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Document and Entity Information - USD ($)	12 Months Ended
Document and Entity Information - USD ($)	Dec. 31, 2012	Feb. 15, 2013	Jun. 30, 2012
Document and Entity Information [Abstract]
Entity Registrant Name	NBT BANCORP INC
Entity Central Index Key	0000790359
Current Fiscal Year End Date	--12-31
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Filer Category	Large Accelerated Filer
Entity Public Float			$ 688,194,085
Entity Common Stock, Shares Outstanding		33,795,298
Document Fiscal Year Focus	2012
Document Fiscal Period Focus	FY
Document Type	10-K
Amendment Flag	false
Document Period End Date	Dec. 31, 2012

Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2012	Dec. 31, 2011
Assets
Cash and due from banks	$ 157,094	$ 128,517
Short-term interest bearing accounts	6,574	864
Securities available for sale, at fair value	1,147,999	1,244,619
Securities held to maturity (fair value $61,535 and $72,198)	60,563	70,811
Trading securities	3,918	3,062
Federal Reserve and Federal Home Loan Bank stock	29,920	27,020
Loans	4,277,616	3,800,203
Less allowance for loan losses	69,334	71,334
Net loans	4,208,282	3,728,869
Premises and equipment, net	77,875	74,541
Goodwill	152,373	132,029
Intangible assets, net	16,962	18,194
Bank owned life insurance	80,702	77,626
Other assets	99,997	92,254
Total assets	6,042,259	5,598,406
Liabilities
Demand (noninterest bearing)	1,242,712	1,052,906
Savings, NOW, and money market	2,558,376	2,381,116
Time	983,261	933,127
Total deposits	4,784,349	4,367,149
Short-term borrowings	162,941	181,592
Long-term debt	367,492	370,344
Trust preferred debentures	75,422	75,422
Other liabilities	69,782	65,789
Total liabilities	5,459,986	5,060,296
Stockholders' equity
Preferred stock, $0.01 par value; authorized 2,500,000 shares at December 31, 2012 and 2011	0	0
Common stock, $0.01 par value. Authorized 100,000,000 shares at December 31, 2012 and 50,000,000 at December 31, 2011; issued 39,305,131 at December 31, 2012 and 38,035,539 at December 31, 2011	393	380
Additional paid-in-capital	346,692	317,329
Retained earnings	357,558	329,981
Accumulated other comprehensive loss	(5,880)	(6,104)
Common stock in treasury, at cost, 5,529,781 and 4,878,829 shares at December 31, 2012 and 2011, respectively	(116,490)	(103,476)
Total stockholders' equity	582,273	538,110
Total liabilities and stockholders' equity	$ 6,042,259	$ 5,598,406

Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2012	Dec. 31, 2011
Assets
Securities held to maturity fair value	$ 61,535	$ 72,198
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	50,000,000
Common stock, shares issued (in shares)	39,305,131	38,035,539
Common stock in treasury, at cost (in shares)	5,529,781	4,878,829

Consolidated Statements of Income - USD ($) $ in Thousands	12 Months Ended
Consolidated Statements of Income - USD ($) $ in Thousands	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Interest, fee, and dividend income
Interest and fees on loans	$ 208,458	$ 204,370	$ 213,429
Securities available for sale	27,005	31,083	36,167
Securities held to maturity	2,378	2,886	3,968
Other	1,556	1,658	2,174
Total interest, fee, and dividend income	239,397	239,997	255,738
Interest expense
Deposits	18,848	23,020	30,354
Short-term borrowings	188	205	402
Long-term debt	14,428	14,404	18,314
Trust preferred debentures	1,730	2,092	4,140
Total interest expense	35,194	39,721	53,210
Net interest income	204,203	200,276	202,528
Provision for loan losses	20,269	20,737	29,809
Net interest income after provision for loan losses	183,934	179,539	172,719
Noninterest income
Insurance and other financial services revenue	22,387	20,843	18,867
Service charges on deposit accounts	18,225	21,464	24,041
ATM and debit card fees	12,358	11,642	10,035
Retirement plan administration fees	10,097	8,918	10,356
Trust	9,172	8,864	7,722
Bank owned life insurance income	3,077	3,085	3,316
Net securities gains	599	150	3,274
Other	11,412	5,345	6,277
Total noninterest income	87,327	80,311	83,888
Noninterest expense
Salaries and employee benefits	104,815	99,212	93,718
Occupancy	17,415	16,363	15,350
Data processing and communications	13,437	12,271	12,347
Professional fees and outside services	10,463	8,921	9,032
Equipment	9,627	8,864	8,317
Office supplies and postage	6,489	6,073	6,102
FDIC expenses	3,832	4,267	6,081
Advertising	2,889	3,460	3,487
Amortization of intangible assets	3,394	3,046	3,072
Loan collection and other real estate owned	2,560	2,631	3,036
Merger expenses	2,608	804	0
Prepayment penalty on long-term debt	0	0	4,526
Other	16,358	14,764	13,223
Total noninterest expense	193,887	180,676	178,291
Income before income tax expense	77,374	79,174	78,316
Income tax expense	22,816	21,273	20,912
Net income	$ 54,558	$ 57,901	$ 57,404
Earnings per share
Basic (in dollars per share)	$ 1.63	$ 1.72	$ 1.67
Diluted (in dollars per share)	$ 1.62	$ 1.71	$ 1.66

Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Consolidated Statements of Comprehensive Income [Abstract]
Net income	$ 54,558	$ 57,901	$ 57,404
Other comprehensive (loss) income, net of tax
Unrealized net holding (losses) gains arising during the year (pre-tax amounts of $(2,471), $12,757, and $(6,660))	(1,492)	7,703	(4,021)
Reclassification adjustment for net gains related to securities available for sale included in net income (pre-tax amounts of $599, $150, and $3,274)	(362)	(90)	(1,977)
Amortization of prior service cost and actuarial gains (pre-tax amounts of $3,593, $1,665, and $1,768)	2,092	999	1,060
Increase in unrecognized actuarial loss and prior service cost (pre-tax amounts of $(24), $(15,546), and $(2,596))	(14)	(9,381)	(1,560)
Total other comprehensive income (loss)	224	(769)	(6,498)
Comprehensive income	$ 54,782	$ 57,132	$ 50,906

- Definition

The change in equity [net assets] of a business enterprise during a period from transactions and other events and circumstances from non-owner sources which are attributable to the reporting entity. It includes all changes in equity during a period except those resulting from investments by owners and distributions to owners, but excludes any and all transactions which are directly or indirectly attributable to that ownership interest in subsidiary equity which is not attributable to the parent.

+ References

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+ Details

- Definition

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

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+ Details

- Definition

The adjustment out of other comprehensive income for prior service costs recognized as a component of net period benefit cost during the period, after tax.

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+ Details

- Definition

The accumulated change in the value of either the projected benefit obligation or the plan assets resulting from experience different from that assumed or from a change in an actuarial assumption that has not been recognized in net periodic benefit cost, after tax.

+ References

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- Definition

This element represents Other Comprehensive Income or Loss, Net of Tax, for the period attributable to the parent entity. Includes deferred gains or losses on qualifying hedges, unrealized holding gains or losses on available-for-sale securities, minimum pension liability, and cumulative translation adjustment.

+ References

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+ Details

- Definition

Reclassification adjustment for unrealized gains or losses realized upon the sale of securities, after tax.

+ References

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+ Details

- Definition

Appreciation or loss in value (before reclassification adjustment) of the total of unsold securities during the period being reported on, net of tax. Reclassification adjustments include: (1) the unrealized holding gain (loss), net of tax, at the date of the transfer for a debt security from the held-to-maturity category transferred into the available-for-sale category. Also includes the unrealized gain (loss) at the date of transfer for a debt security from the available-for-sale category transferred into the held-to-maturity category; (2) the unrealized gains (losses) realized upon the sale of securities, after tax; and (3) the unrealized gains (losses) realized upon the write-down of securities, after tax.

+ References

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-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 130
-Paragraph 24
-Subparagraph b
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 130
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-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
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-Section 45
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Reference 7: http://www.xbrl.org/2003/role/presentationRef
-Publisher AICPA
-Name Accounting Research Bulletin (ARB)
-Number 51
-Paragraph 38
-Subparagraph c(3)
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

+ Details

Consolidated Statements of Comprehensive Income (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Other comprehensive (loss) income, net of tax
Unrealized net holding (losses) gains arising during the period, pre-tax amounts	$ (2,471)	$ 12,757	$ (6,660)
Reclassification adjustment for net gains related to securities available for sale included in net income, pre-tax amounts	599	150	3,274
Amortization of prior service cost and actuarial gains, pre-tax amounts	3,593	1,665	1,768
Decrease in unrecognized actuarial loss, pre-tax amounts	$ (24)	$ (15,546)	$ (2,596)

- Definition

Tax effect on adjustment out of other comprehensive income for prior service costs recognized as a component of net period benefit cost during the period.

+ References

+ Details

- Definition

Gross appreciation or the gross loss in value of the total of unsold available-for-sale securities during the period being reported (except when designated as a fair value hedge).

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 115
-Paragraph 13
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 130
-Paragraph 24
-Subparagraph b
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 130
-Paragraph 17
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 4: http://www.xbrl.org/2003/role/presentationRef
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-Publisher AICPA
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-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

+ Details

Consolidated Statements of Changes in Stockholders' Equity - USD ($) $ in Thousands	Total	Common Stock [Member]	Additional Paid-in-Capital [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive (Loss) Income [Member]	Common Stock in Treasury [Member]
Beginning Balance at Dec. 31, 2009	$ 505,123	$ 380	$ 311,164	$ 270,232	$ 1,163	$ (77,816)
Net income	57,404	0	0	57,404	0	0
Cash dividends	(27,577)	0	0	(27,577)	0	0
Net issuance of common shares	(477)	0	0	0	0	(477)
Net issuance of shares to employee stock plans, including tax benefit	1,815	0	(923)	(262)	0	3,000
Stock-based compensation	3,782	0	3,782	0	0	0
Other comprehensive income	(6,498)	0	0	0	(6,498)	0
Ending Balance at Dec. 31, 2010	533,572	380	314,023	299,797	(5,335)	(75,293)
Net income	57,901	0	0	57,901	0	0
Cash dividends	(27,063)	0	0	(27,063)	0	0
Purchases of treasury shares	(30,502)	0	0	0	0	(30,502)
Net issuance of shares to employee stock plans, including tax benefit	1,727	0	62	(654)	0	2,319
Stock-based compensation	3,244	0	3,244	0	0	0
Other comprehensive income	(769)	0	0	0	(769)	0
Ending Balance at Dec. 31, 2011	538,110	380	317,329	329,981	(6,104)	(103,476)
Net income	54,558	0	0	54,558	0	0
Cash dividends	(26,712)	0	0	(26,712)	0	0
Purchases of treasury shares	(15,490)	0	0	0	0	(15,490)
Net issuance of shares for acquisition	25,824	13	25,811	0	0	0
Net issuance of shares to employee stock plans, including tax benefit	1,395	0	(812)	(269)	0	2,476
Stock-based compensation	4,364	0	4,364	0	0	0
Other comprehensive income	224	0	0	0	224	0
Ending Balance at Dec. 31, 2012	$ 582,273	$ 393	$ 346,692	$ 357,558	$ (5,880)	$ (116,490)

- Definition

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

Value of stock (or other type of equity) issued during the period as a result of any equity-based compensation plan other than an employee stock ownership plan (ESOP), net of stock value of such awards forfeited. Stock issued could result from the issuance of restricted stock, the exercise of stock options, stock issued under employee stock purchase plans, and/or other employee benefit plans.

+ References + Details

- Definition

Equity impact of the cost of common and preferred stock that were repurchased during the period. Recorded using the cost method.

+ References + Details

Consolidated Statements of Changes in Stockholders' Equity (Parenthetical) - $ / shares	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Consolidated Statements of Changes in Stockholders' Equity [Abstract]
Cash dividends - per share (in dollars per share)	$ 0.80	$ 0.80	$ 0.80
Net issuance of common shares (in shares)			23,810
Purchase of treasury shares (in shares)	769,568	1,458,609
Net issuance of shares for acquisition (in shares)	1,269,592
Net issuance of shares to employee stock plans, including tax benefit (in shares)	118,616	112,512	141,146

- Definition

Number of shares of stock issued during the period pursuant to acquisitions.

+ References + Details

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Operating activities
Net income	$ 54,558	$ 57,901	$ 57,404
Adjustments to reconcile net income to net cash provided by operating activities
Provision for loan losses	20,269	20,737	29,809
Depreciation and amortization of premises and equipment	6,276	5,463	5,327
Net accretion on securities	2,408	1,597	1,468
Amortization of intangible assets	3,394	3,046	3,072
Stock based compensation	4,364	3,244	3,782
Bank owned life insurance income	(3,077)	(3,085)	(3,316)
Trading security purchases	(753)	(447)	(184)
Unrealized (gains) losses in trading securities	(103)	193	(214)
Deferred income tax benefit	(10)	(9,478)	(14,955)
Proceeds from sale of loans held for sale	65,160	13,545	83,143
Originations of loans held for sale	(66,252)	(14,167)	(80,469)
Net gains on sales of loans held for sale	(2,469)	(329)	(911)
Net security gains	(599)	(151)	(3,274)
Net gains on sales of other real estate owned	(988)	(2,531)	(517)
Net decrease (increase) in other assets	6,804	(3,579)	6,627
Net increase in other liabilities	(128)	11,806	2,645
Net cash provided by operating activities	88,854	83,765	89,437
Investing activities
Net cash provided by acquisitions	52,871	81,467	0
Securities available for sale:
Proceeds from maturities, calls, and principal paydowns	573,828	541,555	511,394
Proceeds from sales	1,790	2,437	103,253
Purchases	(483,858)	(648,048)	(635,319)
Securities held to maturity:
Proceeds from maturities, calls, and principal paydowns	31,506	47,186	112,399
Purchases	(20,193)	(20,736)	(48,701)
Net (increase) decrease in loans	(277,530)	(172,920)	7,292
Net (increase) decrease in Federal Reserve and FHLB stock	(1,886)	226	8,733
Proceeds from bank owned life insurance	0	758	2,767
Purchases of premises and equipment, net	(6,994)	(9,954)	(6,510)
Proceeds from sales of other real estate owned	3,616	2,531	3,186
Net cash (used in) provided by investing activities	(126,850)	(175,498)	58,494
Financing activities
Net increase in deposits	135,095	87,992	41,306
Net (decrease) increase in short-term borrowings	(18,651)	22,158	3,457
Proceeds from issuance of long-term debt	0	156	0
Repayments of long-term debt	(3,354)	(2,146)	(184,824)
Excess tax benefit from exercise of stock options	8	341	140
Proceeds from the issuance of shares to employee benefit plans and other stock plans	1,387	1,386	1,675
Purchase of treasury stock	(15,490)	(30,502)	(477)
Cash dividends and payment for fractional shares	(26,712)	(27,063)	(27,577)
Net cash provided by (used in) financing activities	72,283	52,322	(166,300)
Net increase (decrease) in cash and cash equivalents	34,287	(39,411)	(18,369)
Cash and cash equivalents at beginning of year	129,381	168,792	187,161
Cash and cash equivalents at end of year	163,668	129,381	168,792
Cash paid during the period for:
Interest	35,344	40,135	54,668
Income taxes, net of refund	25,512	31,258	37,033
Noncash investing activities:
Loans transferred to other real estate owned	2,734	2,927	1,212
Acquisitions:
Fair value of assets acquired	258,467	67,020	0
Fair value of liabilities assumed	285,012	148,487	0
Fair value of debt issued in purchase combination	$ 502	$ 2,460	$ 0

Summary of Significant Accounting Policies

12 Months Ended

Dec. 31, 2012

Summary of Significant Accounting Policies [Abstract]

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"), NBT Holdings, Inc., and NBT Financial Services, Inc., conform, in all material respects, to accounting principles generally accepted 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 preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from these estimates.

Estimates associated with the allowance for loan losses, other real estate owned (OREO), income taxes, pension expense, fair values of financial instruments and status of contingencies and other-than-temporary impairment on investments are particularly susceptible to material change in the near term.

The following is a description of significant policies and practices:

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. 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 an entity is present when an enterprise has a variable interest, or a combination of variable interests, that will absorb a majority of the entity's expected losses, receive a majority of the entity's expected residual returns, or both. The enterprise with a controlling financial interest, known as the primary beneficiary, consolidates the VIE. The Company's wholly owned subsidiaries CNBF Capital Trust I, NBT Statutory Trust I and NBT Statutory 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 Report

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 solely in the geographical regions of central and upstate New York, northeastern Pennsylvania, western Massachusetts, southern New Hampshire and Burlington, Vermont. 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 available for sale, held to maturity or trading. Held to maturity debt securities are those that the Company has the ability and intent to hold until maturity. Available for sale securities are recorded at fair value. Unrealized holding gains and losses, net of the related tax effect, on available for sale securities are excluded from earnings and are reported in stockholders' equity and the statement of comprehensive income as a component of accumulated other comprehensive income or loss. Held to maturity securities are recorded at amortized cost. Trading 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. Declines in the fair value of held-to-maturity and available-for-sale securities below their cost that are deemed to be other than temporary are reflected in earnings as realized losses or in other comprehensive income, depending on whether the Company intends to sell the security or more likely than not will be required to sell the security before recovery of its amortized cost basis less any current-period credit loss. If the Company intends to sell the security or more likely than not will be required to sell the security before recovery of its amortized cost basis less any current-period credit loss, the other-than-temporary impairment shall be recognized in earnings equal to the entire difference between the investment's amortized cost basis and its fair value at the balance sheet date. If the Company does not intend to sell the security and it is not more likely than not that the entity will be required to sell the security before recovery of its amortized cost basis less any current-period credit loss, the other-than-temporary impairment shall be separated into (a) the amount representing the credit loss and (b) the amount related to all other factors. The amount of the total other-than-temporary impairment related to the credit loss shall be recognized in earnings. The amount of the total other-than-temporary impairment related to other factors shall be recognized in other comprehensive income, net of applicable taxes.

In estimating other-than-temporary impairment losses, management considers, among other things, (i) the length of time and the extent to which the fair value has been less than cost, (ii) the financial condition and near-term prospects of the issuer, and (iii) the historical and implied volatility of the fair value of the security.

Non-marketable equity securities are carried at cost.

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.

Investments in Federal Reserve 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.

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.

Lease receivables primarily represent automobile financing to customers through direct financing leases and are carried at the aggregate of the lease payments receivable and the estimated residual values, net of unearned income and net deferred lease origination fees and costs. Net deferred lease origination fees and costs are amortized under the effective interest method over the estimated lives of the leases. The estimated residual value related to the total lease portfolio is reviewed and if there has been a decline in the estimated fair value of the total residual value that is judged by management to be other-than-temporary a loss is recognized. Adjustments related to such other-than-temporary declines in estimated fair value are recorded in noninterest expense in the consolidated statements of income.

For all loan classes within the Company's loan portfolio, loans are placed on nonaccrual status when timely collection of principal and interest in accordance with contractual terms is doubtful. Loans are transferred to nonaccrual status generally when principal or interest payments become 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 loan 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 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.

Commercial type loans are considered impaired when it is probable that the borrower will not repay the loan according to the original contractual terms of the loan agreement, and all loan types are considered impaired if the loan is restructured in a troubled debt restructuring ("TDR"). In determining that we will be unable to collect all principal and interest payments due in accordance with the contractual terms of the loan agreements, we consider factors such as payment history and changes in the financial condition of individual borrowers, local economic conditions, historical loss experience and the conditions of the various markets in which the collateral may be liquidated.

A loan is considered to be a 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 include the reduction of interest rates, forgiveness of all or a portion of principal or interest, or other modifications at interest rates that are less than the current market rate for new obligations with similar risk. 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 Loan Losses

The allowance for loan losses is the amount which, in the opinion of management, is necessary to absorb probable losses inherent in the loan portfolio. The allowance is determined based upon numerous considerations, including local and regional conditions, the growth and composition of the loan portfolio with respect to the mix between the various types of loans and their related risk characteristics, a review of the value of collateral supporting the loans, comprehensive reviews of the loan portfolio by the independent loan review staff and management, as well as consideration of volume and trends of delinquencies, nonperforming loans, and loan charge-offs. Loan losses are charged off against the allowance, while recoveries of amounts previously charged off are credited to the allowance. As a result of tests of adequacy, required additions to the allowance for loan losses are made periodically by charges to the provision for loan losses.

The allowance for loan losses related to impaired loans is based on discounted cash flows using the loan's initial effective interest rate or the fair value of the collateral for certain loans where repayment of the loan is expected to be provided solely by the underlying collateral (collateral dependent loans). The Company's impaired loans are generally collateral dependent. The Company considers the estimated cost to sell, on a discounted basis, when determining the fair value of collateral in the measurement of impairment if those costs are expected to reduce the cash flows available to repay or otherwise satisfy the loans.

Management believes that the allowance for loan losses is adequate. While management uses available information to recognize loan losses, future additions to the allowance for loan losses may be necessary based on changes in economic conditions or changes in the values of properties securing loans in the process of foreclosure. In addition, various regulatory agencies, as an integral part of their examination process, periodically review the Company's allowance for loan losses. Such agencies may require the Company to recognize additions to the allowance for loan losses based on their judgments about information available to them at the time of their examination which may not be currently available to management.

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.

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 other real estate owned, 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 at December 31, 2012 and 2011 was approximately $2.3 million and $2.2 million, respectively.

Acquired Loans

Acquired loans are initially measured at fair value as of the acquisition date without carryover of historical allowance for loan losses.

For loans that meet the criteria stipulated in ASC 310-30, the Company shall recognize the accretable yield, which is defined as the excess of all cash flows expected at acquisition over the initial fair value of the loan, as interest income on a level-yield basis over the expected remaining life of the loan. The excess of the loan's contractually required payments over the cash flows expected to be collected is the nonaccretable difference. The nonaccretable difference shall not be recognized as an adjustment of yield, a loss accrual, or a valuation allowance. Decreases in the expected cash flows in subsequent periods require the establishment of an allowance for loan losses. Improvements in expected cash flows in future periods result in a reduction of the nonaccretable discount, with such amount reclassified as part of the accretable yield and subsequently recognized in interest income over the remaining lives of the acquired loans on a level-yield basis if the amount and timing of future cash flows is reasonably estimable.

Acquired loans that met the criteria for nonaccrual of interest prior to the acquisition are considered performing upon acquisition, regardless of whether the customer is contractually delinquent, if the Company can reasonably estimate the timing and amount of the expected cash flows on such loans and if the Company expects to fully collect the new carrying value of the loans. As such, the Company may no longer consider the loan to be nonaccrual or nonperforming and may accrue interest on these loans, including the impact of any accretable yield. As such, charge-offs on acquired loans are first applied to the nonaccretable difference and then to any allowance for loan losses recognized subsequent to acquisition.

For loans that meet the criteria stipulated in ASC 310-20, the Company shall amortize/accrete into interest income the premium/discount determined at the date of purchase on a level-yield basis over the life of the loan. Subsequent to the acquisition date, the methods utilized to estimate the required allowance for loan losses are similar to originated loans. Loans accounted for under ASC 310-20 are placed on nonaccrual status when past due in accordance with the Company's nonaccrual policy.

Subsequent to acquisition the estimate of cash flows expected to be collected on loans accounted for in accordance with ASC 310-20 is periodically re-assessed. These re-assessments involve the use of key assumptions and estimates, similar to those used in the initial estimate of fair value. A decrease in expected cash flows in subsequent periods may indicate that the loan pool is impaired, which would require the establishment of an allowance for loan losses by a charge to the provision for credit losses.

An acquired loan may be resolved either through receipt of payment (in full or in part) from the borrower, the sale of the loan to a third party, or foreclosure of the collateral. In the event of a sale of the loan, a gain or loss on sale is recognized and reported within noninterest income based on the difference between the sales proceeds and the carrying amount of the loan. In other cases, individual loans are removed from the pool based on comparing the amount received from its resolution (fair value of the underlying collateral less costs to sell in the case of a foreclosure) with its outstanding balance. Any difference between these amounts is recorded as a charge-off through the allowance for loan losses. Acquired loans subject to modification are not removed from the pool even if those loans would otherwise be deemed troubled debt restructurings as the pool, and not the individual loan, represents the unit of account.

Goodwill and Other Intangible Assets

Goodwill and 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 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. Goodwill impairment tests are performed on an annual basis or when events or circumstances dictate. In these tests, the fair values of each reporting unit, or segment, is compared to the carrying amount of that reporting unit in order to determine if impairment is indicated. If so, the implied fair value of the reporting unit's goodwill is compared to its carrying amount and the impairment loss is measured by the excess of the carrying value over fair value.

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.

Stock-Based Compensation

We maintain various long-term incentive stock benefit plans under which we grant stock options, restricted stock awards, and restricted stock units to certain directors and key employees. We recognize compensation expense in our income statement over the requisite service period, based on the grant-date fair value of the award. The fair values of options are estimated using the Black-Scholes option pricing model. For restricted stock awards and units, we recognize compensation expense ratably over the vesting period for the fair value of the award, measured at the grant date.

The Company's stock-based employee compensation plan is described in Note 18 "Employee Benefit Plans," of this Report.

Interest Rate Swaps

Beginning in June 2012 with the acquisition of Hampshire First Bank, the Bank offers interest rate swap agreements to its customers. These agreements allow the Bank's customers to effectively fix the interest rate on a variable rate loan by entering into a separate agreement. Simultaneous with the execution of such an agreement with a customer, the Bank enters into a matching interest rate swap agreement with an unrelated third party provider, which allows the Bank to continue to receive the historical variable rate under the loan agreement with the customer. The agreement with the third party is not a hedge contract therefore changes in fair value are recorded through earnings. Assets and liabilities associated with the agreements are recorded in other assets and other liabilities on the balance sheet. Gains and losses are recorded as other noninterest income. The Bank is not subject to any fee or penalty should the customer elect to terminate the interest rate swap agreement prior to maturity. The Bank is exposed to credit loss equal to the fair value of the derivatives (not the notional amount of the derivatives) in the event of nonperformance by the counterparty to the interest rate swap agreements. Additionally, the Bank receives a fee from the customer that is recognized when the Bank has fulfilled its obligations under each agreement, which is generally upon execution of the agreement with the Bank's customer. Since the terms of the two interest rate swap agreements are identical, the income statement impact to the Bank is limited to the fees it receives from the customer.

Other Financial Instuments

The Company is a party to certain other financial instruments with off-balance-sheet risk such as commitments to extend credit, unused lines of credit, as well as certain mortgage 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 credit risk involved in issuing letters of credit is essentially the same as that 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 stand-by letters of credit is recorded upon inception.

Loan Sales and Loan Servicing

The Company originates and services residential mortgage loans for consumers and sells 15-year, 20-year and 30-year residential real estate mortgages in the secondary market when the interest rate environment is determined to be favorable by management, while retaining servicing rights on the sold loans. Loan sales are recorded when the sales are funded. Mortgage servicing rights are recorded at fair value upon sale of the loan. Loans held for sale are recorded at the lower of cost or market.

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 dealer or bank with whom each transaction is executed. The dealers or banks, 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.

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).

Subsequent Events

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

Comprehensive Income

At the Company, comprehensive income represents net income plus other comprehensive income (loss), which consists primarily of the net change in unrealized gains or losses on securities available for sale for the period and changes in the funded status of employee benefit plans. Accumulated other comprehensive (loss) income represents the net unrealized gains or losses on securities available for sale and the previously unrecognized portion of the funded status of employee benefit plans, net of income taxes, as of the consolidated balance sheet dates.

Pension Costs

The Company maintains a noncontributory, defined benefit pension plan covering substantially all employees, as well as supplemental employee retirement plans covering certain 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.

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. Trust income is recognized on the accrual method based on contractual rates applied to the balances of trust accounts.

Fair Value Measurements

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 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;

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 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.

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.

Merger and Acquisition Activity

12 Months Ended

Dec. 31, 2012

Merger and Acquisition Activity [Abstract]

Merger and Acquisition Activity

(2)	Merger and Acquisition Activity

Acquisition of Alliance Financial Corporation

On October 7, 2012, NBT Bancorp and Alliance Financial Corporation ("Alliance") entered into a definitive agreement and plan of merger pursuant to which Alliance will merge with and into NBT Bancorp, with NBT Bancorp continuing as the surviving corporation. The agreement also provides for Alliance Bank, National Association ("Alliance Bank"), a wholly owned subsidiary of Alliance, to be merged with and into NBT Bank following completion of the merger. Alliance, with assets of approximately $1.4 billion at December 31, 2012, is headquartered in Syracuse, N.Y. Its primary subsidiary, Alliance Bank, is a nationally chartered community bank with 26 banking locations in central New York. The transaction is valued at approximately $233.4 million, to be paid in the form of shares of the Company's common stock. Subject to the required approvals of NBT Bancorp and Alliance shareholders, requisite regulatory approvals (which were received in early 2013) and other customary closing conditions, the merger is expected to be completed in early 2013.

Acquisition of Hampshire First Bank

On June 8, 2012, the Company acquired all of the outstanding common shares of Hampshire First Bank ("Hampshire First"). The five banking centers operated by Hampshire First located in Manchester, Londonderry, Nashua, Keene and Portsmouth, New Hampshire continue to do business under the Hampshire First name as a division of the Bank. This business combination is a strategic extension of the Company's franchise.

Hampshire First shareholders received approximately 1.3 million shares of the Company's common stock and $17.2 million in cash. On the acquisition date, Hampshire First had approximately 2.8 million outstanding common shares. Under the terms of the merger agreement between the Company, NBT Bank and Hampshire First, the Company paid $15.00 per share for 35% of the outstanding Hampshire First common shares, while the remaining 65% of outstanding Hampshire First shares received 0.7019 shares of the Company's common stock for each share. The Company's common stock issued in this exchange were valued at $20.34 per share based on the average of the daily closing price of the Company's common stock for the ten trading days immediately prior to June 8, 2012. The Company paid $2.6 million in cash to retire outstanding Hampshire First stock options and warrants.

The results of Hampshire First's operations are included in the Consolidated Statements of Income from the date of acquisition. In connection with the merger, the consideration paid, the assets acquired, and the liabilities assumed were recorded at fair value on the date of acquisition, as summarized in the following tables, in thousands, as of June 8, 2012

Consideration Paid:
NBT Bancorp common stock issued to Hampshire First common stockholders	$	25,824
Cash consideration paid to Hampshire First common stockholders		14,616
Cash consideration paid for Hampshire First employee stock options and warrants		2,583
Total consideration paid	$	43,023

Recognized Amounts of Identifiable Assets Acquired and (Liabilities Assumed), At Fair Value:
Cash and short term investments	$	22,149
Loans		218,801
Federal Home Loan Bank common stock		1,014
Core deposit intangibles		797
Other assets		12,926
Deposits		(228,198	)
Borrowings		(41	)
Other liabilities		(2,848	)
Total identifiable net assets	$	24,600

Goodwill	$	18,423

The fair values for most loans acquired from Hampshire First were estimated using cash flow projections based on the remaining maturity and repricing terms. Cash flows were adjusted by estimating future credit losses and the rate of prepayments. Projected monthly cash flows were then discounted to present value using a risk-adjusted market rate for similar loans. The Company acquired the loan portfolio at a fair value discount of approximately $5.7 million. The discount represents expected credit losses, net of market interest rate adjustments. The discount on loans receivable will be amortized to interest income over the estimated remaining life of the acquired loans using the level yield method.

To estimate the fair value of collateral dependent problem loans, we analyzed the value of the underlying collateral of the loans, assuming the fair values of the loans were derived from the eventual sale of the collateral. We discounted those values using market derived rates of return, with consideration given to the period of time and costs associated with the foreclosure and disposition of the collateral. There was no carryover of Hampshire First's allowance for credit losses associated with the loans we acquired as the loans were initially recorded at fair value.

Information about the acquired loan portfolio as of June 8, 2012 is as follows (in thousands):

Contractually required principal and interest at acquisition	$	226,631
Contractual cash flows not expected to be collected		(7,985	)
Expected cash flows at acquisition		218,646
Interest component of expected cash flows (accretable premium)		155
Fair value of acquired loans	$	218,801

The core deposit intangible asset recognized as part of the Hampshire First merger is being amortized over its estimated useful life of approximately ten years utilizing an accelerated method.

The goodwill is not amortized for book purposes and is not deductible for tax purposes.

The fair value of savings and transaction deposit accounts acquired from Hampshire First was assumed to approximate the carrying value as these accounts have no stated maturity and are payable on demand. Certificates of deposit were valued by comparing the contractual cost of the portfolio to an identical portfolio bearing current market rates. The projected cash was calculated by discounting their contractual cash flows at a market rate for a certificate of deposit with a corresponding maturity.

In addition to the goodwill and intangible assets from the Hampshire First merger noted above, the Company also acquired approximately $1.9 million of goodwill and $1.4 million of other intangible assets from other acquisition activity during 2012.

- Definition

The entire disclosure for a business combination (or series of individually immaterial business combinations) completed during the period, including background, timing, and recognized assets and liabilities. The disclosure may include leverage buyout transactions (as applicable).

+ References

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-Publisher FASB
-Name Emerging Issues Task Force (EITF)
-Number 88-16
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 2: http://www.xbrl.org/2003/role/presentationRef
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+ Details

Earnings Per Share

12 Months Ended

Dec. 31, 2012

Earnings Per Share [Abstract]

Earnings Per Share

(3)	Earnings Per Share

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

	Years ended December 31,
	2012						2011						2010
	Net		Weighted average		Per share		Net		Weighted average		Per share		Net		Weighted average		Per share
(In thousands, except per share data)	income		shares		amount		income		shares		amount		income		shares		amount

Basic earnings per share	$	54,558		33,379	$	1.63	$	57,901		33,662	$	1.72	$	57,404		34,275	$	1.67

Effect of dilutive securities

Stock based compensation				340						262						234

Diluted earnings per share	$	54,558		33,719	$	1.62	$	57,901		33,924	$	1.71	$	57,404		34,509	$	1.66

There were approximately 1,193,000, 1,258,000, and 1,309,000 weighted average stock options for the years ended December 31, 2012, 2011, and 2010, respectively, that were not considered in the calculation of diluted earnings per share since the stock options' exercise prices were greater than the average market price during these periods.

Federal Reserve Bank Requirement

12 Months Ended

Dec. 31, 2012

Federal Reserve Bank Requirement [Abstract]

Federal Reserve Bank Requirement

(4)	Federal Reserve Bank Requirement

The Company is required to maintain reserve balances with the Federal Reserve Bank of New York. The required average total reserve for NBT Bank for the 14-day maintenance period ending December 26, 2012 was $35.2 million.

Securities

12 Months Ended

Dec. 31, 2012

Securities [Abstract]

Securities

(5)	Securities

The amortized cost, estimated fair value, and unrealized gains and losses of securities available for sale are as follows:

(In thousands)	Amortized cost		Unrealized gains		Unrealized losses		Estimated fair value
December 31, 2012
U.S. Treasury	$	63,668	$	757	$	-	$	64,425
Federal Agency		281,398		1,507		91		282,814
State & municipal		82,675		4,127		-		86,802
Mortgage-backed		237,461		12,820		-		250,281
Collateralized mortgage obligations		443,972		5,751		-		449,723
Corporate		-		-		-		-
Other securities		11,210		2,832		88		13,954
Total securities available for sale	$	1,120,384	$	27,794	$	179	$	1,147,999
December 31, 2011
U.S. Treasury	$	81,006	$	1,228	$	-	$	82,234
Federal Agency		254,983		879		16		255,846
State & municipal		99,176		5,624		11		104,789
Mortgage-backed		310,767		14,629		-		325,396
Collateralized mortgage obligations		459,067		6,458		51		465,474
Corporate		-		-		-		-
Other securities		8,935		2,021		76		10,880
Total securities available for sale	$	1,213,934	$	30,839	$	154	$	1,244,619

In the available for sale category at December 31, 2012, federal agency securities were comprised of Government-Sponsored Enterprise ("GSE") securities; mortgaged-backed securities were comprised of GSEs with an amortized cost of $221.1 million and a fair value of $232.3 million and US Government Agency securities with an amortized cost of $16.4 million and a fair value of $18.0 million; Collateral Mortgage Obligations ("CMOs") were comprised of GSEs with an amortized cost of $399.2 million and a fair value of $403.6 million and U.S. Government Agency securities with an amortized cost of $44.8 million and a fair value of $46.2 million. At December 31, 2012, all of the mortgaged-backed securities held to maturity were comprised of U.S. Government Agency securities.

In the available for sale category at December 31, 2011, federal agency securities were comprised of GSE securities; mortgaged-backed securities were comprised of GSEs with an amortized cost of $290.2 million and a fair value of $303.0 million and U.S. Government Agency securities with an amortized cost of $20.5 million and a fair value of $22.4 million; CMOs were comprised of GSEs with an amortized cost of $398.3 million and a fair value of $402.4 million and U.S. Government Agency securities with an amortized cost of $60.8 million and a fair value of $63.1 million.

The following table sets forth information with regard to sales transactions of securities available for sale:

	Years ended December 31
(In thousands)	2012		2011			2010
Proceeds from sales	$	1,790	$	2,437		$	103,253
Gross realized gains	$	442	$	7		$	3,170
Gross realized losses		-		(165	)		(25	)
Net securities gains (losses)	$	442	$	(158	)	$	3,145

In addition to gains (losses) from sales transactions, the Company also recorded gains from calls on securities available for sale of approximately $0.2 million for the year ended December 31, 2012, $0.3 million for the year ended December 31, 2011, and $0.1 million for the year ended December 31, 2010.

At December 31, 2012 and 2011, securities available for sale with amortized costs totaling $1.2 billion, respectively, were pledged to secure public deposits and for other purposes required or permitted by law. Additionally, at December 31, 2012, securities available for sale with an amortized cost of $209.0 million were pledged as collateral for securities sold under the repurchase agreements.

The amortized cost, estimated fair value, and unrealized gains and losses of securities held to maturity are as follows:

	Amortized		Unrealized		Unrealized		Estimated
(In thousands)	cost		gains		losses		fair value
December 31, 2012
Mortgage-backed	$	1,168	$	184	$	-	$	1,352
State & municipal		59,395		788		-		60,183
Total securities held to maturity	$	60,563	$	972	$	-	$	61,535
December 31, 2011
Mortgage-backed	$	1,447	$	213	$	-	$	1,660
State & municipal		69,364		1,174		-		70,538
Total securities held to maturity	$	70,811	$	1,387	$	-	$	72,198

At December 31, 2012 and 2011, all of the mortgaged-backed securities held to maturity were comprised of U.S. Government Agency securities.

The following table sets forth information with regard to investment securities with unrealized losses at December 31, 2012 and 2011, 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
Security Type:	Fair Value		Unrealized losses			Number of Positions		Fair Value		Unrealized losses			Number of Positions		Fair Value		Unrealized losses			Number of Positions

December 31, 2012
U.S. Treasury	$	-	$	-			-	$	-	$	-			-	$	-	$	-			-
Federal agency		39,906		(91	)		4		-		-			-		39,906		(91	)		4
State & municipal		-		-			-		-		-			-		-		-			-
Mortgage-backed		-		-			-		-		-			-		-		-			-
Collateralized mortgage obligations		23		-			2		-		-			-		23		-			2
Other securities		468		(6	)		1		167		(82	)		1		635		(88	)		2
Total securities with unrealized losses	$	40,397	$	(97	)		7	$	167	$	(82	)		1	$	40,564	$	(179	)		8

December 31, 2011
U.S. Treasury	$	-	$	-			-	$	-	$	-			-	$	-	$	-			-
Federal agency		34,996		(16	)		3		-		-			-		34,996		(16	)		3
State & municipal		957		(10	)		3		377		(1	)		2		1,334		(11	)		5
Mortgage-backed		-		-			-		-		-			-		-		-			-
Collateralized mortgage obligations		27,368		(51	)		3		-		-			-		27,368		(51	)		3
Other securities		645		(76	)		2		-		-			-		645		(76	)		2
Total securities with unrealized losses	$	63,966	$	(153	)		11	$	377	$	(1	)		2	$	64,343	$	(154	)		13

Management has the intent to hold the securities classified as held to maturity until they mature, at which time it is believed the Company will receive full value for the securities. Furthermore, as of December 31, 2012, management also had intent to hold, and will not be required to sell, the securities classified as available for sale for a period of time sufficient for a recovery of cost, which may be until maturity. The unrealized losses are due to increases in market interest rates over the yields available at the time the underlying securities were purchased. When necessary, the Company has performed a discounted cash flow analysis to determine whether or not it will receive the contractual principal and interest on certain securities. The fair value is expected to recover as the bonds approach their maturity date or repricing date or if market yields for such investments decline. As of December 31, 2012, management believes the impairments detailed in the table above are temporary and no other-than-temporary impairment losses have been realized in the Company's consolidated statements of income.

The following tables set forth information with regard to contractual maturities of debt securities at December 31, 2012:

(In thousands)	Amortized cost		Estimated fair value
Debt securities classified as available for sale
Within one year	$	26,678	$	26,788
From one to five years		193,142		195,953
From five to ten years		311,575		319,229
After ten years		577,779		592,075
	$	1,109,174	$	1,134,045
Debt securities classified as held to maturity
Within one year	$	25,184	$	25,258
From one to five years		27,413		28,118
From five to ten years		5,425		5,434
After ten years		2,541		2,725
	$	60,563	$	61,535

Maturities of mortgage-backed, CMOs 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, there were no holdings, when taken in the aggregate, of any single issuer that exceeded 10% of consolidated stockholders' equity at December 31, 2012 and 2011.

- Definition

Tabular disclosure of investments in certain debt and equity securities (and certain other trading assets) which include all debt and equity securities (other than those equity securities accounted for under the equity or cost methods of accounting) with readily determinable fair values. Other trading assets include assets that are carried on the balance sheet at fair value and held for trading purposes. A debt security represents a creditor relationship with an enterprise that is in the form of a security. Debt securities include, among other items, US Treasury securities, US government securities, municipal securities, corporate bonds, convertible debt, commercial paper, and all securitized debt instruments. An equity security represents an ownership interest in an enterprise or the right to acquire or dispose of an ownership interest in an enterprise at fixed or determinable prices. Equity securities include, among other things, common stock, certain preferred stock, warrant rights, call options, and put options, but do not include convertible debt. An entity may opt to provide the reader with additional narrative text to better understand the nature of investments in debt and equity securities (and other trading assets).

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 115
-Paragraph 3, 19, 20, 21, 22, 137
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 30
-Section 50
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=6379141&loc=d3e15032-111544

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=6872113&loc=d3e27161-111563

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 320
-Section 50
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=6957658&loc=d3e62557-112803

Reference 5: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 9
-URI http://asc.fasb.org/extlink&oid=6872113&loc=d3e27357-111563

Reference 6: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 6
-URI http://asc.fasb.org/extlink&oid=6872113&loc=d3e27290-111563

Reference 7: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 10
-URI http://asc.fasb.org/extlink&oid=6872113&loc=d3e27405-111563

Reference 8: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=6872113&loc=d3e27232-111563

Reference 9: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Debt Security
-URI http://asc.fasb.org/extlink&oid=6509901
-Topic 320

Reference 10: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Equity Security
-URI http://asc.fasb.org/extlink&oid=6511694
-Topic 320

+ Details

Loans

12 Months Ended

Dec. 31, 2012

Loans [Abstract]

Loans

(6)

Loans

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

	At December 31,
(In thousands)	2012		2011
Residential real estate mortgages	$	651,107	$	581,511
Commercial		694,799		611,298
Commercial real estate		1,072,807		888,879
Real estate construction and development		123,078		93,977
Agricultural and agricultural real estate mortgages		112,687		108,423
Consumer		1,047,856		946,470
Home equity		575,282		569,645
Total loans	$	4,277,616	$	3,800,203

Included in the above loans are net deferred loan origination costs totaling $0.9 million and $1.6 million at December 31, 2012 and 2011, respectively. The Company had residential loans held for sale totaling $3.8 million as of December 31, 2012 and $2.7 million as of December 31, 2011.

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

- Definition

The entire disclosure for claims held for amounts due a company. Examples include trade accounts receivables, notes receivables, loans receivables.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 02
-Paragraph 3, 4
-Article 5

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 03
-Paragraph 7
-Article 9

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher AICPA
-Name Statement of Position (SOP)
-Number 01-6
-Paragraph 13
-Subparagraph d
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Article 4
-Section 08
-Paragraph k

Reference 5: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.3,4)
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 6: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=6965416&loc=d3e5074-111524

Reference 7: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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-Paragraph 3
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Reference 8: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08.(k))
-URI http://asc.fasb.org/extlink&oid=6881521&loc=d3e23780-122690

Reference 9: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 11
-URI http://asc.fasb.org/extlink&oid=6965416&loc=d3e5162-111524

+ Details

Allowance for Loan Losses and Credit Quality of Loans

12 Months Ended

Dec. 31, 2012

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

Allowance for Loan Losses and Credit Quality of Loans and Leases

(7)	Allowance for Loan Losses and Credit Quality of Loans

Allowance for Loan Losses

The allowance for loan losses is maintained at a level estimated by management to provide adequately for risk of probable losses inherent in the current loan portfolio. The adequacy of the allowance for loan losses is continuously monitored. It is assessed for adequacy using a methodology designed to ensure the level of the allowance reasonably reflects the loan portfolio's risk profile. It is evaluated to ensure that it is sufficient to absorb all reasonably estimable credit losses inherent in the current loan portfolio.

To develop and document a systematic methodology for determining the allowance for loan losses, the Company has divided the loan portfolio into three portfolio segments, each with different risk characteristics and methodologies for assessing risk. Each portfolio segment is broken down into class segments where appropriate. Class segments contain unique measurement attributes, risk characteristics and methods for monitoring and assessing risk that are necessary to develop the allowance for loan losses. Unique characteristics such as borrower type, loan type, collateral type, and risk characteristics define each class segment. The following table illustrates the portfolio and class segments for the Company's loan portfolio:

Portfolio	Class
Commercial Loans	Commercial
	Commercial Real Estate
	Agricultural
	Agricultural Real Estate
	Business Banking

Consumer Loans	Indirect
	Home Equity
	Direct

Residential Real Estate Mortgages

COMMERCIAL LOANS

Commercial – The Company offers a variety of loan options to meet the specific needs of our commercial customers including term loans, time notes and lines of credit. Such loans are made available to businesses for working capital such as inventory and receivables, business expansion and equipment purchases. Generally, a collateral lien is placed on equipment or other assets owned by the borrower. These loans carry a higher risk than commercial real estate loans by the nature of the underlying collateral, which can be business assets such as equipment and accounts receivable and is generally less liquid than real estate. To reduce the risk, management also attempts to secure real estate as collateral and obtain personal guarantees of the borrowers.

Commercial Real Estate – The Company offers commercial real estate loans to finance real estate purchases, refinancings, expansions and improvements to commercial properties. Commercial real estate loans are made to finance the purchases of real property which generally consists of real estate with completed structures. These commercial real estate loans are secured by first liens on the real estate, which may include apartments, commercial structures, housing businesses, healthcare facilities, and other non owner-occupied facilities. These loans are typically less risky than commercial loans, since they are secured by real estate and buildings. 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.

Agricultural – The Company offers a variety of agricultural loans to meet the needs of our agricultural customers including term loans, time notes, and lines of credit. These loans are made to purchase livestock, purchase and modernize equipment, and finance seasonal crop expenses. Generally, a collateral lien is placed on the livestock, equipment, produce inventories, and/or receivables owned by the borrower. These loans may carry a higher risk than commercial and agricultural real estate loans due to the industry price volatility and the perishable nature of the underlying collateral. To reduce these risks, management may attempt to secure these loans with additional real estate collateral, obtain personal guarantees of the borrowers, or obtain government loan guarantees to provide further support.

Agricultural Real Estate – The Company offers real estate loans to our agricultural customers to finance farm related real estate purchases, refinancings, expansions, and improvements to agricultural properties. Agricultural real estate loans are made to finance the purchases and improvements of farm properties that generally consist of barns, production facilities, and land. The agricultural real estate loans are secured by first liens on the farm real estate. Because they are secured by land and buildings, these loans may be less risky than agricultural loans. 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 75% of the appraised value of the property. Government loan guarantees may be obtained to provide further support.

Business Banking - The Company offers a variety of loan options to meet the specific needs of our small business customers including term loans, small business mortgages and lines of credit. Such loans are generally less than $500 thousand and are made available to businesses for working capital such as inventory and receivables, business expansion, equipment purchases, and agricultural needs. Generally, a collateral lien is placed on equipment or other assets owned by the borrower such as inventory and/or receivables. These loans carry a higher risk than commercial loans due to the smaller size of the borrower and lower levels of capital. To reduce the risk, the Company obtains personal guarantees of the owners for a majority of the loans.

CONSUMER LOANS

Indirect – The Company maintains relationships with many dealers primarily in the communities that we serve. Through these relationships, the company finances the purchases of automobiles and recreational vehicles (such as campers, boats, etc.) indirectly through dealer relationships. Approximately 70% of the indirect relationships represent automobile financing. 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. The majority of indirect consumer loans are underwritten on a secured basis using the underlying collateral being financed.

Home Equity – The Company offers fixed home equity loans as well as home equity lines of credit to consumers to finance home improvements, debt consolidation, education and other uses. Consumers are able to borrower up to 85% of the equity in their homes. The Company originates home equity lines of credit and second mortgage loans (loans secured by a second lien position on one-to-four-family residential real estate). These loans carry a higher risk than first mortgage residential loans as they are in a second position with respect to collateral. 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.

Direct – The Company offers a variety of consumer installment loans to finance vehicle purchases, mobile home purchases and personal expenditures. Most of these loans carry a fixed rate of interest with principal repayment terms typically ranging from one to ten years, based upon the nature of the collateral and the size of the loan. The majority of consumer loans are underwritten on a secured basis using the underlying collateral being financed or a customer's deposit account. In addition to installment loans, the Company also offers personal lines of credit and overdraft protection. A minimal amount of loans are unsecured, which carry a higher risk of loss.

RESIDENTIAL REAL ESTATE LOANS

Residential real estate loans consist primarily of loans secured by first or second deeds of trust on primary residences. We originate adjustable-rate and fixed-rate, one-to-four-family residential real estate loans for the construction, purchase or refinancing of a mortgage. These loans are collateralized by owner-occupied properties located in the Company's market area. When market conditions are favorable, for longer term, fixed-rate residential mortgages without escrow, the Company retains the servicing, but sells the right to receive principal and interest to Freddie Mac when market conditions are favorable. This practice allows the Company to manage interest rate risk, liquidity risk, and credit risk. Loans on one-to-four-family residential real estate 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.

Allowance for Loan Loss Calculation

Management considers the accounting policy relating to the allowance for loan losses to be a critical accounting policy given the inherent uncertainty in evaluating the levels of the allowance required to cover credit losses in the portfolio and the material effect that such judgments can have on the consolidated results of operations.

For purposes of evaluating the adequacy of the allowance, the Company considers a number of significant factors that affect the collectibility of the portfolio. For individually analyzed loans, these include estimates of loss exposure, which reflect the facts and circumstances that affect the likelihood of repayment of such loans as of the evaluation date. For homogeneous pools of loans, estimates of the Company's exposure to credit loss reflect a current assessment of a number of factors, which could affect collectibility. These factors include: past loss experience; size, trend, composition, and nature of loans; changes in lending policies and procedures, including underwriting standards and collection, charge-offs and recoveries; trends experienced in nonperforming and delinquent loans; current economic conditions in the Company's market; portfolio concentrations that may affect loss experienced across one or more components of the portfolio; the effect of external factors such as competition, legal and regulatory requirements; and the experience, ability, and depth of lending management and staff. In addition, various regulatory agencies, as an integral component of their examination process, periodically review the Company's allowance for loan losses. Such agencies may require the Company to make loan grade changes as well as recognize additions to the allowance based on their examinations.

After a thorough consideration of the factors discussed above, any required additions to the allowance for loan losses are made periodically by charges to the provision for loan losses. These charges are necessary to maintain the allowance at a level which management believes is reasonably reflective of overall inherent risk of probable loss in the portfolio. While management uses available information to recognize losses on loans, additions to the allowance may fluctuate from one reporting period to another. These fluctuations are reflective of changes in risk associated with portfolio content and/or changes in management's assessment of any or all of the determining factors discussed above. The following table illustrates the changes in the allowance for loan losses by portfolio segment for the years ended December 31, 2012 and 2011

Allowance for Loan Losses
(in thousands)

Years ended December 31							Residential
	Commercial			Consumer			Real Estate
	Loans			Loans			Mortgages			Unallocated			Total
Balance as of December 31, 2011	$	38,831		$	26,049		$	6,249		$	205		$	71,334
Charge-offs		(8,750	)		(15,848	)		(1,906	)		-			(26,504	)
Recoveries		1,641			2,556			38			-			4,235
Provision		3,902			14,405			1,871			91			20,269
Ending Balance as of December 31, 2012	$	35,624		$	27,162		$	6,252		$	296		$	69,334

Balance as of December 31, 2010	$	40,101		$	26,126		$	4,627		$	380		$	71,234
Charge-offs		(8,969	)		(14,209	)		(1,310	)		-			(24,488	)
Recoveries		1,438			2,406			7			-			3,851
Provision		6,261			11,726			2,925			(175	)		20,737
Ending Balance as of December 31, 2011	$	38,831		$	26,049		$	6,249		$	205		$	71,334

Balance as of December 31, 2009	$	36,599		$	26,664		$	3,002		$	285		$	66,550
Charge-offs		(12,969	)		(15,692	)		(1,176	)		-			(29,837	)
Recoveries		1,922			2,747			43			-			4,712
Provision		14,549			12,407			2,758			95			29,809
Ending Balance as of December 31, 2010	$	40,101		$	26,126		$	4,627		$	380		$	71,234

The following table illustrates the allowance for loan losses and the recorded investment by portfolio segment as of December 31, 2012 and 2011:

Allowance for Loan Losses and Recorded Investment in Loans
(in thousands)

					Residential
	Commercial		Consumer		Real Estate
	Loans		Loans		Mortgages		Unallocated		Total
As of December 31, 2012
Allowance for loan losses	$	35,624	$	27,162	$	6,252	$	296	$	69,334
Allowance for loans individually evaluated for impairment	$	2,848	$	-	$	-			$	2,848
Allowance for loans collectively evaluated for impairment	$	32,776	$	27,162	$	6,252	$	296	$	66,486
Ending balance of loans	$	2,003,371	$	1,623,138	$	651,107			$	4,277,616
Ending balance of loans individually evaluated for impairment	$	11,972	$	-	$	-			$	11,972
Ending balance of loans collectively evaluated for impairment	$	1,991,399	$	1,623,138	$	651,107			$	4,265,644

As of December 31, 2011
Allowance for loan losses	$	38,831	$	26,049	$	6,249	$	205	$	71,334
Allowance for loans individually evaluated for impairment	$	175	$	-	$	-			$	175
Allowance for loans collectively evaluated for impairment	$	38,656	$	26,049	$	6,249	$	205	$	71,159
Ending balance of loans	$	1,702,577	$	1,516,115	$	581,511			$	3,800,203
Ending balance of loans individually evaluated for impairment	$	6,219	$	-	$	-			$	6,219
Ending balance of loans collectively evaluated for impairment	$	1,696,358	$	1,516,115	$	581,511			$	3,793,984

Credit Quality of Loans

For all loan classes within the Company's loan portfolio, loans are placed on nonaccrual status when timely collection of principal and interest in accordance with contractual terms is doubtful. Loans are transferred to nonaccrual status generally when principal or interest payments become ninety days delinquent, unless the loan is well secured and in the process of collection, or sooner when management concludes or 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 loan losses.

The following table illustrates the Company's nonaccrual loans by loan class as of December 31, 2012 and 2011:

Loans on Nonaccrual Status
As of December 31, 2012

(In thousands)	December 31, 2012		December 31, 2011
Commercial Loans
Commercial	$	4,985	$	1,699
Commercial Real Estate		7,977		4,868
Agricultural		699		3,307
Agricultural Real Estate		1,038		2,067
Business Banking		6,738		7,446
		21,437		19,387

Consumer Loans
Indirect		1,557		1,550
Home Equity		7,247		7,931
Direct		266		378
		9,070		9,859

Residential Real Estate Mortgages		9,169		9,044

Total Nonaccrual	$	39,676	$	38,290

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

Age Analysis of Past Due Loans

As of December 31, 2012

(in thousands)


					Greater Than								Recorded
	31-60 Days		61-90 Days		90 Days		Total						Total
	Past Due		Past Due		Past Due		Past Due						Loans and
	Accruing		Accruing		Accruing		Accruing		Non-Accrual		Current		Leases
Commercial
Commercial	$	-	$	-	$	-	$	-	$	4,985	$	556,496	$	561,481
Commercial Real Estate		126		-		-		126		7,977		966,692		974,795
Agricultural		22		-		-		22		699		63,037		63,758
Agricultural Real Estate		108		-		103		211		1,038		36,128		37,377
Business Banking		3,019		708		45		3,772		6,738		355,450		365,960
		3,275		708		148		4,131		21,437		1,977,803		2,003,371

Consumer
Indirect		10,956		2,477		1,205		14,638		1,557		964,802		980,997
Home Equity		6,065		1,223		681		7,969		7,247		560,066		575,282
Direct		717		144		84		945		266		65,648		66,859
		17,738		3,844		1,970		23,552		9,070		1,590,516		1,623,138

Residential Real Estate Mortgages		1,839		725		330		2,894		9,169		639,044		651,107
	$	22,852	$	5,277	$	2,448	$	30,577	$	39,676	$	4,207,363	$	4,277,616

Age Analysis of Past Due Loans

As of December 31, 2011

(in thousands)


					Greater Than								Recorded
	31-60 Days		61-90 Days		90 Days		Total						Total
	Past Due		Past Due		Past Due		Past Due						Loans and
	Accruing		Accruing		Accruing		Accruing		Non-Accrual		Current		Leases
Commercial Loans
Commercial	$	663	$	50	$	-	$	713	$	1,699	$	508,662	$	511,074
Commercial Real Estate		1,942		-		-		1,942		4,868		828,089		834,899
Agricultural		77		13		-		90		3,307		63,140		66,537
Agricultural Real Estate		-		-		50		50		2,067		31,809		33,926
Business Banking		1,871		1,024		-		2,895		7,446		245,800		256,141
		4,553		1,087		50		5,690		19,387		1,677,500		1,702,577

Consumer Loans
Indirect		12,141		2,584		1,283		16,008		1,550		855,545		873,103
Home Equity		5,823		1,277		954		8,054		7,931		553,660		569,645
Direct		831		191		140		1,162		378		71,827		73,367
		18,795		4,052		2,377		25,224		9,859		1,481,032		1,516,115

Residential Real Estate Mortgages		2,003		139		763		2,905		9,044		569,562		581,511
	$	25,351	$	5,278	$	3,190	$	33,819	$	38,290	$	3,728,094	$	3,800,203

There were no material commitments to extend further credit to borrowers with nonperforming loans. Within nonaccrual loans, there were approximately $2.2 million and $4.0 million of TDR loans at December 31, 2012 and 2011, respectively.

Impaired loans, which primarily consist of nonaccruing commercial, commercial real estate, agricultural, agricultural real estate and business banking loans, as well as certain consumer and residential real estate loans that have been modified in a TDR were $26.0 million at December 31, 2012 and $22.4 million at December 31, 2011.

The methodology used to establish the allowance for loan losses on impaired loans incorporates specific allocations on loans analyzed individually. Classified loans, including all TDRs and commercial loans that are graded substandard or below, with outstanding balances of $500 thousand or more are evaluated for impairment through the Company's quarterly status review process. In determining that we will be unable to collect all principal and interest payments due in accordance with the contractual terms of the loan agreements, we consider factors such as payment history and changes in the financial condition of individual borrowers, local economic conditions, historical loss experience and the conditions of the various markets in which the collateral may be liquidated. For loans that are evaluated for impairment, impairment is measured by one of three methods: 1) the fair value of collateral less cost to sell, 2) present value of expected future cash flows or 3) the loan's observable market price. These impaired loans are reviewed on a quarterly basis for changes in the measurement of impairment. For impaired loans measured using the present value of expected cash flow method, any change to the previously recognized impairment loss is recognized as a change to the allowance account and recorded in the consolidated statement of income as a component of the provision for credit losses. At December 31, 2012, $8.4 million of the total impaired loans had a specific reserve allocation of $2.8 million compared to $0.5 million of impaired loans at December 31, 2011 which had a specific reserve allocation of $0.2 million.

The following provides additional information on impaired loans for the years ended December 31, 2012 and 2011:

Impaired Loans
	December 31, 2012						December 31, 2011
	Recorded		Unpaid				Recorded		Unpaid
	Investment		Principal				Investment		Principal
	Balance		Balance		Related		Balance		Balance		Related
(in thousands)	(Book)		(Legal)		Allowance		(Book)		(Legal)		Allowance
With no related allowance recorded:
Commercial Loans
Commercial	$	650	$	709			$	1,243	$	2,723
Commercial Real Estate		3,909		4,753				4,868		7,165
Agricultural		699		1,019				3,307		4,166
Agricultural Real Estate		1,038		1,225				2,067		2,288
Business Banking		6,738		9,269				7,446		9,976
Total Commercial Loans		13,034		16,975				18,931		26,318

Consumer Loans
Home Equity		2,553		2,657				2,000		2,103

Residential Real Estate Mortgages		2,011		2,308				1,040		1,125
		17,598		21,940				21,971		29,546

With an allowance recorded:
Commercial Loans
Commercial	$	4,335	$	4,340	$	2,241	$	456	$	808	$	175
Commercial Real Estate		4,068		5,689		607		-		-		-
Agricultural		-		-		-		-		-		-
Agricultural Real Estate		-		-		-		-		-		-
		8,403		10,029		2,848		456		808		175

Total:	$	26,001	$	31,969	$	2,848	$	22,427	$	30,354	$	175

The following table summarizes the average recorded investments on impaired loans and the interest income recognized for the years ended December 31, 2012, 2011 and 2010:

	December 31, 2012						December 31, 2011						December 31, 2010
	Average		Interest Income				Average		Interest Income				Average		Interest Income
	Recorded		Recognized				Recorded		Recognized				Recorded		Recognized
(in thousands)	Investment		Accrual		Cash		Investment		Accrual		Cash		Investment		Accrual		Cash
With no related allowance recorded:
Commercial Loans
Commercial	$	1,421	$	25	$	25	$	2,322	$	94	$	94	$	1,898	$	113	$	113
Commercial Real Estate		6,167		70		70		4,794		163		163		4,219		317		317
Agricultural		2,611		368		368		3,013		133		133		2,990		82		82
Agricultural Real Estate		1,575		86		86		1,719		109		109		1,929		150		150
Business Banking		6,636		227		227		6,121		266		266		4,959		234		234
Consumer Loans
Home Equity		1,877		66		66		1,904		91		91		-		-		-
Residential Real Estate Mortgages		1,143		73		73		926		58		58		132		6		6
	$	21,429	$	915	$	915	$	20,798	$	914	$	914	$	16,127	$	902	$	902

With an allowance recorded:
Commercial Loans
Commercial	$	4,217	$	43	$	43	$	861	$	86	$	86	$	2,366	$	118	$	118
Commercial Real Estate		339		-		-		287		-		-		1,234		-		-
Agricultural		-		-		-		791		68		68		1,386		150		150
Agricultural Real Estate		-		-		-		357		18		18		816		67		67
	$	4,556	$	43	$	43	$	2,295	$	172	$	172	$	5,802	$	335	$	335

Total:	$	25,985	$	958	$	958	$	23,094	$	1,086	$	1,086	$	21,929	$	1,237	$	1,237

There has been significant disruption and volatility in the financial and capital markets since the second half of 2008. Turmoil in the mortgage market adversely impacted both domestic and global markets and led to a significant credit and liquidity crisis in many domestic markets. These market conditions were attributable to a variety of factors, in particular the fallout associated with subprime mortgage loans (a type of lending we have never actively pursued). The disruption was exacerbated by the decline of the real estate and housing market. However, in the markets in which the Company does business, the disruption has been less significant than in the national market. For example, our real estate market has not suffered the extreme declines seen nationally and our unemployment rate, while notably higher than in prior periods, is still below the national average.

While we continue to adhere to prudent underwriting standards, as a lender we may be adversely impacted by general economic weaknesses and, in particular, a sharp downturn in the housing market nationally. Decreases in real estate values could adversely affect the value of property used as collateral for our loans. Adverse changes in the economy may have a negative effect on the ability of our borrowers to make timely loan payments, which would have an adverse impact on our earnings. A further increase in loan delinquencies would decrease our net interest income and adversely impact our loan loss experience, causing increases in our provision and allowance for loan losses.

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

Commercial Grading System

For commercial and agricultural loans, the Company uses a grading system that relies on quantifiable and measurable characteristics when available. This would include 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. The grading system for commercial and agricultural loans is as follows:

•

4 – 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 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. Because of high probability of loss, nonaccrual treatment is required for doubtful assets.

•

3 – 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 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.

•

2 – 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 (declining revenues or margins) or may be struggling with an ill-proportioned balance sheet (e.g., increasing inventory without an increase in sales, high leverage, 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.

•

1 – 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.

Business Banking Grading System

Business Banking loans are graded as either Classified or Non-classified:

•

Classified

Classified loans are inadequately protected by the current worth and paying capacity of the obligor or, if applicable, the collateral pledged. These loans have a well-defined weakness, or weaknesses, that jeopardize the liquidation of the debt, or in some cases make collection or liquidation in full, on the basis of currently existing facts, conditions, and values, highly questionable and improbable. They are characterized by the distinct possibility that the Company will sustain some loss if the deficiencies are not corrected. Classified loans have a high probability of payment default, or a high probability of total or substantial loss. These loans require more intensive supervision by management and 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. When the likelihood of full collection of interest and principal may be in doubt; classified loans are considered to have a nonaccrual status. In some cases, classified loans are considered uncollectible and of such little value that their continuance as assets is not warranted.

•

Non-classified

Loans graded as Non-classified encompass all loans not graded as Classified. Non-classified loans are in compliance with loan covenants, and payments are generally made as agreed.

Consumer and Residential Mortgage Grading System

Consumer and Residential Mortgage loans are graded as either Performing or Nonperforming. Nonperforming loans are loans that are 1) over 90 days past due and interest is still accruing or 2) on nonaccrual status. All loans not meeting any of these three criteria are considered Performing.

The following tables illustrates the Company's credit quality by loan class for the years ended December 31, 2012 and 2011:

Credit Quality Indicators

As of December 31, 2012

Commercial Credit Exposure			Commercial				Agricultural
By Internally Assigned Grade:	Commercial		Real Estate		Agricultural		Real Estate		Total
Pass	$	522,985	$	901,928	$	57,347	$	33,472	$	1,515,732
Special Mention		18,401		32,135		13		3		50,552
Substandard		17,351		40,732		6,362		3,902		68,347
Doubtful		2,744		-		36		-		2,780
Total	$	561,481	$	974,795	$	63,758	$	37,377	$	1,637,411

Business Banking Credit Exposure	Business
By Internally Assigned Grade:	Banking								Total
Non-classified	$	342,528							$	342,528
Classified		23,432								23,432
Total	$	365,960							$	365,960

Consumer Credit Exposure
By Payment Activity:	Indirect		Home Equity		Direct				Total
Performing	$	978,235	$	567,354	$	66,509			$	1,612,098
Nonperforming		2,762		7,928		350				11,040
Total	$	980,997	$	575,282	$	66,859			$	1,623,138

Residential Mortgage Credit Exposure	Residential
By Payment Activity:	Mortgage								Total
Performing	$	641,608							$	641,608
Nonperforming		9,499								9,499
Total	$	651,107							$	651,107

Credit Quality Indicators

As of December 31, 2011

Commercial Credit Exposure			Commercial				Agricultural
By Internally Assigned Grade:	Commercial		Real Estate		Agricultural		Real Estate		Total
Pass	$	470,332	$	758,673	$	58,481	$	28,927	$	1,316,413
Special Mention		10,346		24,478		42		10		34,876
Substandard		29,940		51,748		7,945		4,989		94,622
Doubtful		456		-		69		-		525
Total	$	511,074	$	834,899	$	66,537	$	33,926	$	1,446,436

Business Banking Credit Exposure	Business
By Internally Assigned Grade:	Banking								Total
Non-classified	$	237,887							$	237,887
Classified		18,254								18,254
Total	$	256,141							$	256,141

Consumer Credit Exposure
By Payment Activity:	Indirect		Home Equity		Direct				Total
Performing	$	870,270	$	560,760	$	72,849			$	1,503,879
Nonperforming		2,833		8,885		518				12,236
Total	$	873,103	$	569,645	$	73,367			$	1,516,115

Residential Mortgage Credit Exposure	Residential
By Payment Activity:	Mortgage								Total
Performing	$	571,704							$	571,704
Nonperforming		9,807								9,807
Total	$	581,511							$	581,511

Modifications

The Company's loan portfolio includes certain loans that have been modified in a TDR, where economic concessions have been granted to borrowers who have experienced or are expected to experience financial difficulties. These concessions typically result from the Company's loss mitigation activities and could include reductions in the interest rate, payment extensions, forgiveness of principal, forbearance or other actions. Certain TDRs are classified as nonperforming at the time of restructure and may only be returned to performing status after considering the borrower's sustained repayment performance for a reasonable period, generally six months.

When the Company modifies a loan, management evaluates any possible impairment based on the present value of the expected future cash flows, discounted at the contractual interest rate of the original loan agreement, except when the sole (remaining) source of repayment for the loan is the operation or liquidation of the collateral. In these cases, management uses the current fair value of the collateral, less selling costs, instead of discounted cash flows. If management determines that the value of the modified loan is less than the recorded investment in the loan (net of previous charge-offs, deferred loan fees or costs and unamortized premium or discount), impairment is recognized by segment or class of loan as applicable, through an allowance estimate or a charge-off to the allowance. Segment and class status is determined by the loan's classification at origination.

Modifications made during the year ended December 31, 2012 consisted of four commercial loans totaling $6.6 million, one business banking loan totaling $0.1 million, 18 home equity loans totaling $0.9 million and 12 residential real estate mortgages totaling $1.2 million. For all such modifications, the pre-and post-outstanding recorded investment amount remained unchanged. During the year ended December 31, 2012, there were two residential real estate loans classified as TDRs totaling $0.3 million and one home equity loan totaling less than $0.1 million that subsequently defaulted on their renegotiated terms.

Modifications made during the year ended December 31, 2011 consisted of three commercial loans totaling $0.7 million, 25 home equity loans totaling $2.4 million and four residential real estate mortgages totaling $0.8 million. The pre- and post-outstanding recorded investment amount remained unchanged for this loan. During the year ended December 31, 2011, there were two commercial loans classified as TDRs totaling $0.7 million, seven home equity loans classified as TDRs totaling $0.6 million and two residential real estate loans classified as TDRs totaling $0.4 million that subsequently defaulted on their renegotiated terms.

Related Party Transactions

12 Months Ended

Dec. 31, 2012

Related Party Transactions

(8)	Related Party Transactions

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 collectibility 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)	2012			2011
Balance at January 1	$	2,537		$	2,914
New loans		750			25
Adjustment due to change in composition of related parties		(130	)		328
Repayments		(367	)		(730	)
Balance at December 31	$	2,790		$	2,537

- Definition

The entire disclosure for related party transactions, including the nature of the relationship(s), a description of the transactions, the amount of the transactions, the effects of any change in the method of establishing the terms of the transaction from the previous period, stated interest rate, expiration date, terms and manner of settlement per the agreement with the related party, and amounts due to or from related parties. If the entity and one or more other entities are under common ownership or management control and this control affects the operating results or financial position, disclosure includes the nature of the control relationship even if there are no transactions between the entities. Disclosure may also include the aggregate amount of current and deferred tax expense for each statement of earnings presented where the entity is a member of a group that files a consolidated tax return, the amount of any tax related balances due to or from affiliates as of the date of each statement of financial position presented, the principal provisions of the method by which the consolidated amount of current and deferred tax expense is allocated to the members of the group and the nature and effect of any changes in that method. Examples of related party transactions include transactions between (a) a parent company and its subsidiary; (b) subsidiaries of a common parent; (c) and entity and its principal owners; and (d) affiliates.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Article 4
-Section 08
-Paragraph k

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Article 3A
-Section 04
-Paragraph b

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 57
-Paragraph 1-4
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 850
-SubTopic 10
-Section 50
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=6457730&loc=d3e39622-107864

Reference 5: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 850
-SubTopic 10
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6457730&loc=d3e39549-107864

Reference 6: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 850
-SubTopic 10
-Section 50
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=6457730&loc=d3e39603-107864

Reference 7: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08.(k))
-URI http://asc.fasb.org/extlink&oid=6881521&loc=d3e23780-122690

Reference 8: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 850
-SubTopic 10
-Section 50
-Paragraph 6
-URI http://asc.fasb.org/extlink&oid=6457730&loc=d3e39691-107864

Reference 9: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 850
-SubTopic 10
-Section 50
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=6457730&loc=d3e39678-107864

+ Details

Premises and Equipment, Net

12 Months Ended

Dec. 31, 2012

Premises and Equipment, Net [Abstract]

Premises and Equipment, Net

(9)	Premises and Equipment, Net

A summary of premises and equipment follows:

	December 31,
(In thousands)	2012		2011
Land, buildings, and improvements	$	109,601	$	103,399
Equipment		51,321		47,646
Construction in progress		-		75
Premises and equipment before accumulated depreciation		160,922		151,120
Accumulated depreciation		83,047		76,579
Total premises and equipment	$	77,875	$	74,541

Land, buildings, and improvements with a carrying value of approximately $2.7 million and $2.9 million at December 31, 2012 and 2011, respectively, are pledged to secure long-term borrowings. Buildings and improvements are depreciated based on useful lives of 15 to 40 years. Equipment is depreciated based on useful lives of three to ten years.

Rental expense included in occupancy expense amounted to $6.4 million in 2012, $5.6 million in 2011, and $5.3 million in 2010. The future minimum rental payments related to noncancelable operating leases with original terms of one year or more are as follows at December 31, 2012 (in thousands):

Future Minimum Rental Payments

2013	$	5,727
2014		5,453
2015		4,714
2016		4,309
2017		4,063
Thereafter		28,314
Total	$	52,580

- Definition

The entire disclosure for long-lived, physical assets that are used in the normal conduct of business to produce goods and services and not intended for resale. Examples include land, buildings, machinery and equipment, and other types of furniture and equipment including, but not limited to, office equipment, furniture and fixtures, and computer equipment and software. This disclosure may include property plant and equipment accounting policies and methodology, a schedule of property, plant and equipment gross, additions, deletions, transfers and other changes, depreciation, depletion and amortization expense, net, accumulated depreciation, depletion and amortization expense and useful lives, income statement disclosures, assets held for sale and public utility disclosures.

+ References + Details

Goodwill and other Intangible Assets

12 Months Ended

Dec. 31, 2012

Goodwill and other Intangible Assets [Abstract]

Goodwill and other Intangible Assets

(10)	Goodwill and other Intangible Assets

A summary of goodwill is as follows:

(In thousands)
January 1, 2012		132,029
Goodwill Acquired		20,344
December 31, 2012	$	152,373

January 1, 2011		114,841
Goodwill Acquired		17,188
December 31, 2011	$	132,029

The Company has intangible assets with definite useful lives capitalized on its consolidated balance sheet in the form of core deposit and other identified intangible assets. These intangible assets are amortized over their estimated useful lives, which range primarily from one to twelve years.

A summary of core deposit and other intangible assets follows:

	December 31,
(In thousands)	2012		2011

Core deposit intangibles
Gross carrying amount	$	13,240	$	11,966
Less: accumulated amortization		7,794		6,401
Net carrying amount		5,446		5,565

Other Identified intangible assets
Gross carrying amount		21,743		20,919
Less: accumulated amortization		10,227		8,290
Net carrying amount		11,516		12,629

Total intangibles
Gross carrying amount		34,983		32,885
Less: accumulated amortization		18,021		14,691
Net carrying amount	$	16,962	$	18,194

Amortization expense on intangible assets with definite useful lives totaled $3.4 million for 2012, $3.0 million for 2011 and $3.1 million for 2010. Amortization expense on intangible assets with definite useful lives is expected to total $3.3 million for 2013, $3.1 million for 2014, $2.9 million for 2015, $1.8 million for 2016, $1.4 million for 2017 and $2.4 million thereafter. Other identified intangible assets include customer lists, non-competes, and trademark intangibles, of which $2.0 million will not amortize.

- Definition

The entire disclosure for the aggregate amount of goodwill and a description of intangible assets, which may include (a) for amortizable intangible assets (also referred to as finite-lived intangible assets), the carrying amount, the amount of any significant residual value, and the weighted-average amortization period, (b) for intangible assets not subject to amortization (also referred to as indefinite-lived intangible assets), the carrying amount, and (c) the amount of research and development assets acquired and written off in the period, including the line item in the income statement in which the amounts written off are aggregated, if not readily apparent from the income statement. Also discloses (a) for amortizable intangibles assets in total and by major class, the gross carrying amount and accumulated amortization, the total amortization expense for the period, and the estimated aggregate amortization expense for each of the five succeeding fiscal years, (b) for intangible assets not subject to amortization the carrying amount in total and by major class, and (c) for goodwill, in total and for each reportable segment, the changes in the carrying amount of goodwill during the period (including the aggregate amount of goodwill acquired, the aggregate amount of impairment losses recognized, and the amount of goodwill included in the gain (loss) on disposal of a reporting unit). If any part of goodwill has not been allocated to a reportable segment, discloses the unallocated amount and the reasons for not allocating. For each impairment loss recognized related to an intangible asset (excluding goodwill), discloses: (a) a description of the impaired intangible asset and the facts and circumstances leading to the impairment, (b) the amount of the impairment loss and the method for determining fair value, (c) the caption in the income statement or the statement of activities in which the impairment loss is aggregated, and (d) the segment in which the impaired intangible asset is reported. For each goodwill impairment loss recognized, discloses: (a) a description of the facts and circumstances leading to the impairment, (b) the amount of the impairment loss and the method of determining the fair value of the associated reporting unit, and (c) if a recognized impairment loss is an estimate not finalized and the reasons why the estimate is not final. May also disclose the nature and amount of any significant adjustments made to a previous estimate of an impairment loss.

+ References + Details

Deposits

12 Months Ended

Dec. 31, 2012

Deposits [Abstract]

Deposits

(11)

Deposits

The following table sets forth the maturity distribution of time deposits at December 31, 2012 (in thousands):

Time deposits
Within one year	$	454,235
After one but within two years		326,502
After two but within three years		109,348
After three but within four years		49,222
After four but within five years		35,972
After five years		7,982
Total	$	983,261

Time deposits of $100,000 or more aggregated $352.3 million and $305.7 million December 31, 2012 and 2011, respectively.

- Definition

The entire disclosure for deposit liabilities including data and tables. It may include a description of the entity's deposit liabilities, the aggregate amount of time deposits (including certificates of deposit) in denominations of $100,000 or more at the balance sheet date; the aggregate amount of any demand deposits that have been reclassified as loan balances, such as overdrafts, at the balance sheet date; deposits that are received on terms other than those in the normal course of business, the amount of accrued interest on deposit liabilities; securities, mortgage loans or other financial instruments that serve as collateral for deposits; for time deposits having a remaining term of more than one year, the aggregate amount of maturities for each of the five years following the balance sheet date; and the weighted average interest rate for all deposit liabilities held by the entity.

+ References + Details

Short-Term Borrowings

12 Months Ended

Dec. 31, 2012

Short-Term Borrowings [Abstract]

Short-Term Borrowings

(12)	Short-Term Borrowings

Short-term borrowings totaled $162.9 million and $181.6 million at December 31, 2012 and 2011, 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 had unused lines of credit with the FHLB available for short-term financing of approximately $418 million and $323 million at December 31, 2012 and 2011, respectively. Borrowings on these 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:

(Dollars In thousands)	2012			2011			2010
Federal funds purchased
Balance at year-end	$	10,000		$	27,000			-
Average during the year		12,658			3,017			-
Maximum month end balance		60,000			28,000			-
Weighted average rate during the year		0.27	%		0.11	%		-
Weighted average rate at December 31		0.27	%		0.13	%		-

Securities sold under repurchase agreements
Balance at year-end	$	152,941		$	154,592		$	159,184
Average during the year		153,084			150,663			157,964
Maximum month end balance		165,977			178,414			169,278
Weighted average rate during the year		0.10	%		0.13	%		0.25	%
Weighted average rate at December 31		0.10	%		0.10	%		0.15	%

Other short-term borrowings
Balance at year-end		-			-		$	250
Average during the year		-			249			250
Maximum month end balance		-			250			250
Weighted average rate during the year		-			-			-
Weighted average rate at December 31		-			-			-

See Note 5 for additional information regarding securities pledged as collateral for securities sold under the repurchase agreements.

Long-Term Debt

12 Months Ended

Dec. 31, 2012

Long-Term Debt [Abstract]

Long-Term Debt

(13)	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, certain of its mortgage-backed securities and a blanket lien on its residential real estate mortgage loans. A summary as of December 31, 2012 and 2011 is as follows:

	As of December 31, 2012										As of December 31, 2011

Maturity	Amount		Weighted Average Rate			Callable Amount		Weighted Average Rate			Amount		Weighted Average Rate			Callable Amount		Weighted Average Rate
2013		119,502		3.87	%		100,000		3.71	%		119,400		3.87	%		100,000		3.71	%
2014		2,610		1.89	%		-		-			2,604		2.00	%		-		-
2015		250		0.00	%		-		-			-		0.00	%		-		-
2016		70,000		4.21	%		70,000		4.21	%		70,000		4.21	%		70,000		4.21	%
2017		100,000		3.89	%		100,000		3.89	%		100,000		3.89	%		100,000		3.89	%
2018		75,000		3.61	%		75,000		3.61	%		75,000		3.61	%		75,000		3.61	%
2021		130		4.00	%		-		-			-		0.00	%		-		-
2025		-		0.00	%		-		-			3,340		2.75	%		-		-
	$	367,492				$	345,000				$	370,344				$	345,000

Trust Preferred Debentures

12 Months Ended

Dec. 31, 2012

Trust Preferred Debentures [Abstract]

Trust Preferred Debentures

(14)	Trust Preferred Debentures

The Company has issued a total of $75.4 million of junior subordinated deferrable interest debentures to three wholly owned Delaware statutory business trusts, CNBF Capital Trust I ("CNBF Trust I"), NBT Statutory Trust I ("NBT Trust I") and NBT Statutory Trust II ("NBT Trust II", and, together with CNBF Trust I and NBT Trust I, the "Trusts"). The Trusts are considered variable interest entities for which the Company is not the primary beneficiary. Accordingly, the accounts of the Trusts are not included in the Company's consolidated financial statements. See Note 1 — Summary of Significant Accounting Policies for additional information about the Company's consolidation policy. Details of the Company's transactions with these trusts are presented below.

CNBF Trust I

In June 1999, CNBF Trust I issued $18.0 million of floating rate (three-month LIBOR plus 275 basis points) trust preferred securities, which represent beneficial interests in the assets of CNBF Trust I. The trust preferred securities will mature on August 31, 2029 and are redeemable with the approval of the Federal Reserve Board in whole or in part at the option of the Company at any time after September 1, 2009 and in whole at any time upon the occurrence of certain events affecting their tax or regulatory capital treatment. Distributions on the trust preferred securities are payable quarterly in arrears on March 31, June 30, September 30 and December 31 of each year. CNBF Trust I also issued $0.7 million of common equity securities to the Company. The proceeds of the offering of the trust preferred securities and common equity securities were used to purchase $18.7 million of floating rate (three-month LIBOR plus 275 basis points) junior subordinated deferrable interest debentures issued by the Company, which have terms substantially similar to the trust preferred securities.

NBT Trust I

In November 2005, NBT Trust I issued $5.0 million of fixed rate (at 6.30%) trust preferred securities, which represent beneficial interests in the assets of the trust. The rate converted to a floating rate (three-month LIBOR plus 140 basis points) in November 2010. The trust preferred securities will mature on December 1, 2035 and are redeemable with the approval of the Federal Reserve Board in whole or in part at the option of the Corporation at any time after December 1, 2010 and in whole at any time upon the occurrence of certain events affecting their tax or regulatory capital treatment. Distributions on the trust preferred securities are payable quarterly in arrears on March 15, June 15, September 15 and December 15 of each year. NBT Trust I also issued $0.2 million of common equity securities to the Company. The proceeds of the offering of the trust preferred securities and common equity securities were used to purchase $5.2 million of fixed rate (at 6.30%) junior subordinated deferrable interest debentures issued by the Corporation, which have terms substantially similar to the trust preferred securities.

NBT Trust II

In connection with acquisition of CNB, the Company formed NBT Trust II in February 2006 to fund the cash portion of the acquisition as well as to provide regulatory capital. NBT Trust II issued $50.0 million of fixed rate (at 6.195%) trust preferred securities, which represent beneficial interests in the assets of NBT Trust II. In February 2011, the rate converted to a floating rate (three-month LIBOR plus 140 basis points). The trust preferred securities will mature on March 15, 2036 and are redeemable with the approval of the Federal Reserve Board in whole or in part at the option of the Company at any time after March 15, 2011 and in whole at any time upon the occurrence of certain events affecting their tax or regulatory capital treatment. Distributions on the trust preferred securities are payable quarterly in arrears on March 15, June 15, September 15 and December 15 of each year. NBT Trust II also issued $1.5 million of common equity securities to the Company. The proceeds of the offering of the trust preferred securities and common equity securities were used to purchase $51.5 million of fixed rate (at 6.195%) junior subordinated deferrable interest debentures issued by the Corporation, which have terms substantially similar to 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.

Payments of distributions on the trust preferred securities and payments on redemption of the trust preferred securities are guaranteed by the Company on a limited basis. The Company also entered into an agreement as to expenses and liabilities with the Trusts pursuant to which it agreed, on a subordinated basis, to pay any costs, expenses or liabilities of each Trust other than those arising under the trust preferred securities. The obligations of the Company under the junior subordinated debentures, the related indentures, the trust agreements establishing the Trusts, the guarantees and the agreements as to expenses and liabilities, in the aggregate, constitute a full and unconditional guarantee by the Company of each Trust's obligations under the trust preferred securities.

Despite the fact that the accounts of CNBF Trust I, NBT Trust I, and NBT Trust II are not included in the Company's consolidated financial statements, $74 million of the $75 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 Act 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.

Income Taxes

12 Months Ended

Dec. 31, 2012

Income Taxes [Abstract]

Income Taxes

(15)	Income Taxes

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

	Years ended December 31,
	2012			2011			2010
Current
Federal	$	21,011		$	29,274		$	34,124
State		1,815			1,477			1,743
		22,826			30,751			35,867

Deferred
Federal		(13	)		(8,129	)		(12,121	)
State		3			(1,349	)		(2,834	)
		(10	)		(9,478	)		(14,955	)
Total income tax expense	$	22,816		$	21,273		$	20,912

Not included in the above table are items that were recorded to stockholders' equity of approximately ($0.1 million), ($0.5 million), and ($4.3 million) for 2012, 2011, and 2010, respectively, relating to deferred taxes on the unrealized (gain) loss on available for sale securities, tax benefits recognized with respect to stock options exercised, and deferred taxes related to pension plans.

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)	2012		2011
Deferred tax assets
Allowance for loan losses	$	26,687	$	27,487
Deferred compensation		5,362		4,911
Postretirement benefit obligation		1,600		1,036
Fair value adjustments from acquisitions		3,633		2,227
Accrued liabilities		1,524		1,482
Stock-based compensation expense		5,726		4,440
Other		1,933		1,214
Total deferred tax assets		46,465		42,797
Deferred tax liabilities
Pension and executive retirement		7,676		6,916
Unrealized gains on securities available for sale		10,939		12,156
Premises and equipment, primarily due to accelerated depreciation		1,980		2,340
Equipment leasing		582		3,090
Deferred loan costs		873		767
Intangible amortization		13,146		11,081
Other		154		494
Total deferred tax liabilities		35,350		36,844
Net deferred tax asset at year-end		11,115		5,953
Net deferred tax asset (liability) at beginning of year		5,953		(4,023	)
Increase in net deferred tax asset	$	5,162	$	9,976

Realization of deferred tax assets is dependent upon the generation of future taxable income or the existence of sufficient taxable income within the available carryback period. A valuation allowance is provided 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, 2012 and 2011.

A reconciliation of the beginning and ending balance of gross unrecognized tax benefits is as follows:

(In thousands)	2012			2011			2010
Balance at January 1	$	888		$	3,081		$	2,287
Additions for tax positions of prior years		-			-			1,714
Reduction for tax positions of prior years		(888	)		(2,193	)		(920	)
Balance at December 31	$	-		$	888		$	3,081

At December 31, 2012, the Company had no ASC 740-10 unrecognized tax benefits with $.9 million and $3.1 million of unrecognized tax benefits at December 31, 2011 and 2010, respectively. The Company does not expect the total amount of unrecognized tax benefits to significantly increase within the next twelve months. During 2012 and 2011 there was a reduction of reserves for Federal tax benefits for expiration of the statute of limitations of prior years' tax filings and in 2011 the Company reached a settlement with New York State on franchise tax examinations for the years 2003 through 2007. As a result, unrecognized tax benefits were reduced $0.9 million and $2.2 million for 2012 and 2011, respectively, with a reduction of tax expense of $0.8 million in 2012 and $1.5 million in 2011.

The Company is no longer subject to U.S. Federal and New York State examination by tax authorities for years prior to 2008.

The Company recognizes interest accrued and penalties related to unrecognized tax benefits in income tax expense. The total amount of accrued interest at December 31, 2011 was approximately $0.1 million. Net interest impacting the Company's 2011 and 2010 tax expense was $0.3 million and $0.3 million, respectively.

The following is a reconciliation of the provision for income taxes to the amount computed by applying the applicable Federal statutory rate of 35% to income before taxes:

	Years ended December 31
(In thousands)	2012			2011			2010
Federal income tax at statutory rate	$	27,081		$	27,711		$	27,410
Tax exempt income		(2,536	)		(2,925	)		(3,448	)
Net increase in CSV of life insurance		(908	)		(919	)		(939	)
Low income housing tax credits		(629	)		(782	)		(296	)
State taxes, net of federal tax benefit		1,182			764			756
State audit settlements		-			(681	)		(1,465	)
Other, net		(1,374	)		(1,895	)		(1,106	)
Income tax expense	$	22,816		$	21,273		$	20,912

- Definition

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.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 08
-Paragraph h
-Article 4

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
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-Number 109
-Paragraph 136, 172
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Reference 3: http://www.xbrl.org/2003/role/presentationRef
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Reference 4: http://www.xbrl.org/2003/role/presentationRef
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-Subparagraph (SX 210.4-08.(h))
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+ Details

Stockholders Equity

12 Months Ended

Dec. 31, 2012

Stockholders Equity [Abstract]

Stockholders Equity

(16)	Stockholders' Equity

In accordance with accounting standards, unrealized gains on available for sale securities and unrecognized actuarial gains or losses and prior service costs associated with the Company's pension and postretirement benefit plans are included in accumulated other comprehensive loss. For the years ended December 31, components of accumulated other comprehensive loss are:

(In thousands)	2012			2011
Unrecognized prior service cost and net actuarial loss on pension plans	$	(22,555	)	$	(24,633	)
Unrealized net holding gains on available for sale securities		16,675			18,529
Accumulated other comprehensive income (loss)	$	(5,880	)	$	(6,104	)

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 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, 2012, approximately $21.3 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 being in 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.

In October 2004, the Company adopted a Stockholder Rights Plan (the "Plan") designed to ensure that any potential acquirer of the Company negotiate with the board of directors and that all Company stockholders are treated equitably in the event of a takeover attempt. At that time, the Company paid a dividend of one Preferred Share Purchase Right (a "Right") for each outstanding share of common stock of the Company. Similar rights are attached to each share of the Company's common stock issued after November 16, 2004. Under the Plan, the Rights will not be exercisable until a person or group acquires beneficial ownership of 15% or more of the Company's outstanding common stock or begins a tender or exchange offer for 15% or more of the Company's outstanding common stock. Additionally, until the occurrence of such an event, the Rights are not severable from the Company's common stock and, therefore, the Rights will be transferred upon the transfer of shares of the Company's common stock. Upon the occurrence of such events, each Right entitles the holder to purchase one one-hundredth of a share of Series A Junior Participating Preferred Stock of the Company, no par value and $0.01 stated value per share, at a price of $70.

The Plan also provides that upon the occurrence of certain specified events, the holders of Rights will be entitled to acquire additional equity interests in the Company or in the acquiring entity and such interests will have a market value of two times the Right's exercise price of $70. The Rights, which expire October 24, 2014, are redeemable in whole, but not in part, at the Company's option prior to the time they are exercisable, for a price of $0.001 per Right.

- Definition

The entire disclosure for shareholders' equity, comprised of portions attributable to the parent entity and noncontrolling interest, if any, including other comprehensive income (as applicable). Including, but not limited to: (1) balances of common stock, preferred stock, additional paid-in capital, other capital and retained earnings; (2) accumulated balance for each classification of other comprehensive income and total amount of comprehensive income; (3) amount and nature of changes in separate accounts, including the number of shares authorized and outstanding, number of shares issued upon exercise and conversion, and for other comprehensive income, the adjustments for reclassifications to net income; (4) rights and privileges of each class of stock authorized; (5) basis of treasury stock, if other than cost, and amounts paid and accounting treatment for treasury stock purchased significantly in excess of market; (6) dividends paid or payable per share and in the aggregate for each class of stock for each period presented; (7) dividend restrictions and accumulated preferred dividends in arrears (in aggregate and per share amount); (8) retained earnings appropriations or restrictions, such as dividend restrictions; (9) impact of change in accounting principle, initial adoption of new accounting principle and correction of an error in previously issued financial statements; (10) shares held in trust for Employee Stock Ownership Plan (ESOP); (11) deferred compensation related to issuance of capital stock; (12) note received for issuance of stock; (13) unamortized discount on shares; (14) description, terms, and number of warrants or rights outstanding; (15) shares under subscription and subscription receivables, effective date of new retained earnings after quasi-reorganization and deficit eliminated by quasi-reorganization and, for a period of at least ten years after the effective date, the point in time from which the new retained dates; and (16) retroactive effective of subsequent change in capital structure.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher AICPA
-Name Accounting Principles Board Opinion (APB)
-Number 12
-Paragraph 10
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 04
-Article 3

Reference 3: http://www.xbrl.org/2003/role/presentationRef
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-Name Regulation S-X (SX)
-Number 210
-Article 4
-Section 08
-Paragraph d

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher AICPA
-Name Accounting Research Bulletin (ARB)
-Number 43
-Chapter 1
-Section B
-Paragraph 7, 11A
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 5: http://www.xbrl.org/2003/role/presentationRef
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-Name Statement of Financial Accounting Standard (FAS)
-Number 129
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-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 6: http://www.xbrl.org/2003/role/presentationRef
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Reference 7: http://www.xbrl.org/2003/role/presentationRef
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-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 8: http://www.xbrl.org/2003/role/presentationRef
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Reference 9: http://www.xbrl.org/2003/role/presentationRef
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Reference 10: http://www.xbrl.org/2003/role/presentationRef
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Reference 22: http://www.xbrl.org/2003/role/presentationRef
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+ Details

Regulatory Capital Requirements

12 Months Ended

Dec. 31, 2012

Regulatory Capital Requirements [Abstract]

Regulatory Capital Requirements

(17)	Regulatory Capital Requirements

The Company and NBT 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, NBT 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 NBT 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. As of December 31, 2012 and 2011, the Company and NBT 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, under capitalized, significantly under capitalized, and critically under capitalized. As of December 31, 2012, the most recent notification from NBT Bank's regulators categorized NBT Bank as well capitalized under the regulatory framework for prompt corrective action. To be categorized as well capitalized NBT 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 NBT Bank's category.

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			For classification as well capitalized
As of December 31, 2012
Total Capital (to risk weighted assets):
Company	$	560,745		12.25	%		8.00	%		10.00	%
NBT Bank		505,027		11.08	%		8.00	%		10.00	%
Tier I Capital (to risk weighted assets)
Company		503,359		11.00	%		4.00	%		6.00	%
NBT Bank		447,909		9.83	%		4.00	%		6.00	%
Tier I Capital (to average assets)
Company		503,359		8.54	%		4.00	%		5.00	%
NBT Bank		447,909		7.62	%		4.00	%		5.00	%

As of December 31, 2011
Total Capital (to risk weighted assets):
Company	$	528,674		12.81	%		8.00	%		10.00	%
NBT Bank		506,246		12.28	%		8.00	%		10.00	%
Tier I Capital (to risk weighted assets)
Company		476,837		11.56	%		4.00	%		6.00	%
NBT Bank		454,476		11.03	%		4.00	%		6.00	%
Tier I Capital (to average assets)
Company		476,837		8.74	%		4.00	%		5.00	%
NBT Bank		454,476		8.35	%		4.00	%		5.00	%

- Definition

The entire disclosure for banks, savings institutions, and credit unions, for regulatory capital requirements imposed by the Federal Reserve System (FRB), the Federal Deposit Insurance Corporation (FDIC), the Office of Thrift Supervision (OTS) or for any state imposed capital requirements, as applicable. The disclosure may include (1) a description of regulatory capital requirements (a) for capital adequacy purposes and (b) established by the prompt corrective action provisions of Section 38 of the Federal Depository Insurance Act; (2) the actual or possible material effects of noncompliance with such requirements; (3) whether the entity is in compliance with the regulatory capital requirements including (a) required and actual ratios and amounts of Tier 1 leverage, Tier 1 risk-based, and total risk-based capital, tangible capital (for savings institutions), and Tier 3 capital for market risk (for certain banks and bank holding companies), (b) factors that may significantly affect capital adequacy; (4) the prompt corrective action category in which the entity was classified as of its most recent notification; (5) whether management believes any conditions or events since notification have changed the entity's category. Also may include additional information that might be disclosed in situations where substantial doubt about the entity's ability to continue as a going concern for a reasonable period of time.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher AICPA
-Name Audit and Accounting Guide (AAG)
-Number AAG-DEP
-Chapter 17
-Paragraph 15, 16, 17
-IssueDate 2006-05-01
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 505
-Section 50
-Paragraph 1B
-URI http://asc.fasb.org/extlink&oid=6918689&loc=SL5958570-112826

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 505
-Section 50
-Paragraph 1E
-URI http://asc.fasb.org/extlink&oid=6918689&loc=SL5958574-112826

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 505
-Section 50
-Paragraph 1D
-URI http://asc.fasb.org/extlink&oid=6918689&loc=SL5958573-112826

Reference 5: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 505
-Section 50
-Paragraph 1F
-URI http://asc.fasb.org/extlink&oid=6918689&loc=SL5958575-112826

Reference 6: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 505
-Section 50
-Paragraph 1A
-URI http://asc.fasb.org/extlink&oid=6918689&loc=SL5958569-112826

Reference 7: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 505
-Section 50
-Paragraph 1G
-URI http://asc.fasb.org/extlink&oid=6918689&loc=SL5958577-112826

Reference 8: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 505
-Section 50
-Paragraph 1C
-URI http://asc.fasb.org/extlink&oid=6918689&loc=SL5958572-112826

Reference 9: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 505
-Section 50
-Paragraph 1H
-URI http://asc.fasb.org/extlink&oid=6918689&loc=d3e65071-112826

Reference 10: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 505
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6918689&loc=SL5958568-112826

+ Details

Employee Benefit Plans

12 Months Ended

Dec. 31, 2012

Employee Benefit Plans [Abstract]

Employee Benefit Plans

(18)	Employee Benefit Plans

Defined Benefit Postretirement Plans

The Company has a qualified, noncontributory, defined benefit pension plan covering substantially all of its employees at December 31, 2012. Benefits paid from the plan are based on age, years of service, compensation, social security benefits, and are determined in accordance with defined formulas. The Company's policy is to fund the pension plan in accordance with ERISA standards. Assets of the plan are invested in publicly traded stocks and bonds. Prior to January 1, 2000, the Company's 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.

In addition to the pension plan, the Company also provides supplemental employee retirement plans to certain current and former executives. These supplemental employee retirement plans and the defined benefit pension plan are collectively referred to herein as "Pension Benefits."

Also, the Company provides certain health care benefits for retired employees. Benefits are accrued over the employees' active service period. Only employees that were employed by NBT Bank on or before January 1, 2000 are eligible to receive postretirement 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 postretirement health care as benefits are paid. The Company elected to recognize the transition obligation on a delayed basis over twenty years. These postretirement benefits are referred to herein as "Other Benefits."

Accounting standards require an employer to: (1) recognize the overfunded or underfunded status of defined benefit postretirement 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 accumulated other comprehensive loss, which have not yet been recognized as components of net periodic benefit cost, related to pensions and other postretirement benefits at December 31, 2012 are summarized below. The Company expects that $3.0 million in net actuarial loss and $0.2 million in prior service credit will be recognized as components of net periodic benefit cost in 2013.

	Pension Benefits				Other Benefits
(In thousands)	2012		2011		2012			2011
Net actuarial loss	$	35,478	$	37,914	$	2,277		$	2,323
Prior service cost		141		1,430		(672	)		(874	)
Total amounts recognized in accumulated other comprehensive loss (pre-tax)	$	35,619	$	39,344	$	1,605		$	1,449

A December 31 measurement date is used for the pension, supplemental pension and postretirement 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 postretirement benefits:

	Pension Benefits						Other Benefits
(In thousands)	2012			2011			2012			2011
Change in benefit obligation
Benefit obligation at beginning of year	$	78,024		$	70,229		$	3,985		$	4,554
Service cost		3,122			2,589			20			17
Interest cost		3,145			3,544			155			202
Plan participants' contributions		-			-			233			263
Actuarial loss (gain)		5,941			5,935			136			(562	)
Amendments		(1,006	)		-			-			-
Benefits paid		(4,097	)		(4,273	)		(458	)		(489	)
Projected benefit obligation at end of year		85,129			78,024			4,071			3,985
Change in plan assets
Fair value of plan assets at beginning of year		91,575			97,821			-			-
Actual return (loss) on plan assets		11,733			(2,452	)		-			-
Employer contributions		493			479			225			226
Plan participants' contributions		-			-			233			263
Benefits paid		(4,097	)		(4,273	)		(458	)		(489	)
Fair value of plan assets at end of year		99,704			91,575			-			-

Funded status at year end	$	14,575		$	13,551		$	(4,071	)	$	(3,985	)

Effective March 1, 2013, the pension 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. This amendment resulted in a reduction to the projected benefit obligation as of December 31, 2012 as noted in the table above.

The funded status of the pension and other postretirement benefit plans has been recognized as follows in the consolidated balance sheets at December 31, 2012 and 2011. 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 $84.5 million and $76.5 million at December 31, 2012 and 2011, respectively. The accumulated benefit obligation for other postretirement benefits was $4.1 million and $4.0 million at December 31, 2012 and 2011, respectively.

	Pension Benefits						Other Benefits
(In thousands)	2012			2011			2012			2011
Other assets	$	27,062		$	23,972		$	-		$	-
Other liabilities		(12,487	)		(10,421	)		(4,071	)		(3,985	)
Funded status	$	14,575		$	13,551		$	(4,071	)	$	(3,985	)

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

	Years ended December 31,
(In thousands)	2012			2011			2010
Weighted average assumptions:
The following assumptions were used to determine benefit obligations:
Discount rate		3.50	%		4.10	%		5.15	%
Expected long-term return on plan assets		7.50	%		7.50	%		8.00	%
Rate of compensation increase		3.00	%		3.00	%		3.00	%

The following assumptions were used to determine net periodic pension cost:
Discount rate		4.10	%		5.15	%		5.70	%
Expected long-term return on plan assets		7.50	%		8.00	%		8.00	%
Rate of compensation increase		3.00	%		3.00	%		3.00	%

Net periodic benefit cost and other amounts recognized in other comprehensive income (loss) for the years ended December 31 included the following components:

	Pension Benefits									Other Benefits
(In thousands)	2012			2011			2010			2012			2011			2010
Components of net periodic benefit cost
Service cost	$	3,122		$	2,589		$	2,254		$	20		$	17		$	17
Interest cost		3,145			3,544			3,613			155			202			228
Expected return on plan assets		(6,686	)		(7,720	)		(7,166	)		-			-			-
Amortization of prior service cost		283			309			322			(202	)		(202	)		(202	)
Amortization of unrecognized net loss		3,330			1,353			1,447			182			205			201
Net periodic pension cost	$	3,194		$	75		$	470		$	155		$	222		$	244

Other changes in plan assets and benefit obligations recognized in other comprehensive income (pre-tax)
Net loss (gain)	$	894		$	16,108		$	1,620		$	136		$	(562	)	$	955
Prior service cost		(1,006	)		-			21			-			-			-
Amortization of prior service cost		(283	)		(309	)		(322	)		202			202			202
Amortization of unrecognized net gain		(3,330	)		(1,353	)		(1,447	)		(182	)		(205	)		(201	)
Total recognized in other comprehensive loss (income)		(3,725	)		14,446			(128	)		156			(565	)		956

Total recognized in net periodic benefit cost and other comprehensive income (loss) - pre-tax	$	(531	)	$	14,521		$	342		$	311		$	(343	)	$	1,200

The following table sets forth estimated future benefit payments for the pension plans and other postretirement benefit plans:

	Pension		Other
	Benefits		Benefits

2013		5,247		215
2014		5,243		224
2015		5,285		234
2016		7,767		242
2017		5,942		250
2018 - 2022		29,180		1,311

The Company is not required to make contributions to the defined benefit plan in 2013.

For measurement purposes, the annual rates of increase in the per capita cost of covered medical and prescription drug benefits for fiscal year 2012 were assumed to be 6.0 to 6.5 percent. The rates were assumed to decrease gradually to 5.0 percent for fiscal year 2018 and remain at that level thereafter. Assumed health care cost trend rates have a significant effect on amounts reported for health care plans. A one-percentage point change in the health care trend rates would have the following effects as of and for the year ended December 31, 2012:

(In thousands)	One Percentage point increase		One Percentage point decrease
Increase (decrease) on total service and interest cost components	$	24	$	(20	)
Increase (decrease) on postretirement accumulated benefit obligation		503		(426	)

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 2013			2012			2011
Cash and cash equivalents		0 - 20	%		5	%		2	%
Fixed income securities		20 - 40	%		29	%		34	%
Equities		40 - 80	%		66	%		64	%
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, 2012 and 2011 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 as of December 31, 2012 and 2011:

	Quoted Prices in		Significant		Significant
	Active Markets for		Other		Unobservable		Balance
	Identical Assets		Observable Inputs		Inputs		as of
	(Level 1)		(Level 2)		(Level 3)		December 31, 2012
Cash and Cash Equivalents	$	5,464	$	-	$	-	$	5,464
Foreign Equity Mutual Funds		9,763		-		-		9,763
Equity Mutual Funds		13,110		-		-		13,110
US Government Bonds		-		12,744		-		12,744
Corporate Bonds		-		13,604		-		13,604
Common Stock		40,430		-		-		40,430
Municipal bonds and Notes		-		1,805		-		1,805
Foreign Bonds and Notes		-		1,137		-		1,137
Foreign Equity		1,647		-		-		1,647
Totals	$	70,414	$	29,290	$	-	$	99,704

	Quoted Prices in		Significant		Significant
	Active Markets for		Other		Unobservable		Balance
	Identical Assets		Observable Inputs		Inputs		as of
	(Level 1)		(Level 2)		(Level 3)		December 31, 2011
Cash and Cash Equivalents	$	1,503	$	-	$	-	$	1,503
Foreign Equity Mutual Funds		6,577		-		-		6,577
Equity Mutual Funds		9,902		-		-		9,902
US Government Bonds		-		15,683		-		15,683
Corporate Bonds		-		12,954		-		12,954
Common Stock		33,850		-		-		33,850
Municipal bonds and Notes		-		1,799		-		1,799
Foreign Bonds and Notes		-		1,096		-		1,096
Foreign Equity		8,211		-		-		8,211
Totals	$	60,043	$	31,532	$	-	$	91,575

The plan had no financial instruments recorded at fair value on a nonrecurring basis as of December 31, 2012.

Determination of Assumed Rate of Return

The expected long-term rate-of-return on assets is 7.5% at December 31, 2012. 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 $1.8 million in 2012, $3.7 million in 2011, and $3.5 million in 2010.

Omnibus Incentive Plan

In April 2008, the Company adopted the NBT Bancorp Inc. 2008 Omnibus Incentive Plan (the "Plan"). Under the terms of the Plan, options and other equity-based awards are granted to directors and employees to increase their direct proprietary interest in the operations and success of the Company. The Plan assumed all prior equity-based incentive plans and any new equity-based awards are granted under the terms of the Plan. Under terms of the 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. Options granted have a vesting period of four years and terminate ten years from the date of the grant. Shares issued as a result of stock option exercises and vesting of restricted shares and stock unit awards are funded from the Company's treasury stock. Restricted shares granted under the Plan vest after five years for employees and three years for non-employee directors. Restricted stock units granted under the Plan may have different terms and conditions. Performance shares and units granted under the Plan for executives may have different terms and conditions.

The per share weighted average fair value of stock options granted during 2012, 2011, and 2010 was $4.57, $5.45, and $5.03, respectively. The fair value of each award is estimated on the grant date using the Black-Scholes option pricing model with the following weighted average assumptions used for grants in the years ended December 31. Historical information was the primary basis for the selection of the expected volatility, expected dividend yield and the expected lives of the options. The risk-free interest rate was selected based upon yields of the U.S. Treasury issues with a term equal to the expected life of the option being valued:

	Years ended December 31,
	2012			2011			2010
Dividend yield		3.94	%		3.31%–3.82	%		3.27%–3.96	%
Expected volatility		34.64	%		33.75%–34.36	%		33.00%–33.86	%
Risk-free interest rates		1.24	%		1.48%–2.81	%		1.90%–3.17	%
Expected life		7 years			7 years			7 years

The following table summarizes information concerning stock options outstanding at December 31, 2012:

	Number of Shares			Weighted average exercise price		Weighted Average Remaining Contractual Term (in yrs)		Aggregate Intrinsic Value
Outstanding at December 31, 2011		1,863,590		$	22.41
Granted		150			20.30
Exercised		(108,817	)		17.53
Forfeited		(11,150	)		21.92
Expired		(48,211	)		22.50
Outstanding at December 31, 2012		1,695,562		$	22.72		4.58	$	51,236

Exercisable at December 31, 2012		1,480,737		$	22.83		4.21	$	43,043

Expected to Vest		205,476		$	21.97		7.01	$	7,752

Total stock-based compensation expense for stock option awards totaled $0.5 million for the year ended December 31, 2012, $0.9 million for the year ended December 31, 2011, and $1.8 million for the year ended December 31, 2010. Cash proceeds, tax benefits and intrinsic value related to total stock options exercised is as follows:

	Years ended
(dollars in thousands)	2012		2011		2010
Proceeds from stock options exercised	$	1,908	$	2,255	$	1,778
Tax benefits related to stock options exercised		8		341		140
Intrinsic value of stock options exercised		498		897		574
Fair value of shares vested during the year		1,656		1,597		1,800

The Company has outstanding restricted and deferred stock awards granted from various plans at December 31, 2012. The Company recognized $3.7 million in stock-based compensation expense related to these stock awards for the year ended December 31, 2012, $3.2 million for the year ended December 31, 2011, and $2.0 million for the year ended December 31, 2010. Tax benefits recognized with respect to restricted stock awards and stock units were $1.5 million, $1.2 million and $0.7 million for the years ended December 31, 2012, 2011 and 2010, respectively. Unrecognized compensation cost related to restricted stock awards and stock units totaled $4.7 million at December 31, 2012 and will be recognized over 2.5 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 awards outstanding as of December 31, 2012:

	Number			Weighted-Average
	of			Grant Date Fair
	Shares			Value
Unvested Restricted Stock Awards
Unvested at January 1, 2012		155,376		$	23.92
Forfeited		(3,500	)	$	21.96
Vested		(34,726	)	$	22.61
Unvested at December 31, 2012		117,150		$	24.36

The following table summarizes information for unvested restricted stock units outstanding as of December 31, 2012:

	Number			Weighted-Average
	of			Grant Date Fair
	Shares			Value
Unvested Restricted Stock Units
Unvested at January 1, 2012		241,907		$	23.95
Forfeited		(5,103	)		-
Vested		(37,068	)		-
Granted		206,322			22.38
Unvested at December 31, 2012		406,058		$	25.64

The Company has 4.4 million securities remaining available to be granted as part of the Plan at December 31, 2012.

- Definition

The entire disclosure for pension and other postretirement benefits.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 132R
-Paragraph 5
-Subparagraph a
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 132R
-Paragraph 5
-Subparagraph b
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 132R
-Paragraph 5
-Subparagraph h
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 132R
-Paragraph 5
-Subparagraph q
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 5: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 132R
-Paragraph 8
-Subparagraph m
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 6: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 106
-Paragraph 518
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 7: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 87
-Paragraph 264
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 8: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Emerging Issues Task Force (EITF)
-Number 03-2
-Paragraph 8
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 9: http://www.xbrl.org/2003/role/presentationRef
-Publisher AICPA
-Name Accounting Principles Board Opinion (APB)
-Number 30
-Paragraph 26
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 10: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name FASB Staff Position (FSP)
-Number FAS106-2
-Paragraph 20, 21, 22
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 11: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 158
-Paragraph 7, 21, 22
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 12: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 132R
-Paragraph 5, 6, 7, 8
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 13: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Implementation Guide (Q and A)
-Number FAS88
-Paragraph 63
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 14: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-URI http://asc.fasb.org/topic&trid=2235017

+ Details

Commitments and Contingent Liabilities

12 Months Ended

Dec. 31, 2012

Commitments and Contingent Liabilities [Abstract]

Commitments and Contingent Liabilities

(19)	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, 2012, 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, and the greater Burlington, Vermont area. Accordingly, the ultimate collectibility 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 mortgage loans sold to investors with recourse. 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)	2012		2011
Unused lines of credit	$	163,626	$	161,551
Commitments to extend credits, primarily variable rate		678,093		603,322
Standby letters of credit		37,510		26,783
Commercial letters of credit		16,607		15,218
Loans sold with recourse		13,690		16,175

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 stand-by letters of credit to third parties. These stand-by letters of credit are frequently issued in support of third party debt, such as corporate debt issuances, industrial revenue bonds, and municipal securities. The risk involved in issuing stand-by 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 terms of five years or less and expire unused; therefore, the total amounts do not necessarily represent future cash requirements. The fair value of the Company's stand-by letters of credit at December 31, 2012 and 2011 was not significant.

The total amount of loans serviced by the Company for unrelated third parties was approximately $308.4 million and $301.9 million at December 31, 2012 and 2011, respectively.

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. In the opinion of management, the aggregate amount involved in such proceedings at December 31, 2012 is not material to the consolidated balance sheets or results of operations of the Company.

- Definition

The entire disclosure for commitments and contingencies.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name FASB Interpretation (FIN)
-Number 14
-Paragraph 3
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 5
-Paragraph 9, 10, 11, 12
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.25)
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 450
-SubTopic 20
-Section 50
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=6952336&loc=d3e14435-108349

Reference 5: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 460
-SubTopic 10
-Section 50
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=6398077&loc=d3e12565-110249

Reference 6: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 440
-SubTopic 10
-Section 50
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=6394976&loc=d3e25287-109308

Reference 7: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 20
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6449706&loc=d3e16207-108621

+ Details

Parent Company Financial Information

12 Months Ended

Dec. 31, 2012

Parent Company Financial Information [Abstract]

Parent Company Financial Information

(20)	Parent Company Financial Information

Condensed Balance Sheets

	December 31,
(In thousands)	2012		2011
Assets
Cash and cash equivalents	$	23,095	$	2,454
Securities available for sale, at estimated fair value		12,866		9,825
Trading securities		3,371		2,550
Investment in subsidiaries, on equity basis		635,851		622,885
Other assets		48,324		48,153
Total assets	$	723,507	$	685,867
Liabilities and Stockholders' Equity
Total liabilities	$	141,234	$	147,757
Stockholders' equity		582,273		538,110
Total liabilities and stockholders' equity	$	723,507	$	685,867

Condensed Income Statements

	Years ended December 31,
(In thousands)	2012			2011			2010
Dividends from subsidiaries	$	79,175		$	54,400		$	12,000
Management fee from subsidiaries		78,665			69,430			68,228
Securities gains (losses)		442			(31	)		1,814
Interest, dividend and other income		720			628			1,136
Total revenue		159,002			124,427			83,178
Operating expense		79,015			75,254			72,436
Income before income tax benefit and equity in undistributed income of subsidiaries		79,987			49,173			10,742
Income tax (expense) benefit		(284	)		1,340			282
Dividends in excess of income (equity in undistributed income) of subsidiaries		(25,145	)		7,388			46,380
Net income	$	54,558		$	57,901		$	57,404

Statements of Cash Flow

	Years ended December 31,
(In thousands)	2012			2011			2010
Operating activities
Net income	$	54,558		$	57,901		$	57,404
Adjustments to reconcile net income to net cash provided by operating activities
Stock-based compensation		4,364			3,244			3,782
Gain (Loss) on sales of available-for-sale securities		442			31			(1,814	)
Dividends in excess of income (equity in undistributed income) of subsidiaries		25,145			(7,388	)		(46,380	)
Net change in other liabilities		(3,181	)		15,311			2,155
Net change in other assets		2,030			(11,607	)		(2,605	)
Net cash provided by operating activities		83,358			57,492			12,542
Investing activities
Purchases of available-for-sale securities		(4,163	)		(968	)		(1,745	)
Sales and maturities of available-for-sale securities		1,445			71			7,807
Net cash used in acquisitions		(14,612	)		-			-
Purchases of premises and equipment		(1,240	)		(1,656	)		(321	)
Net cash (used in) provided by investing activities		(18,570	)		(2,553	)		5,741
Financing activities
Proceeds from the issuance of shares to employee benefit plans and other stock plans		1,387			1,386			1,675
Payments on long-term debt		(3,340	)		(140	)		(135	)
Purchases of treasury shares		(15,490	)		(30,502	)		(477	)
Cash dividends and payments for fractional shares		(26,712	)		(27,063	)		(27,577	)
Excess tax benefit from exercise of stock options		8			341			140
Net cash used in financing activities		(44,147	)		(55,978	)		(26,374	)
Net increase (decrease) in cash and cash equivalents		20,641			(1,039	)		(8,091	)
Cash and cash equivalents at beginning of year		2,454			3,493			11,584
Cash and cash equivalents at end of year	$	23,095		$	2,454		$	3,493

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.

- Definition

The entire disclosure for condensed financial information, including the financial position, cash flows, and the results of operations of the registrant (parent company) as of the same dates or for the same periods for which audited consolidated financial statements are being presented. Alternatively, the details of this disclosure can be reported by the specific parent company taxonomy elements, indicating the appropriate date and period contexts in an instance document.

+ References + Details

Fair Values of Financial Instruments

12 Months Ended

Dec. 31, 2012

Fair Values of Financial Instruments [Abstract]

Fair Values of Financial Instruments

(21)	Fair Values of Financial Instruments

The following table sets forth information with regard to estimated fair values of financial instruments at December 31, 2012 and December 31, 2011. 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, securities available for sale, trading securities, accrued interest receivable, non-maturity deposits, short-term borrowings, accrued interest payable, and interest rate swaps.

			December 31, 2012				December 31, 2011
(In thousands)	Fair Value Hierarchy		Carrying amount		Estimated fair value		Carrying amount		Estimated fair value
Financial assets
Securities held to maturity		2	$	60,563	$	61,535	$	70,811	$	72,198
Net loans		3		4,208,282		4,313,244		3,728,869		3,821,640
Financial liabilities
Time deposits		2	$	983,261	$	994,376	$	933,127	$	942,437
Long-term debt		2		367,492		407,404		370,344		427,107
Trust preferred debentures		2		75,422		74,147		75,422		75,422

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 trust and investment management operation that contributes net fee income annually. The trust and investment 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.

Securities Held to Maturity

The fair value of the Company's investment securities held to maturity 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

The fair value of the Company's loans was estimated by discounting the expected future cash flows using the current interest rates at which similar loans would be made for the same remaining maturities. 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.

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.

Trust Preferred Debentures

The fair value of trust preferred debentures has been estimated using a discounted cash flow analysis.

The following table sets forth the Company's financial assets and liabilities measured on a recurring basis that were accounted for at fair value as of December 31, 2012 and December 31, 2011. 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):

	Quoted Prices in		Significant		Significant
	Active Markets for		Other		Unobservable		Balance
	Identical Assets		Observable Inputs		Inputs		as of
	(Level 1)		(Level 2)		(Level 3)		December 31, 2012
Assets:
Securities Available for Sale:
U.S. Treasury	$	64,425	$	-	$	-	$	64,425
Federal Agency		-		282,814		-		282,814
State & municipal		-		86,802		-		86,802
Mortgage-backed		-		250,281		-		250,281
Collateralized mortgage obligations		-		449,723		-		449,723
Other securities		11,866		2,088		-		13,954
Total Securities Available for Sale	$	76,291	$	1,071,708	$	-	$	1,147,999
Trading Securities		3,918		-		-		3,918
Interest Rate Swaps		-		1,490		-		1,490
Total	$	80,208	$	1,073,198	$	-	$	1,153,407

Liabilities:
Interest Rate Swaps	$	-	$	1,490	$	-	$	1,490
Total	$	-	$	1,490	$	-	$	1,490

	Quoted Prices in		Significant		Significant
	Active Markets for		Other		Unobservable		Balance
	Identical Assets		Observable Inputs		Inputs		as of
	(Level 1)		(Level 2)		(Level 3)		December 31, 2011
Assets:
Securities Available for Sale:
U.S. Treasury	$	82,233	$	-	$	-	$	82,233
Federal Agency		-		255,846		-		255,846
State & municipal		-		104,789		-		104,789
Mortgage-backed		-		325,397		-		325,397
Collateralized mortgage obligations		-		465,475		-		465,475
Other securities		8,825		2,054		-		10,879
Total Securities Available for Sale	$	91,058	$	1,153,561	$	-	$	1,244,619

Trading Securities		3,062		-		-		3,062
Total	$	94,120	$	1,153,561	$	-	$	1,247,681

Fair values for securities are based on quoted market prices or dealer quotes, where available. Where quoted market prices are not available, fair values are based on quoted market prices of comparable instruments. When necessary, the Company utilizes matrix pricing from a third party pricing vendor to determine fair value pricing. Matrix prices are based on quoted prices for securities with similar coupons, ratings, and maturities, rather than on specific bids and offers for the designated security.

FASB ASC Topic 820 requires disclosure of assets and liabilities measured and recorded at fair value on a nonrecurring basis. In accordance with the provisions of FASB ASC Topic 310, the Company had collateral dependent impaired loans with a carrying value of approximately $8.4 million which had specific reserves included in the allowance for loan losses of $2.8 million at December 31, 2012. The Company uses the fair value of underlying collateral to estimate the specific reserves for collateral dependent impaired loans. The fair value of underlying collateral is generally determined through independent appraisals, which generally include various Level 3 inputs which are not identifiable. The appraisals may be adjusted by management for qualitative factors such as economic conditions and estimated liquidation expenses ranging from 10% to 35%. Based on the valuation techniques used, the fair value measurements for collateral dependent impaired loans are classified as Level 3.

FASB ASC Topic 825 gives entities the option to measure eligible financial assets, financial liabilities and Company commitments at fair value (i.e., the fair value option), on an instrument-by-instrument basis, that are otherwise not permitted to be accounted for at fair value under other accounting standards. The election to use the fair value option is available when an entity first recognizes a financial asset or financial liability or upon entering into a Company commitment. Subsequent changes in fair value must be recorded in earnings. As of December 31, 2012, the Company has not elected the fair value option for any eligible items.

- Definition

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.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 133
-Paragraph 44A, 44B
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 107
-Paragraph 15C, 15D
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 107
-Paragraph 15A
-Subparagraph a-d
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 107
-Paragraph 15B
-Subparagraph a, b
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 5: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 107
-Paragraph 3, 10, 14, 15
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 6: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 157
-Paragraph 32, 33, 34
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 7: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 159
-Paragraph 17-22, 27, 28
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 8: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=6925170&loc=d3e19207-110258

Reference 9: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
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-Section 50
-Paragraph 21
-URI http://asc.fasb.org/extlink&oid=6947722&loc=d3e13537-108611

Reference 10: http://www.xbrl.org/2003/role/presentationRef
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-Name Accounting Standards Codification
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Reference 11: http://www.xbrl.org/2003/role/presentationRef
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-Name Accounting Standards Codification
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-Topic 820
-SubTopic 10
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-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=6925170&loc=d3e19296-110258

+ Details

Summary of Significant Accounting Policies (Policies)	12 Months Ended
Summary of Significant Accounting Policies (Policies)	Dec. 31, 2012
Summary of Significant Accounting Policies [Abstract]
Consolidation	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. 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 an entity is present when an enterprise has a variable interest, or a combination of variable interests, that will absorb a majority of the entity's expected losses, receive a majority of the entity's expected residual returns, or both. The enterprise with a controlling financial interest, known as the primary beneficiary, consolidates the VIE. The Company's wholly owned subsidiaries CNBF Capital Trust I, NBT Statutory Trust I and NBT Statutory 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 Report	Segment Report 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 solely in the geographical regions of central and upstate New York, northeastern Pennsylvania, western Massachusetts, southern New Hampshire and Burlington, Vermont. The Company has no reportable operating segments.
Cash Equivalents	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	Securities The Company classifies its securities at date of purchase as either available for sale, held to maturity or trading. Held to maturity debt securities are those that the Company has the ability and intent to hold until maturity. Available for sale securities are recorded at fair value. Unrealized holding gains and losses, net of the related tax effect, on available for sale securities are excluded from earnings and are reported in stockholders' equity and the statement of comprehensive income as a component of accumulated other comprehensive income or loss. Held to maturity securities are recorded at amortized cost. Trading 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. Declines in the fair value of held-to-maturity and available-for-sale securities below their cost that are deemed to be other than temporary are reflected in earnings as realized losses or in other comprehensive income, depending on whether the Company intends to sell the security or more likely than not will be required to sell the security before recovery of its amortized cost basis less any current-period credit loss. If the Company intends to sell the security or more likely than not will be required to sell the security before recovery of its amortized cost basis less any current-period credit loss, the other-than-temporary impairment shall be recognized in earnings equal to the entire difference between the investment's amortized cost basis and its fair value at the balance sheet date. If the Company does not intend to sell the security and it is not more likely than not that the entity will be required to sell the security before recovery of its amortized cost basis less any current-period credit loss, the other-than-temporary impairment shall be separated into (a) the amount representing the credit loss and (b) the amount related to all other factors. The amount of the total other-than-temporary impairment related to the credit loss shall be recognized in earnings. The amount of the total other-than-temporary impairment related to other factors shall be recognized in other comprehensive income, net of applicable taxes. In estimating other-than-temporary impairment losses, management considers, among other things, (i) the length of time and the extent to which the fair value has been less than cost, (ii) the financial condition and near-term prospects of the issuer, and (iii) the historical and implied volatility of the fair value of the security. Non-marketable equity securities are carried at cost. 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. Investments in Federal Reserve 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.
Loans	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. Lease receivables primarily represent automobile financing to customers through direct financing leases and are carried at the aggregate of the lease payments receivable and the estimated residual values, net of unearned income and net deferred lease origination fees and costs. Net deferred lease origination fees and costs are amortized under the effective interest method over the estimated lives of the leases. The estimated residual value related to the total lease portfolio is reviewed and if there has been a decline in the estimated fair value of the total residual value that is judged by management to be other-than-temporary a loss is recognized. Adjustments related to such other-than-temporary declines in estimated fair value are recorded in noninterest expense in the consolidated statements of income. For all loan classes within the Company's loan portfolio, loans are placed on nonaccrual status when timely collection of principal and interest in accordance with contractual terms is doubtful. Loans are transferred to nonaccrual status generally when principal or interest payments become 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 loan 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 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. Commercial type loans are considered impaired when it is probable that the borrower will not repay the loan according to the original contractual terms of the loan agreement, and all loan types are considered impaired if the loan is restructured in a troubled debt restructuring ("TDR"). In determining that we will be unable to collect all principal and interest payments due in accordance with the contractual terms of the loan agreements, we consider factors such as payment history and changes in the financial condition of individual borrowers, local economic conditions, historical loss experience and the conditions of the various markets in which the collateral may be liquidated. A loan is considered to be a 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 include the reduction of interest rates, forgiveness of all or a portion of principal or interest, or other modifications at interest rates that are less than the current market rate for new obligations with similar risk. 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 LoanLosses	Allowance for Loan Losses The allowance for loan losses is the amount which, in the opinion of management, is necessary to absorb probable losses inherent in the loan portfolio. The allowance is determined based upon numerous considerations, including local and regional conditions, the growth and composition of the loan portfolio with respect to the mix between the various types of loans and their related risk characteristics, a review of the value of collateral supporting the loans, comprehensive reviews of the loan portfolio by the independent loan review staff and management, as well as consideration of volume and trends of delinquencies, nonperforming loans, and loan charge-offs. Loan losses are charged off against the allowance, while recoveries of amounts previously charged off are credited to the allowance. As a result of tests of adequacy, required additions to the allowance for loan losses are made periodically by charges to the provision for loan losses. The allowance for loan losses related to impaired loans is based on discounted cash flows using the loan's initial effective interest rate or the fair value of the collateral for certain loans where repayment of the loan is expected to be provided solely by the underlying collateral (collateral dependent loans). The Company's impaired loans are generally collateral dependent. The Company considers the estimated cost to sell, on a discounted basis, when determining the fair value of collateral in the measurement of impairment if those costs are expected to reduce the cash flows available to repay or otherwise satisfy the loans. Management believes that the allowance for loan losses is adequate. While management uses available information to recognize loan losses, future additions to the allowance for loan losses may be necessary based on changes in economic conditions or changes in the values of properties securing loans in the process of foreclosure. In addition, various regulatory agencies, as an integral part of their examination process, periodically review the Company's allowance for loan losses. Such agencies may require the Company to recognize additions to the allowance for loan losses based on their judgments about information available to them at the time of their examination which may not be currently available to management.
Premises and Equipment	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.
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 other real estate owned, 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 at December 31, 2012 and 2011 was approximately $2.3 million and $2.2 million, respectively.
Acquired Loans	Acquired Loans Acquired loans are initially measured at fair value as of the acquisition date without carryover of historical allowance for loan losses. For loans that meet the criteria stipulated in ASC 310-30, the Company shall recognize the accretable yield, which is defined as the excess of all cash flows expected at acquisition over the initial fair value of the loan, as interest income on a level-yield basis over the expected remaining life of the loan. The excess of the loan's contractually required payments over the cash flows expected to be collected is the nonaccretable difference. The nonaccretable difference shall not be recognized as an adjustment of yield, a loss accrual, or a valuation allowance. Decreases in the expected cash flows in subsequent periods require the establishment of an allowance for loan losses. Improvements in expected cash flows in future periods result in a reduction of the nonaccretable discount, with such amount reclassified as part of the accretable yield and subsequently recognized in interest income over the remaining lives of the acquired loans on a level-yield basis if the amount and timing of future cash flows is reasonably estimable. Acquired loans that met the criteria for nonaccrual of interest prior to the acquisition are considered performing upon acquisition, regardless of whether the customer is contractually delinquent, if the Company can reasonably estimate the timing and amount of the expected cash flows on such loans and if the Company expects to fully collect the new carrying value of the loans. As such, the Company may no longer consider the loan to be nonaccrual or nonperforming and may accrue interest on these loans, including the impact of any accretable yield. As such, charge-offs on acquired loans are first applied to the nonaccretable difference and then to any allowance for loan losses recognized subsequent to acquisition. For loans that meet the criteria stipulated in ASC 310-20, the Company shall amortize/accrete into interest income the premium/discount determined at the date of purchase on a level-yield basis over the life of the loan. Subsequent to the acquisition date, the methods utilized to estimate the required allowance for loan losses are similar to originated loans. Loans accounted for under ASC 310-20 are placed on nonaccrual status when past due in accordance with the Company's nonaccrual policy. Subsequent to acquisition the estimate of cash flows expected to be collected on loans accounted for in accordance with ASC 310-20 is periodically re-assessed. These re-assessments involve the use of key assumptions and estimates, similar to those used in the initial estimate of fair value. A decrease in expected cash flows in subsequent periods may indicate that the loan pool is impaired, which would require the establishment of an allowance for loan losses by a charge to the provision for credit losses. An acquired loan may be resolved either through receipt of payment (in full or in part) from the borrower, the sale of the loan to a third party, or foreclosure of the collateral. In the event of a sale of the loan, a gain or loss on sale is recognized and reported within noninterest income based on the difference between the sales proceeds and the carrying amount of the loan. In other cases, individual loans are removed from the pool based on comparing the amount received from its resolution (fair value of the underlying collateral less costs to sell in the case of a foreclosure) with its outstanding balance. Any difference between these amounts is recorded as a charge-off through the allowance for loan losses. Acquired loans subject to modification are not removed from the pool even if those loans would otherwise be deemed troubled debt restructurings as the pool, and not the individual loan, represents the unit of account.
Goodwill and Other Intangible Assets	Goodwill and Other Intangible Assets Goodwill and 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 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. Goodwill impairment tests are performed on an annual basis or when events or circumstances dictate. In these tests, the fair values of each reporting unit, or segment, is compared to the carrying amount of that reporting unit in order to determine if impairment is indicated. If so, the implied fair value of the reporting unit's goodwill is compared to its carrying amount and the impairment loss is measured by the excess of the carrying value over fair value.
Treasury Stock	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 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.
Stock-Based Compensation	Stock-Based Compensation We maintain various long-term incentive stock benefit plans under which we grant stock options, restricted stock awards, and restricted stock units to certain directors and key employees. We recognize compensation expense in our income statement over the requisite service period, based on the grant-date fair value of the award. The fair values of options are estimated using the Black-Scholes option pricing model. For restricted stock awards and units, we recognize compensation expense ratably over the vesting period for the fair value of the award, measured at the grant date. The Company's stock-based employee compensation plan is described in Note 18 "Employee Benefit Plans," of this Report.
Interest Rate Swaps	Interest Rate Swaps Beginning in June 2012 with the acquisition of Hampshire First Bank, the Bank offers interest rate swap agreements to its customers. These agreements allow the Bank's customers to effectively fix the interest rate on a variable rate loan by entering into a separate agreement. Simultaneous with the execution of such an agreement with a customer, the Bank enters into a matching interest rate swap agreement with an unrelated third party provider, which allows the Bank to continue to receive the historical variable rate under the loan agreement with the customer. The agreement with the third party is not a hedge contract therefore changes in fair value are recorded through earnings. Assets and liabilities associated with the agreements are recorded in other assets and other liabilities on the balance sheet. Gains and losses are recorded as other noninterest income. The Bank is not subject to any fee or penalty should the customer elect to terminate the interest rate swap agreement prior to maturity. The Bank is exposed to credit loss equal to the fair value of the derivatives (not the notional amount of the derivatives) in the event of nonperformance by the counterparty to the interest rate swap agreements. Additionally, the Bank receives a fee from the customer that is recognized when the Bank has fulfilled its obligations under each agreement, which is generally upon execution of the agreement with the Bank's customer. Since the terms of the two interest rate swap agreements are identical, the income statement impact to the Bank is limited to the fees it receives from the customer.
Other Financial Instruments	Other Financial Instuments The Company is a party to certain other financial instruments with off-balance-sheet risk such as commitments to extend credit, unused lines of credit, as well as certain mortgage 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 credit risk involved in issuing letters of credit is essentially the same as that 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 stand-by letters of credit is recorded upon inception.
Loan Sales and Loan Servicing	Loan Sales and Loan Servicing The Company originates and services residential mortgage loans for consumers and sells 15-year, 20-year and 30-year residential real estate mortgages in the secondary market when the interest rate environment is determined to be favorable by management, while retaining servicing rights on the sold loans. Loan sales are recorded when the sales are funded. Mortgage servicing rights are recorded at fair value upon sale of the loan. Loans held for sale are recorded at the lower of cost or market.
Repurchase Agreements	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 dealer or bank with whom each transaction is executed. The dealers or banks, 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.
Earnings Per Share	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).
Subsequent Events	Subsequent Events The Company has evaluated subsequent events for potential recognition and/or disclosure and there were none identified.
Comprehensive Income	Comprehensive Income At the Company, comprehensive income represents net income plus other comprehensive income (loss), which consists primarily of the net change in unrealized gains or losses on securities available for sale for the period and changes in the funded status of employee benefit plans. Accumulated other comprehensive (loss) income represents the net unrealized gains or losses on securities available for sale and the previously unrecognized portion of the funded status of employee benefit plans, net of income taxes, as of the consolidated balance sheet dates.
Pension Costs	Pension Costs The Company maintains a noncontributory, defined benefit pension plan covering substantially all employees, as well as supplemental employee retirement plans covering certain 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.
Trust Operations	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. Trust income is recognized on the accrual method based on contractual rates applied to the balances of trust accounts.
Fair Value Measurements	Fair Value Measurements 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 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; 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 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. 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.

Merger and Acquisition Activity (Tables)

12 Months Ended

Dec. 31, 2012

Merger and Acquisition Activity [Abstract]

Consideration paid, assets acquired, and liabilities assumed

Consideration Paid:
NBT Bancorp common stock issued to Hampshire First common stockholders	$	25,824
Cash consideration paid to Hampshire First common stockholders		14,616
Cash consideration paid for Hampshire First employee stock options and warrants		2,583
Total consideration paid	$	43,023

Recognized Amounts of Identifiable Assets Acquired and (Liabilities Assumed), At Fair Value:
Cash and short term investments	$	22,149
Loans		218,801
Federal Home Loan Bank common stock		1,014
Core deposit intangibles		797
Other assets		12,926
Deposits		(228,198	)
Borrowings		(41	)
Other liabilities		(2,848	)
Total identifiable net assets	$	24,600

Goodwill	$	18,423

Acquired loan portfolio

Information about the acquired loan portfolio as of June 8, 2012 is as follows (in thousands):

Contractually required principal and interest at acquisition	$	226,631
Contractual cash flows not expected to be collected		(7,985	)
Expected cash flows at acquisition		218,646
Interest component of expected cash flows (accretable premium)		155
Fair value of acquired loans	$	218,801

- Definition

Tabular disclosure of a material business combination completed during the period, including background, timing, and recognized assets and liabilities. This table does not include leveraged buyouts.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 141
-Paragraph 51
-Subparagraph a
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 141
-Paragraph 52
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 141R
-Paragraph 68
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 141R
-Appendix F
-Paragraph F4
-Subparagraph e

Reference 5: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 10
-Section 50
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=6972119&loc=d3e1392-128463

Reference 6: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 10
-Section 50
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=6972119&loc=d3e1486-128463

+ Details

Earnings Per Share (Tables)

12 Months Ended

Dec. 31, 2012

Earnings Per Share [Abstract]

Reconciliation of basic and diluted earnings per share

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

	Years ended December 31,
	2012						2011						2010
	Net		Weighted average		Per share		Net		Weighted average		Per share		Net		Weighted average		Per share
(In thousands, except per share data)	income		shares		amount		income		shares		amount		income		shares		amount

Basic earnings per share	$	54,558		33,379	$	1.63	$	57,901		33,662	$	1.72	$	57,404		34,275	$	1.67

Effect of dilutive securities

Stock based compensation				340						262						234

Diluted earnings per share	$	54,558		33,719	$	1.62	$	57,901		33,924	$	1.71	$	57,404		34,509	$	1.66

Securities (Tables)

12 Months Ended

Dec. 31, 2012

Securities [Abstract]

Amortized cost, estimated fair value, and unrealized gains and losses of securities available for sale

The amortized cost, estimated fair value, and unrealized gains and losses of securities available for sale are as follows:

(In thousands)	Amortized cost		Unrealized gains		Unrealized losses		Estimated fair value
December 31, 2012
U.S. Treasury	$	63,668	$	757	$	-	$	64,425
Federal Agency		281,398		1,507		91		282,814
State & municipal		82,675		4,127		-		86,802
Mortgage-backed		237,461		12,820		-		250,281
Collateralized mortgage obligations		443,972		5,751		-		449,723
Corporate		-		-		-		-
Other securities		11,210		2,832		88		13,954
Total securities available for sale	$	1,120,384	$	27,794	$	179	$	1,147,999
December 31, 2011
U.S. Treasury	$	81,006	$	1,228	$	-	$	82,234
Federal Agency		254,983		879		16		255,846
State & municipal		99,176		5,624		11		104,789
Mortgage-backed		310,767		14,629		-		325,396
Collateralized mortgage obligations		459,067		6,458		51		465,474
Corporate		-		-		-		-
Other securities		8,935		2,021		76		10,880
Total securities available for sale	$	1,213,934	$	30,839	$	154	$	1,244,619

Schedule of sales transactions of securities available for sale

The following table sets forth information with regard to sales transactions of securities available for sale:

	Years ended December 31
(In thousands)	2012		2011			2010
Proceeds from sales	$	1,790	$	2,437		$	103,253
Gross realized gains	$	442	$	7		$	3,170
Gross realized losses		-		(165	)		(25	)
Net securities gains (losses)	$	442	$	(158	)	$	3,145

Amortized cost, estimated fair value, and unrealized gains and losses of securities held to maturity

The amortized cost, estimated fair value, and unrealized gains and losses of securities held to maturity are as follows:

	Amortized		Unrealized		Unrealized		Estimated
(In thousands)	cost		gains		losses		fair value
December 31, 2012
Mortgage-backed	$	1,168	$	184	$	-	$	1,352
State & municipal		59,395		788		-		60,183
Total securities held to maturity	$	60,563	$	972	$	-	$	61,535
December 31, 2011
Mortgage-backed	$	1,447	$	213	$	-	$	1,660
State & municipal		69,364		1,174		-		70,538
Total securities held to maturity	$	70,811	$	1,387	$	-	$	72,198

Investment securities with unrealized losses

	Less than 12 months							12 months or longer							Total
Security Type:	Fair Value		Unrealized losses			Number of Positions		Fair Value		Unrealized losses			Number of Positions		Fair Value		Unrealized losses			Number of Positions

December 31, 2012
U.S. Treasury	$	-	$	-			-	$	-	$	-			-	$	-	$	-			-
Federal agency		39,906		(91	)		4		-		-			-		39,906		(91	)		4
State & municipal		-		-			-		-		-			-		-		-			-
Mortgage-backed		-		-			-		-		-			-		-		-			-
Collateralized mortgage obligations		23		-			2		-		-			-		23		-			2
Other securities		468		(6	)		1		167		(82	)		1		635		(88	)		2
Total securities with unrealized losses	$	40,397	$	(97	)		7	$	167	$	(82	)		1	$	40,564	$	(179	)		8

December 31, 2011
U.S. Treasury	$	-	$	-			-	$	-	$	-			-	$	-	$	-			-
Federal agency		34,996		(16	)		3		-		-			-		34,996		(16	)		3
State & municipal		957		(10	)		3		377		(1	)		2		1,334		(11	)		5
Mortgage-backed		-		-			-		-		-			-		-		-			-
Collateralized mortgage obligations		27,368		(51	)		3		-		-			-		27,368		(51	)		3
Other securities		645		(76	)		2		-		-			-		645		(76	)		2
Total securities with unrealized losses	$	63,966	$	(153	)		11	$	377	$	(1	)		2	$	64,343	$	(154	)		13

Contractual maturities of debt securities

The following tables set forth information with regard to contractual maturities of debt securities at December 31, 2012:

(In thousands)	Amortized cost		Estimated fair value
Debt securities classified as available for sale
Within one year	$	26,678	$	26,788
From one to five years		193,142		195,953
From five to ten years		311,575		319,229
After ten years		577,779		592,075
	$	1,109,174	$	1,134,045
Debt securities classified as held to maturity
Within one year	$	25,184	$	25,258
From one to five years		27,413		28,118
From five to ten years		5,425		5,434
After ten years		2,541		2,725
	$	60,563	$	61,535

- Definition

Tabular disclosure of available-for-sale securities which consist of all investments in certain debt and equity securities neither classified as trading or held-to-maturity securities. A debt security represents a creditor relationship with an enterprise. Debt securities include, among other items, US Treasury securities, US government securities, municipal securities, corporate bonds, convertible debt, commercial paper, and all securitized debt instruments. An equity security represents an ownership interest in an enterprise or the right to acquire or dispose of an ownership interest in an enterprise at fixed or determinable prices. Equity securities include, among other things, common stock, certain preferred stock, warrant rights, call options, and put options, but do not include convertible debt.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Emerging Issues Task Force (EITF)
-Number 03-1
-Paragraph 21
-Subparagraph a, b
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name FASB Staff Position (FSP)
-Number FAS115-1/124-1
-Paragraph 17
-Subparagraph a, b
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 115
-Paragraph 19, 20, 21
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 4: http://www.xbrl.org/2003/role/presentationRef
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+ Details

- Definition

Tabular disclosure of all investments in certain debt and equity securities for which the entity has the positive intent and ability to hold until maturity.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 115
-Paragraph 137
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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+ Details

Loans (Tables)

12 Months Ended

Dec. 31, 2012

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)	2012		2011
Residential real estate mortgages	$	651,107	$	581,511
Commercial		694,799		611,298
Commercial real estate		1,072,807		888,879
Real estate construction and development		123,078		93,977
Agricultural and agricultural real estate mortgages		112,687		108,423
Consumer		1,047,856		946,470
Home equity		575,282		569,645
Total loans	$	4,277,616	$	3,800,203

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

12 Months Ended

Dec. 31, 2012

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

Allowance for loan losses by portfolio

Allowance for Loan Losses
(in thousands)

Years ended December 31							Residential
	Commercial			Consumer			Real Estate
	Loans			Loans			Mortgages			Unallocated			Total
Balance as of December 31, 2011	$	38,831		$	26,049		$	6,249		$	205		$	71,334
Charge-offs		(8,750	)		(15,848	)		(1,906	)		-			(26,504	)
Recoveries		1,641			2,556			38			-			4,235
Provision		3,902			14,405			1,871			91			20,269
Ending Balance as of December 31, 2012	$	35,624		$	27,162		$	6,252		$	296		$	69,334

Balance as of December 31, 2010	$	40,101		$	26,126		$	4,627		$	380		$	71,234
Charge-offs		(8,969	)		(14,209	)		(1,310	)		-			(24,488	)
Recoveries		1,438			2,406			7			-			3,851
Provision		6,261			11,726			2,925			(175	)		20,737
Ending Balance as of December 31, 2011	$	38,831		$	26,049		$	6,249		$	205		$	71,334

Balance as of December 31, 2009	$	36,599		$	26,664		$	3,002		$	285		$	66,550
Charge-offs		(12,969	)		(15,692	)		(1,176	)		-			(29,837	)
Recoveries		1,922			2,747			43			-			4,712
Provision		14,549			12,407			2,758			95			29,809
Ending Balance as of December 31, 2010	$	40,101		$	26,126		$	4,627		$	380		$	71,234

The following table illustrates the allowance for loan losses and the recorded investment by portfolio segment as of December 31, 2012 and 2011:

Allowance for Loan Losses and Recorded Investment in Loans
(in thousands)

					Residential
	Commercial		Consumer		Real Estate
	Loans		Loans		Mortgages		Unallocated		Total
As of December 31, 2012
Allowance for loan losses	$	35,624	$	27,162	$	6,252	$	296	$	69,334
Allowance for loans individually evaluated for impairment	$	2,848	$	-	$	-			$	2,848
Allowance for loans collectively evaluated for impairment	$	32,776	$	27,162	$	6,252	$	296	$	66,486
Ending balance of loans	$	2,003,371	$	1,623,138	$	651,107			$	4,277,616
Ending balance of loans individually evaluated for impairment	$	11,972	$	-	$	-			$	11,972
Ending balance of loans collectively evaluated for impairment	$	1,991,399	$	1,623,138	$	651,107			$	4,265,644

As of December 31, 2011
Allowance for loan losses	$	38,831	$	26,049	$	6,249	$	205	$	71,334
Allowance for loans individually evaluated for impairment	$	175	$	-	$	-			$	175
Allowance for loans collectively evaluated for impairment	$	38,656	$	26,049	$	6,249	$	205	$	71,159
Ending balance of loans	$	1,702,577	$	1,516,115	$	581,511			$	3,800,203
Ending balance of loans individually evaluated for impairment	$	6,219	$	-	$	-			$	6,219
Ending balance of loans collectively evaluated for impairment	$	1,696,358	$	1,516,115	$	581,511			$	3,793,984

Past due and nonperforming loans by loan class

The following table illustrates the Company's nonaccrual loans by loan class as of December 31, 2012 and 2011:

Loans on Nonaccrual Status
As of December 31, 2012

(In thousands)	December 31, 2012		December 31, 2011
Commercial Loans
Commercial	$	4,985	$	1,699
Commercial Real Estate		7,977		4,868
Agricultural		699		3,307
Agricultural Real Estate		1,038		2,067
Business Banking		6,738		7,446
		21,437		19,387

Consumer Loans
Indirect		1,557		1,550
Home Equity		7,247		7,931
Direct		266		378
		9,070		9,859

Residential Real Estate Mortgages		9,169		9,044

Total Nonaccrual	$	39,676	$	38,290

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

Age Analysis of Past Due Loans

As of December 31, 2012

(in thousands)


					Greater Than								Recorded
	31-60 Days		61-90 Days		90 Days		Total						Total
	Past Due		Past Due		Past Due		Past Due						Loans and
	Accruing		Accruing		Accruing		Accruing		Non-Accrual		Current		Leases
Commercial
Commercial	$	-	$	-	$	-	$	-	$	4,985	$	556,496	$	561,481
Commercial Real Estate		126		-		-		126		7,977		966,692		974,795
Agricultural		22		-		-		22		699		63,037		63,758
Agricultural Real Estate		108		-		103		211		1,038		36,128		37,377
Business Banking		3,019		708		45		3,772		6,738		355,450		365,960
		3,275		708		148		4,131		21,437		1,977,803		2,003,371

Consumer
Indirect		10,956		2,477		1,205		14,638		1,557		964,802		980,997
Home Equity		6,065		1,223		681		7,969		7,247		560,066		575,282
Direct		717		144		84		945		266		65,648		66,859
		17,738		3,844		1,970		23,552		9,070		1,590,516		1,623,138

Residential Real Estate Mortgages		1,839		725		330		2,894		9,169		639,044		651,107
	$	22,852	$	5,277	$	2,448	$	30,577	$	39,676	$	4,207,363	$	4,277,616

Age Analysis of Past Due Loans

As of December 31, 2011

(in thousands)


					Greater Than								Recorded
	31-60 Days		61-90 Days		90 Days		Total						Total
	Past Due		Past Due		Past Due		Past Due						Loans and
	Accruing		Accruing		Accruing		Accruing		Non-Accrual		Current		Leases
Commercial Loans
Commercial	$	663	$	50	$	-	$	713	$	1,699	$	508,662	$	511,074
Commercial Real Estate		1,942		-		-		1,942		4,868		828,089		834,899
Agricultural		77		13		-		90		3,307		63,140		66,537
Agricultural Real Estate		-		-		50		50		2,067		31,809		33,926
Business Banking		1,871		1,024		-		2,895		7,446		245,800		256,141
		4,553		1,087		50		5,690		19,387		1,677,500		1,702,577

Consumer Loans
Indirect		12,141		2,584		1,283		16,008		1,550		855,545		873,103
Home Equity		5,823		1,277		954		8,054		7,931		553,660		569,645
Direct		831		191		140		1,162		378		71,827		73,367
		18,795		4,052		2,377		25,224		9,859		1,481,032		1,516,115

Residential Real Estate Mortgages		2,003		139		763		2,905		9,044		569,562		581,511
	$	25,351	$	5,278	$	3,190	$	33,819	$	38,290	$	3,728,094	$	3,800,203

Impaired loans and specific reserve allocations

The following provides additional information on impaired loans for the years ended December 31, 2012 and 2011:

Impaired Loans
	December 31, 2012						December 31, 2011
	Recorded		Unpaid				Recorded		Unpaid
	Investment		Principal				Investment		Principal
	Balance		Balance		Related		Balance		Balance		Related
(in thousands)	(Book)		(Legal)		Allowance		(Book)		(Legal)		Allowance
With no related allowance recorded:
Commercial Loans
Commercial	$	650	$	709			$	1,243	$	2,723
Commercial Real Estate		3,909		4,753				4,868		7,165
Agricultural		699		1,019				3,307		4,166
Agricultural Real Estate		1,038		1,225				2,067		2,288
Business Banking		6,738		9,269				7,446		9,976
Total Commercial Loans		13,034		16,975				18,931		26,318

Consumer Loans
Home Equity		2,553		2,657				2,000		2,103

Residential Real Estate Mortgages		2,011		2,308				1,040		1,125
		17,598		21,940				21,971		29,546

With an allowance recorded:
Commercial Loans
Commercial	$	4,335	$	4,340	$	2,241	$	456	$	808	$	175
Commercial Real Estate		4,068		5,689		607		-		-		-
Agricultural		-		-		-		-		-		-
Agricultural Real Estate		-		-		-		-		-		-
		8,403		10,029		2,848		456		808		175

Total:	$	26,001	$	31,969	$	2,848	$	22,427	$	30,354	$	175

The following table summarizes the average recorded investments on impaired loans and the interest income recognized for the years ended December 31, 2012, 2011 and 2010:

	December 31, 2012						December 31, 2011						December 31, 2010
	Average		Interest Income				Average		Interest Income				Average		Interest Income
	Recorded		Recognized				Recorded		Recognized				Recorded		Recognized
(in thousands)	Investment		Accrual		Cash		Investment		Accrual		Cash		Investment		Accrual		Cash
With no related allowance recorded:
Commercial Loans
Commercial	$	1,421	$	25	$	25	$	2,322	$	94	$	94	$	1,898	$	113	$	113
Commercial Real Estate		6,167		70		70		4,794		163		163		4,219		317		317
Agricultural		2,611		368		368		3,013		133		133		2,990		82		82
Agricultural Real Estate		1,575		86		86		1,719		109		109		1,929		150		150
Business Banking		6,636		227		227		6,121		266		266		4,959		234		234
Consumer Loans
Home Equity		1,877		66		66		1,904		91		91		-		-		-
Residential Real Estate Mortgages		1,143		73		73		926		58		58		132		6		6
	$	21,429	$	915	$	915	$	20,798	$	914	$	914	$	16,127	$	902	$	902

With an allowance recorded:
Commercial Loans
Commercial	$	4,217	$	43	$	43	$	861	$	86	$	86	$	2,366	$	118	$	118
Commercial Real Estate		339		-		-		287		-		-		1,234		-		-
Agricultural		-		-		-		791		68		68		1,386		150		150
Agricultural Real Estate		-		-		-		357		18		18		816		67		67
	$	4,556	$	43	$	43	$	2,295	$	172	$	172	$	5,802	$	335	$	335

Total:	$	25,985	$	958	$	958	$	23,094	$	1,086	$	1,086	$	21,929	$	1,237	$	1,237

Financing receivable credit quality by loan class

The following tables illustrates the Company's credit quality by loan class for the years ended December 31, 2012 and 2011:

Credit Quality Indicators

As of December 31, 2012

Commercial Credit Exposure			Commercial				Agricultural
By Internally Assigned Grade:	Commercial		Real Estate		Agricultural		Real Estate		Total
Pass	$	522,985	$	901,928	$	57,347	$	33,472	$	1,515,732
Special Mention		18,401		32,135		13		3		50,552
Substandard		17,351		40,732		6,362		3,902		68,347
Doubtful		2,744		-		36		-		2,780
Total	$	561,481	$	974,795	$	63,758	$	37,377	$	1,637,411

Business Banking Credit Exposure	Business
By Internally Assigned Grade:	Banking								Total
Non-classified	$	342,528							$	342,528
Classified		23,432								23,432
Total	$	365,960							$	365,960

Consumer Credit Exposure
By Payment Activity:	Indirect		Home Equity		Direct				Total
Performing	$	978,235	$	567,354	$	66,509			$	1,612,098
Nonperforming		2,762		7,928		350				11,040
Total	$	980,997	$	575,282	$	66,859			$	1,623,138

Residential Mortgage Credit Exposure	Residential
By Payment Activity:	Mortgage								Total
Performing	$	641,608							$	641,608
Nonperforming		9,499								9,499
Total	$	651,107							$	651,107

Credit Quality Indicators

As of December 31, 2011

Commercial Credit Exposure			Commercial				Agricultural
By Internally Assigned Grade:	Commercial		Real Estate		Agricultural		Real Estate		Total
Pass	$	470,332	$	758,673	$	58,481	$	28,927	$	1,316,413
Special Mention		10,346		24,478		42		10		34,876
Substandard		29,940		51,748		7,945		4,989		94,622
Doubtful		456		-		69		-		525
Total	$	511,074	$	834,899	$	66,537	$	33,926	$	1,446,436

Business Banking Credit Exposure	Business
By Internally Assigned Grade:	Banking								Total
Non-classified	$	237,887							$	237,887
Classified		18,254								18,254
Total	$	256,141							$	256,141

Consumer Credit Exposure
By Payment Activity:	Indirect		Home Equity		Direct				Total
Performing	$	870,270	$	560,760	$	72,849			$	1,503,879
Nonperforming		2,833		8,885		518				12,236
Total	$	873,103	$	569,645	$	73,367			$	1,516,115

Residential Mortgage Credit Exposure	Residential
By Payment Activity:	Mortgage								Total
Performing	$	571,704							$	571,704
Nonperforming		9,807								9,807
Total	$	581,511							$	581,511

Related Party Transactions (Tables)

12 Months Ended

Dec. 31, 2012

Related Party Loans

(In thousands)	2012			2011
Balance at January 1	$	2,537		$	2,914
New loans		750			25
Adjustment due to change in composition of related parties		(130	)		328
Repayments		(367	)		(730	)
Balance at December 31	$	2,790		$	2,537

Premises and Equipment, Net (Tables)

12 Months Ended

Dec. 31, 2012

Premises and Equipment, Net [Abstract]

Summary of premises and equipment

A summary of premises and equipment follows:

	December 31,
(In thousands)	2012		2011
Land, buildings, and improvements	$	109,601	$	103,399
Equipment		51,321		47,646
Construction in progress		-		75
Premises and equipment before accumulated depreciation		160,922		151,120
Accumulated depreciation		83,047		76,579
Total premises and equipment	$	77,875	$	74,541

Future minimum rental payments related to noncancelable operating leases

Future Minimum Rental Payments

2013	$	5,727
2014		5,453
2015		4,714
2016		4,309
2017		4,063
Thereafter		28,314
Total	$	52,580

- Definition

Tabular disclosure of a lessee's leasing arrangements including: (1) the basis on which contingent rental payments are determined, (2) the existence and terms of renewal or purchase options and escalation clauses, (3) restrictions imposed by lease arrangements, such as those concerning dividends, additional debt, and further leasing, (4) rent holidays, rent concessions, or leasehold improvement incentives and unusual provisions or conditions. Disclosure may also include the specific period used to amortize material leasehold improvements made at the inception of the lease or during the lease term. Additionally, for operating leases having initial or remaining noncancelable lease terms in excess of one year: (a) future minimum rental payments required as of the date of the latest balance sheet presented, in the aggregate and for each of the five succeeding fiscal years, (b) the total of minimum rentals to be received in the future under noncancelable subleases as of the date of the latest balance sheet presented, and (c) for all operating leases, rental expense for each period for which an income statement is presented, with separate amounts for minimum rentals, contingent rentals, and sublease rentals. Rental payments under leases with terms of a month or less that were not renewed need not be included.

+ References + Details

Goodwill and other Intangible Assets (Tables)

12 Months Ended

Dec. 31, 2012

Goodwill and other Intangible Assets [Abstract]

Summary of goodwill

A summary of goodwill is as follows:

(In thousands)
January 1, 2012		132,029
Goodwill Acquired		20,344
December 31, 2012	$	152,373

January 1, 2011		114,841
Goodwill Acquired		17,188
December 31, 2011	$	132,029

Summary of core deposit and other intangible assets

A summary of core deposit and other intangible assets follows:

	December 31,
(In thousands)	2012		2011

Core deposit intangibles
Gross carrying amount	$	13,240	$	11,966
Less: accumulated amortization		7,794		6,401
Net carrying amount		5,446		5,565

Other Identified intangible assets
Gross carrying amount		21,743		20,919
Less: accumulated amortization		10,227		8,290
Net carrying amount		11,516		12,629

Total intangibles
Gross carrying amount		34,983		32,885
Less: accumulated amortization		18,021		14,691
Net carrying amount	$	16,962	$	18,194

- Definition

Tabular disclosure of goodwill by reportable segment and in total. Disclosure details may include, but are not limited to, the carrying amount of goodwill, goodwill acquired during the year, goodwill impairment losses recognized, goodwill written-off due to the sale of a business unit, goodwill not yet allocated, and any other changes to goodwill.

+ References + Details

Deposits (Tables)

12 Months Ended

Dec. 31, 2012

Deposits [Abstract]

Maturity distribution of time deposits

The following table sets forth the maturity distribution of time deposits at December 31, 2012 (in thousands):

Time deposits
Within one year	$	454,235
After one but within two years		326,502
After two but within three years		109,348
After three but within four years		49,222
After four but within five years		35,972
After five years		7,982
Total	$	983,261

Short-Term Borrowings (Tables)

12 Months Ended

Dec. 31, 2012

Short-Term Borrowings [Abstract]

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

(Dollars In thousands)	2012			2011			2010
Federal funds purchased
Balance at year-end	$	10,000		$	27,000			-
Average during the year		12,658			3,017			-
Maximum month end balance		60,000			28,000			-
Weighted average rate during the year		0.27	%		0.11	%		-
Weighted average rate at December 31		0.27	%		0.13	%		-

Securities sold under repurchase agreements
Balance at year-end	$	152,941		$	154,592		$	159,184
Average during the year		153,084			150,663			157,964
Maximum month end balance		165,977			178,414			169,278
Weighted average rate during the year		0.10	%		0.13	%		0.25	%
Weighted average rate at December 31		0.10	%		0.10	%		0.15	%

Other short-term borrowings
Balance at year-end		-			-		$	250
Average during the year		-			249			250
Maximum month end balance		-			250			250
Weighted average rate during the year		-			-			-
Weighted average rate at December 31		-			-			-

Long-Term Debt (Tables)

12 Months Ended

Dec. 31, 2012

Long-Term Debt [Abstract]

Schedule of Long-term Debt

	As of December 31, 2012										As of December 31, 2011

Maturity	Amount		Weighted Average Rate			Callable Amount		Weighted Average Rate			Amount		Weighted Average Rate			Callable Amount		Weighted Average Rate
2013		119,502		3.87	%		100,000		3.71	%		119,400		3.87	%		100,000		3.71	%
2014		2,610		1.89	%		-		-			2,604		2.00	%		-		-
2015		250		0.00	%		-		-			-		0.00	%		-		-
2016		70,000		4.21	%		70,000		4.21	%		70,000		4.21	%		70,000		4.21	%
2017		100,000		3.89	%		100,000		3.89	%		100,000		3.89	%		100,000		3.89	%
2018		75,000		3.61	%		75,000		3.61	%		75,000		3.61	%		75,000		3.61	%
2021		130		4.00	%		-		-			-		0.00	%		-		-
2025		-		0.00	%		-		-			3,340		2.75	%		-		-
	$	367,492				$	345,000				$	370,344				$	345,000

Income Taxes (Tables)

12 Months Ended

Dec. 31, 2012

Income Taxes [Abstract]

Components of income tax expense attributable to operations

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

	Years ended December 31,
	2012			2011			2010
Current
Federal	$	21,011		$	29,274		$	34,124
State		1,815			1,477			1,743
		22,826			30,751			35,867

Deferred
Federal		(13	)		(8,129	)		(12,121	)
State		3			(1,349	)		(2,834	)
		(10	)		(9,478	)		(14,955	)
Total income tax expense	$	22,816		$	21,273		$	20,912

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)	2012		2011
Deferred tax assets
Allowance for loan losses	$	26,687	$	27,487
Deferred compensation		5,362		4,911
Postretirement benefit obligation		1,600		1,036
Fair value adjustments from acquisitions		3,633		2,227
Accrued liabilities		1,524		1,482
Stock-based compensation expense		5,726		4,440
Other		1,933		1,214
Total deferred tax assets		46,465		42,797
Deferred tax liabilities
Pension and executive retirement		7,676		6,916
Unrealized gains on securities available for sale		10,939		12,156
Premises and equipment, primarily due to accelerated depreciation		1,980		2,340
Equipment leasing		582		3,090
Deferred loan costs		873		767
Intangible amortization		13,146		11,081
Other		154		494
Total deferred tax liabilities		35,350		36,844
Net deferred tax asset at year-end		11,115		5,953
Net deferred tax asset (liability) at beginning of year		5,953		(4,023	)
Increase in net deferred tax asset	$	5,162	$	9,976

Reconciliation of gross unrecognized tax benefits

A reconciliation of the beginning and ending balance of gross unrecognized tax benefits is as follows:

(In thousands)	2012			2011			2010
Balance at January 1	$	888		$	3,081		$	2,287
Additions for tax positions of prior years		-			-			1,714
Reduction for tax positions of prior years		(888	)		(2,193	)		(920	)
Balance at December 31	$	-		$	888		$	3,081

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 of 35% to income before taxes:

	Years ended December 31
(In thousands)	2012			2011			2010
Federal income tax at statutory rate	$	27,081		$	27,711		$	27,410
Tax exempt income		(2,536	)		(2,925	)		(3,448	)
Net increase in CSV of life insurance		(908	)		(919	)		(939	)
Low income housing tax credits		(629	)		(782	)		(296	)
State taxes, net of federal tax benefit		1,182			764			756
State audit settlements		-			(681	)		(1,465	)
Other, net		(1,374	)		(1,895	)		(1,106	)
Income tax expense	$	22,816		$	21,273		$	20,912

- Definition

Tabular disclosure of tax positions taken in the tax returns filed or to be filed for which it is more likely than not that the tax position will not be sustained upon examination by taxing authorities (i.e., uncertain tax positions) and other types of income tax contingencies, including: (1) the policy on classification of interest and penalties; (2) a tabular reconciliation of the total amounts of unrecognized tax benefits at the beginning and end of the period; the total amount(s) of: (3) unrecognized tax benefits that, if recognized, would affect the effective tax rate, and (4) interest and penalties recognized in each of the income statement and balance sheet; (5) for positions for which it is reasonably possible that the total amounts unrecognized will significantly change within 12 months of the reporting date the: (i) nature of the uncertainty, (ii) nature of the event that could occur that would cause the change, and (iii) an estimate of the range of the reasonably possible change or a statement that an estimate of the range cannot be made; and (6) a description of tax years that remain subject to examination by major tax jurisdictions.

+ References + Details

Stockholders Equity (Tables)

12 Months Ended

Dec. 31, 2012

Stockholders Equity [Abstract]

Components of accumulated other comprehensive (loss) income

(In thousands)	2012			2011
Unrecognized prior service cost and net actuarial loss on pension plans	$	(22,555	)	$	(24,633	)
Unrealized net holding gains on available for sale securities		16,675			18,529
Accumulated other comprehensive income (loss)	$	(5,880	)	$	(6,104	)

Regulatory Capital Requirements (Tables)

12 Months Ended

Dec. 31, 2012

Regulatory Capital Requirements [Abstract]

Schedule of 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			For classification as well capitalized
As of December 31, 2012
Total Capital (to risk weighted assets):
Company	$	560,745		12.25	%		8.00	%		10.00	%
NBT Bank		505,027		11.08	%		8.00	%		10.00	%
Tier I Capital (to risk weighted assets)
Company		503,359		11.00	%		4.00	%		6.00	%
NBT Bank		447,909		9.83	%		4.00	%		6.00	%
Tier I Capital (to average assets)
Company		503,359		8.54	%		4.00	%		5.00	%
NBT Bank		447,909		7.62	%		4.00	%		5.00	%

As of December 31, 2011
Total Capital (to risk weighted assets):
Company	$	528,674		12.81	%		8.00	%		10.00	%
NBT Bank		506,246		12.28	%		8.00	%		10.00	%
Tier I Capital (to risk weighted assets)
Company		476,837		11.56	%		4.00	%		6.00	%
NBT Bank		454,476		11.03	%		4.00	%		6.00	%
Tier I Capital (to average assets)
Company		476,837		8.74	%		4.00	%		5.00	%
NBT Bank		454,476		8.35	%		4.00	%		5.00	%

Employee Benefit Plans (Tables)

12 Months Ended

Dec. 31, 2012

Employee Benefit Plans [Abstract]

Components of accumulated other comprehensive income (loss), net periodic benefit cost

	Pension Benefits				Other Benefits
(In thousands)	2012		2011		2012			2011
Net actuarial loss	$	35,478	$	37,914	$	2,277		$	2,323
Prior service cost		141		1,430		(672	)		(874	)
Total amounts recognized in accumulated other comprehensive loss (pre-tax)	$	35,619	$	39,344	$	1,605		$	1,449

Changes in benefit obligations, changes in plan assets, and the funded status of the pension plans and postretirement benefits

	Pension Benefits						Other Benefits
(In thousands)	2012			2011			2012			2011
Change in benefit obligation
Benefit obligation at beginning of year	$	78,024		$	70,229		$	3,985		$	4,554
Service cost		3,122			2,589			20			17
Interest cost		3,145			3,544			155			202
Plan participants' contributions		-			-			233			263
Actuarial loss (gain)		5,941			5,935			136			(562	)
Amendments		(1,006	)		-			-			-
Benefits paid		(4,097	)		(4,273	)		(458	)		(489	)
Projected benefit obligation at end of year		85,129			78,024			4,071			3,985
Change in plan assets
Fair value of plan assets at beginning of year		91,575			97,821			-			-
Actual return (loss) on plan assets		11,733			(2,452	)		-			-
Employer contributions		493			479			225			226
Plan participants' contributions		-			-			233			263
Benefits paid		(4,097	)		(4,273	)		(458	)		(489	)
Fair value of plan assets at end of year		99,704			91,575			-			-

Funded status at year end	$	14,575		$	13,551		$	(4,071	)	$	(3,985	)

Amounts recognized in balance sheet

	Pension Benefits						Other Benefits
(In thousands)	2012			2011			2012			2011
Other assets	$	27,062		$	23,972		$	-		$	-
Other liabilities		(12,487	)		(10,421	)		(4,071	)		(3,985	)
Funded status	$	14,575		$	13,551		$	(4,071	)	$	(3,985	)

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,
(In thousands)	2012			2011			2010
Weighted average assumptions:
The following assumptions were used to determine benefit obligations:
Discount rate		3.50	%		4.10	%		5.15	%
Expected long-term return on plan assets		7.50	%		7.50	%		8.00	%
Rate of compensation increase		3.00	%		3.00	%		3.00	%

The following assumptions were used to determine net periodic pension cost:
Discount rate		4.10	%		5.15	%		5.70	%
Expected long-term return on plan assets		7.50	%		8.00	%		8.00	%
Rate of compensation increase		3.00	%		3.00	%		3.00	%

Components of net periodic pension benefits and other benefit costs

Net periodic benefit cost and other amounts recognized in other comprehensive income (loss) for the years ended December 31 included the following components:

	Pension Benefits									Other Benefits
(In thousands)	2012			2011			2010			2012			2011			2010
Components of net periodic benefit cost
Service cost	$	3,122		$	2,589		$	2,254		$	20		$	17		$	17
Interest cost		3,145			3,544			3,613			155			202			228
Expected return on plan assets		(6,686	)		(7,720	)		(7,166	)		-			-			-
Amortization of prior service cost		283			309			322			(202	)		(202	)		(202	)
Amortization of unrecognized net loss		3,330			1,353			1,447			182			205			201
Net periodic pension cost	$	3,194		$	75		$	470		$	155		$	222		$	244

Other changes in plan assets and benefit obligations recognized in other comprehensive income (pre-tax)
Net loss (gain)	$	894		$	16,108		$	1,620		$	136		$	(562	)	$	955
Prior service cost		(1,006	)		-			21			-			-			-
Amortization of prior service cost		(283	)		(309	)		(322	)		202			202			202
Amortization of unrecognized net gain		(3,330	)		(1,353	)		(1,447	)		(182	)		(205	)		(201	)
Total recognized in other comprehensive loss (income)		(3,725	)		14,446			(128	)		156			(565	)		956

Total recognized in net periodic benefit cost and other comprehensive income (loss) - pre-tax	$	(531	)	$	14,521		$	342		$	311		$	(343	)	$	1,200

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 postretirement benefit plans:

	Pension		Other
	Benefits		Benefits

2013		5,247		215
2014		5,243		224
2015		5,285		234
2016		7,767		242
2017		5,942		250
2018 - 2022		29,180		1,311

Effect of one-percentage point change in assumed health care cost trend rates

(In thousands)	One Percentage point increase		One Percentage point decrease
Increase (decrease) on total service and interest cost components	$	24	$	(20	)
Increase (decrease) on postretirement accumulated benefit obligation		503		(426	)

Target and actual allocations of defined benefit pension plan's assets

	Target 2013			2012			2011
Cash and cash equivalents		0 - 20	%		5	%		2	%
Fixed income securities		20 - 40	%		29	%		34	%
Equities		40 - 80	%		66	%		64	%
Total					100	%		100	%

Financial instruments recorded at fair value on a recurring basis by the Plan

	Quoted Prices in		Significant		Significant
	Active Markets for		Other		Unobservable		Balance
	Identical Assets		Observable Inputs		Inputs		as of
	(Level 1)		(Level 2)		(Level 3)		December 31, 2012
Cash and Cash Equivalents	$	5,464	$	-	$	-	$	5,464
Foreign Equity Mutual Funds		9,763		-		-		9,763
Equity Mutual Funds		13,110		-		-		13,110
US Government Bonds		-		12,744		-		12,744
Corporate Bonds		-		13,604		-		13,604
Common Stock		40,430		-		-		40,430
Municipal bonds and Notes		-		1,805		-		1,805
Foreign Bonds and Notes		-		1,137		-		1,137
Foreign Equity		1,647		-		-		1,647
Totals	$	70,414	$	29,290	$	-	$	99,704

	Quoted Prices in		Significant		Significant
	Active Markets for		Other		Unobservable		Balance
	Identical Assets		Observable Inputs		Inputs		as of
	(Level 1)		(Level 2)		(Level 3)		December 31, 2011
Cash and Cash Equivalents	$	1,503	$	-	$	-	$	1,503
Foreign Equity Mutual Funds		6,577		-		-		6,577
Equity Mutual Funds		9,902		-		-		9,902
US Government Bonds		-		15,683		-		15,683
Corporate Bonds		-		12,954		-		12,954
Common Stock		33,850		-		-		33,850
Municipal bonds and Notes		-		1,799		-		1,799
Foreign Bonds and Notes		-		1,096		-		1,096
Foreign Equity		8,211		-		-		8,211
Totals	$	60,043	$	31,532	$	-	$	91,575

Fair value assumptions

	Years ended December 31,
	2012			2011			2010
Dividend yield		3.94	%		3.31%–3.82	%		3.27%–3.96	%
Expected volatility		34.64	%		33.75%–34.36	%		33.00%–33.86	%
Risk-free interest rates		1.24	%		1.48%–2.81	%		1.90%–3.17	%
Expected life		7 years			7 years			7 years

Stock option activity

The following table summarizes information concerning stock options outstanding at December 31, 2012:

	Number of Shares			Weighted average exercise price		Weighted Average Remaining Contractual Term (in yrs)		Aggregate Intrinsic Value
Outstanding at December 31, 2011		1,863,590		$	22.41
Granted		150			20.30
Exercised		(108,817	)		17.53
Forfeited		(11,150	)		21.92
Expired		(48,211	)		22.50
Outstanding at December 31, 2012		1,695,562		$	22.72		4.58	$	51,236

Exercisable at December 31, 2012		1,480,737		$	22.83		4.21	$	43,043

Expected to Vest		205,476		$	21.97		7.01	$	7,752

Cash proceeds, tax benefits and intrinsic value of stock options exercised

	Years ended
(dollars in thousands)	2012		2011		2010
Proceeds from stock options exercised	$	1,908	$	2,255	$	1,778
Tax benefits related to stock options exercised		8		341		140
Intrinsic value of stock options exercised		498		897		574
Fair value of shares vested during the year		1,656		1,597		1,800

Unvested restricted awards and unvested restricted units activity

	Number			Weighted-Average
	of			Grant Date Fair
	Shares			Value
Unvested Restricted Stock Awards
Unvested at January 1, 2012		155,376		$	23.92
Forfeited		(3,500	)	$	21.96
Vested		(34,726	)	$	22.61
Unvested at December 31, 2012		117,150		$	24.36

The following table summarizes information for unvested restricted stock units outstanding as of December 31, 2012:

	Number			Weighted-Average
	of			Grant Date Fair
	Shares			Value
Unvested Restricted Stock Units
Unvested at January 1, 2012		241,907		$	23.95
Forfeited		(5,103	)		-
Vested		(37,068	)		-
Granted		206,322			22.38
Unvested at December 31, 2012		406,058		$	25.64

Commitments and Contingent Liabilities (Tables)

12 Months Ended

Dec. 31, 2012

Commitments and Contingent Liabilities [Abstract]

Schedule of maximum commitments potential obligation

	At December 31,
(In thousands)	2012		2011
Unused lines of credit	$	163,626	$	161,551
Commitments to extend credits, primarily variable rate		678,093		603,322
Standby letters of credit		37,510		26,783
Commercial letters of credit		16,607		15,218
Loans sold with recourse		13,690		16,175

- Definition

Tabular disclosure of each guarantee obligation, or each group of similar guarantee obligations, including (a) the nature of the guarantee, including its term, how it arose, and the events or circumstances that would require the guarantor to perform under the guarantee; (b) the maximum potential amount of future payments (undiscounted) the guarantor could be required to make under the guarantee; (c) the current carrying amount of the liability, if any, for the guarantor's obligations under the guarantee; and (d) the nature of any recourse provisions under the guarantee, and any assets held either as collateral or by third parties, and any relevant related party disclosure. Excludes disclosures about product warranties.

+ References + Details

Parent Company Financial Information (Tables)

12 Months Ended

Dec. 31, 2012

Parent Company Financial Information [Abstract]

Parent company financial information

Condensed Balance Sheets

	December 31,
(In thousands)	2012		2011
Assets
Cash and cash equivalents	$	23,095	$	2,454
Securities available for sale, at estimated fair value		12,866		9,825
Trading securities		3,371		2,550
Investment in subsidiaries, on equity basis		635,851		622,885
Other assets		48,324		48,153
Total assets	$	723,507	$	685,867
Liabilities and Stockholders' Equity
Total liabilities	$	141,234	$	147,757
Stockholders' equity		582,273		538,110
Total liabilities and stockholders' equity	$	723,507	$	685,867

Condensed Income Statements

	Years ended December 31,
(In thousands)	2012			2011			2010
Dividends from subsidiaries	$	79,175		$	54,400		$	12,000
Management fee from subsidiaries		78,665			69,430			68,228
Securities gains (losses)		442			(31	)		1,814
Interest, dividend and other income		720			628			1,136
Total revenue		159,002			124,427			83,178
Operating expense		79,015			75,254			72,436
Income before income tax benefit and equity in undistributed income of subsidiaries		79,987			49,173			10,742
Income tax (expense) benefit		(284	)		1,340			282
Dividends in excess of income (equity in undistributed income) of subsidiaries		(25,145	)		7,388			46,380
Net income	$	54,558		$	57,901		$	57,404

Statements of Cash Flow

	Years ended December 31,
(In thousands)	2012			2011			2010
Operating activities
Net income	$	54,558		$	57,901		$	57,404
Adjustments to reconcile net income to net cash provided by operating activities
Stock-based compensation		4,364			3,244			3,782
Gain (Loss) on sales of available-for-sale securities		442			31			(1,814	)
Dividends in excess of income (equity in undistributed income) of subsidiaries		25,145			(7,388	)		(46,380	)
Net change in other liabilities		(3,181	)		15,311			2,155
Net change in other assets		2,030			(11,607	)		(2,605	)
Net cash provided by operating activities		83,358			57,492			12,542
Investing activities
Purchases of available-for-sale securities		(4,163	)		(968	)		(1,745	)
Sales and maturities of available-for-sale securities		1,445			71			7,807
Net cash used in acquisitions		(14,612	)		-			-
Purchases of premises and equipment		(1,240	)		(1,656	)		(321	)
Net cash (used in) provided by investing activities		(18,570	)		(2,553	)		5,741
Financing activities
Proceeds from the issuance of shares to employee benefit plans and other stock plans		1,387			1,386			1,675
Payments on long-term debt		(3,340	)		(140	)		(135	)
Purchases of treasury shares		(15,490	)		(30,502	)		(477	)
Cash dividends and payments for fractional shares		(26,712	)		(27,063	)		(27,577	)
Excess tax benefit from exercise of stock options		8			341			140
Net cash used in financing activities		(44,147	)		(55,978	)		(26,374	)
Net increase (decrease) in cash and cash equivalents		20,641			(1,039	)		(8,091	)
Cash and cash equivalents at beginning of year		2,454			3,493			11,584
Cash and cash equivalents at end of year	$	23,095		$	2,454		$	3,493

Fair Values of Financial Instruments (Tables)

12 Months Ended

Dec. 31, 2012

Fair Values of Financial Instruments [Abstract]

Fair Value of Financial Instruments By Balance Sheet Grouping

			December 31, 2012				December 31, 2011
(In thousands)	Fair Value Hierarchy		Carrying amount		Estimated fair value		Carrying amount		Estimated fair value
Financial assets
Securities held to maturity		2	$	60,563	$	61,535	$	70,811	$	72,198
Net loans		3		4,208,282		4,313,244		3,728,869		3,821,640
Financial liabilities
Time deposits		2	$	983,261	$	994,376	$	933,127	$	942,437
Long-term debt		2		367,492		407,404		370,344		427,107
Trust preferred debentures		2		75,422		74,147		75,422		75,422

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

	Quoted Prices in		Significant		Significant
	Active Markets for		Other		Unobservable		Balance
	Identical Assets		Observable Inputs		Inputs		as of
	(Level 1)		(Level 2)		(Level 3)		December 31, 2012
Assets:
Securities Available for Sale:
U.S. Treasury	$	64,425	$	-	$	-	$	64,425
Federal Agency		-		282,814		-		282,814
State & municipal		-		86,802		-		86,802
Mortgage-backed		-		250,281		-		250,281
Collateralized mortgage obligations		-		449,723		-		449,723
Other securities		11,866		2,088		-		13,954
Total Securities Available for Sale	$	76,291	$	1,071,708	$	-	$	1,147,999
Trading Securities		3,918		-		-		3,918
Interest Rate Swaps		-		1,490		-		1,490
Total	$	80,208	$	1,073,198	$	-	$	1,153,407

Liabilities:
Interest Rate Swaps	$	-	$	1,490	$	-	$	1,490
Total	$	-	$	1,490	$	-	$	1,490

	Quoted Prices in		Significant		Significant
	Active Markets for		Other		Unobservable		Balance
	Identical Assets		Observable Inputs		Inputs		as of
	(Level 1)		(Level 2)		(Level 3)		December 31, 2011
Assets:
Securities Available for Sale:
U.S. Treasury	$	82,233	$	-	$	-	$	82,233
Federal Agency		-		255,846		-		255,846
State & municipal		-		104,789		-		104,789
Mortgage-backed		-		325,397		-		325,397
Collateralized mortgage obligations		-		465,475		-		465,475
Other securities		8,825		2,054		-		10,879
Total Securities Available for Sale	$	91,058	$	1,153,561	$	-	$	1,244,619

Trading Securities		3,062		-		-		3,062
Total	$	94,120	$	1,153,561	$	-	$	1,247,681

- Definition

Tabular disclosure of the fair value of financial instruments (as defined), including financial assets and financial liabilities (collectively, as defined), and the measurements of those instruments, assets, and liabilities. Such certain disclosures about the financial instruments, assets, and liabilities include: (1) the fair value of the required items together with their carrying amounts (as appropriate) and (2) the methodology and assumptions used in developing such estimates of fair value.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 107
-Paragraph 10
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 107
-Paragraph 14
-Subparagraph a
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 107
-Paragraph 15
-Subparagraph b-d
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 157
-Paragraph 32
-Subparagraph a, c(1), c(2), c(3), d
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 5: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 159
-Paragraph 18
-Subparagraph c(2), d, e, f
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 6: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 159
-Paragraph 19
-Subparagraph a, b, c(1), d(1)
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 7: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 10
-Subparagraph (a)
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-Name Accounting Standards Codification
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-Name Accounting Standards Codification
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-Paragraph 2
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Reference 12: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=6447952&loc=d3e13220-108610

+ Details

Summary of Significant Accounting Policies (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011
Summary of Significant Accounting Policies [Abstract]
Balance of OREO	$ 2.3	$ 2.2
Standby letters of credit, description	typically have one year expirations with an option to renew upon annual review
Mortgage loans on real estate, by loan disclosure	The Company originates and services residential mortgage loans for consumers and sells 15-year, 20-year and 30-year residential real estate mortgages in the secondary market when the interest rate environment is determined to be favorable by management, while retaining servicing rights on the sold loans.

Merger and Acquisition Activity (Details) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2012 USD ($) $ / shares shares	Dec. 31, 2011 USD ($)	Jun. 08, 2012 USD ($) $ / shares shares
Business Acquisition [Line Items]
Goodwill acquired during period	$ 20,344	$ 17,188
Alliance Financial Corporation [Member]
Business Acquisition [Line Items]
Date of acquisition agreement	Oct. 07, 2012
Assets of entity to be acquired	$ 1,400,000
Number of banking centers operated by acquiree	26
Cost of entity to be acquired contracted purchase price	$ 233,400
Hampshire First Bank [Member]
Business Acquisition [Line Items]
Date of acquisition	Jun. 08, 2012
Number of banking centers operated by acquiree	5
Number of shares of common stock issued to acquiree shareholders (in shares) \| shares	1,300,000
Cash paid			$ 17,200
Outstanding common shares on acquisition date (in shares) \| shares			2,800,000
Share price of outstanding common shares paid for in cash (in dollars per share) \| $ / shares	$ 15.00
Percentage of outstanding common shares paid for in cash (in hundredths)	35.00%
Percentage of outstanding common shares exchanged for Company's common stock (in hundredths)	65.00%
Exchange ratio of Company's stock for each share of acquiree's stock (in shares) \| shares			0.7019
Stock price of shares issued in exchange (in dollars per share) \| $ / shares			$ 20.34
Consideration Paid [Abstract]
NBT Bancorp common stock issued to Hampshire First common stockholders			$ 25,824
Cash consideration paid to Hampshire First common stockholders			14,616
Cash consideration paid for Hampshire First employee stock options and warrants			2,583
Total consideration paid			43,023
Recognized Amounts of Identifiable Assets Acquired and (Liabilities Assumed), At Fair Value [Abstract]
Cash and short term investments			22,149
Loans			218,801
Federal Home Loan Bank common stock			1,014
Core deposit intangibles			797
Other assets			12,926
Deposits			(228,198)
Borrowings			(41)
Other liabilities			(2,848)
Total identifiable net assets			24,600
Goodwill			18,423
Information about acquired loan portfolio [Abstract]
Contractually required principal and interest at acquisition			226,631
Contractual cash flows not expected to be collected			(7,985)
Expected cash flows at acquisition			218,646
Interest component of expected cash flows (accretable premium)			155
Fair value of acquired loans			218,801
Loans acquired during period fair value discount			$ 5,700
Other Acquisitions [Member]
Business Acquisition [Line Items]
Goodwill acquired during period	$ 1,900
Other intangible assets acquired during period	$ 1,400

Earnings Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Basic earnings per share [Abstract]
Net income available to common shareholders	$ 54,558	$ 57,901	$ 57,404
Weighted average common shares, basic (in shares)	33,379,000	33,662,000	34,275,000
Basic EPS (in dollars per share)	$ 1.63	$ 1.72	$ 1.67
Diluted earnings per share [Abstract]
Net income available to common shareholders	$ 54,558	$ 57,901	$ 57,404
Dilutive effect of stock based compensation (in shares)	340,000	262,000	234,000
Weighted average common shares, diluted (in shares)	33,719,000	33,924,000	34,509,000
Diluted EPS (in dollars per share)	$ 1.62	$ 1.71	$ 1.66
Stock options excluded from calculation of diluted EPS (in shares)	1,193,000	1,258,000	1,309,000

- Definition

Securities (including those issuable pursuant to contingent stock agreements) that could potentially dilute basic earnings per share (EPS) or earnings per unit (EPU) in the future that were not included in the computation of diluted EPS or EPU because to do so would increase EPS or EPU amounts or decrease loss per share or unit amounts for the period presented.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 128
-Paragraph 13, 14
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 128
-Paragraph 171
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 128
-Paragraph 40
-Subparagraph c
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 260
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (c)
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Reference 5: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Diluted Earnings Per Share
-URI http://asc.fasb.org/extlink&oid=6510752

Reference 6: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Contingent Stock Agreement
-URI http://asc.fasb.org/extlink&oid=6508534

Reference 7: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Antidilution
-URI http://asc.fasb.org/extlink&oid=6505113

Reference 8: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Emerging Issues Task Force (EITF)
-Number 07-4
-Paragraph 4
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

+ Details

- Definition

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

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 128
-Paragraph 36, 37, 38
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Article 5
-Section 03
-Paragraph 20

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 04
-Article 7
-Paragraph 18

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 04
-Paragraph 21
-Article 9

Reference 5: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 225
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03.21)
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Reference 6: http://www.xbrl.org/2003/role/presentationRef
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-Name Accounting Standards Codification
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-Paragraph 1
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-URI http://asc.fasb.org/extlink&oid=6879464&loc=d3e573970-122913

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-Publisher FASB
-Name Emerging Issues Task Force (EITF)
-Number 07-4
-Paragraph 4
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

+ Details

- Definition

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.

+ References + Details

- Definition

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

+ References

+ Details

- Definition

The average number of shares or units issued and outstanding that are used in calculating diluted EPS or earnings per unit (EPU), determined based on the timing of issuance of shares or units in the period.

+ References + Details

- Definition

Number of [basic] shares or units, after adjustment for contingently issuable shares or units and other shares or units not deemed outstanding, determined by relating the portion of time within a reporting period that common shares or units have been outstanding to the total time in that period.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 128
-Paragraph 171
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 128
-Paragraph 40
-Subparagraph a
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 128
-Paragraph 8
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 4: http://www.xbrl.org/2003/role/presentationRef
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Reference 6: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Weighted-Average Number of Common Shares Outstanding
-URI http://asc.fasb.org/extlink&oid=6528421

Reference 7: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Emerging Issues Task Force (EITF)
-Number 07-4
-Paragraph 4
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

+ Details

Federal Reserve Bank Requirement (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2012	Dec. 26, 2012
Federal Reserve Bank Requirement [Abstract]
Federal Reserve Bank maintenance period	14 days
Average reserve at Federal Reserve Bank for maintenance period		$ 35.2

Securities (Details) - USD ($) $ in Thousands	12 Months Ended
Securities (Details) - USD ($) $ in Thousands	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Schedule of Available-for-sale Securities [Line Items]
Amortized cost	$ 1,120,384	$ 1,213,934
Unrealized gains	27,794	30,839
Unrealized losses	179	154
Estimated fair value	1,147,999	1,244,619
Amortized cost of mortgage-backed securities comprised of Government Sponsored Enterprise Securities	221,100	290,200
Fair value of mortgage-backed securities comprised of Government Sponsored Enterprise Securities	232,300	303,000
Amortized cost of mortgage-backed securities comprised of US Government Agency Securities	16,400	20,500
Fair value of mortgage-backed securities comprised of US Government Agency Securities	18,000	22,400
Amortized cost of collateralized mortgage obligations comprised of Government Sponsored Enterprise Securities	399,200	398,300
Fair value of collateralized mortgage obligations comprised of Government Sponsored Enterprise Securities	403,600	402,400
Amortized cost of collateralized mortgage obligations comprised of US Government Agency Securities	44,800	60,800
Fair value of collateralized mortgage obligations comprised of US Government Agency Securities	46,200	63,100
Unrealized Loss Position, Fair Value [Abstract]
Less Than 12 Months, Fair Value	40,397	63,966
12 Months or Longer, Fair Value	167	377
Total, Fair Value	40,564	64,343
Unrealized Loss Position, Unrealized Losses [Abstract]
Less Than 12 Months, Unrealized Losses	(97)	(153)
12 Months or Longer, Unrealized Losses	(82)	(1)
Total, Unrealized Losses	$ (179)	$ (154)
Unrealized Loss Position, Number of Positions [Abstract]
Less Than 12 Months, Number of Positions	7	11
12 Months or Longer, Number of Positions	1	2
Total, Number of Positions	8	13
Sales transactions of securities available for sale [Abstract]
Proceeds from sales	$ 1,790	$ 2,437	$ 103,253
Gross realized gains	442	7	3,170
Gross realized losses	0	(165)	(25)
Net securities gains (losses)	442	(158)	3,145
Gains from calls on securities available for sale	200	300	$ 100
Amortized costs of securities available for sale pledged to secure public deposits	1,200,000	1,200,000
Amortized costs of securities available for sale pledged as collateral for repurchase agreements	209,000
Schedule of Held-to-maturity Securities [Line Items]
Amortized cost	60,563	70,811
Unrealized gains	972	1,387
Unrealized losses	0	0
Estimated fair value	61,535	$ 72,198
Available-for-sale Securities, Debt Maturities, Amortized Cost Basis [Abstract]
Within one year	26,678
From one to five years	193,142
From five to ten years	311,575
After ten years	577,779
Total, Amortized Cost	1,109,174
Available-for-sale Securities, Debt Maturities, Fair Value [Abstract]
Within one year	26,788
From one to five years	195,953
From five to ten years	319,229
After ten years	592,075
Total, Fair Value	1,134,045
Held-to-maturity Securities, Debt Maturities, Net Carrying Amount [Abstract]
Within one year	25,184
From one to five years	27,413
From five to ten years	5,425
After ten years	2,541
Securities held to maturity	60,563
Held-to-maturity Securities, Debt Maturities, Fair Value [Abstract]
Within one year	25,258
From one to five years	28,118
From five to ten years	5,434
After ten years	2,725
Total, Fair Value	$ 61,535
Consolidated stockholders' equity threshold percentage that no single issuer of securities exceeded except for U.S. Government securities. (in hundredths)	10.00%	10.00%
US Treasury [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized cost	$ 63,668	$ 81,006
Unrealized gains	757	1,228
Unrealized losses	0	0
Estimated fair value	64,425	82,234
Unrealized Loss Position, Fair Value [Abstract]
Less Than 12 Months, Fair Value	0	0
12 Months or Longer, Fair Value	0	0
Total, Fair Value	0	0
Unrealized Loss Position, Unrealized Losses [Abstract]
Less Than 12 Months, Unrealized Losses	0	0
12 Months or Longer, Unrealized Losses	0	0
Total, Unrealized Losses	$ 0	$ 0
Unrealized Loss Position, Number of Positions [Abstract]
Less Than 12 Months, Number of Positions	0	0
12 Months or Longer, Number of Positions	0	0
Total, Number of Positions	0	0
Federal Agency [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized cost	$ 281,398	$ 254,983
Unrealized gains	1,507	879
Unrealized losses	91	16
Estimated fair value	282,814	255,846
Unrealized Loss Position, Fair Value [Abstract]
Less Than 12 Months, Fair Value	39,906	34,996
12 Months or Longer, Fair Value	0	0
Total, Fair Value	39,906	34,996
Unrealized Loss Position, Unrealized Losses [Abstract]
Less Than 12 Months, Unrealized Losses	(91)	(16)
12 Months or Longer, Unrealized Losses	0	0
Total, Unrealized Losses	$ (91)	$ (16)
Unrealized Loss Position, Number of Positions [Abstract]
Less Than 12 Months, Number of Positions	4	3
12 Months or Longer, Number of Positions	0	0
Total, Number of Positions	4	3
State & Municipal [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized cost	$ 82,675	$ 99,176
Unrealized gains	4,127	5,624
Unrealized losses	0	11
Estimated fair value	86,802	104,789
Unrealized Loss Position, Fair Value [Abstract]
Less Than 12 Months, Fair Value	0	957
12 Months or Longer, Fair Value	0	377
Total, Fair Value	0	1,334
Unrealized Loss Position, Unrealized Losses [Abstract]
Less Than 12 Months, Unrealized Losses	0	(10)
12 Months or Longer, Unrealized Losses	0	(1)
Total, Unrealized Losses	$ 0	$ (11)
Unrealized Loss Position, Number of Positions [Abstract]
Less Than 12 Months, Number of Positions	0	3
12 Months or Longer, Number of Positions	0	2
Total, Number of Positions	0	5
Mortgage-backed [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized cost	$ 237,461	$ 310,767
Unrealized gains	12,820	14,629
Unrealized losses	0	0
Estimated fair value	250,281	325,396
Unrealized Loss Position, Fair Value [Abstract]
Less Than 12 Months, Fair Value	0	0
12 Months or Longer, Fair Value	0	0
Total, Fair Value	0	0
Unrealized Loss Position, Unrealized Losses [Abstract]
Less Than 12 Months, Unrealized Losses	0	0
12 Months or Longer, Unrealized Losses	0	0
Total, Unrealized Losses	$ 0	$ 0
Unrealized Loss Position, Number of Positions [Abstract]
Less Than 12 Months, Number of Positions	0	0
12 Months or Longer, Number of Positions	0	0
Total, Number of Positions	0	0
Collateralized Mortgage Obligations [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized cost	$ 443,972	$ 459,067
Unrealized gains	5,751	6,458
Unrealized losses	0	51
Estimated fair value	449,723	465,474
Unrealized Loss Position, Fair Value [Abstract]
Less Than 12 Months, Fair Value	23	27,368
12 Months or Longer, Fair Value	0	0
Total, Fair Value	23	27,368
Unrealized Loss Position, Unrealized Losses [Abstract]
Less Than 12 Months, Unrealized Losses	0	(51)
12 Months or Longer, Unrealized Losses	0	0
Total, Unrealized Losses	$ 0	$ (51)
Unrealized Loss Position, Number of Positions [Abstract]
Less Than 12 Months, Number of Positions	2	3
12 Months or Longer, Number of Positions	0	0
Total, Number of Positions	2	3
Corporate [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized cost	$ 0	$ 0
Unrealized gains	0	0
Unrealized losses	0	0
Estimated fair value	0	0
Other Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized cost	11,210	8,935
Unrealized gains	2,832	2,021
Unrealized losses	88	76
Estimated fair value	13,954	10,880
Unrealized Loss Position, Fair Value [Abstract]
Less Than 12 Months, Fair Value	468	645
12 Months or Longer, Fair Value	167	0
Total, Fair Value	635	645
Unrealized Loss Position, Unrealized Losses [Abstract]
Less Than 12 Months, Unrealized Losses	(6)	(76)
12 Months or Longer, Unrealized Losses	(82)	0
Total, Unrealized Losses	$ (88)	$ (76)
Unrealized Loss Position, Number of Positions [Abstract]
Less Than 12 Months, Number of Positions	1	2
12 Months or Longer, Number of Positions	1	0
Total, Number of Positions	2	2
Mortgage-backed [Member]
Schedule of Held-to-maturity Securities [Line Items]
Amortized cost	$ 1,168	$ 1,447
Unrealized gains	184	213
Unrealized losses	0	0
Estimated fair value	1,352	1,660
State & Municipal [Member]
Schedule of Held-to-maturity Securities [Line Items]
Amortized cost	59,395	69,364
Unrealized gains	788	1,174
Unrealized losses	0	0
Estimated fair value	$ 60,183	$ 70,538

Loans (Details) - USD ($) $ in Thousands	Dec. 31, 2012	Dec. 31, 2011
Accounts, Notes, Loans and Financing Receivable [Line Items]
Net Loans	$ 4,277,616	$ 3,800,203
Deferred loan origination costs, net	900	1,600
Residential loans held for sale	3,800	2,700
Residential Real Estate Mortgages [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Net Loans	651,107	581,511
Commercial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Net Loans	694,799	611,298
Commercial Real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Net Loans	1,072,807	888,879
Real Estate Construction and Development [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Net Loans	123,078	93,977
Agricultural and Agricultural Real Estate Mortgages [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Net Loans	112,687	108,423
Consumer [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Net Loans	1,047,856	946,470
Home Equity [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Net Loans	$ 575,282	$ 569,645

Allowance for Loan Losses and Credit Quality of Loans, Allowance for Loan Losses (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2012	Dec. 31, 2011
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan portfolio segments	3
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Balance as of Beginning of Period	$ 71,334	$ 71,234	$ 66,550
Charge-offs	(26,504)	(24,488)	(29,837)
Recoveries	4,235	3,851	4,712
Provision	20,269	20,737	29,809
Balance as of Ending of Period	69,334	71,334	71,234
Allowance loan losses [Abstract]
Allowance for loan losses	71,334	71,334	71,234	$ 69,334	$ 71,334
Allowance for loans individually evaluated for impairment				2,848	175
Allowance for loans collectively evaluated for impairment				66,486	71,159
Ending balance of loans				4,277,616	3,800,203
Ending balance of loans individually evaluated for impairment				11,972	6,219
Ending balance of loans collectively evaluated for impairment				4,265,644	3,793,984
Commercial Loans [Member]
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Balance as of Beginning of Period	38,831	40,101	36,599
Charge-offs	(8,750)	(8,969)	(12,969)
Recoveries	1,641	1,438	1,922
Provision	3,902	6,261	14,549
Balance as of Ending of Period	35,624	38,831	40,101
Allowance loan losses [Abstract]
Allowance for loan losses	38,831	38,831	40,101	35,624	38,831
Allowance for loans individually evaluated for impairment				2,848	175
Allowance for loans collectively evaluated for impairment				32,776	38,656
Ending balance of loans				2,003,371	1,702,577
Ending balance of loans individually evaluated for impairment				11,972	6,219
Ending balance of loans collectively evaluated for impairment				$ 1,991,399	1,696,358
Commercial Loans [Member] \| Commercial Real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Real estate loan amount, percentage of appraised value or purchase price of the property, maximum (in hundredths)				80.00%
Commercial Loans [Member] \| Agricultural Real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Real estate loan amount, percentage of appraised value or purchase price of the property, maximum (in hundredths)				75.00%
Allowance loan losses [Abstract]
Ending balance of loans				$ 37,377	33,926
Commercial Loans [Member] \| Business Banking [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Business banking loans, maximum amount				500
Allowance loan losses [Abstract]
Ending balance of loans				365,960	256,141
Consumer Loans [Member]
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Balance as of Beginning of Period	26,049	26,126	26,664
Charge-offs	(15,848)	(14,209)	(15,692)
Recoveries	2,556	2,406	2,747
Provision	14,405	11,726	12,407
Balance as of Ending of Period	27,162	26,049	26,126
Allowance loan losses [Abstract]
Allowance for loan losses	$ 26,049	26,049	26,126	27,162	26,049
Allowance for loans individually evaluated for impairment				0	0
Allowance for loans collectively evaluated for impairment				27,162	26,049
Ending balance of loans				1,623,138	1,516,115
Ending balance of loans individually evaluated for impairment				0	0
Ending balance of loans collectively evaluated for impairment				$ 1,623,138	1,516,115
Consumer Loans [Member] \| Indirect [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Percentage of automobile financing to indirect relationships with dealers (in hundredths)				70.00%
Principal repayment term of loan, minimum (in years)	3 years
Principal repayment term of loan, maximum (in years)	6 years
Allowance loan losses [Abstract]
Ending balance of loans				$ 980,997	873,103
Consumer Loans [Member] \| Home Equity [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Home equity loan amount, percentage of equity in home, maximum (in hundredths)	85.00%
Consumer Loans [Member] \| Direct [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Principal repayment term of loan, minimum (in years)	1 year
Principal repayment term of loan, maximum (in years)	10 years
Allowance loan losses [Abstract]
Ending balance of loans				$ 66,859	73,367
Residential Real Estate Mortgages [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Real estate loan amount, percentage of appraised value or purchase price of the property, maximum (in hundredths)				85.00%
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Balance as of Beginning of Period	$ 6,249	4,627	3,002
Charge-offs	(1,906)	(1,310)	(1,176)
Recoveries	38	7	43
Provision	1,871	2,925	2,758
Balance as of Ending of Period	6,252	6,249	4,627
Allowance loan losses [Abstract]
Allowance for loan losses	6,249	6,249	4,627	$ 6,252	6,249
Allowance for loans individually evaluated for impairment				0	0
Allowance for loans collectively evaluated for impairment				6,252	6,249
Ending balance of loans				651,107	581,511
Ending balance of loans individually evaluated for impairment				0	0
Ending balance of loans collectively evaluated for impairment				651,107	581,511
Unallocated [Member]
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Balance as of Beginning of Period	205	380	285
Charge-offs	0	0	0
Recoveries	0	0	0
Provision	91	(175)	95
Balance as of Ending of Period	296	205	380
Allowance loan losses [Abstract]
Allowance for loan losses	$ 205	$ 205	$ 380	296	205
Allowance for loans collectively evaluated for impairment				$ 296	$ 205

Allowance for Loan Losses and Credit Quality of Loans, Past Due Loans (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011
Financing Receivable, Recorded Investment, Aging [Abstract]
Minimum number of days past due for nonaccrual loan status (in days)	90 days
Financing Receivable, Recorded Investment, Past Due [Abstract]
31 - 60 Days Past Due Accruing	$ 22,852	$ 25,351
61 - 90 Days Past Due Accruing	5,277	5,278
Greater Than 90 Days Past Due Accruing	2,448	3,190
Total Past Due Accruing	30,577	33,819
Non-Accrual	39,676	38,290
Current	4,207,363	3,728,094
Recorded Total Loans and Leases	4,277,616	3,800,203
Within non accrual loans [Member]
Financing Receivable, Recorded Investment, Past Due [Abstract]
Troubled debt restructured loans amount	2,200	4,000
Commercial Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Abstract]
Recorded Total Loans and Leases	2,003,371	1,702,577
Commercial Loans [Member] \| Commercial [Member]
Financing Receivable, Recorded Investment, Past Due [Abstract]
31 - 60 Days Past Due Accruing	0	663
61 - 90 Days Past Due Accruing	0	50
Greater Than 90 Days Past Due Accruing	0	0
Total Past Due Accruing	0	713
Non-Accrual	4,985	1,699
Current	556,496	508,662
Recorded Total Loans and Leases	561,481	511,074
Commercial Loans [Member] \| Commercial Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Abstract]
31 - 60 Days Past Due Accruing	126	1,942
61 - 90 Days Past Due Accruing	0	0
Greater Than 90 Days Past Due Accruing	0	0
Total Past Due Accruing	126	1,942
Non-Accrual	7,977	4,868
Current	966,692	828,089
Recorded Total Loans and Leases	974,795	834,899
Commercial Loans [Member] \| Agricultural [Member]
Financing Receivable, Recorded Investment, Past Due [Abstract]
31 - 60 Days Past Due Accruing	22	77
61 - 90 Days Past Due Accruing	0	13
Greater Than 90 Days Past Due Accruing	0	0
Total Past Due Accruing	22	90
Non-Accrual	699	3,307
Current	63,037	63,140
Recorded Total Loans and Leases	63,758	66,537
Commercial Loans [Member] \| Agricultural Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Abstract]
31 - 60 Days Past Due Accruing	108	0
61 - 90 Days Past Due Accruing	0	0
Greater Than 90 Days Past Due Accruing	103	50
Total Past Due Accruing	211	50
Non-Accrual	1,038	2,067
Current	36,128	31,809
Recorded Total Loans and Leases	37,377	33,926
Commercial Loans [Member] \| Business Banking [Member]
Financing Receivable, Recorded Investment, Past Due [Abstract]
31 - 60 Days Past Due Accruing	3,019	1,871
61 - 90 Days Past Due Accruing	708	1,024
Greater Than 90 Days Past Due Accruing	45	0
Total Past Due Accruing	3,772	2,895
Non-Accrual	6,738	7,446
Current	355,450	245,800
Recorded Total Loans and Leases	365,960	256,141
Commercial Loans [Member] \| Total Commercial Loan [Member]
Financing Receivable, Recorded Investment, Past Due [Abstract]
31 - 60 Days Past Due Accruing	3,275	4,553
61 - 90 Days Past Due Accruing	708	1,087
Greater Than 90 Days Past Due Accruing	148	50
Total Past Due Accruing	4,131	5,690
Non-Accrual	21,437	19,387
Current	1,977,803	1,677,500
Recorded Total Loans and Leases	2,003,371	1,702,577
Consumer Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Abstract]
Recorded Total Loans and Leases	1,623,138	1,516,115
Consumer Loans [Member] \| Indirect [Member]
Financing Receivable, Recorded Investment, Past Due [Abstract]
31 - 60 Days Past Due Accruing	10,956	12,141
61 - 90 Days Past Due Accruing	2,477	2,584
Greater Than 90 Days Past Due Accruing	1,205	1,283
Total Past Due Accruing	14,638	16,008
Non-Accrual	1,557	1,550
Current	964,802	855,545
Recorded Total Loans and Leases	980,997	873,103
Consumer Loans [Member] \| Home Equity Member]
Financing Receivable, Recorded Investment, Past Due [Abstract]
31 - 60 Days Past Due Accruing	6,065	5,823
61 - 90 Days Past Due Accruing	1,223	1,277
Greater Than 90 Days Past Due Accruing	681	954
Total Past Due Accruing	7,969	8,054
Non-Accrual	7,247	7,931
Current	560,066	553,660
Recorded Total Loans and Leases	575,282	569,645
Consumer Loans [Member] \| Direct [Member]
Financing Receivable, Recorded Investment, Past Due [Abstract]
31 - 60 Days Past Due Accruing	717	831
61 - 90 Days Past Due Accruing	144	191
Greater Than 90 Days Past Due Accruing	84	140
Total Past Due Accruing	945	1,162
Non-Accrual	266	378
Current	65,648	71,827
Recorded Total Loans and Leases	66,859	73,367
Consumer Loans [Member] \| Total Consumer Loan [Member]
Financing Receivable, Recorded Investment, Past Due [Abstract]
31 - 60 Days Past Due Accruing	17,738	18,795
61 - 90 Days Past Due Accruing	3,844	4,052
Greater Than 90 Days Past Due Accruing	1,970	2,377
Total Past Due Accruing	23,552	25,224
Non-Accrual	9,070	9,859
Current	1,590,516	1,481,032
Recorded Total Loans and Leases	1,623,138	1,516,115
Residential Real Estate Mortgages [Member]
Financing Receivable, Recorded Investment, Past Due [Abstract]
31 - 60 Days Past Due Accruing	1,839	2,003
61 - 90 Days Past Due Accruing	725	139
Greater Than 90 Days Past Due Accruing	330	763
Total Past Due Accruing	2,894	2,905
Non-Accrual	9,169	9,044
Current	639,044	569,562
Recorded Total Loans and Leases	$ 651,107	$ 581,511

Allowance for Loan Losses and Credit Quality of Loans, Impaired Loans (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Allowance for Loan Losses and Credit Quality of Loans and Leases [Abstract]
Impaired loans modified in TDR	$ 26,000	$ 22,400
Minimum balance for classified loans to be evaluated individually for impairment	500
Financing Receivable, Impaired [Line Items]
Recorded Investment Balance (Book)	8,400
With No Allowance Recorded [Member]
Financing Receivable, Impaired [Line Items]
Recorded Investment Balance (Book)	17,598	21,971
Unpaid Principal Balance (Legal)	21,940	29,546
Average Recorded Investment	21,429	20,798	$ 16,127
Interest Income Recognized Accrual	915	914	902
Interest Income Recognized Cash	915	914	902
With No Allowance Recorded [Member] \| Commercial Loans [Member] \| Commercial [Member]
Financing Receivable, Impaired [Line Items]
Recorded Investment Balance (Book)	650	1,243
Unpaid Principal Balance (Legal)	709	2,723
Average Recorded Investment	1,421	2,322	1,898
Interest Income Recognized Accrual	25	94	113
Interest Income Recognized Cash	25	94	113
With No Allowance Recorded [Member] \| Commercial Loans [Member] \| Commercial Real Estate [Member]
Financing Receivable, Impaired [Line Items]
Recorded Investment Balance (Book)	3,909	4,868
Unpaid Principal Balance (Legal)	4,753	7,165
Average Recorded Investment	6,167	4,794	4,219
Interest Income Recognized Accrual	70	163	317
Interest Income Recognized Cash	70	163	317
With No Allowance Recorded [Member] \| Commercial Loans [Member] \| Agricultural [Member]
Financing Receivable, Impaired [Line Items]
Recorded Investment Balance (Book)	699	3,307
Unpaid Principal Balance (Legal)	1,019	4,166
Average Recorded Investment	2,611	3,013	2,990
Interest Income Recognized Accrual	368	133	82
Interest Income Recognized Cash	368	133	82
With No Allowance Recorded [Member] \| Commercial Loans [Member] \| Agricultural Real Estate [Member]
Financing Receivable, Impaired [Line Items]
Recorded Investment Balance (Book)	1,038	2,067
Unpaid Principal Balance (Legal)	1,225	2,288
Average Recorded Investment	1,575	1,719	1,929
Interest Income Recognized Accrual	86	109	150
Interest Income Recognized Cash	86	109	150
With No Allowance Recorded [Member] \| Commercial Loans [Member] \| Business Banking [Member]
Financing Receivable, Impaired [Line Items]
Recorded Investment Balance (Book)	6,738	7,446
Unpaid Principal Balance (Legal)	9,269	9,976
Average Recorded Investment	6,636	6,121	4,959
Interest Income Recognized Accrual	227	266	234
Interest Income Recognized Cash	227	266	234
With No Allowance Recorded [Member] \| Commercial Loans [Member] \| Total Commercial Loans [Member]
Financing Receivable, Impaired [Line Items]
Recorded Investment Balance (Book)	13,034	18,931
Unpaid Principal Balance (Legal)	16,975	26,318
With No Allowance Recorded [Member] \| Consumer Loans [Member] \| Home Equity [Member]
Financing Receivable, Impaired [Line Items]
Recorded Investment Balance (Book)	2,553	2,000
Unpaid Principal Balance (Legal)	2,657	2,103
Average Recorded Investment	1,877	1,904	0
Interest Income Recognized Accrual	66	91	0
Interest Income Recognized Cash	66	91	0
With No Allowance Recorded [Member] \| Residential Real Estate Mortgages [Member]
Financing Receivable, Impaired [Line Items]
Recorded Investment Balance (Book)	2,011	1,040
Unpaid Principal Balance (Legal)	2,308	1,125
Average Recorded Investment	1,143	926	132
Interest Income Recognized Accrual	73	58	6
Interest Income Recognized Cash	73	58	6
With An Allowance Recorded [Member]
Financing Receivable, Impaired [Line Items]
Recorded Investment Balance (Book)	26,001	22,427
Unpaid Principal Balance (Legal)	31,969	30,354
Related Allowance	2,848	175
Average Recorded Investment	25,985	23,094	21,929
Interest Income Recognized Accrual	958	1,086	1,237
Interest Income Recognized Cash	958	1,086	1,237
With An Allowance Recorded [Member] \| Commercial Loans [Member]
Financing Receivable, Impaired [Line Items]
Recorded Investment Balance (Book)	8,403	456
Unpaid Principal Balance (Legal)	10,029	808
Related Allowance	2,848	175
Average Recorded Investment	4,556	2,295	5,802
Interest Income Recognized Accrual	43	172	335
Interest Income Recognized Cash	43	172	335
With An Allowance Recorded [Member] \| Commercial Loans [Member] \| Commercial [Member]
Financing Receivable, Impaired [Line Items]
Recorded Investment Balance (Book)	4,335	456
Unpaid Principal Balance (Legal)	4,340	808
Related Allowance	2,241	175
Average Recorded Investment	4,217	861	2,366
Interest Income Recognized Accrual	43	86	118
Interest Income Recognized Cash	43	86	118
With An Allowance Recorded [Member] \| Commercial Loans [Member] \| Commercial Real Estate [Member]
Financing Receivable, Impaired [Line Items]
Recorded Investment Balance (Book)	4,068	0
Unpaid Principal Balance (Legal)	5,689	0
Related Allowance	607	0
Average Recorded Investment	339	287	1,234
Interest Income Recognized Accrual	0	0	0
Interest Income Recognized Cash	0	0	0
With An Allowance Recorded [Member] \| Commercial Loans [Member] \| Agricultural [Member]
Financing Receivable, Impaired [Line Items]
Recorded Investment Balance (Book)	0	0
Unpaid Principal Balance (Legal)	0	0
Related Allowance	0	0
Average Recorded Investment	0	791	1,386
Interest Income Recognized Accrual	0	68	150
Interest Income Recognized Cash	0	68	150
With An Allowance Recorded [Member] \| Commercial Loans [Member] \| Agricultural Real Estate [Member]
Financing Receivable, Impaired [Line Items]
Recorded Investment Balance (Book)	0	0
Unpaid Principal Balance (Legal)	0	0
Related Allowance	0	0
Average Recorded Investment	0	357	816
Interest Income Recognized Accrual	0	18	67
Interest Income Recognized Cash	$ 0	$ 18	$ 67

Allowance for Loan Losses and Credit Quality of Loans, Credit Quality by Loan Class (Details) - USD ($) $ in Thousands	Dec. 31, 2012	Dec. 31, 2011
Commercial Credit Exposure [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	$ 1,637,411	$ 1,446,436
Commercial Credit Exposure [Member] \| Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	1,515,732	1,316,413
Commercial Credit Exposure [Member] \| Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	50,552	34,876
Commercial Credit Exposure [Member] \| Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	68,347	94,622
Commercial Credit Exposure [Member] \| Doubtful [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	2,780	525
Commercial Credit Exposure [Member] \| Commercial [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	561,481	511,074
Commercial Credit Exposure [Member] \| Commercial [Member] \| Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	522,985	470,332
Commercial Credit Exposure [Member] \| Commercial [Member] \| Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	18,401	10,346
Commercial Credit Exposure [Member] \| Commercial [Member] \| Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	17,351	29,940
Commercial Credit Exposure [Member] \| Commercial [Member] \| Doubtful [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	2,744	456
Commercial Credit Exposure [Member] \| Commercial Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	974,795	834,899
Commercial Credit Exposure [Member] \| Commercial Real Estate [Member] \| Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	901,928	758,673
Commercial Credit Exposure [Member] \| Commercial Real Estate [Member] \| Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	32,135	24,478
Commercial Credit Exposure [Member] \| Commercial Real Estate [Member] \| Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	40,732	51,748
Commercial Credit Exposure [Member] \| Commercial Real Estate [Member] \| Doubtful [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	0	0
Commercial Credit Exposure [Member] \| Agricultural [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	63,758	66,537
Commercial Credit Exposure [Member] \| Agricultural [Member] \| Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	57,347	58,481
Commercial Credit Exposure [Member] \| Agricultural [Member] \| Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	13	42
Commercial Credit Exposure [Member] \| Agricultural [Member] \| Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	6,362	7,945
Commercial Credit Exposure [Member] \| Agricultural [Member] \| Doubtful [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	36	69
Commercial Credit Exposure [Member] \| Agricultural Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	37,377	33,926
Commercial Credit Exposure [Member] \| Agricultural Real Estate [Member] \| Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	33,472	28,927
Commercial Credit Exposure [Member] \| Agricultural Real Estate [Member] \| Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	3	10
Commercial Credit Exposure [Member] \| Agricultural Real Estate [Member] \| Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	3,902	4,989
Commercial Credit Exposure [Member] \| Agricultural Real Estate [Member] \| Doubtful [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	0	0
Commercial Credit Exposure [Member] \| Business Banking [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	365,960	256,141
Commercial Credit Exposure [Member] \| Business Banking [Member] \| Non-classified [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	342,528	237,887
Commercial Credit Exposure [Member] \| Business Banking [Member] \| Classified [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	23,432	18,254
Consumer Credit Exposure [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	1,623,138	1,516,115
Consumer Credit Exposure [Member] \| Performing [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	1,612,098	1,503,879
Consumer Credit Exposure [Member] \| Nonperforming [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	11,040	12,236
Consumer Credit Exposure [Member] \| Indirect [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	980,997	873,103
Consumer Credit Exposure [Member] \| Indirect [Member] \| Performing [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	978,235	870,270
Consumer Credit Exposure [Member] \| Indirect [Member] \| Nonperforming [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	2,762	2,833
Consumer Credit Exposure [Member] \| Home Equity Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	575,282	569,645
Consumer Credit Exposure [Member] \| Home Equity Member] \| Performing [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	567,354	560,760
Consumer Credit Exposure [Member] \| Home Equity Member] \| Nonperforming [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	7,928	8,885
Consumer Credit Exposure [Member] \| Direct [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	66,859	73,367
Consumer Credit Exposure [Member] \| Direct [Member] \| Performing [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	66,509	72,849
Consumer Credit Exposure [Member] \| Direct [Member] \| Nonperforming [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	350	518
Residential Mortgage Credit Exposure [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	651,107	581,511
Residential Mortgage Credit Exposure [Member] \| Performing [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	641,608	571,704
Residential Mortgage Credit Exposure [Member] \| Nonperforming [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	$ 9,499	$ 9,807

Allowance for Loan Losses and Credit Quality of Loans, Troubled Debt Restructurings (Details) $ in Millions	12 Months Ended
	Dec. 31, 2012 USD ($)	Dec. 31, 2011 USD ($)
Financing Receivable, Modifications [Line Items]
Period of sustained repayment performance for nonperforming TDRs to be returned to performing status (in months)	6 months
Subsequent Default [Member] \| Home Equity [Member]
Financing Receivable, Modifications [Line Items]
Number of contracts	1
Pre-modification oustanding recorded investment	$ 0.1
Business Banking [Member]
Financing Receivable, Modifications [Line Items]
Number of contracts	1
Pre-modification oustanding recorded investment	$ 0.1
Home Equity [Member]
Financing Receivable, Modifications [Line Items]
Number of contracts	18	25
Pre-modification oustanding recorded investment	$ 0.9	$ 2.4
Home Equity [Member] \| Subsequent Default [Member]
Financing Receivable, Modifications [Line Items]
Number of contracts		7
Pre-modification oustanding recorded investment		$ 0.6
Commercial Loans [Member]
Financing Receivable, Modifications [Line Items]
Number of contracts	4	3
Pre-modification oustanding recorded investment	$ 6.6	$ 0.7
Commercial Loans [Member] \| Subsequent Default [Member]
Financing Receivable, Modifications [Line Items]
Number of contracts		2
Pre-modification oustanding recorded investment		$ 0.7
Residential Real Estate Mortgages [Member]
Financing Receivable, Modifications [Line Items]
Number of contracts	12	4
Pre-modification oustanding recorded investment	$ 1.2	$ 0.8
Residential Real Estate Mortgages [Member] \| Subsequent Default [Member]
Financing Receivable, Modifications [Line Items]
Number of contracts	2	2
Pre-modification oustanding recorded investment	$ 0.3	$ 0.4

Related Party Transactions (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011
Loans and Leases Receivable, Related Parties [Roll Forward]
Balance at January 1	$ 2,537	$ 2,914
New loans	750	25
Adjustment due to change in composition of related parties	(130)	328
Repayments	(367)	(730)
Balance at December 31	$ 2,790	$ 2,537

Premises and Equipment, Net (Details) $ in Thousands	12 Months Ended
Premises and Equipment, Net (Details) $ in Thousands	Dec. 31, 2012 USD ($)	Dec. 31, 2011 USD ($)	Dec. 31, 2010 USD ($)
Property, Plant and Equipment [Line Items]
Premises and equipment before accumulated depreciation	$ 160,922	$ 151,120
Accumulated depreciation	83,047	76,579
Total premises and equipment	77,875	74,541
Rental expense	6,400	5,600	$ 5,300
Operating Leases, Future Minimum Payments Due [Abstract]
2013	5,727
2014	5,453
2015	4,714
2016	4,309
2017	4,063
Thereafter	28,314
Total	52,580
Land, Buildings and Improvements [Member]
Property, Plant and Equipment [Line Items]
Premises and equipment before accumulated depreciation	109,601	103,399
Pledged to secure long-term borrowings	2,700	2,900
Equipment [Member]
Property, Plant and Equipment [Line Items]
Premises and equipment before accumulated depreciation	$ 51,321	47,646
Equipment [Member] \| Minimum [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, useful life (in years)	3
Equipment [Member] \| Maximum [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, useful life (in years)	10
Construction In Progress [Member]
Property, Plant and Equipment [Line Items]
Premises and equipment before accumulated depreciation	$ 0	$ 75
Building and Building Improvements [Member] \| Minimum [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, useful life (in years)	15
Building and Building Improvements [Member] \| Maximum [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, useful life (in years)	40

Goodwill and other Intangible Assets (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2012 USD ($)	Dec. 31, 2011 USD ($)	Dec. 31, 2010 USD ($)
Goodwill [Roll Forward]
Beginning Balance	$ 132,029	$ 114,841
Goodwill acquired	20,344	17,188
Ending Balance	152,373	132,029	$ 114,841
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	34,983	32,885
Less: accumulated amortization	18,021	14,691
Net carrying amount	16,962	18,194
Amortization Expense
Amortization of intangible assets	3,394	3,046	$ 3,072
Future Amortization Expense
2013	3,300
2014	3,100
2015	2,900
2016	1,800
2017	1,400
Thereafter	2,400
Indefinite-lived intangible assets (Excluding goodwill)	$ 2,000
Minimum [Member]
Finite-Lived Intangible Assets [Line Items]
Intangible asset useful life (in years)	1
Maximum [Member]
Finite-Lived Intangible Assets [Line Items]
Intangible asset useful life (in years)	12
Core Deposits [Member]
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	$ 13,240	11,966
Less: accumulated amortization	7,794	6,401
Net carrying amount	5,446	5,565
Other Intangible Assets [Member]
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	21,743	20,919
Less: accumulated amortization	10,227	8,290
Net carrying amount	$ 11,516	$ 12,629

Deposits (Details) - USD ($) $ in Thousands	Dec. 31, 2012	Dec. 31, 2011
Maturities of Time Deposits [Abstract]
Within one year	$ 454,235
After one but within two years	326,502
After two but within three years	109,348
After three but within four years	49,222
After four but within five years	35,972
After five years	7,982
Total	983,261	$ 933,127
Time Deposits, $100,000 or More [Abstract]
Time deposits of $100,000 or more	$ 352,300	$ 305,700

Short-Term Borrowings (Details) - USD ($) $ in Thousands	12 Months Ended
Short-Term Borrowings (Details) - USD ($) $ in Thousands	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Short-term Debt [Line Items]
Balance at year-end	$ 162,941	$ 181,592
FHLB, unused lines of credit available for short-term financing	418,000	323,000
Federal Funds Purchased [Member]
Short-term Debt [Line Items]
Balance at year-end	10,000	27,000	$ 0
Average during the year	12,658	3,017	0
Maximum month end balance	$ 60,000	$ 28,000	$ 0
Weighted average rate during the year (in hundredths)	0.27%	0.11%	0.00%
Weighted average rate at December 31 (in hundredths)	0.27%	0.13%	0.00%
Securities Sold under Agreements to Repurchase [Member]
Short-term Debt [Line Items]
Balance at year-end	$ 152,941	$ 154,592	$ 159,184
Average during the year	153,084	150,663	157,964
Maximum month end balance	$ 165,977	$ 178,414	$ 169,278
Weighted average rate during the year (in hundredths)	0.10%	0.13%	0.25%
Weighted average rate at December 31 (in hundredths)	0.10%	0.10%	0.15%
Other Short-Term Borrowings [Member]
Short-term Debt [Line Items]
Balance at year-end	$ 0	$ 0	$ 250
Average during the year	0	249	250
Maximum month end balance	$ 0	$ 250	$ 250
Weighted average rate during the year (in hundredths)	0.00%	0.00%	0.00%
Weighted average rate at December 31 (in hundredths)	0.00%	0.00%	0.00%

Long-Term Debt (Details) - USD ($) $ in Thousands	12 Months Ended
Long-Term Debt (Details) - USD ($) $ in Thousands	Dec. 31, 2012	Dec. 31, 2011
Long-Term Debt by Maturity Periods [Abstract]
Amount	$ 367,492	$ 370,344
Callable Amount	$ 345,000	$ 345,000
2013 [Member]
Long-Term Debt by Maturity Periods [Abstract]
Maturity year	Dec. 31, 2013	Dec. 31, 2013
Amount	$ 119,502	$ 119,400
Weighted Average Rate (in hundredths)	3.87%	3.87%
Callable Amount	$ 100,000	$ 100,000
Weighted Average Rate Callable portion	3.71%	3.71%
2014 [Member]
Long-Term Debt by Maturity Periods [Abstract]
Maturity year	Dec. 31, 2014	Dec. 31, 2014
Amount	$ 2,610	$ 2,604
Weighted Average Rate (in hundredths)	1.89%	2.00%
Callable Amount	$ 0	$ 0
Weighted Average Rate Callable portion	0.00%	0.00%
2015 [Member]
Long-Term Debt by Maturity Periods [Abstract]
Maturity year	Dec. 31, 2015	Dec. 31, 2015
Amount	$ 250	$ 0
Weighted Average Rate (in hundredths)	0.00%	0.00%
Callable Amount	$ 0	$ 0
Weighted Average Rate Callable portion	0.00%	0.00%
2016 [Member]
Long-Term Debt by Maturity Periods [Abstract]
Maturity year	Dec. 31, 2016	Dec. 31, 2016
Amount	$ 70,000	$ 70,000
Weighted Average Rate (in hundredths)	4.21%	4.21%
Callable Amount	$ 70,000	$ 70,000
Weighted Average Rate Callable portion	4.21%	4.21%
2017 [Member]
Long-Term Debt by Maturity Periods [Abstract]
Maturity year	Dec. 31, 2017	Dec. 31, 2017
Amount	$ 100,000	$ 100,000
Weighted Average Rate (in hundredths)	3.89%	3.89%
Callable Amount	$ 100,000	$ 100,000
Weighted Average Rate Callable portion	3.89%	3.89%
2018 [Member]
Long-Term Debt by Maturity Periods [Abstract]
Maturity year	Dec. 31, 2018	Dec. 31, 2018
Amount	$ 75,000	$ 75,000
Weighted Average Rate (in hundredths)	3.61%	3.61%
Callable Amount	$ 75,000	$ 75,000
Weighted Average Rate Callable portion	3.61%	3.61%
2021 [Member]
Long-Term Debt by Maturity Periods [Abstract]
Maturity year	Dec. 31, 2021	Dec. 31, 2021
Amount	$ 130	$ 0
Weighted Average Rate (in hundredths)	4.00%	0.00%
Callable Amount	$ 0	$ 0
Weighted Average Rate Callable portion	0.00%	0.00%
2025 [Member]
Long-Term Debt by Maturity Periods [Abstract]
Maturity year	Dec. 31, 2025	Dec. 31, 2025
Amount	$ 0	$ 3,340
Weighted Average Rate (in hundredths)	0.00%	2.75%
Callable Amount	$ 0	$ 0
Weighted Average Rate Callable portion	0.00%	0.00%

Trust Preferred Debentures (Details) $ in Millions	12 Months Ended
Trust Preferred Debentures (Details) $ in Millions	Dec. 31, 2012 USD ($)
Debt Instrument [Line Items]
Proceeds from issuance of junior subordinated deferrable interest debentures to wholly owned trusts	$ 75.4
Wholly owned Delaware statutory business trusts - variable interest entities	three wholly owned Delaware statutory business trusts
Fixed rate to convert to a floating rate (in years)	5 years
Deferral period of payments of interest, description	ten consecutive semi-annual periods with respect to each deferral period
Tier I risk based regulatory capital included from Trust preferred securities issued by subsidiary trusts	$ 74.0
Minimum assets for bank holding companies to be subject to the same capital requirements as insured depository institutions	500.0
CNBF Capital Trust I VIE Entity Not Primary Beneficiary [Member] \| CNBF Capital Trust I Debenture [Member]
Debt Instrument [Line Items]
Trust preferred debt owed to trust	18.7
Trust preferred securities outstanding	$ 18.0
Issuance Date	Jun. 30, 1999
Interest Rate	three-month LIBOR plus 275 basis points
Final maturity date	Aug. 31, 2029
Common equity securities issued by Variable Interest Entity to NBT	$ 0.7
CNBF Trust I securities owned by bank	1.0
NBT Statutory Trust I VIE Entity Not Primary Beneficiary [Member] \| NBT Statutory Trust I Debenture [Member]
Debt Instrument [Line Items]
Trust preferred debt owed to trust	5.2
Trust preferred securities outstanding	$ 5.0
Issuance Date	Nov. 30, 2005
Interest Rate	three-month LIBOR plus 140 basis points
Final maturity date	Dec. 01, 2035
Common equity securities issued by Variable Interest Entity to NBT	$ 0.2
Original issuance fixed interest rate (in hundredths)	6.30%
NBT Statutory Trust II VIE Entity Not Primary Beneficiary [Member] \| NBT Statutory Trust II Debenture [Member]
Debt Instrument [Line Items]
Trust preferred debt owed to trust	$ 51.5
Trust preferred securities outstanding	$ 50.0
Issuance Date	Feb. 28, 2006
Interest Rate	three-month LIBOR plus 140 basis points
Final maturity date	Mar. 15, 2036
Common equity securities issued by Variable Interest Entity to NBT	$ 1.5
Original issuance fixed interest rate (in hundredths)	6.195%

Income Taxes (Details) - USD ($) $ in Thousands	12 Months Ended
Income Taxes (Details) - USD ($) $ in Thousands	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Current [Abstract]
Federal	$ 21,011	$ 29,274	$ 34,124
State	1,815	1,477	1,743
Current tax expense (benefit)	22,826	30,751	35,867
Deferred [Abstract]
Federal	(13)	(8,129)	(12,121)
State	3	(1,349)	(2,834)
Deferred tax expense (benefit)	(10)	(9,478)	(14,955)
Total income tax expense	22,816	21,273	20,912
Income tax recorded to stockholders' equity	(100)	(500)	(4,300)
Deferred tax assets [Abstract]
Allowance for loan and lease losses	26,687	27,487
Deferred compensation	5,362	4,911
Postretirement benefit obligation	1,600	1,036
Fair value adjustments from acquisitions	3,633	2,227
Accrued liabilities	1,524	1,482
Stock-based compensation expense	5,726	4,440
Other	1,933	1,214
Total deferred tax assets	46,465	42,797
Deferred tax liabilities [Abstract]
Pension and executive retirement	7,676	6,916
Unrealized gains on securities available for sale	10,939	12,156
Premises and equipment, primarily due to accelerated depreciation	1,980	2,340
Equipment leasing	582	3,090
Deferred loan costs	873	767
Intangible amortization	13,146	11,081
Other	154	494
Total deferred tax liabilities	35,350	36,844
Net deferred tax asset at year-end	11,115	5,953	(4,023)
Net deferred tax asset (liability) at beginning of year	5,953	(4,023)
Increase in net deferred tax asset	5,162	9,976
Reconciliation of gross unrecognized tax benefits [Roll Forward]
Balance, beginning of period	888	3,081	2,287
Additions for tax positions of prior years	0	0	1,714
Reduction for tax positions of prior years	(888)	(2,193)	(920)
Balance, end of period	0	888	3,081
Decrease in tax expense resulting from lapse of statute of limitations	$ 800	1,500
Accrued interest		100
Net interest		300	300
Federal statutory income tax rate (in hundredths)	35.00%
Income tax reconciliation [Abstract]
Federal income tax at statutory rate	$ 27,081	27,711	27,410
Tax exempt income	(2,536)	(2,925)	(3,448)
Net increase in CSV of life insurance	(908)	(919)	(939)
Low income housing tax credits	(629)	(782)	(296)
State taxes, net of federal tax benefit	1,182	764	756
State audit settlements	0	(681)	(1,465)
Other, net	(1,374)	(1,895)	(1,106)
Income tax expense	$ 22,816	$ 21,273	$ 20,912

Stockholders Equity (Details) $ in Thousands	12 Months Ended
Stockholders Equity (Details) $ in Thousands	Dec. 31, 2012 USD ($) $ / shares shares	Dec. 31, 2011 USD ($)
Stockholders Equity [Abstract]
Unrecognized prior service cost and net actuarial loss on pension plans	$ (22,555)	$ (24,633)
Unrealized net holding gains on available for sale securities	16,675	18,529
Accumulated other comprehensive income (loss)	$ (5,880)	$ (6,104)
Class of Warrant or Right [Line Items]
Future dividend payment restrictions	The approval of the Office of 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.
Statutory amount available for dividend payments	$ 21,300
Series A Junior Participating Preferred Stock [Member]
Class of Warrant or Right [Line Items]
Purchase entitlement (in shares) \| shares	0.01
Stated value of purchase entitlement (in dollars per share) \| $ / shares	$ 0.01
Exercise price (in dollars per share) \| $ / shares	$ 70.00
Stockholder Rights Plan [Member]
Class of Warrant or Right [Line Items]
Preferred share purchase right dividend per common share (in shares) \| shares	1
Beneficial ownership of outstanding common stock basis for right exercise, minimum (in hundredths)	15.00%
Tender or exchange offer of outstanding common stock rights to exercise, minimum (in hundredths)	15.00%
Market value of additional equity interests rights, description	two times the Right's exercise price of $70
Preferred Share Purchase Right exercise price (in dollars per right) \| $ / shares	0.001

Regulatory Capital Requirements (Details) - USD ($) $ in Thousands	Dec. 31, 2012	Dec. 31, 2011
Total Capital (to risk weighted assets) [Abstract]
Total capital to risk weighted assets	$ 560,745	$ 528,674
Total capital to risk weighted assets (in hundredths)	12.25%	12.81%
Minimum capital required for capital adequacy to risk weighted assets (in hundredths)	8.00%	8.00%
Capital required for classification as well capitalized to risk weighted assets (in hundredths)	10.00%	10.00%
Tier I Capital (to risk weighted assets) [Abstract]
Tier I capital to risk weighted assets	$ 503,359	$ 476,837
Tier I capital to risk weighted assets (in hundredths)	11.00%	11.56%
Minimum Tier one capital required for capital adequacy to risk weighted assets(in hundredths)	4.00%	4.00%
Tier one capital required for classification as well capitalized to risk weighted assets (in hundredths)	6.00%	6.00%
Tier I Capital (to average assets) [Abstract]
Tier I capital to average assets	$ 503,359	$ 476,837
Tier I capital to average assets (in hundredths)	8.54%	8.74%
Minimum Tier I leverage capital required for capital adequacy to average assets (in hundredths)	4.00%	4.00%
Tier I leverage capital required for classification as well capitalized to average assets (in hundredths)	5.00%	5.00%
NBT Bank [Member]
Total Capital (to risk weighted assets) [Abstract]
Total capital to risk weighted assets	$ 505,027	$ 506,246
Total capital to risk weighted assets (in hundredths)	11.08%	12.28%
Minimum capital required for capital adequacy to risk weighted assets (in hundredths)	8.00%	8.00%
Capital required for classification as well capitalized to risk weighted assets (in hundredths)	10.00%	10.00%
Tier I Capital (to risk weighted assets) [Abstract]
Tier I capital to risk weighted assets	$ 447,909	$ 454,476
Tier I capital to risk weighted assets (in hundredths)	9.83%	11.03%
Minimum Tier one capital required for capital adequacy to risk weighted assets(in hundredths)	4.00%	4.00%
Tier one capital required for classification as well capitalized to risk weighted assets (in hundredths)	6.00%	6.00%
Tier I Capital (to average assets) [Abstract]
Tier I capital to average assets	$ 447,909	$ 454,476
Tier I capital to average assets (in hundredths)	7.62%	8.35%
Minimum Tier I leverage capital required for capital adequacy to average assets (in hundredths)	4.00%	4.00%
Tier I leverage capital required for classification as well capitalized to average assets (in hundredths)	5.00%	5.00%

Employee Benefit Plans (Details)	12 Months Ended
Employee Benefit Plans (Details)	Dec. 31, 2012 USD ($) $ / shares shares	Dec. 31, 2011 USD ($) $ / shares shares	Dec. 31, 2010 USD ($) $ / shares	Dec. 31, 2012 USD ($) $ / shares shares	Dec. 31, 2011 USD ($)	Dec. 31, 2010 USD ($)
Defined Benefit Plan Disclosure [Line Items]
Transition obligation period of recognition	20 years
Net actuarial loss that will be amortized from Accumulated other comprehensive income (loss) in next fiscal year	$ 3,000,000
Prior service credit that will be amortized from Accumulated other comprehensive income (loss) in next fiscal year	$ 200,000
Assumptions used to determine benefit obligations [Abstract]
Discount rate (in hundredths)				3.50%	4.10%	5.15%
Expected long-term return on plan assets (in hundredths)				7.50%	7.50%	8.00%
Rate of compensation increase (in hundredths)				3.00%	3.00%	3.00%
Assumptions used to determine net periodic pension cost [Abstract]
Discount rate (in hundredths)	4.10%	5.15%	5.70%
Expected long-term return on plan assets (in hundredths)	7.50%	7.50%	8.00%
Rate of compensation increase (in hundredths)	3.00%	3.00%	3.00%
Estimate future benefit payments [Abstract]
Annual rates of increase in the per capita cost of covered medical and prescription drug benefits, minimum (in hundredths)	6.00%
Annual rates of increase in the per capita cost of covered medical and prescription drug benefits, maximum (in hundredths)	6.50%
Ultimate health care cost trend rate (in hundredths)	5.00%
Actual plan asset allocations [Abstract]
Actual plan asset allocations (in hundredths)				100.00%	100.00%
Employer contributions to 401 (k) plan	$ 1,800,000	$ 3,700,000	$ 3,500,000
Effect of one-percentage point change in assumed health care cost trend rates [Abstract]
One-percentage point Increase on total service and interest cost components	24,000
One-percentage point (decrease) on total service and interest cost components	(20,000)
One-percentage point Increase on postretirement accumulated benefit obligation	503,000
One-percentage point (decrease) on postretirement accumulated benefit obligation	$ (426,000)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock awards termination period	10 years
Stock options additional disclosures [Abstract]
Stock-based compensation expense	$ 4,364,000	$ 3,244,000	$ 3,782,000
Restricted Stock and restricted stock additional disclosures [Abstract]
Number of shares available for future grant (in shares) \| shares				4,400,000
Fair value assumptions [Abstract]
Dividend yield (in hundredths)	3.94%
Dividend yield, minimum (in hundredths)		3.31%	3.27%
Dividend yield, maximum (in hundredths)		3.82%	3.96%
Expected volatility (in hundredths)	34.64%
Expected volatility, minimum (in hundredths)		33.75%	33.00%
Expected volatility, maximum (in hundredths)		34.36%	33.86%
Risk-free interest rates (in hundredths)	1.24%
Risk-free interest rates, minimum (in hundredths)		1.48%	1.90%
Risk-free interest rates, maximum (in hundredths)		2.81%	3.17%
Expected life (in years)	7	7	7
Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock awards vesting period	4 years
Weighted average fair value of stock options granted (in dollars per share) \| $ / shares	$ 4.57	$ 5.45	$ 5.03
Stock options [Roll Forward]
Outstanding, Beginning of period (in shares) \| shares	1,863,590
Granted (in shares) \| shares	150
Exercised (in shares) \| shares	(108,817)
Forfeited (in shares) \| shares	(11,150)
Expired (in shares) \| shares	(48,211)
Outstanding, End of period (in shares) \| shares	1,695,562	1,863,590
Exercisable, End of period (in shares) \| shares	1,480,737
Expected to Vest (in shares) \| shares				205,476
Stock options additional disclosures [Abstract]
Weighted average exercise price, Outstanding, Beginning of period (in dollars per share) \| $ / shares	$ 22.41
Weighted average exercise price, Granted (in dollars per share) \| $ / shares				$ 20.30
Weighted average exercise price, Exercised (in dollars per share) \| $ / shares				17.53
Weighted average exercise price, Forfeited (in dollars per share) \| $ / shares				21.92
Weighted average exercise price, Expired (in dollars per share) \| $ / shares				22.50
Weighted average exercise price, Outstanding, End of period (in dollars per share) \| $ / shares	$ 22.72	$ 22.41
Weighted average exercise price, Exercisable, End of period (in dollars per share) \| $ / shares				22.83
Weighted average exercise price, Expected to Vest (in dollars per share) \| $ / shares				$ 21.97
Weighted Average Remaining Contractual Term, Outstanding, End of period (in years)				4.58
Weighted Average Remaining Contractual Term, Exercisable, End of period (in years)	4.21
Weighted Average Remaining Contractual Term, Expected to Vest (in years)	7.01
Aggregate Intrinsic Value, Outstanding, End of period				$ 51,236
Aggregate Intrinsic Value, Exercisable, End of period				43,043
Aggregate Intrinsic Value, Expected to Vest				7,752
Stock-based compensation expense	$ 500,000	$ 900,000	$ 1,800,000
Proceeds from stock options exercised	1,908,000	2,255,000	1,778,000
Tax benefits related to stock options exercised	8,000	341,000	140,000
Intrinsic value of stock options exercised	498,000	897,000	574,000
Fair value of shares vested during the year	$ 1,656,000	$ 1,597,000	1,800,000
Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted shares vesting period for employees, minimum	5 years
Restricted shares vesting period for non-employee directors, minimum	3 years
Stock options additional disclosures [Abstract]
Unrecognized compensation cost				$ 4,700,000
Unrecognized compensation cost, weighted average period of recognition (in years)	2.5
Restricted Stock and restricted stock [Roll Forward]
Unvested, Beginning of period (in shares) \| shares	155,376
Forfeited (in shares) \| shares	(3,500)
Vested (in shares) \| shares	(34,726)
Unvested, End of period (in shares) \| shares	117,150	155,376
Restricted Stock and restricted stock additional disclosures [Abstract]
Weighted-average grant date fair value, Unvested, Beginning of period (in dollars per share) \| $ / shares	$ 23.92
Weighted-average grant date fair value, Forfeited (in dollars per share) \| $ / shares				$ 21.96
Weighted-average grant date fair value, Vested (in dollars per share) \| $ / shares	22.61
Weighted-average grant date fair value, Unvested, End of period (in dollars per share) \| $ / shares	$ 24.36	$ 23.92
Restricted Stock Units (RSUs) [Member]
Restricted Stock and restricted stock [Roll Forward]
Unvested, Beginning of period (in shares) \| shares	241,907
Forfeited (in shares) \| shares	(5,103)
Vested (in shares) \| shares	(37,068)
Granted (in shares) \| shares	206,322
Unvested, End of period (in shares) \| shares	406,058	241,907
Restricted Stock and restricted stock additional disclosures [Abstract]
Weighted-average grant date fair value, Unvested, Beginning of period (in dollars per share) \| $ / shares	$ 23.95
Weighted-average grant date fair value, Forfeited (in dollars per share) \| $ / shares				$ 0
Weighted-average grant date fair value, Vested (in dollars per share) \| $ / shares	0
Weighted-average grant date fair value, Granted (in dollars per share) \| $ / shares	22.38
Weighted-average grant date fair value, Unvested, End of period (in dollars per share) \| $ / shares	$ 25.64	$ 23.95
Restricted and Deferred Stock Awards [Member]
Stock options additional disclosures [Abstract]
Stock-based compensation expense	$ 3,700,000	$ 3,200,000	2,000,000
Tax benefit from compensation expense	1,500,000	1,200,000	700,000
Pension Benefits [Member]
Accumulated other comprehensive income (loss), before tax [Abstract]
Net actuarial loss				$ 35,478,000	$ 37,914,000
Prior service cost				141,000	1,430,000
Total amounts recognized in accumulated other comprehensive loss (pre-tax)				35,619,000	39,344,000
Change in benefit obligation [Roll Forward]
Benefit obligation at beginning of period	78,024,000	70,229,000
Service cost	3,122,000	2,589,000	2,254,000
Interest cost	3,145,000	3,544,000	3,613,000
Plan participants' contributions	0	0
Actuarial loss (gain)	5,941,000	5,935,000
Amendments	(1,006,000)	0
Benefits paid	(4,097,000)	(4,273,000)
Projected benefit obligation at end of period	85,129,000	78,024,000	70,229,000
Change in plan assets [Roll Forward]
Fair value of plan assets at beginning of period	91,575,000	97,821,000
Actual return (loss) on plan assets	11,733,000	(2,452,000)
Employer contributions	493,000	479,000
Plan participants' contributions	0	0
Benefits paid	(4,097,000)	(4,273,000)
Fair value of plan assets at end of period	99,704,000	91,575,000	97,821,000
Funded status				14,575,000	13,551,000
Accumulated benefit obligation				84,500,000	76,500,000
Amounts recognized in Balance Sheet [Abstract]
Other assets				27,062,000	23,972,000
Other liabilities				(12,487,000)	(10,421,000)
Funded status				14,575,000	13,551,000
Components of net periodic benefit cost [Abstract]
Service cost	3,122,000	2,589,000	2,254,000
Interest cost	3,145,000	3,544,000	3,613,000
Expected return on plan assets	(6,686,000)	(7,720,000)	(7,166,000)
Amortization of prior service cost	283,000	309,000	322,000
Amortization of unrecognized net loss	3,330,000	1,353,000	1,447,000
Net periodic pension cost	3,194,000	75,000	470,000
Other changes in plan assets and benefit obligation recognized in other comprehensive income (pre-tax) [Abstract]
Net loss (gain)	894,000	16,108,000	1,620,000
Prior service cost	(1,006,000)	0	21,000
Amortization of prior service cost	(283,000)	(309,000)	(322,000)
Amortization of unrecognized net gain	(3,330,000)	(1,353,000)	(1,447,000)
Total recognized in other comprehensive loss (income)	(3,725,000)	14,446,000	(128,000)
Total recognized in net periodic benefit cost and other comprehensive income (loss) - pre-tax	(531,000)	14,521,000	342,000
Estimate future benefit payments [Abstract]
2013				5,247,000
2014				5,243,000
2015				5,285,000
2016				7,767,000
2017				5,942,000
2018 - 2022				29,180,000
Actual plan asset allocations [Abstract]
Fair value of plan assets	91,575,000	91,575,000	97,821,000	99,704,000	91,575,000	$ 97,821,000
Pension Benefits [Member] \| Level 1 [Member]
Change in plan assets [Roll Forward]
Fair value of plan assets at beginning of period	60,043,000
Fair value of plan assets at end of period	70,414,000	60,043,000
Actual plan asset allocations [Abstract]
Fair value of plan assets	70,414,000	60,043,000		70,414,000	60,043,000
Pension Benefits [Member] \| Level 2 [Member]
Change in plan assets [Roll Forward]
Fair value of plan assets at beginning of period	31,532,000
Fair value of plan assets at end of period	29,290,000	31,532,000
Actual plan asset allocations [Abstract]
Fair value of plan assets	29,290,000	31,532,000		29,290,000	31,532,000
Pension Benefits [Member] \| Level 3 [Member]
Change in plan assets [Roll Forward]
Fair value of plan assets at beginning of period	0
Fair value of plan assets at end of period	0	0
Actual plan asset allocations [Abstract]
Fair value of plan assets	0	0		$ 0	$ 0
Pension Benefits [Member] \| Cash and Cash Equivalents [Member]
Change in plan assets [Roll Forward]
Fair value of plan assets at beginning of period	1,503,000
Fair value of plan assets at end of period	$ 5,464,000	1,503,000
Target asset allocations [Abstract]
Target allocation percentage of assets, range minimum (in hundredths)	0.00%
Target allocation percentage of assets, range maximum (in hundredths)	20.00%
Actual plan asset allocations [Abstract]
Actual plan asset allocations (in hundredths)				5.00%	2.00%
Fair value of plan assets	$ 5,464,000	1,503,000		$ 5,464,000	$ 1,503,000
Pension Benefits [Member] \| Cash and Cash Equivalents [Member] \| Level 1 [Member]
Change in plan assets [Roll Forward]
Fair value of plan assets at beginning of period	1,503,000
Fair value of plan assets at end of period	5,464,000	1,503,000
Actual plan asset allocations [Abstract]
Fair value of plan assets	5,464,000	1,503,000		5,464,000	1,503,000
Pension Benefits [Member] \| Cash and Cash Equivalents [Member] \| Level 2 [Member]
Change in plan assets [Roll Forward]
Fair value of plan assets at beginning of period	0
Fair value of plan assets at end of period	0	0
Actual plan asset allocations [Abstract]
Fair value of plan assets	0	0		0	0
Pension Benefits [Member] \| Cash and Cash Equivalents [Member] \| Level 3 [Member]
Change in plan assets [Roll Forward]
Fair value of plan assets at beginning of period	0
Fair value of plan assets at end of period	0	0
Actual plan asset allocations [Abstract]
Fair value of plan assets	$ 0	0		$ 0	$ 0
Pension Benefits [Member] \| Fixed Income Securities [Member]
Target asset allocations [Abstract]
Target allocation percentage of assets, range minimum (in hundredths)	20.00%
Target allocation percentage of assets, range maximum (in hundredths)	40.00%
Actual plan asset allocations [Abstract]
Actual plan asset allocations (in hundredths)				29.00%	34.00%
Pension Benefits [Member] \| Equity Securities [Member]
Target asset allocations [Abstract]
Target allocation percentage of assets, range minimum (in hundredths)	40.00%
Target allocation percentage of assets, range maximum (in hundredths)	80.00%
Actual plan asset allocations [Abstract]
Actual plan asset allocations (in hundredths)				66.00%	64.00%
Pension Benefits [Member] \| Foreign Equity Mutual Funds [Member]
Change in plan assets [Roll Forward]
Fair value of plan assets at beginning of period	$ 6,577,000
Fair value of plan assets at end of period	9,763,000	6,577,000
Actual plan asset allocations [Abstract]
Fair value of plan assets	9,763,000	6,577,000		$ 9,763,000	$ 6,577,000
Pension Benefits [Member] \| Foreign Equity Mutual Funds [Member] \| Level 1 [Member]
Change in plan assets [Roll Forward]
Fair value of plan assets at beginning of period	6,577,000
Fair value of plan assets at end of period	9,763,000	6,577,000
Actual plan asset allocations [Abstract]
Fair value of plan assets	9,763,000	6,577,000		9,763,000	6,577,000
Pension Benefits [Member] \| Foreign Equity Mutual Funds [Member] \| Level 2 [Member]
Change in plan assets [Roll Forward]
Fair value of plan assets at beginning of period	0
Fair value of plan assets at end of period	0	0
Actual plan asset allocations [Abstract]
Fair value of plan assets	0	0		0	0
Pension Benefits [Member] \| Foreign Equity Mutual Funds [Member] \| Level 3 [Member]
Change in plan assets [Roll Forward]
Fair value of plan assets at beginning of period	0
Fair value of plan assets at end of period	0	0
Actual plan asset allocations [Abstract]
Fair value of plan assets	0	0		0	0
Pension Benefits [Member] \| Equity Mutual Funds [Member]
Change in plan assets [Roll Forward]
Fair value of plan assets at beginning of period	9,902,000
Fair value of plan assets at end of period	13,110,000	9,902,000
Actual plan asset allocations [Abstract]
Fair value of plan assets	13,110,000	9,902,000		13,110,000	9,902,000
Pension Benefits [Member] \| Equity Mutual Funds [Member] \| Level 1 [Member]
Change in plan assets [Roll Forward]
Fair value of plan assets at beginning of period	9,902,000
Fair value of plan assets at end of period	13,110,000	9,902,000
Actual plan asset allocations [Abstract]
Fair value of plan assets	13,110,000	9,902,000		13,110,000	9,902,000
Pension Benefits [Member] \| Equity Mutual Funds [Member] \| Level 2 [Member]
Change in plan assets [Roll Forward]
Fair value of plan assets at beginning of period	0
Fair value of plan assets at end of period	0	0
Actual plan asset allocations [Abstract]
Fair value of plan assets	0	0		0	0
Pension Benefits [Member] \| Equity Mutual Funds [Member] \| Level 3 [Member]
Change in plan assets [Roll Forward]
Fair value of plan assets at beginning of period	0
Fair value of plan assets at end of period	0	0
Actual plan asset allocations [Abstract]
Fair value of plan assets	0	0		0	0
Pension Benefits [Member] \| US Government Bonds [Member]
Change in plan assets [Roll Forward]
Fair value of plan assets at beginning of period	15,683,000
Fair value of plan assets at end of period	12,744,000	15,683,000
Actual plan asset allocations [Abstract]
Fair value of plan assets	12,744,000	15,683,000		12,744,000	15,683,000
Pension Benefits [Member] \| US Government Bonds [Member] \| Level 1 [Member]
Change in plan assets [Roll Forward]
Fair value of plan assets at beginning of period	0
Fair value of plan assets at end of period	0	0
Actual plan asset allocations [Abstract]
Fair value of plan assets	0	0		0	0
Pension Benefits [Member] \| US Government Bonds [Member] \| Level 2 [Member]
Change in plan assets [Roll Forward]
Fair value of plan assets at beginning of period	15,683,000
Fair value of plan assets at end of period	12,744,000	15,683,000
Actual plan asset allocations [Abstract]
Fair value of plan assets	12,744,000	15,683,000		12,744,000	15,683,000
Pension Benefits [Member] \| US Government Bonds [Member] \| Level 3 [Member]
Change in plan assets [Roll Forward]
Fair value of plan assets at beginning of period	0
Fair value of plan assets at end of period	0	0
Actual plan asset allocations [Abstract]
Fair value of plan assets	0	0		0	0
Pension Benefits [Member] \| Corporate Bonds [Member]
Change in plan assets [Roll Forward]
Fair value of plan assets at beginning of period	12,954,000
Fair value of plan assets at end of period	13,604,000	12,954,000
Actual plan asset allocations [Abstract]
Fair value of plan assets	13,604,000	12,954,000		13,604,000	12,954,000
Pension Benefits [Member] \| Corporate Bonds [Member] \| Level 1 [Member]
Change in plan assets [Roll Forward]
Fair value of plan assets at beginning of period	0
Fair value of plan assets at end of period	0	0
Actual plan asset allocations [Abstract]
Fair value of plan assets	0	0		0	0
Pension Benefits [Member] \| Corporate Bonds [Member] \| Level 2 [Member]
Change in plan assets [Roll Forward]
Fair value of plan assets at beginning of period	12,954,000
Fair value of plan assets at end of period	13,604,000	12,954,000
Actual plan asset allocations [Abstract]
Fair value of plan assets	13,604,000	12,954,000		13,604,000	12,954,000
Pension Benefits [Member] \| Corporate Bonds [Member] \| Level 3 [Member]
Change in plan assets [Roll Forward]
Fair value of plan assets at beginning of period	0
Fair value of plan assets at end of period	0	0
Actual plan asset allocations [Abstract]
Fair value of plan assets	0	0		0	0
Pension Benefits [Member] \| Common Stock [Member]
Change in plan assets [Roll Forward]
Fair value of plan assets at beginning of period	33,850,000
Fair value of plan assets at end of period	40,430,000	33,850,000
Actual plan asset allocations [Abstract]
Fair value of plan assets	40,430,000	33,850,000		40,430,000	33,850,000
Pension Benefits [Member] \| Common Stock [Member] \| Level 1 [Member]
Change in plan assets [Roll Forward]
Fair value of plan assets at beginning of period	33,850,000
Fair value of plan assets at end of period	40,430,000	33,850,000
Actual plan asset allocations [Abstract]
Fair value of plan assets	40,430,000	33,850,000		40,430,000	33,850,000
Pension Benefits [Member] \| Common Stock [Member] \| Level 2 [Member]
Change in plan assets [Roll Forward]
Fair value of plan assets at beginning of period	0
Fair value of plan assets at end of period	0	0
Actual plan asset allocations [Abstract]
Fair value of plan assets	0	0		0	0
Pension Benefits [Member] \| Common Stock [Member] \| Level 3 [Member]
Change in plan assets [Roll Forward]
Fair value of plan assets at beginning of period	0
Fair value of plan assets at end of period	0	0
Actual plan asset allocations [Abstract]
Fair value of plan assets	0	0		0	0
Pension Benefits [Member] \| Municipal Bonds and Notes [Member]
Change in plan assets [Roll Forward]
Fair value of plan assets at beginning of period	1,799,000
Fair value of plan assets at end of period	1,805,000	1,799,000
Actual plan asset allocations [Abstract]
Fair value of plan assets	1,805,000	1,799,000		1,805,000	1,799,000
Pension Benefits [Member] \| Municipal Bonds and Notes [Member] \| Level 1 [Member]
Change in plan assets [Roll Forward]
Fair value of plan assets at beginning of period	0
Fair value of plan assets at end of period	0	0
Actual plan asset allocations [Abstract]
Fair value of plan assets	0	0		0	0
Pension Benefits [Member] \| Municipal Bonds and Notes [Member] \| Level 2 [Member]
Change in plan assets [Roll Forward]
Fair value of plan assets at beginning of period	1,799,000
Fair value of plan assets at end of period	1,805,000	1,799,000
Actual plan asset allocations [Abstract]
Fair value of plan assets	1,805,000	1,799,000		1,805,000	1,799,000
Pension Benefits [Member] \| Municipal Bonds and Notes [Member] \| Level 3 [Member]
Change in plan assets [Roll Forward]
Fair value of plan assets at beginning of period	0
Fair value of plan assets at end of period	0	0
Actual plan asset allocations [Abstract]
Fair value of plan assets	0	0		0	0
Pension Benefits [Member] \| Foreign Bonds and Notes [Member]
Change in plan assets [Roll Forward]
Fair value of plan assets at beginning of period	1,096,000
Fair value of plan assets at end of period	1,137,000	1,096,000
Actual plan asset allocations [Abstract]
Fair value of plan assets	1,137,000	1,096,000		1,137,000	1,096,000
Pension Benefits [Member] \| Foreign Bonds and Notes [Member] \| Level 1 [Member]
Change in plan assets [Roll Forward]
Fair value of plan assets at beginning of period	0
Fair value of plan assets at end of period	0	0
Actual plan asset allocations [Abstract]
Fair value of plan assets	0	0		0	0
Pension Benefits [Member] \| Foreign Bonds and Notes [Member] \| Level 2 [Member]
Change in plan assets [Roll Forward]
Fair value of plan assets at beginning of period	1,096,000
Fair value of plan assets at end of period	1,137,000	1,096,000
Actual plan asset allocations [Abstract]
Fair value of plan assets	1,137,000	1,096,000		1,137,000	1,096,000
Pension Benefits [Member] \| Foreign Bonds and Notes [Member] \| Level 3 [Member]
Change in plan assets [Roll Forward]
Fair value of plan assets at beginning of period	0
Fair value of plan assets at end of period	0	0
Actual plan asset allocations [Abstract]
Fair value of plan assets	0	0		0	0
Pension Benefits [Member] \| Foreign Equity [Member]
Change in plan assets [Roll Forward]
Fair value of plan assets at beginning of period	8,211,000
Fair value of plan assets at end of period	1,647,000	8,211,000
Actual plan asset allocations [Abstract]
Fair value of plan assets	1,647,000	8,211,000		1,647,000	8,211,000
Pension Benefits [Member] \| Foreign Equity [Member] \| Level 1 [Member]
Change in plan assets [Roll Forward]
Fair value of plan assets at beginning of period	8,211,000
Fair value of plan assets at end of period	1,647,000	8,211,000
Actual plan asset allocations [Abstract]
Fair value of plan assets	1,647,000	8,211,000		1,647,000	8,211,000
Pension Benefits [Member] \| Foreign Equity [Member] \| Level 2 [Member]
Change in plan assets [Roll Forward]
Fair value of plan assets at beginning of period	0
Fair value of plan assets at end of period	0	0
Actual plan asset allocations [Abstract]
Fair value of plan assets	0	0		0	0
Pension Benefits [Member] \| Foreign Equity [Member] \| Level 3 [Member]
Change in plan assets [Roll Forward]
Fair value of plan assets at beginning of period	0
Fair value of plan assets at end of period	0	0
Actual plan asset allocations [Abstract]
Fair value of plan assets	0	0		0	0
Other Benefits [Member]
Accumulated other comprehensive income (loss), before tax [Abstract]
Net actuarial loss				2,277,000	2,323,000
Prior service cost				(672,000)	(874,000)
Total amounts recognized in accumulated other comprehensive loss (pre-tax)				1,605,000	1,449,000
Change in benefit obligation [Roll Forward]
Benefit obligation at beginning of period	3,985,000	4,554,000
Service cost	20,000	17,000	17,000
Interest cost	155,000	202,000	228,000
Plan participants' contributions	233,000	263,000
Actuarial loss (gain)	136,000	(562,000)
Amendments	0	0
Benefits paid	(458,000)	(489,000)
Projected benefit obligation at end of period	4,071,000	3,985,000	4,554,000
Change in plan assets [Roll Forward]
Fair value of plan assets at beginning of period	0	0
Actual return (loss) on plan assets	0	0
Employer contributions	225,000	226,000
Plan participants' contributions	233,000	263,000
Benefits paid	(458,000)	(489,000)
Fair value of plan assets at end of period	0	0	0
Funded status				(4,071,000)	(3,985,000)
Accumulated benefit obligation				4,100,000	4,000,000
Amounts recognized in Balance Sheet [Abstract]
Other assets				0	0
Other liabilities				(4,071,000)	(3,985,000)
Funded status				(4,071,000)	(3,985,000)
Components of net periodic benefit cost [Abstract]
Service cost	20,000	17,000	17,000
Interest cost	155,000	202,000	228,000
Expected return on plan assets	0	0	0
Amortization of prior service cost	(202,000)	(202,000)	(202,000)
Amortization of unrecognized net loss	182,000	205,000	201,000
Net periodic pension cost	155,000	222,000	244,000
Other changes in plan assets and benefit obligation recognized in other comprehensive income (pre-tax) [Abstract]
Net loss (gain)	136,000	(562,000)	955,000
Prior service cost	0	0	0
Amortization of prior service cost	202,000	202,000	202,000
Amortization of unrecognized net gain	(182,000)	(205,000)	(201,000)
Total recognized in other comprehensive loss (income)	156,000	(565,000)	956,000
Total recognized in net periodic benefit cost and other comprehensive income (loss) - pre-tax	311,000	(343,000)	1,200,000
Estimate future benefit payments [Abstract]
2013				215,000
2014				224,000
2015				234,000
2016				242,000
2017				250,000
2018 - 2022				1,311,000
Actual plan asset allocations [Abstract]
Fair value of plan assets	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0

Commitments and Contingent Liabilities (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011
Commitments and Contingent Liabilities [Abstract]
Percentage of the Company's loans secured by real estate (in hundredths)	59.00%
Guarantor Obligations [Line Items]
Loans serviced by the Company for unrelated third parties	$ 308,400	$ 301,900
Unused lines of Credit [Member]
Guarantor Obligations [Line Items]
Commitments - maximum potential obligation	163,626	161,551
Commitment to Extend Credits [Member]
Guarantor Obligations [Line Items]
Commitments - maximum potential obligation	678,093	603,322
Standby Letters of Credit [Member]
Guarantor Obligations [Line Items]
Commitments - maximum potential obligation	$ 37,510	26,783
Obligation instrument term	five years or less and expire unused
Commercial Letters of Credit [Member]
Guarantor Obligations [Line Items]
Commitments - maximum potential obligation	$ 16,607	15,218
Loans Sold with Recourse [Member]
Guarantor Obligations [Line Items]
Commitments - maximum potential obligation	$ 13,690	$ 16,175

Parent Company Financial Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Assets [Abstract]
Cash and cash equivalents	$ 129,381	$ 129,381	$ 168,792	$ 163,668	$ 129,381	$ 168,792	$ 187,161
Securities available for sale, at estimated fair value				1,147,999	1,244,619
Trading securities				3,918	3,062
Other assets				99,997	92,254
Total assets				6,042,259	5,598,406
Liabilities and Stockholders' Equity [Abstract]
Total liabilities				5,459,986	5,060,296
Stockholders' equity				582,273	538,110	533,572	505,123
Total liabilities and stockholders' equity				6,042,259	5,598,406
Condensed Income Statements [Abstract]
Securities gains (losses)	599	150	3,274
Interest, dividend and other income	239,397	239,997	255,738
Income before income tax benefit and equity in undistributed income of subsidiaries	77,374	79,174	78,316
Income tax (expense) benefit	(22,816)	(21,273)	(20,912)
Net income	54,558	57,901	57,404
Operating activities [Abstract]
Net income	54,558	57,901	57,404
Adjustments to reconcile net income to net cash provided by operating activities [Abstract]
Stock based compensation	4,364	3,244	3,782
Gain (Loss) on sales of available-for-sale securities	(442)	(7)	(3,170)
Net change in other liabilities	(128)	11,806	2,645
Net change in other assets	6,804	(3,579)	6,627
Net cash provided by operating activities	88,854	83,765	89,437
Investing activities [Abstract]
Purchases of available-for-sale securities	(483,858)	(648,048)	(635,319)
Sales and maturities of available-for-sale securities	573,828	541,555	511,394
Purchases of premises and equipment	(6,994)	(9,954)	(6,510)
Net cash (used in) provided by investing activities	(126,850)	(175,498)	58,494
Financing activities [Abstract]
Payments on long-term debt	(3,354)	(2,146)	(184,824)
Purchases of treasury shares	(15,490)	(30,502)
Cash dividends and payments for fractional shares	(26,712)	(27,063)	(27,577)
Excess tax benefit from exercise of stock options	8	341	140
Net cash provided by (used in) financing activities	72,283	52,322	(166,300)
Net increase (decrease) in cash and cash equivalents	34,287	(39,411)	(18,369)
Cash and cash equivalents at beginning of year	129,381	168,792	187,161
Cash and cash equivalents at end of year	163,668	129,381	168,792
NBT Bancorp Inc [Member]
Assets [Abstract]
Cash and cash equivalents	23,095	2,454	3,493	23,095	2,454	$ 3,493	$ 11,584
Securities available for sale, at estimated fair value				12,866	9,825
Trading securities				3,371	2,550
Investment in subsidiaries, on equity basis				635,851	622,885
Other assets				48,324	48,153
Total assets				723,507	685,867
Liabilities and Stockholders' Equity [Abstract]
Total liabilities				141,234	147,757
Stockholders' equity				582,273	538,110
Total liabilities and stockholders' equity				$ 723,507	$ 685,867
Condensed Income Statements [Abstract]
Dividends from subsidiaries	79,175	54,400	12,000
Management fee from subsidiaries	78,665	69,430	68,228
Securities gains (losses)	442	(31)	1,814
Interest, dividend and other income	720	628	1,136
Total revenue	159,002	124,427	83,178
Operating expense	79,015	75,254	72,436
Income before income tax benefit and equity in undistributed income of subsidiaries	79,987	49,173	10,742
Income tax (expense) benefit	(284)	1,340	282
Equity in undistributed income of subsidiaries	(25,145)	7,388	46,380
Net income	54,558	57,901	57,404
Operating activities [Abstract]
Net income	54,558	57,901	57,404
Adjustments to reconcile net income to net cash provided by operating activities [Abstract]
Stock based compensation	4,364	3,244	3,782
Gain (Loss) on sales of available-for-sale securities	442	31	(1,814)
Equity in undistributed income of subsidiaries	25,145	(7,388)	(46,380)
Net change in other liabilities	(3,181)	15,311	2,155
Net change in other assets	2,030	(11,607)	(2,605)
Net cash provided by operating activities	83,358	57,492	12,542
Investing activities [Abstract]
Purchases of available-for-sale securities	(4,163)	(968)	(1,745)
Sales and maturities of available-for-sale securities	1,445	71	7,807
Net cash used in acquisitions	(14,612)	0	0
Purchases of premises and equipment	(1,240)	(1,656)	(321)
Net cash (used in) provided by investing activities	(18,570)	(2,553)	5,741
Financing activities [Abstract]
Proceeds from the issuance of shares to employee benefit plans and other stock plans	1,387	1,386	1,675
Payments on long-term debt	(3,340)	(140)	(135)
Purchases of treasury shares	(15,490)	(30,502)	(477)
Cash dividends and payments for fractional shares	(26,712)	(27,063)	(27,577)
Excess tax benefit from exercise of stock options	8	341	140
Net cash provided by (used in) financing activities	(44,147)	(55,978)	(26,374)
Net increase (decrease) in cash and cash equivalents	20,641	(1,039)	(8,091)
Cash and cash equivalents at beginning of year	2,454	3,493	11,584
Cash and cash equivalents at end of year	$ 23,095	$ 2,454	$ 3,493

Fair Values of Financial Instruments (Details) - USD ($) $ in Thousands	Dec. 31, 2012	Dec. 31, 2011
Financial liabilities [Abstract]
Time deposits	$ 983,261	$ 933,127
Long-term debt	367,492	370,344
Trust preferred debentures	75,422	75,422
Securities Available for Sale [Abstract]
Total Securities Available for Sale	1,147,999	1,244,619
Trading Securities	3,918	3,062
Liabilities [Abstract]
Collateral dependent impaired loans with no specific reserve	8,400
Reserves on collateral dependent impaired loans	$ 2,800
Liquidation expense ratio on impaired collateral minimum (in hundredths)	10.00%
Liquidation expense ratio on impaired collateral maximum (in hundredths)	35.00%
Carrying Amount [Member] \| Fair Value, Inputs, Level 2 [Member]
Financial assets [Abstract]
Securities held to maturity	$ 60,563	70,811
Financial liabilities [Abstract]
Time deposits	983,261	933,127
Long-term debt	367,492	370,344
Trust preferred debentures	75,422	75,422
Carrying Amount [Member] \| Fair Value, Inputs, Level 3 [Member]
Financial assets [Abstract]
Net Loans	4,208,282	3,728,869
Estimated Fair Value [Member] \| Fair Value, Inputs, Level 2 [Member]
Financial assets [Abstract]
Securities held to maturity	61,535	72,198
Financial liabilities [Abstract]
Time deposits	994,376	942,437
Long-term debt	407,404	427,107
Trust preferred debentures	74,147	75,422
Estimated Fair Value [Member] \| Fair Value, Inputs, Level 3 [Member]
Financial assets [Abstract]
Net Loans	4,313,244	3,821,640
Fair Value, Measurements, Recurring [Member]
Securities Available for Sale [Abstract]
U.S. Treasury	64,425	82,233
Federal Agency	282,814	255,846
State & municipal	86,802	104,789
Mortgage-backed	250,281	325,397
Collateralized mortgage obligations	449,723	465,475
Other securities	13,954	10,879
Total Securities Available for Sale	1,147,999	1,244,619
Trading Securities	3,918	3,062
Interest Rate Swaps	1,490
Total	1,153,407	1,247,681
Liabilities [Abstract]
Interest Rate Swaps	1,490
Total	1,490
Fair Value, Measurements, Recurring [Member] \| Fair Value, Inputs, Level 1 [Member]
Securities Available for Sale [Abstract]
U.S. Treasury	64,425	82,233
Federal Agency	0	0
State & municipal	0	0
Mortgage-backed	0	0
Collateralized mortgage obligations	0	0
Other securities	11,866	8,825
Total Securities Available for Sale	76,291	91,058
Trading Securities	3,918	3,062
Interest Rate Swaps	0
Total	80,208	94,120
Liabilities [Abstract]
Interest Rate Swaps	0
Total	0
Fair Value, Measurements, Recurring [Member] \| Fair Value, Inputs, Level 2 [Member]
Securities Available for Sale [Abstract]
U.S. Treasury	0	0
Federal Agency	282,814	255,846
State & municipal	86,802	104,789
Mortgage-backed	250,281	325,397
Collateralized mortgage obligations	449,723	465,475
Other securities	2,088	2,054
Total Securities Available for Sale	1,071,708	1,153,561
Trading Securities	0	0
Interest Rate Swaps	1,490
Total	1,073,198	1,153,561
Liabilities [Abstract]
Interest Rate Swaps	1,490
Total	1,490
Fair Value, Measurements, Recurring [Member] \| Fair Value, Inputs, Level 3 [Member]
Securities Available for Sale [Abstract]
U.S. Treasury	0	0
Federal Agency	0	0
State & municipal	0	0
Mortgage-backed	0	0
Collateralized mortgage obligations	0	0
Other securities	0	0
Total Securities Available for Sale	0	0
Trading Securities	0	0
Interest Rate Swaps	0
Total	0	$ 0
Liabilities [Abstract]
Interest Rate Swaps	0
Total	$ 0