair value, disclosure would include: (a) information pertinent to estimating fair value (including, carrying amount, effective interest rate, and maturity, and (b) the reasons why it is not practicable to estimate fair value; (3) significant concentrations of credit risk including: (a) information about the activity, region, or economic characteristics identifying a concentration, (b) the maximum amount of loss the entity is exposed to based on the gross fair value of the related item, (c) policy for requiring collateral or other security and information as to accessing such collateral or security, and (d) the nature and brief description of such collateral or security; (4) quantitative information about market risks and how such risks are managed; (5) for items measured on both a recurring and nonrecurring basis information regarding the inputs used to develop the fair value measurement; and (6) for items presented in the financial statement for which fair value measurement is elected: (a) information necessary to understand the reasons for the election, (b) discussion of the effect of fair value changes on earnings, (c) a description of [similar groups] items for which the election is made and the relation thereof to the balance sheet, the aggregate carrying value of items included in the balance sheet that are not eligible for the election; (7) all other required (as defined) and desired information.

Regulatory Capital Requirements [Abstract]

Goodwill and Other Intangible Assets (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Goodwill [Roll Forward]
Beginning balance	$ 280,541	$ 280,541
Goodwill acquired	663	0
Ending balance	281,204	280,541	$ 280,541
Finite-Lived Intangible Assets [Abstract]
Gross carrying amount	31,340	32,460
Less: accumulated amortization	23,999	23,533
Net carrying amount	7,341	8,927
Impairment of goodwill	0	0
Amortization Expense [Abstract]
Amortization of intangible assets	2,263	2,808	3,395
Future Amortization Expense [Abstract]
2023	1,900
2024	1,600
2025	1,200
2026	1,000
2027	700
Thereafter	1,000
Impairment of intangible assets	$ 0	0	$ 0
Minimum [Member]
Finite-Lived Intangible Assets [Abstract]
Intangible asset useful life	1 year
Maximum [Member]
Finite-Lived Intangible Assets [Abstract]
Intangible asset useful life	20 years
Core Deposits Intangibles [Member]
Finite-Lived Intangible Assets [Abstract]
Gross carrying amount	$ 6,161	7,435
Less: accumulated amortization	6,133	7,258
Net carrying amount	28	177
Identified Intangible Assets [Member]
Finite-Lived Intangible Assets [Abstract]
Gross carrying amount	25,179	25,025
Less: accumulated amortization	17,866	16,275
Net carrying amount	$ 7,313	$ 8,750

Regulatory Capital Requirements (Tables)

12 Months Ended

Dec. 31, 2022

Compliance with Regulatory Compliance Requirements Under Banking Regulations

The Company and NBT Bank’s actual capital amounts and ratios are presented as follows:

	Actual					Regulatory Ratio Requirements
(Dollars in thousands)	Amount		Ratio			Minimum Capital Adequacy			Minimum plus Buffer			For Classification as Well- Capitalized
As of December 31, 2022
Tier I Capital (to average assets)
Company	$	1,193,336		10.32	%		4.00	%					5.00	%
NBT Bank		1,133,481		9.86	%		4.00	%					5.00	%
Common Equity Tier 1 Capital
Company		1,096,336		12.12	%		4.50	%		7.00	%		6.50	%
NBT Bank		1,133,481		12.63	%		4.50	%		7.00	%		6.50	%
Tier I Capital (to risk-weighted assets)
Company		1,193,336		13.19	%		6.00	%		8.50	%		8.00	%
NBT Bank		1,133,481		12.63	%		6.00	%		8.50	%		8.00	%
Total Capital (to risk-weighted assets)
Company		1,391,182		15.38	%		8.00	%		10.50	%		10.00	%
NBT Bank		1,233,327		13.74	%		8.00	%		10.50	%		10.00	%

As of December 31, 2021
Tier I Capital (to average assets)
Company	$	1,103,661		9.41	%		4.00	%					5.00	%
NBT Bank		1,087,990		9.32	%		4.00	%					5.00	%
Common Equity Tier 1 Capital
Company		1,006,661		12.25	%		4.50	%		7.00	%		6.50	%
NBT Bank		1,087,990		13.36	%		4.50	%		7.00	%		6.50	%
Tier I Capital (to risk-weighted assets)
Company		1,103,661		13.43	%		6.00	%		8.50	%		8.00	%
NBT Bank		1,087,990		13.36	%		6.00	%		8.50	%		8.00	%
Total Capital (to risk-weighted assets)
Company		1,292,669		15.73	%		8.00	%		10.50	%		10.00	%
NBT Bank		1,176,998		14.45	%		8.00	%		10.50	%		10.00	%

Securities (Policies)	12 Months Ended
Securities (Policies)	Dec. 31, 2022
Securities [Abstract]
Investment, Policy	The Company does not believe the AFS securities that were in an unrealized loss position as of December 31, 2022 and 2021, which consisted of 415 and 149 individual securities, respectively, represented a credit loss impairment. AFS debt securities in unrealized loss positions are evaluated for impairment related to credit losses at least quarterly. As of December 31, 2022 and 2021, the majority of the AFS securities in an unrealized loss position consisted of debt securities issued by U.S. government agencies or U.S. government-sponsored enterprises that carry the explicit and/or implicit guarantee of the U.S. government, which are widely recognized as “risk-free” and have a long history of zero credit losses. Total gross unrealized losses were primarily attributable to changes in interest rates, relative to when the investment securities were purchased, and not due to the credit quality of the investment securities. The Company does not intend to sell, nor is it more likely than not that the Company will be required to sell the security before recovery of its amortized cost basis, which may be at maturity. The Company elected to exclude accrued interest receivable (“AIR”) from the amortized cost basis of debt securities. AIR on AFS debt securities totaled $4.2 million at December 31, 2022 and $3.9 million at December 31, 2021 and is excluded from the estimate of credit losses and reported in the other assets financial statement line. None of the bank’s HTM debt securities were past due or on nonaccrual status as of December 31, 2022 and 2021. There was no accrued interest reversed against interest income for the years ended December 31, 2022 and 2021 as all securities remained on accrual status. In addition, there were no collateral-dependent HTM debt securities as of December 31, 2022 and 2021. As of December 31, 2022 and 2021, 70% and 56%, respectively, of the Company’s HTM debt securities were issued by U.S. government agencies or U.S. government-sponsored enterprises. These securities carry the explicit and/or implicit guarantee of the U.S. government, are widely recognized as “risk free,” and have a long history of zero credit loss. Therefore, the Company did not record an allowance for credit losses for these securities as of December 31, 2022 and 2021. The remaining HTM debt securities at December 31, 2022 and 2021 were comprised of state and municipal obligations generally with bond ratings of A to AAA. Utilizing the CECL approach, the Company determined that the expected credit loss on its HTM municipal bond portfolio was immaterial and therefore no allowance for credit loss was recorded as of December 31, 2022 and 2021. AIR on HTM debt securities totaled $3.8 million at December 31, 2022 and $2.7 million at December 31, 2021 and is excluded from the estimate of credit losses and reported in the other assets financial statement line.

Securities, AFS Securities in Continuous Unrealized Loss Position (Details) $ in Thousands	Dec. 31, 2022 USD ($) Position	Dec. 31, 2021 USD ($) Position
Unrealized Loss Position, Fair Value [Abstract]
Less than 12 months	$ 509,788	$ 811,115
12 months or longer	1,012,964	253,578
Total	1,522,752	1,064,693
Unrealized Loss Position, Unrealized Losses [Abstract]
Less than 12 months	(36,681)	(13,238)
12 months or longer	(180,014)	(8,704)
Total	$ (216,695)	$ (21,942)
Unrealized Loss Position, Number of Positions [Abstract]
Less than 12 months \| Position	245	127
12 months or longer \| Position	170	22
Total \| Position	415	149
AIR on AFS debt securities	$ 4,200	$ 3,900
Debt Securities, Available-for-Sale, Accrued Interest, after Allowance for Credit Loss, Statement of Financial Position [Extensible Enumeration]	Other Assets	Other Assets
U.S. Treasury [Member]
Unrealized Loss Position, Fair Value [Abstract]
Less than 12 months	$ 55,616	$ 49,105
12 months or longer	66,042	0
Total	121,658	49,105
Unrealized Loss Position, Unrealized Losses [Abstract]
Less than 12 months	(3,864)	(6)
12 months or longer	(7,369)	0
Total	$ (11,233)	$ (6)
Unrealized Loss Position, Number of Positions [Abstract]
Less than 12 months \| Position	5	2
12 months or longer \| Position	3	0
Total \| Position	8	2
Federal Agency [Member]
Unrealized Loss Position, Fair Value [Abstract]
Less than 12 months	$ 0	$ 41,618
12 months or longer	206,419	198,313
Total	206,419	239,931
Unrealized Loss Position, Unrealized Losses [Abstract]
Less than 12 months	0	(1,846)
12 months or longer	(42,000)	(6,677)
Total	$ (42,000)	$ (8,523)
Unrealized Loss Position, Number of Positions [Abstract]
Less than 12 months \| Position	0	4
12 months or longer \| Position	16	12
Total \| Position	16	16
State & Municipal [Member]
Unrealized Loss Position, Fair Value [Abstract]
Less than 12 months	$ 3,679	$ 87,515
12 months or longer	78,395	0
Total	82,074	87,515
Unrealized Loss Position, Unrealized Losses [Abstract]
Less than 12 months	(341)	(1,559)
12 months or longer	(13,849)	0
Total	$ (14,190)	$ (1,559)
Unrealized Loss Position, Number of Positions [Abstract]
Less than 12 months \| Position	2	61
12 months or longer \| Position	64	0
Total \| Position	66	61
Mortgage-Backed [Member]
Unrealized Loss Position, Fair Value [Abstract]
Less than 12 months	$ 204,447	$ 281,217
12 months or longer	267,926	39,491
Total	472,373	320,708
Unrealized Loss Position, Unrealized Losses [Abstract]
Less than 12 months	(15,048)	(4,319)
12 months or longer	(47,303)	(1,525)
Total	$ (62,351)	$ (5,844)
Unrealized Loss Position, Number of Positions [Abstract]
Less than 12 months \| Position	149	24
12 months or longer \| Position	32	6
Total \| Position	181	30
Collateralized Mortgage Obligations [Member]
Unrealized Loss Position, Fair Value [Abstract]
Less than 12 months	$ 211,612	$ 341,673
12 months or longer	374,376	15,774
Total	585,988	357,447
Unrealized Loss Position, Unrealized Losses [Abstract]
Less than 12 months	(14,458)	(5,495)
12 months or longer	(66,299)	(502)
Total	$ (80,757)	$ (5,997)
Unrealized Loss Position, Number of Positions [Abstract]
Less than 12 months \| Position	77	34
12 months or longer \| Position	49	4
Total \| Position	126	38
Corporate [Member]
Unrealized Loss Position, Fair Value [Abstract]
Less than 12 months	$ 34,434	$ 9,987
12 months or longer	19,806	0
Total	54,240	9,987
Unrealized Loss Position, Unrealized Losses [Abstract]
Less than 12 months	(2,970)	(13)
12 months or longer	(3,194)	0
Total	$ (6,164)	$ (13)
Unrealized Loss Position, Number of Positions [Abstract]
Less than 12 months \| Position	12	2
12 months or longer \| Position	6	0
Total \| Position	18	2

Income Taxes

12 Months Ended

Dec. 31, 2022

Income Taxes [Abstract]

Income Taxes

11. Income Taxes

The significant components of income tax expense attributable to operations are as follows:

	Years Ended December 31,
(In thousands)	2022			2021		2020
Current
Federal	$	51,077		$	35,483	$	36,358
State		12,934			8,626		9,768
Total Current	$	64,011		$	44,109	$	46,126

Deferred
Federal	$	(15,862	)	$	507	$	(14,021	)
State		(3,988	)		357		(3,406	)
Total Deferred	$	(19,850	)	$	864	$	(17,427	)
Total income tax expense	$	44,161		$	44,973	$	28,699

The tax effects of temporary differences that give rise to significant portions of the deferred tax assets and deferred tax liabilities are as follows:

	December 31,
(In thousands)	2022		2021
Deferred tax assets:
Allowance for loan losses	$	24,792	$	22,479
Lease liability		6,273		6,744
Deferred compensation		9,181		9,584
Loan fees		33,389		12,936
Stock-based compensation expense		2,822		2,679
Unrealized losses on securities		53,663		1,482
Other		6,027		7,109
Total deferred tax assets	$	136,147	$	63,013
Deferred tax liabilities:
Pension benefits	$	13,103	$	16,137
Lease right-of-use asset		5,877		5,681
Amortization of intangible assets		14,112		13,187
Premises and equipment, primarily due to accelerated depreciation		4,889		4,962
Other		846		1,008
Total deferred tax liabilities	$	38,827	$	40,975
Net deferred tax asset at year-end	$	97,320	$	22,038
Net deferred tax asset at beginning of year		22,038		15,117
Increase in net deferred tax asset	$	75,282	$	6,921

Realization of deferred tax assets is dependent upon the generation of future taxable income. A valuation allowance is recorded when it is more likely than not that some portion of the deferred tax asset will not be realized. Based on available evidence, gross deferred tax assets will ultimately be realized and a valuation allowance was not deemed necessary at December 31, 2022 and 2021.

The following is a reconciliation of the provision for income taxes to the amount computed by applying the applicable Federal statutory rate to income before taxes:

	Years Ended December 31,
(In thousands)	2022			2021			2020
Federal income tax at statutory rate	$	41,193		$	41,971		$	27,948
Tax exempt income		(984	)		(1,014	)		(981	)
Net increase in cash surrender value of life insurance		(1,215	)		(1,230	)		(1,135	)
Federal tax credits		(2,417	)		(1,884	)		(1,705	)
State taxes, net of federal tax benefit		7,067			7,097			5,026
Other, net		517			33			(454	)
Income tax expense	$	44,161		$	44,973		$	28,699

A reconciliation of the beginning and ending balance of Federal and State gross unrecognized tax benefits (“UTBs”) is as follows:

(In thousands)	2022		2021
Balance at January 1	$	1,545	$	1,178
Additions for tax positions of prior years		3		80
Current period tax positions		394		287
Balance at December 31	$	1,942	$	1,545
Amount that would affect the effective tax rate if recognized, gross of tax	$	1,535	$	1,221

The Company recognizes interest and penalties on the income tax expense line in the accompanying consolidated statements of income. The Company monitors changes in tax statutes and regulations to determine if significant changes will occur over the next 12 months. As of December 31, 2022, no significant changes to UTBs are projected; however, tax audit examinations are possible, but it is not reasonably possible to estimate when examinations in subsequent years will be completed. The Company recognized an insignificant amount of interest expense related to UTBs in the consolidated statement of income for the year ended December 31, 2022.

As of December 31, 2022, the Company is no longer subject to U.S. Federal tax examination by tax authorities for years prior to 2019. The tax years 2015 to 2019 are currently being audited by New York State.

The entire disclosure for income taxes. Disclosures may include net deferred tax liability or asset recognized in an enterprise's statement of financial position, net change during the year in the total valuation allowance, approximate tax effect of each type of temporary difference and carryforward that gives rise to a significant portion of deferred tax liabilities and deferred tax assets, utilization of a tax carryback, and tax uncertainties information.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 50
-Paragraph 21
-URI https://asc.fasb.org/extlink&oid=121826272&loc=d3e32857-109319

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SAB Topic 11.C)
-URI https://asc.fasb.org/extlink&oid=122134291&loc=d3e330215-122817

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 50
-Paragraph 17
-Subparagraph (b)
-URI https://asc.fasb.org/extlink&oid=121826272&loc=d3e32809-109319

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SAB TOPIC 6.I.5.Q1)
-URI https://asc.fasb.org/extlink&oid=122134291&loc=d3e330036-122817

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 50
-Paragraph 14
-URI https://asc.fasb.org/extlink&oid=121826272&loc=d3e32705-109319

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 270
-Section 50
-Paragraph 1
-URI https://asc.fasb.org/extlink&oid=6424409&loc=d3e44925-109338

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-URI https://asc.fasb.org/topic&trid=2144680

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 30
-Section 50
-Paragraph 2
-Subparagraph (a)
-URI https://asc.fasb.org/extlink&oid=6424122&loc=d3e41874-109331

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08(h)(2))
-URI https://asc.fasb.org/extlink&oid=120395691&loc=d3e23780-122690

Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Assets
Cash and due from banks	$ 166,488	$ 157,775
Short-term interest-bearing accounts	30,862	1,111,296
Equity securities, at fair value	30,784	33,550
Securities available for sale, at fair value	1,527,225	1,687,361
Securities held to maturity (fair value $812,647 and $735,260, respectively)	919,517	733,210
Federal Reserve and Federal Home Loan Bank stock	44,713	25,098
Loans held for sale	562	830
Loans	8,150,147	7,498,459
Less allowance for loan losses	100,800	92,000
Net loans	8,049,347	7,406,459
Premises and equipment, net	69,047	72,093
Goodwill	281,204	280,541
Intangible assets, net	7,341	8,927
Bank owned life insurance	232,409	228,238
Other assets	379,797	266,733
Total assets	11,739,296	12,012,111
Liabilities
Demand (noninterest bearing)	3,617,324	3,689,556
Savings, NOW and money market	5,444,837	6,043,441
Time	433,772	501,472
Total deposits	9,495,933	10,234,469
Short-term borrowings	585,012	97,795
Long-term debt	4,815	13,995
Subordinated debt, net	96,927	98,490
Junior subordinated debt	101,196	101,196
Other liabilities	281,859	215,713
Total liabilities	10,565,742	10,761,658
Stockholders' equity
Preferred stock, $0.01 par value. Authorized 2,500,000 shares at December 31, 2022 and 2021	0	0
Common stock, $0.01 par value. Authorized 100,000,000 shares at December 31, 2022 and 2021, issued 49,651,493 at December 31, 2022 and 2021	497	497
Additional paid-in-capital	577,853	576,976
Retained earnings	958,433	856,203
Accumulated other comprehensive loss	(190,034)	(23,344)
Common stock in treasury, at cost, 6,793,670 and 6,483,481 shares at December 31, 2022 and 2021, respectively	(173,195)	(159,879)
Total stockholders' equity	1,173,554	1,250,453
Total liabilities and stockholders' equity	$ 11,739,296	$ 12,012,111

Securities, AFS Debt Securities, Contractual Maturities (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Available-for-sale Securities, Debt Maturities, Amortized Cost [Abstract]
Within one year	$ 682
From one to five years	402,807
From five to ten years	582,736
After ten years	757,657
Amortized cost	1,743,882	$ 1,694,806
Available-for-sale Securities, Debt Maturities, Estimated Fair Value [Abstract]
Within one year	675
From one to five years	361,295
From five to ten years	506,036
After ten years	659,219
Fair value	$ 1,527,225	$ 1,687,361

Allowance for Credit Losses and Credit Quality of Loans, Allowance for Credit Losses on Off-Balance Sheet Credit Exposures (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Allowance for Credit Losses and Credit Quality of Loans [Abstract]
Allowance for credit losses	$ 100,800	$ 92,000	$ 110,000	$ 75,999
Unfunded Commitment [Member]
Allowance for Credit Losses and Credit Quality of Loans [Abstract]
Allowance for credit losses	$ 5,100	$ 5,100

Amount of allowance for credit loss on financing receivable. Excludes allowance for financing receivable covered under loss sharing agreement.

Components of Accumulated Other Comprehensive (Loss) Income

Recent Accounting Pronouncements (Policies)	12 Months Ended
Recent Accounting Pronouncements (Policies)	Dec. 31, 2022
Recent Accounting Pronouncements [Abstract]
Recently Adopted Accounting Standards and Accounting Standards Issued Not Yet Adopted	Recently Adopted Accounting Standards In March 2020, the FASB issued ASU 2020-04, Reference Rate Reform (Topic 848): Facilitation of the Effects of Reference Rate Reform on Financial Reporting. On January 7, 2021, the FASB issued ASU 2021-01, which refines the scope of Topic 848 and clarifies some of its guidance. ASU 2020-04 and related amendments provide temporary optional expedients and exceptions to the existing guidance for applying GAAP to affected contract modifications and hedge accounting relationships in the transition away from the London Interbank Offered Rate (“LIBOR”) or other interbank offered rates on financial reporting. The guidance also allows a one-time election to sell and/or reclassify to AFS or trading HTM debt securities that reference an interest rate affected by reference rate reform. The amendments in this ASU are effective March 12, 2020 through December 31, 2022 and permits relief solely for reference rate reform actions and permits different elections over the effective date for legacy and new activity. In December 2020, the FASB issued ASU 2022-06, Reference Rate Reform (Topic 848): Deferral of the Sunset Date of Topic 848. The ASU extends the period of time companies can utilize the reference rate reform relief guidance provided by ASU 2020-04 and ASU 2021-01. The guidance which was effective upon issuance, defers the sunset date from December 31, 2022 to December 31, 2024, after which companies will no longer be permitted to apply the relief guidance in Topic 848. The adoption did not have a material impact on the consolidated financial statements and related disclosures. Accounting Standards Issued Not Yet Adopted In March 2022, the FASB issued ASU 2022-02, Financial Instruments - CECL Losses (Topic 326): Troubled Debt Restructurings and Vintage Disclosures. The ASU eliminates the guidance on Troubled Debt Restructurings (“TDRs”) and requires an evaluation on all loan modifications to determine if they result in a new loan or a continuation of the existing loan. The ASU also requires that entities disclose current-period gross charge-offs by year of origination. The elimination of the TDR guidance may be adopted prospectively for loan modifications after adoption or on a modified retrospective basis, which would also apply to loans previously modified, resulting in a cumulative effect adjustment to retained earnings in the period of adoption for changes in the allowance for credit losses. The amendments in this ASU are effective for the Company on January 1, 2023, with early adoption permitted. The adoption is not expected to have a material impact on the consolidated financial statements and related disclosures.

Securities, Held to Maturity (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Held-to-maturity securities, fair value to amortized cost [Abstract]
Amortized cost	$ 919,517	$ 733,210
Unrealized gains	209	10,040
Unrealized losses	(107,079)	(7,990)
Estimated fair value	812,647	735,260
Allowance for credit losses on HTM securities	0	0
Transactions of HTM securities [Abstract]
Gains from calls on HTM securities	4	29	$ 24
Held-to-maturity securities sold, amortized cost	0	0	1,000
Held-to-maturity securities sold, realized loss			$ 1
Federal Agency [Member]
Held-to-maturity securities, fair value to amortized cost [Abstract]
Amortized cost	100,000	100,000
Unrealized gains	0	0
Unrealized losses	(20,678)	(4,365)
Estimated fair value	79,322	95,635
Mortgage-backed Securities, Government-Sponsored Enterprises [Member]
Held-to-maturity securities, fair value to amortized cost [Abstract]
Amortized cost	249,511	161,462
Unrealized gains	0	2,232
Unrealized losses	(36,819)	(1,319)
Estimated fair value	212,692	162,375
Mortgage-Backed, U.S. Government Agency Securities [Member]
Held-to-maturity securities, fair value to amortized cost [Abstract]
Amortized cost	18,396	9,112
Unrealized gains	4	514
Unrealized losses	(619)	0
Estimated fair value	17,781	9,626
Collateralized Mortgage Obligations, Government-Sponsored Enterprises [Member]
Held-to-maturity securities, fair value to amortized cost [Abstract]
Amortized cost	207,738	94,342
Unrealized gains	200	1,932
Unrealized losses	(14,876)	(129)
Estimated fair value	193,062	96,145
Collateralized Mortgage Obligations, U.S. Government Agency Securities [Member]
Held-to-maturity securities, fair value to amortized cost [Abstract]
Amortized cost	66,628	44,473
Unrealized gains	0	336
Unrealized losses	(9,842)	(674)
Estimated fair value	56,786	44,135
State & Municipal [Member]
Held-to-maturity securities, fair value to amortized cost [Abstract]
Amortized cost	277,244	323,821
Unrealized gains	5	5,026
Unrealized losses	(24,245)	(1,503)
Estimated fair value	253,004	327,344
Public Deposits and Other Purposes [Member]
Securities pledged [Abstract]
AFS and HTM securities	1,730,000	1,630,000
Securities Sold under Repurchase Agreements [Member]
Securities pledged [Abstract]
AFS and HTM securities	$ 149,500	$ 162,100

Stockholders' Equity (Tables)

12 Months Ended

Dec. 31, 2022

Stockholders' Equity [Abstract]

(In thousands)	2022			2021			2020
Unrecognized prior service cost and net actuarial (losses) on pension plans	$	(26,435	)	$	(16,269	)	$	(20,134	)
Unrealized (losses) on derivatives (cash flow hedges)		-			-			(16	)
Unrealized net holding (losses) gains on AFS securities		(163,599	)		(7,075	)		20,567
AOCI	$	(190,034	)	$	(23,344	)	$	417

Employee Benefit Plans

12 Months Ended

Dec. 31, 2022

Employee Benefit Plans [Abstract]

Employee Benefit Plans

12. Employee Benefit Plans

Defined Benefit Post-Retirement Plans

The Company has a qualified, noncontributory, defined benefit pension plan (“the Plan”) covering substantially all of its employees at December 31, 2022. Benefits paid from the Plan are based on age, years of service, compensation and social security benefits and are determined in accordance with defined formulas. The Company’s policy is to fund the Plan in accordance with Employee Retirement Income Security Act of 1974 standards. Assets of the Plan are invested in publicly traded stocks, bonds and mutual funds. Prior to January 1, 2000, the Plan was a traditional defined benefit plan based on final average compensation. On January 1, 2000, the Plan was converted to a cash balance plan with grandfathering provisions for existing participants. Effective March 1, 2013, the Plan was amended. Benefit accruals for participants who, as of January 1, 2000, elected to continue participating in the traditional defined benefit plan design were frozen as of March 1, 2013. In May 2013, the noncontributory, frozen, defined benefit pension plan assumed from Alliance in the acquisition was merged into the Plan. In addition to the Plan, the Company provides supplemental employee retirement plans to certain current and former executives. The Company also assumed supplemental retirement plans for former executives in the Alliance acquisition. These supplemental employee retirement plans and the Plan are collectively referred to herein as “Pension Benefits.”

In addition, the Company provides certain health care benefits for retired employees. Benefits were accrued over the employees’ active service period. Only employees that were employed by the Company on or before January 1, 2000 are eligible to receive post-retirement health care benefits. The Plan is contributory for participating retirees, requiring participants to absorb certain deductibles and coinsurance amounts with contributions adjusted annually to reflect cost sharing provisions and benefit limitations called for in the Plan. Employees become eligible for these benefits if they reach normal retirement age while working for the Company. For eligible employees described above, the Company funds the cost of post-retirement health care as benefits are paid. The Company elected to recognize the transition obligation on a delayed basis over twenty years. In addition, the Company assumed post-retirement medical life insurance benefits for certain Alliance employees, retirees and their spouses, if applicable, in the Alliance acquisition. These post-retirement benefits are referred to herein as “Other Benefits.”

Accounting standards require an employer to: (1) recognize the overfunded or underfunded status of defined benefit post-retirement plans, which is measured as the difference between plan assets at fair value and the benefit obligation, as an asset or liability in its balance sheet; (2) recognize changes in that funded status in the year in which the changes occur through comprehensive income; and (3) measure the defined benefit plan assets and obligations as of the date of its year-end balance sheet.

The components of AOCI, which have not yet been recognized as components of net periodic benefit cost, related to pensions and other post-retirement benefits are summarized below:

	Pension Benefits						Other Benefits
(In thousands)	2022			2021			2022				2021
Net actuarial loss (gain)		$	35,971		$	21,608		$	(921	)		$	(226	)
Prior service cost (credit)			211			320			(14	)			(8	)
Total amounts recognized in AOCI (pre-tax)		$	36,182		$	21,928		$	(935	)		$	(234	)

	Pension Benefits						Other Benefits
(In thousands)	2022			2021			2022			2021
Change in benefit obligation:
Benefit obligation at beginning of year	$	88,919		$	90,194		$	5,152		$	5,999
Service cost		2,024			2,069			7			8
Interest cost		2,765			2,717			170			163
Plan participants’ contributions		-			-			147			160
Actuarial (gain) loss		(11,158	)		499			(695	)		(543	)
Benefits paid		(6,610	)		(6,560	)		(598	)		(635	)
Projected benefit obligation at end of year	$	75,940		$	88,919		$	4,183		$	5,152
Change in plan assets:
Fair value of plan assets at beginning of year	$	135,867		$	128,563		$	-		$	-
(Loss) gain on plan assets		(17,260	)		12,523			-			-
Employer contributions		1,319			1,341			451			475
Plan participants’ contributions		-			-			147			160
Benefits paid		(6,610	)		(6,560	)		(598	)		(635	)
Fair value of plan assets at end of year	$	113,316		$	135,867		$	-		$	-

Funded (unfunded) status at year end	$	37,376		$	46,948		$	(4,183	)	$	(5,152	)

	Pension Benefits						Other Benefits
(In thousands)	2022			2021			2022			2021
Other assets	$	53,031		$	65,638		$	-		$	-
Other liabilities		(15,655	)		(18,690	)		(4,183	)		(5,152	)
Funded status	$	37,376		$	46,948		$	(4,183	)	$	(5,152	)

The following assumptions were used to determine the benefit obligation and the net periodic pension cost for the years indicated:

	Years Ended December 31,
	2022	2021	2020
Weighted average assumptions:
The following assumptions were used to determine benefit obligations:
Discount rate	5.54% - 5.66%	3.23% - 3.35%	3.08% - 3.25%
Expected long-term return on plan assets	6.70%	6.70%	7.00%
Rate of compensation increase	3.00%	3.00%	3.00%
Interest rate of credit for cash balance plan	3.99%	1.94%	1.62%

The following assumptions were used to determine net periodic pension cost:
Discount rate	3.23% - 3.35%	3.08% - 3.25%	3.69% - 3.73%
Expected long-term return on plan assets	6.70%	7.00%	7.00%
Rate of compensation increase	3.00%	3.00%	3.00%
Interest rate of credit for cash balance plan	1.94%	1.62%	2.28%

Net periodic benefit cost and other amounts recognized in OCI for the years ended December 31 included the following components:

	Pension Benefits									Other Benefits
(In thousands)	2022			2021			2020			2022			2021			2020
Components of net periodic (benefit) cost:
Service cost	$	2,024		$	2,069		$	1,840		$	7		$	8		$	8
Interest cost		2,765			2,717			3,237			170			163			213
Expected return on plan assets		(8,884	)		(8,786	)		(8,410	)		-			-			-
Additional gain due to curtailment		-			-			(74	)		-			-			-
Amortization of prior service cost		108			59			41			6			51			51
Amortization of unrecognized net loss		623			1,263			1,535			-			-			-
Net periodic pension (benefit) cost	$	(3,364	)	$	(2,678	)	$	(1,831	)	$	183		$	222		$	272

Other changes in plan assets and benefit obligations recognized in OCI (pre-tax):
Net loss (gain)	$	14,987		$	(3,237	)	$	(628	)	$	(695	)	$	(543	)	$	192
Additional gain due to curtailment		-			-			7			-			-			-
Amortization of prior service cost		(108	)		(59	)		(41	)		(6	)		(51	)		(51	)
Amortization of unrecognized net loss		(623	)		(1,263	)		(1,535	)		-			-			-
Total recognized in OCI	$	14,256		$	(4,559	)	$	(2,197	)	$	(701	)	$	(594	)	$	141

Total recognized in net periodic cost (benefit) and OCI, pre-tax	$	10,892		$	(7,237	)	$	(4,028	)	$	(518	)	$	(372	)	$	413

The service cost component of the net periodic (benefit) cost is included in Salaries and Employee Benefits and the interest cost, expected return on plan assets and net amortization components are included in Other Noninterest Expense on the consolidated statements of income.

The following table sets forth estimated future benefit payments for the pension plans and other post-retirement benefit plans as of December 31, 2022:

(In thousands)	Pension Benefits		Other Benefits
2023	$	6,824	$	415
2024		7,218		410
2025		7,467		405
2026		7,003		398
2027		7,595		374
2028 - 2032		33,279		1,688

The Company made no voluntary contributions to the pension and other benefit plans during the years ended December 31, 2022 and 2021.

For measurement purposes, the annual rates of increase in the per capita cost of covered medical and prescription drug benefits for fiscal year 2022 were assumed to be 4.5% to 6.5%. The rates were assumed to decrease gradually to 4.0% for fiscal year 2075 and remain at that level thereafter. Assumed health care cost trend rates have a significant effect on amounts reported for health care plans.

Plan Investment Policy

The Company’s key investment objectives in managing its defined benefit plan assets are to ensure that present and future benefit obligations to all participants and beneficiaries are met as they become due; to provide a total return that, over the long-term, maximizes the ratio of the plan assets to liabilities, while minimizing the present value of required Company contributions, at the appropriate levels of risk; to meet statutory requirements and regulatory agencies’ requirements; and to satisfy applicable accounting standards. The Company periodically evaluates the asset allocations, funded status, rate of return assumption and contribution strategy for satisfaction of our investment objectives.

The target and actual allocations expressed as a percentage of the defined benefit pension plan’s assets are as follows:

	Target 2022	2022	2021
Cash and cash equivalents	0 - 15%	3%	2%
Fixed income securities	30 - 60%	38%	37%
Equities	40 - 70%	59%	61%
Total		100%	100%

Only high-quality bonds are to be included in the portfolio. All issues that are rated lower than A by Standard and Poor’s are to be excluded. Equity securities at December 31, 2022 and 2021 do not include any Company common stock.

The following table presents the financial instruments recorded at fair value on a recurring basis by the Plan:

(In thousands)	Level 1		Level 2		December 31, 2022
Cash and cash equivalents	$	3,401	$	-	$	3,401
Foreign equity mutual funds		36,111		-		36,111
Equity mutual funds		30,859		-		30,859
U.S. government bonds		-		20		20
Corporate bonds		-		42,925		42,925
Total	$	70,371	$	42,945	$	113,316

	Level 1		Level 2		December 31, 2021
Cash and cash equivalents	$	3,298	$	-	$	3,298
Foreign equity mutual funds		46,385		-		46,385
Equity mutual funds		36,034		-		36,034
U.S. government bonds		-		33		33
Corporate bonds		-		50,117		50,117
Total	$	85,717	$	50,150	$	135,867

The plan had no financial instruments recorded at fair value on a non-recurring basis as of December 31, 2022 and 2021.

Determination of Assumed Rate of Return

The expected long-term rate-of-return on assets was 6.7% at December 31, 2022 and 2021, respectively. This assumption represents the rate of return on plan assets reflecting the average rate of earnings expected on the funds invested or to be invested to provide for the benefits included in the projected benefit obligation. The assumption has been determined by reflecting expectations regarding future rates of return for the portfolio considering the asset distribution and related historical rates of return. The appropriateness of the assumption is reviewed annually.

Employee 401(k) and Employee Stock Ownership Plans

The Company maintains a 401(k) and employee stock ownership plan (the “401(k) Plan”). The Company contributes to the 401(k) Plan based on employees’ contributions out of their annual salaries. In addition, the Company may also make discretionary contributions to the 401(k) Plan based on profitability. Participation in the 401(k) Plan is contingent upon certain age and service requirements. The employer contributions associated with the 401(k) Plan were $4.0 million in 2022, $3.9 million in 2021 and $3.6 million in 2020.

Other Retirement Benefits

Included in other liabilities is $1.1 million and $1.3 million at December 31, 2022 and 2021, respectively, for supplemental retirement benefits for retired executives from legacy plans assumed in acquisitions. The Company recognized $0.2 million in expense for each of the years ended December 31, 2022, 2021 and 2020, related to these plans.

The entire disclosure for retirement benefits.

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 55
-Paragraph 17
-URI https://asc.fasb.org/extlink&oid=123450688&loc=d3e4179-114921

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section S99
-Paragraph 2
-URI https://asc.fasb.org/extlink&oid=21916913&loc=d3e273930-122802

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (d)(i)
-URI https://asc.fasb.org/extlink&oid=123447040&loc=d3e1928-114920

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (o)
-URI https://asc.fasb.org/extlink&oid=123447040&loc=d3e1928-114920

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (p)
-URI https://asc.fasb.org/extlink&oid=123447040&loc=d3e1928-114920

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 70
-Section 50
-Paragraph 1
-URI https://asc.fasb.org/extlink&oid=49170846&loc=d3e28014-114942

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-URI https://asc.fasb.org/topic&trid=2235017

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 60
-Section 50
-Paragraph 3
-Subparagraph (c)
-URI https://asc.fasb.org/extlink&oid=6414203&loc=d3e39689-114964

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (d)(iv)(03)
-URI https://asc.fasb.org/extlink&oid=123447040&loc=d3e1928-114920

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (q)
-URI https://asc.fasb.org/extlink&oid=123447040&loc=d3e1928-114920

Reference 11: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (r)(1)
-URI https://asc.fasb.org/extlink&oid=123447040&loc=d3e1928-114920

Reference 12: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (d)(iii)
-URI https://asc.fasb.org/extlink&oid=123447040&loc=d3e1928-114920

Reference 13: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (l)
-URI https://asc.fasb.org/extlink&oid=123447040&loc=d3e1928-114920

Reference 14: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (r)(2)
-URI https://asc.fasb.org/extlink&oid=123447040&loc=d3e1928-114920