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Document And Entity Information - USD ($)	12 Months Ended
Document And Entity Information - USD ($)	Dec. 31, 2011	Feb. 15, 2012	Jun. 30, 2011
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			$ 704,029,832
Entity Common Stock, Shares Outstanding		33,243,778
Document Fiscal Year Focus	2011
Document Fiscal Period Focus	FY
Document Type	10-K
Amendment Flag	false
Document Period End Date	Dec. 31, 2011

Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2011	Dec. 31, 2010
Assets
Cash and due from banks	$ 128,517	$ 99,673
Short-term interest bearing accounts	864	69,119
Securities available for sale, at fair value	1,244,619	1,129,368
Securities held to maturity (fair value $72,198 and $98,759)	70,811	97,310
Trading securities	3,062	2,808
Federal Reserve and Federal Home Loan Bank stock	27,020	27,246
Loans and leases	3,800,203	3,610,006
Less allowance for loan and lease losses	71,334	71,234
Net loans and leases	3,728,869	3,538,772
Premises and equipment, net	74,541	67,404
Goodwill	132,029	114,841
Intangible assets, net	18,194	17,543
Bank owned life insurance	77,626	75,301
Other assets	92,254	99,471
Total assets	5,598,406	5,338,856
Liabilities
Demand (noninterest bearing)	1,052,906	911,741
Savings, NOW, and money market	2,381,116	2,291,833
Time	933,127	930,778
Total deposits	4,367,149	4,134,352
Short-term borrowings	181,592	159,434
Long-term debt	370,344	369,874
Trust preferred debentures	75,422	75,422
Other liabilities	65,789	66,202
Total liabilities	5,060,296	4,805,284
Stockholders' equity
Preferred stock, $0.01 par value; authorized 2,500,000 shares at December 31, 2011 and 2010	0	0
Common stock, $0.01 par value. Authorized 50,000,000 shares at December 31, 2011 and 2010; issued 38,035,539 at December 31, 2011 and 2010	380	380
Additional paid-in-capital	317,329	314,023
Retained earnings	329,981	299,797
Accumulated other comprehensive loss	(6,104)	(5,335)
Common stock in treasury, at cost, 4,878,829 and 3,532,732 shares at December 31, 2011 and 2010, respectively	(103,476)	(75,293)
Total stockholders' equity	538,110	533,572
Total liabilities and stockholders' equity	$ 5,598,406	$ 5,338,856

Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2011	Dec. 31, 2010
Assets
Securities held to maturity fair value	$ 72,198	$ 98,759
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)	50,000,000	50,000,000
Common stock, shares issued (in shares)	38,035,539	38,035,539
Common stock in treasury, at cost (in shares)	4,878,829	3,532,732

Consolidated Statements of Income - USD ($) $ in Thousands	12 Months Ended
Consolidated Statements of Income - USD ($) $ in Thousands	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Interest, fee, and dividend income
Interest and fees on loans and leases	$ 204,370	$ 213,429	$ 220,324
Securities available for sale	31,083	36,167	45,972
Securities held to maturity	2,886	3,968	4,894
Other	1,658	2,174	2,203
Total interest, fee, and dividend income	239,997	255,738	273,393
Interest expense
Deposits	23,020	30,354	48,496
Short-term borrowings	205	402	552
Long-term debt	14,404	18,314	23,629
Trust preferred debentures	2,092	4,140	4,247
Total interest expense	39,721	53,210	76,924
Net interest income	200,276	202,528	196,469
Provision for loan and lease losses	20,737	29,809	33,392
Net interest income after provision for loan and lease losses	179,539	172,719	163,077
Noninterest income
Service charges on deposit accounts	21,464	24,041	27,165
Insurance and other financial services revenue	20,843	18,867	17,725
Trust	8,864	7,722	6,719
Net securities gains	150	3,274	144
Bank owned life insurance income	3,085	3,316	3,135
ATM and debit card fees	11,642	10,035	9,339
Retirement plan administration fees	8,918	10,356	9,086
Other	5,345	6,277	6,818
Total noninterest income	80,311	83,888	80,131
Noninterest expense
Salaries and employee benefits	99,212	93,718	85,565
Occupancy	16,363	15,350	14,864
Equipment	8,864	8,317	8,139
Data processing and communications	12,271	12,347	13,238
Professional fees and outside services	8,921	9,032	10,508
Office supplies and postage	6,073	6,102	5,857
Amortization of intangible assets	3,046	3,072	3,246
Loan collection and other real estate owned	2,631	3,036	2,766
Advertising	3,460	3,487	3,455
FDIC expenses	4,267	6,081	8,408
Prepayment penalty on long-term debt	0	4,526	810
Other	15,568	13,223	13,710
Total noninterest expense	180,676	178,291	170,566
Income before income tax expense	79,174	78,316	72,642
Income tax expense	21,273	20,912	20,631
Net income	$ 57,901	$ 57,404	$ 52,011
Earnings per share
Basic (in dollars per share)	$ 1.72	$ 1.67	$ 1.54
Diluted (in dollars per share)	$ 1.71	$ 1.66	$ 1.53

Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Consolidated Statements of Comprehensive Income [Abstract]
Net income	$ 57,901	$ 57,404	$ 52,011
Other comprehensive (loss) income, net of tax
Unrealized net holding gains (losses) arising during the year (pre-tax amounts of $12,757, $(6,660), and $7,438)	7,703	(4,021)	4,490
Reclassification adjustment for net gains related to securities available for sale included in net income (pre-tax amounts of $150, $3,274, and $144)	(90)	(1,977)	(86)
Amortization of prior service cost and actuarial gains (pre-tax amounts of $1,665, $1,767, and $2,581)	999	1,060	1,548
(Decrease) increase in unrecognized actuarial loss (pre-tax amounts of $(15,546), $(2,595), and $5,637)	(9,381)	(1,560)	3,415
Total other comprehensive (loss) income	(769)	(6,498)	9,367
Comprehensive income	$ 57,132	$ 50,906	$ 61,378

- 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.

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- Definition

The net increase or decrease of changes in the value of either the benefit obligation or the plan assets resulting from experience different from that assumed or from a change in an actuarial assumption, or the consequence of a decision to temporarily deviate from the substantive plan.

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- 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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- 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.

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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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- 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.

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+ Details

Consolidated Statements of Comprehensive Income (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Other comprehensive income, net of tax
Unrealized net holding gains (losses) arising during the year, pre-tax amounts	$ 12,757	$ (6,660)	$ 7,438
Reclassification adjustment for net gains related to securities available for sale included in net income, pre-tax amounts	150	3,274	144
Amortization of prior service cost and actuarial gains, pre-tax amounts	1,665	1,767	2,581
(Decrease) increase in unrecognized actuarial loss, pre-tax amounts	$ (15,546)	$ (2,595)	$ 5,637

- Definition

The change in other comprehensive income due to the amortization of the net prior service costs (credit) into net periodic pension costs.

+ References

+ Details

- Definition

Pre tax reclassification adjustment for gains or losses realized upon the sale of securities.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
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+ 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
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+ Details

Consolidated Statements of Changes in Stockholders' Equity - USD ($) $ in Thousands	Common Stock [Member]	Additional Paid-in- Capital [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive (Loss) Income [Member]	Common Stock in Treasury [Member]	Total
Balance at Dec. 31, 2008	$ 365	$ 276,418	$ 245,340	$ (8,204)	$ (82,074)	$ 431,845
Net income	0	0	52,011	0	0	52,011
Cash dividends	0	0	(27,119)	0	0	(27,119)
Net issuance of common shares	15	33,386	0	0	0	33,401
Net issuance of shares to employee stock plans, including tax benefit	0	(1,773)	0	0	4,258	2,485
Stock-based compensation	0	3,133	0	0	0	3,133
Other comprehensive income	0	0	0	9,367	0	9,367
Balance at Dec. 31, 2009	380	311,164	270,232	1,163	(77,816)	505,123
Net income	0	0	57,404	0	0	57,404
Cash dividends	0	0	(27,577)	0	0	(27,577)
Purchase of treasury shares	0	0	0	0	(477)	(477)
Net issuance of shares to employee stock plans, including tax benefit	0	(923)	(262)	0	3,000	1,815
Stock-based compensation	0	3,782	0	0	0	3,782
Other comprehensive income	0	0	0	(6,498)	0	(6,498)
Balance at Dec. 31, 2010	380	314,023	299,797	(5,335)	(75,293)	533,572
Net income	0	0	57,901	0	0	57,901
Cash dividends	0	0	(27,063)	0	0	(27,063)
Purchase of treasury shares	0	0	0	0	(30,502)	(30,502)
Net issuance of shares to employee stock plans, including tax benefit	0	62	(654)	0	2,319	1,727
Stock-based compensation	0	3,244	0	0	0	3,244
Other comprehensive income	0	0	0	(769)	0	(769)
Balance at Dec. 31, 2011	$ 380	$ 317,329	$ 329,981	$ (6,104)	$ (103,476)	$ 538,110

- Definition

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

+ References

+ Details

- Definition

This element represents Other Comprehensive Income or Loss, Net of Tax, for the period. 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. While for technical reasons this element has no balance attribute, the default assumption is a credit balance consistent with its label.

+ References

+ Details

- Definition

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, 2011	Dec. 31, 2010	Dec. 31, 2009
Consolidated Statements of Changes in Stockholders' Equity [Abstract]
Cash dividends - per share (in dollars per share)	$ 0.80	$ 0.80	$ 0.80
Purchase of Treasury Shares (in shares)	1,458,609	23,810	0
Net issuance of common shares (in shares)	0	0	1,576,230
Net issuance of shares to employee stock plans, including tax benefit (in shares)	112,512	141,146	203,480

- Definition

Number of shares (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 any shares forfeited. Shares 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

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Operating activities
Net income	$ 57,901	$ 57,404	$ 52,011
Adjustments to reconcile net income to net cash provided by operating activities
Provision for loan and lease losses	20,737	29,809	33,392
Depreciation and amortization of premises and equipment	5,463	5,327	5,398
Net accretion on securities	1,597	1,468	535
Amortization of intangible assets	3,046	3,072	3,246
Stock based compensation	3,244	3,782	3,133
Bank owned life insurance income	(3,085)	(3,316)	(3,135)
Trading security purchases	(447)	(184)	(460)
Unrealized losses (gains) in trading securities	193	(214)	(543)
Deferred income tax benefit	(9,478)	(14,955)	(1,501)
Proceeds from sale of loans held for sale	13,545	83,143	135,519
Originations and purchases of loans held for sale	(14,167)	(80,469)	(138,583)
Net gains on sales of loans held for sale	(329)	(911)	(953)
Net security gains	(150)	(3,274)	(144)
Net gains on sales of other real estate owned	(2,531)	(517)	(306)
Net (increase) decrease in other assets	(3,579)	6,627	(39,324)
Net increase in other liabilities	11,805	2,645	6,399
Net cash provided by operating activities	83,765	89,437	54,684
Investing activities
Net cash provided by acquisitions	81,467	0	0
Securities available for sale:
Proceeds from maturities, calls, and principal paydowns	541,555	511,394	434,127
Proceeds from sales	2,437	103,253	2,753
Purchases	(648,048)	(635,319)	(426,979)
Securities held to maturity:
Proceeds from maturities, calls, and principal paydowns	47,186	112,399	90,668
Purchases	(20,736)	(48,701)	(110,496)
Net (increase) decrease in loans	(172,920)	7,292	(18,775)
Net decrease in Federal Reserve and FHLB stock	226	8,733	3,066
Proceeds from bank owned life insurance	758	2,767	1,054
Purchases of premises and equipment, net	(9,954)	(6,510)	(6,378)
Proceeds from sales of other real estate owned	2,531	3,186	2,512
Net cash (used in) provided by investing activities	(175,498)	58,494	(28,448)
Financing activities
Net increase in deposits	87,992	41,306	169,788
Net increase (decrease) in short-term borrowings	22,158	3,457	(50,515)
Proceeds from issuance of long-term debt	156	0	0
Repayments of long-term debt	(2,146)	(184,824)	(77,511)
Excess tax benefit from exercise of stock options	341	140	(243)
Proceeds from the issuance of shares to employee benefit plans and other stock plans	1,386	1,675	2,728
Issuance of common stock	0	0	33,401
Purchase of treasury stock	(30,502)	(477)	0
Cash dividends and payments for fractional shares	(27,063)	(27,577)	(27,119)
Net cash provided by (used in) financing activities	52,322	(166,300)	50,529
Net (decrease) increase in cash and cash equivalents	(39,411)	(18,369)	76,765
Cash and cash equivalents at beginning of year	168,792	187,161	110,396
Cash and cash equivalents at end of year	129,381	168,792	187,161
Cash paid during the year for:
Interest	40,135	54,668	79,819
Income taxes, net of refund	31,258	37,033	13,952
Noncash investing activities:
Loans transferred to other real estate owned	2,927	1,212	3,899
Acquisitions:
Fair value of assets acquired	67,020	0	0
Fair value of liabilities assumed	$ 148,487	$ 0	$ 0

Significant Accounting Policies

9 Months Ended

Sep. 30, 2011

Significant Accounting Policies [Abstract]

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, NA (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 and lease 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 northern New York, northeastern Pennsylvania, western Massachusetts and Burlington, Vermont. The Company has identified separate operating segments; however, these segments did not meet the quantitative thresholds for separate disclosure.

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 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, with the exception of small business investment company (SBIC) investments, which are carried at fair value in accordance with SBIC rules.

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 FHLB stock are required for membership in those organizations and are carried at cost since there is no market value available.

Loans and Leases

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 and leases are placed on nonaccrual status when timely collection of principal and interest in accordance with contractual terms is doubtful. Loans and leases 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 or lease 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 and lease 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 and Lease Losses

The allowance for loan and lease losses is the amount which, in the opinion of management, is necessary to absorb probable losses inherent in the loan and lease 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 and lease losses are made periodically by charges to the provision for loan and lease losses.

The allowance for loan and lease 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 and lease losses is adequate. While management uses available information to recognize loan and lease losses, future additions to the allowance for loan and lease 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 and lease losses. Such agencies may require the Company to recognize additions to the allowance for loan and lease 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

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 and lease losses and any subsequent valuation write-downs are charged to other expense. In connection with the determination of the allowance for loan and lease 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, 2011 and 2010 was approximately $2.2 million and $0.9 million, respectively.

Acquired Loans

Loans that we acquire in acquisitions subsequent to January 1, 2009 are recorded at fair value with no carryover of the related allowance for credit losses. Determining the fair value of the loans involves estimating the amount and timing of principal and interest cash flows expected to be collected on the loans and discounting those cash flows at a market rate of interest.

The excess of cash flows expected at acquisition over the estimated fair value is referred to as the accretable discount and is recognized into interest income over the remaining life of the loan. The difference between contractually required payments at acquisition and the cash flows expected to be collected at acquisition is referred to as the nonaccretable discount. The nonaccretable discount represents estimated future credit losses expected to be incurred over the life of the loan. Subsequent decreases to the expected cash flows require us to evaluate the need for an allowance for credit losses. Subsequent improvements in expected cash flows result in the reversal of a corresponding amount of the nonaccretable discount which we then reclassify as accretable discount that is recognized into interest income over the remaining life of the loan using the interest method. Our evaluation of the amount of future cash flows that we expect to collect is performed in a similar manner as that used to determine our allowance for credit losses. Charge-offs of the principal amount on acquired loans would be first applied to the nonaccretable discount portion of the fair value adjustment.

Acquired loans that met the criteria for nonaccrual of interest prior to the acquisition may be considered performing upon acquisition, regardless of whether the customer is contractually delinquent, if we can reasonably estimate the timing and amount of the expected cash flows on such loans and if we expect to fully collect the new carrying value of the loans. As such, we may no longer consider the loan to be nonaccrual or nonperforming and may accrue interest on these loans, including the impact of any accretable discount. We have determined that we can reasonably estimate future cash flows on any such acquired loans that are past due 90 days or more and on which we are accruing interest and we expect to fully collect the carrying value of the loans.

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.

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.

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.

Mergers and Acquisition Activity

12 Months Ended

Dec. 31, 2011

Mergers and Acquisition Activity [Abstract]

Mergers and Acquisition Activity

(2)	Merger and Acquisition Activity

On May 2, 2011, the Company completed the acquisition of Latremore's Insurance Agency, Inc., then headquartered in Chazy, New York. As part of the acquisition, the Company acquired approximately $2.1 million of intangible assets, $1.3 million of goodwill, and $0.1 million of fixed assets for a purchase price of $3.5 million, which has been allocated to NBT Holdings for reporting purposes. The results of operations are included in the consolidated financial statements from the date of acquisition.

Pursuant to a purchase assumption agreement dated July 21, 2011 between the Company, Berkshire Hills Bancorp, Inc., and Legacy Banks, on October 21, 2011, the Company completed the conversion of four Legacy Banks branches to NBT Bank. The branches are located in Berkshire County, Massachusetts in the towns of Great Barrington, Lee, Pittsfield, and North Adams. As part of the acquisition, the Company acquired approximately $39.9 million in loans, $144.8 million in deposits, $12.5 million of goodwill, $1.3 million of intangible assets, and $2.8 million of other assets for a purchase price of $8.9 million, which has been allocated to the Bank for reporting purposes. The results of operations are included in the consolidated financial statements from the date of acquisition.

On October 24, 2011, the Company entered into a definitive agreement with Berkshire Hills Bancorp, Inc. and Legacy Banks to acquire three former Legacy Banks branches in Greene County, NY and deposits and loans of one Legacy Banks branch in Schoharie County, NY. This acquisition closed on January 21, 2012.

On November 16, 2011, the Company entered into a definitive agreement with Hampshire First pursuant to which Hampshire First will merge with and into NBT's banking subsidiary, NBT Bank, N.A. This merger is expected to close in the second quarter of 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

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-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
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 141
-Paragraph 51, 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
-Appendix F
-Paragraph F4
-Subparagraph e

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 141R
-Paragraph 67-73
-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 Accounting Standards Codification
-Topic 805
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-Paragraph 1
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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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Reference 8: http://www.xbrl.org/2003/role/presentationRef
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Reference 14: http://www.xbrl.org/2003/role/presentationRef
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+ Details

Earnings Per Share

12 Months Ended

Dec. 31, 2011

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,
	2011						2010						2009
			Weighted						Weighted						Weighted
(In thousands, except share and per share data)	Net income		average shares		Per share amount		Net income		average shares		Per share amount		Net income		average shares		Per share amount
Basic earnings per share	$	57,901		33,662	$	1.72	$	57,404		34,275	$	1.67	$	52,011		33,723	$	1.54
Effect of dilutive securities

Stock based compensation				262						234						180
Diluted earnings per share	$	57,901		33,924	$	1.71	$	57,404		34,509	$	1.66	$	52,011		33,903	$	1.53

There were approximately 1,258,000, 1,309,000, and 1,245,000 weighted average stock options for the years ended December 31, 2011, 2010, and 2009, 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
Federal Reserve Bank Requirement	Dec. 31, 2011
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. The required average total reserve for NBT Bank for the 14-day maintenance period ending December 31, 2011 was $33.4 million.

Securities

12 Months Ended

Dec. 31, 2011

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, 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
December 31, 2010
U.S. Treasury	$	91,338	$	424	$	482	$	91,280
Federal Agency		350,641		1,905		2,796		349,750
State & municipal		113,821		1,771		655		114,937
Mortgage-backed		233,861		11,666		719		244,808
Collateralized mortgage obligations		293,565		6,574		2,251		297,888
Corporate		20,005		484		-		20,489
Other securities		8,059		2,162		5		10,216
Total securities available for sale	$	1,111,290	$	24,986	$	6,908	$	1,129,368

In the available for sale category at December 31, 2011, federal agency securities were comprised of Government-Sponsored Enterprise (“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 US 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 US Government Agency securities with an amortized cost of $60.8 million and a fair value of $63.1 million. At December 31, 2011, all of the mortgaged-backed securities held to maturity were comprised of US Government Agency securities.

In the available for sale category at December 31, 2010, federal agency securities were comprised of Government-Sponsored Enterprise (“GSE”) securities; mortgaged-backed securities were comprised of GSEs with an amortized cost of $208.9 million and a fair value of $217.9 million and US Government Agency securities with an amortized cost of $25.0 million and a fair value of $26.9 million; CMOs were comprised of GSEs with an amortized cost of $206.0 million and a fair value of $207.0 million and US Government Agency securities with an amortized cost of $87.6 million and a fair value of $90.8 million.

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

	Years ended December 31
(In thousands)	2011			2010			2009
Proceeds from sales	$	2,437		$	103,253		$	2,753
Gross realized gains	$	7		$	3,170		$	154
Gross realized losses		(165	)		(25	)		(49	)
Net securities (losses) gains	$	(158	)	$	3,145		$	105

In addition to (losses) gains from sales transactions, the Company also recorded gains from calls on securities available for sale of approximately $0.3 million for the year ended December 31, 2011, $0.1 for the year ended December 31, 2010, and a nominal gain for the year ended December 31, 2009.

At December 31, 2011 and 2010, securities available for sale with amortized costs totaling $1.2 billion and $0.9 billion, respectively, were pledged to secure public deposits and for other purposes required or permitted by law. Additionally, at December 31, 2011, securities available for sale with an amortized cost of $141.7 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, 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
December 31, 2010
Mortgage-backed	$	1,719	$	200	$	-	$	1,919
State & municipal		95,591		1,249		-		96,840
Total securities held to maturity	$	97,310	$	1,449	$	-	$	98,759

At December 31, 2011 and 2010, all of the mortgaged-backed securities held to maturity were comprised of US Government Agency securities.

The following table sets forth information with regard to investment securities with unrealized losses at December 31, 2011 and 2010, 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, 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

December 31, 2010
U.S. Treasury	$	40,741	$	(482	)		4	$	-	$	-			-	$	40,741	$	(482	)		4
Federal agency		147,012		(2,796	)		12		-		-			-		147,012		(2,796	)		12
State & municipal		22,273		(317	)		31		7,533		(338	)		19		29,806		(655	)		50
Mortgage-backed		44,340		(719	)		3		-		-			-		44,340		(719	)		3
Collateralized mortgage obligations		72,595		(2,251	)		3		-		-			-		72,595		(2,251	)		3
Other securities		95		(5	)		1		-		-			-		95		(5	)		1
Total securities with unrealized losses	$	327,056	$	(6,570	)		54	$	7,533	$	(338	)		19	$	334,589	$	(6,908	)		73

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, 2011, 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, 2011, 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, 2011:

(In thousands)	Amortized cost		Estimated fair value
Debt securities classified as available for sale
Within one year	$	23,867	$	23,941
From one to five years		302,772		305,366
From five to ten years		245,058		254,864
After ten years		633,302		649,568
	$	1,204,999	$	1,233,739

Debt securities classified as held to maturity
Within one year	$	26,315	$	26,383
From one to five years		34,032		35,058
From five to ten years		7,073		7,153
After ten years		3,391		3,604
	$	70,811	$	72,198

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, 2011 and 2010.

Loans and Leases

12 Months Ended

Dec. 31, 2011

Loans and Leases [Abstract]

Loans and Leases

(6)	Loans and Leases

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

	At December 31,
(In thousands)	2011		2010
Residential real estate mortgages	$	581,511	$	548,394
Commercial		611,298		577,731
Commercial real estate		888,879		844,458
Real estate construction and development		93,977		45,444
Agricultural and agricultural real estate mortgages		108,423		112,738
Consumer		946,470		905,563
Home equity		569,645		575,678
Total loans and leases	$	3,800,203	$	3,610,006

Included in the above loans and leases are net deferred loan origination costs totaling $1.6 million and $2.9 million at December 31, 2011 and 2010, respectively. Also included is unearned income of $0.3 million and $1.4 million at December 31, 2011 and 2010, respectively. The decrease in unearned income is due to the run-off of the lease portfolio as the Company ceased lease originations in 2009. The Company had residential loans held for sale totaling $2.7 million as of December 31, 2011 and none as of December 31, 2010.

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
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-Number 210
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Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher AICPA
-Name Statement of Position (SOP)
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-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
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-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 and Lease Losses and Credit Quality of Loans and Leases

12 Months Ended

Dec. 31, 2011

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

Allowance for Loan and Lease Losses and Credit Quality of Loans and Leases

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

Allowance for Loan and Lease Losses

The allowance for loan and lease losses is maintained at a level estimated by management to provide adequately for risk of probable losses inherent in the current loan and lease portfolio. The adequacy of the allowance for loan and lease losses is continuously monitored. It is assessed for adequacy using a methodology designed to ensure the level of the allowance reasonably reflects the loan and lease 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 and lease portfolio.

To develop and document a systematic methodology for determining the allowance for loan and lease 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 and lease 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 $350 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 73% 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 and Lease Loss Calculation

Management considers the accounting policy relating to the allowance for loan and lease 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 and leases, 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 and lease 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 and lease losses are made periodically by charges to the provision for loan and lease 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 and leases, 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 and lease losses by portfolio segment for the years ended December 31, 2011 and 2010:

Allowance for Loan and Lease Losses

(in thousands)

Years ended December 31							Residential
	Commercial			Consumer			Real Estate
	Loans			Loans			Mortgages			Unallocated			Total
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 and lease losses and the recorded investment by portfolio segment as of December 31, 2011 and 2010:

Allowance for Loan and Lease Losses and Recorded Investment in Loans and Leases

(in thousands)

					Residential
	Commercial		Consumer		Real Estate
	Loans		Loans		Mortgages		Unallocated		Total
As of December 31, 2011
Allowance for loan and lease losses	$	38,831	$	26,049	$	6,249	$	205	$	71,334

Allowance for loans and leases individually evaluated for impairment	$	175	$	-	$	-			$	175

Allowance for loans and leases collectively evaluated for impairment	$	38,656	$	26,049	$	6,249	$	205	$	71,159

Ending balance of loans and leases	$	1,702,577	$	1,516,115	$	581,511			$	3,800,203

Ending balance of loans and leases individually evaluated for impairment	$	6,219	$	-	$	-			$	6,219

Ending balance of loans and leases collectively evaluated for impairment	$	1,696,358	$	1,516,115	$	581,511			$	3,793,984

As of December 31, 2010
Allowance for loan and lease losses	$	40,101	$	26,126	$	4,627	$	380	$	71,234

Allowance for loans and leases individually evaluated for impairment	$	2,211	$	-	$	-			$	2,211

Allowance for loans and leases collectively evaluated for impairment	$	37,890	$	26,126	$	4,627	$	380	$	69,023

Ending balance of loans and leases	$	1,580,371	$	1,481,241	$	548,394			$	3,610,006

Ending balance of loans and leases individually evaluated for impairment	$	11,419	$	-	$	-			$	11,419

Ending balance of loans and leases collectively evaluated for impairment	$	1,568,952	$	1,481,241	$	548,394			$	3,598,587

Credit Quality of Loans and Leases

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

The following table illustrates the Company's nonaccrual loans by loan class as of December 31, 2011 and 2010:

Loans on Nonaccrual Status

(In thousands)	December 31, 2011		December 31, 2010
Commercial Loans
Commercial	$	1,699	$	5,837
Commercial Real Estate		4,868		5,687
Agricultural		3,307		4,065
Agricultural Real Estate		2,067		2,429
Business Banking		7,446		7,033
		19,387		25,051

Consumer Loans
Indirect		1,550		1,971
Home Equity		7,931		6,395
Direct		378		399
		9,859		8,765

Residential Real Estate Mortgages		9,044		8,651

Total Nonaccrual	$	38,290	$	42,467

The decrease in commercial nonaccrual loans primarily reflects the charge-off of one large credit and the payoff of two additional large credits in 2011.

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

Age Analysis of Past Due Financing Receivables

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

Age Analysis of Past Due Loans and Leases

As of December 31, 2010

(in thousands)


					Greater Than								Recorded
	31-60 Days		61-90 Days		91 Days		Total						Total
	Past Due		Past Due		Past Due		Past Due						Loans and
	Accruing		Accruing		Accruing		Accruing		Non-Accrual		Current		Leases
Commercial
Commercial	$	136	$	55	$	94	$	285	$	5,837	$	461,633	$	467,755
Commercial Real Estate		1,263		-		-		1,263		5,687		730,285		737,235
Agricultural		63		92		-		155		4,065		63,336		67,556
Agricultural Real Estate		108		-		-		108		2,429		33,400		35,937
Business Banking		2,570		1,183		-		3,753		7,033		261,102		271,888
		4,140		1,330		94		5,564		25,051		1,549,756		1,580,371

Consumer
Indirect		9,307		2,193		862		12,362		1,971		814,594		828,927
Home Equity		5,740		1,756		396		7,892		6,395		561,391		575,678
Direct		927		158		54		1,139		399		75,098		76,636
		15,974		4,107		1,312		21,393		8,765		1,451,083		1,481,241

Residential Real Estate Mortgages		3,002		126		919		4,047		8,651		535,696		548,394
	$	23,116	$	5,563	$	2,325	$	31,004	$	42,467	$	3,536,535	$	3,610,006

There were no material commitments to extend further credit to borrowers with nonperforming loans. Within nonaccrual loans, there were approximately $4.0 million and $1.0 million of TDR loans at December 31, 2011 and 2010, 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 $22.4 million at December 31, 2011 and $25.4 million at December 31, 2010.

The methodology used to establish the allowance for loan and lease 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, 2011, $0.5 million of the total impaired loans had a specific reserve allocation of $0.2 million compared to $6.1 million of impaired loans at December 31, 2010 which had a specific reserve allocation of $2.2 million.

The following provides additional information on impaired loans for the years ended December 31, 2011 and 2010:

Impaired Loans
	December 31, 2011						December 31, 2010
	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	$	1,243	$	2,723			$	2,112	$	2,459
Commercial Real Estate		4,868		7,165				5,687		6,654
Agricultural		3,307		4,166				2,394		2,865
Agricultural Real Estate		2,067		2,288				1,701		1,883
Business Banking		7,446		9,976				7,033		9,395
Total Commercial Loans		18,931		26,318				18,927		23,256

Consumer Loans
Home Equity		2,000		2,103				-		-

Residential Real Estate Mortgages		1,040		1,125				313		339
		21,971		29,546				19,240		23,595

With an allowance recorded:
Commercial Loans
Commercial	$	456	$	808	$	175	$	3,725	$	4,762	$	1,907
Commercial Real Estate		-		-		-		-		-		-
Agricultural		-		-		-		1,671		1,918		281
Agricultural Real Estate		-		-		-		728		784		23
		456		808		175		6,124		7,464		2,211

Total:	$	22,427	$	30,354	$	175	$	25,364	$	31,059	$	2,211

The following table summarizes the average recorded investments on impaired loans and the interest income recognized for the years ended December 31, 2011, 2010 and 2009:

	December 31, 2011						December 31, 2010						December 31, 2009
	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	$	2,322	$	94	$	94	$	1,898	$	113	$	113	$	1,118	$	1,429	$	1,429
Commercial Real Estate		4,794		163		163		4,219		317		317		5,702		2,744		2,744
Agricultural		3,013		133		133		2,990		82		82		1,606		531		531
Agricultural Real Estate		1,719		109		109		1,929		150		150		1,853		589		589
Business Banking		6,121		266		266		4,959		234		234		6,231		917		917
Consumer Loans
Home Equity		1,904		91		91		-		-		-		-		-		-
Res Real Estate Mortgages		926		58		58		132		6		6		-		-		-
	$	20,798	$	914	$	914	$	16,127	$	902	$	902	$	16,509	$	6,210	$	6,210

With an allowance recorded:
Commercial Loans
Commercial	$	861	$	86	$	86	$	2,366	$	118	$	118	$	2,984	$	57	$	57
Commercial Real Estate		287		-		-		1,234		-		-		1,551		-		-
Agricultural		791		68		68		1,386		150		150		2,046		63		63
Agricultural Real Estate		357		18		18		816		67		67		560		5		5
	$	2,295	$	172	$	172	$	5,802	$	335	$	335	$	7,141	$	125	$	125

Total:	$	23,094	$	1,086	$	1,086	$	21,929	$	1,237	$	1,237	$	23,650	$	6,335	$	6,335

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 and lease 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, 2011 and 2010:

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

Credit Quality Indicators

As of December 31, 2010

(in thousands)

Commercial Credit Exposure			Commercial				Agricultural
By Internally Assigned Grade:	Commercial		Real Estate		Agricultural		Real Estate		Total
1 - Pass	$	441,834	$	654,974	$	61,195	$	30,483	$	1,188,486
2 - Special Mention		4,830		35,461		660		936		41,887
3 - Substandard		21,091		46,800		5,606		4,518		78,015
4 - Doubtful		-		-		95		-		95
Total	$	467,755	$	737,235	$	67,556	$	35,937	$	1,308,483

Business Banking Credit Exposure	Business
By Internally Assigned Grade:	Banking								Total
Non-classified	$	253,120							$	253,120
Classified		18,768								18,768
Total	$	271,888							$	271,888

Consumer Credit Exposure
By Payment Activity:	Indirect		Home Equity		Direct				Total
Performing	$	826,956	$	569,283	$	76,237			$	1,472,476
Nonperforming		1,971		6,395		399				8,765
Total	$	828,927	$	575,678	$	76,636			$	1,481,241

Residential Mortgage Credit Exposure	Residential
By Payment Activity:	Mortgage								Total
Performing	$	539,743							$	539,743
Nonperforming		8,651								8,651
Total	$	548,394							$	548,394

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, 2011 consisted of three commercial loans totaling $0.7 million, twenty-five home equity loans totaling $2.4 million and four residential real estate mortgages totaling $0.8 million. For all such modifications, the pre and post outstanding recorded investment amount remained unchanged. 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.

Modifications made during the year ended December 31, 2010 consisted of one commercial loan totaling $0.3 million. The pre and post outstanding recorded investment amount remained unchanged for this loan. During the year ended December 31, 2010, there were no loans classified as TDRs that subsequently defaulted on their renegotiated terms.

As a result of adopting the amendments in Accounting Standards Update (“ASU”) No. 2011-02, “A Creditor's Determination of Whether a Restructuring Is a Troubled Debt Restructuring (Topic 310)”, the Company reassessed all restructurings that occurred on or after the beginning of the current fiscal year (January 1, 2011) for identification as TDRs. The Company identified as TDRs certain receivables for which the allowance for credit losses had previously been measured under a general allowance for credit losses methodology. Upon identifying those receivables as TDRs, the Company identified them as impaired under the guidance in Section 310-10-35 and evaluated TDRs for impairment in accordance with the Company's methodology used to establish the allowance for loan and lease losses on impaired loans. The amendments in ASU No. 2011-02 require prospective application of the impairment measurement guidance in Section 310-10-35 for those receivables newly identified as impaired. Adoption of this amendment had no material impact on the Company's measured of impairment on these loans.

Related Party Transactions

12 Months Ended

Dec. 31, 2011

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)	2011			2010
Balance at January 1	$	2,914		$	1,843
New loans		25			1,174
Adjustment due to change in composition of related parties		328			216
Repayments		(730	)		(319	)
Balance at December 31	$	2,537		$	2,914

- 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, 2011

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)	2011		2010
Land, buildings, and improvements	$	103,399	$	95,970
Equipment		47,646		72,326
Construction in progress		75		342
Premises and equipment before accumulated depreciation		151,120		168,638
Accumulated depreciation		76,579		101,234
Total premises and equipment	$	74,541	$	67,404

Land, buildings, and improvements with a carrying value of approximately $2.9 million and $3.0 million at December 31, 2011 and 2010, 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. During 2011, a physical inventory was conducted resulting in an entry to remove certain fully depreciated assets determined to be no longer in use, with a gross amount totaling approximately $27.1 million. The entry had no impact on the Company's net book value of fixed assets.

Rental expense included in occupancy expense amounted to $5.9 million in 2011, $5.5 million in 2010, and $5.3 million in 2009. The future minimum rental payments related to noncancelable operating leases with original terms of one year or more are as follows at December 31, 2011 (in thousands):

Future Minimum Rental Payments

2012	$	5,337
2013		5,200
2014		4,786
2015		4,365
2016		4,121
Thereafter		25,081
Total	$	48,890

- 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, 2011

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, 2011		114,841
Goodwill resulting from acquisitions		17,188
December 31, 2011	$	132,029

January 1, 2010		114,938
Goodwill resulting from acquisitions		-
Goodwill reclassification		(97	)
December 31, 2010	$	114,841

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)	2011		2010
Core deposit intangibles
Gross carrying amount	$	11,966	$	10,762
Less: accumulated amortization		6,401		5,517
Net carrying amount		5,565		5,245

Identified intangible assets
Gross carrying amount		20,919		18,556
Less: accumulated amortization		8,290		6,259
Net carrying amount		12,629		12,297

Total intangibles
Gross carrying amount		32,885		29,318
Less: accumulated amortization		14,691		11,776
Net carrying amount	$	18,194	$	17,542

Amortization expense on intangible assets with definite useful lives totaled $3.0 million for 2011, $3.1 million for 2010 and $3.2 million for 2009. Amortization expense on intangible assets with definite useful lives is expected to total $3.2 million for 2012, $3.0 million for 2013, $2.8 million for 2014, $2.6 million for 2015, $1.6 million for 2016 and $3.0 million thereafter. Identified intangible assets include customer lists, non-competes, and trademark intangibles. The Company also has $2.0 million in intangible assets that 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, 2011

Deposits [Abstract]

Deposits

(11)

Deposits

The following table sets forth the maturity distribution of time deposits at December 31, 2011 (in thousands):

Time deposits
Within one year	$	444,870
After one but within two years		162,049
After two but within three years		240,228
After three but within four years		50,954
After four but within five years		28,528
After five years		6,498
Total	$	933,127

Time deposits of $100,000 or more aggregated $305.7 million and $264.4 million December 31, 2011 and 2010, 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, 2011

Short-Term Borrowings [Abstract]

Short-Term Borrowings

(12)	Short-Term Borrowings

Short-term borrowings totaled $181.6 million and $159.4 million at December 31, 2011 and 2010, 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 Federal Home Loan Bank (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 $323 million and $284 million at December 31, 2011 and 2010, 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:

(In thousands)	2011			2010			2009
Federal funds purchased
Balance at year-end	$	27,000		$	-		$	-
Average during the year		3,017			-			5,957
Maximum month end balance		28,000			-			50,000
Weighted average rate during the year		0.11	%		-			0.30	%
Weighted average rate at December 31		0.13	%		-			-

Securities sold under repurchase agreements
Balance at year-end	$	154,592		$	159,184		$	155,727
Average during the year		150,663			157,964			133,859
Maximum month end balance		178,414			169,278			166,208
Weighted average rate during the year		0.13	%		0.25	%		0.40	%
Weighted average rate at December 31		0.10	%		0.15	%		0.32	%

Other short-term borrowings
Balance at year-end	$	-		$	250		$	250
Average during the year		249			250			250
Maximum month end balance		250			250			250
Weighted average rate during the year		-			-			0.03	%
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, 2011

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, 2011 and 2010 is as follows:

	As of December 31, 2011										As of December 31, 2010
Maturity	Amount		Weighted Average Rate			Callable Amount		Weighted Average Rate			Amount		Weighted Average Rate			Callable Amount		Weighted Average Rate
2011		-		-			-		-			1,994		4.73	%		1,994		4.73	%
2013		119,400		3.87	%		100,000		3.71	%		119,400		3.87	%		100,000		3.71	%
2014		2,604		2.00	%		-		-			-		-			-		-
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	%
2025		3,340		2.75	%		-		-			3,480		2.75	%		-		-
	$	370,344				$	345,000				$	369,874				$	346,994

Trust Preferred Debentures

12 Months Ended

Dec. 31, 2011

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, NA owns $1.0 million of CNBF Trust I securities). The recently enacted 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, 2011

Income Taxes [Abstract]

Income Taxes

(15)	Income Taxes

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

	Years ended December 31,
	2011			2010			2009
Current
Federal	$	29,274		$	34,124		$	21,046
State		1,477			1,743			1,086
		30,751			35,867			22,132

Deferred
Federal		(8,129	)		(12,121	)		(1,669	)
State		(1,349	)		(2,834	)		168
		(9,478	)		(14,955	)		(1,501	)
Total income tax expense	$	21,273		$	20,912		$	20,631

Not included in the above table are items that were recorded to stockholders' equity of approximately ($0.5 million), ($4.3 million), and $6.1 million for 2011, 2010, and 2009, 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)	2011			2010
Deferred tax assets
Allowance for loan and lease losses	$	27,487		$	27,463
Deferred compensation		4,911			4,653
Postretirement benefit obligation		1,036			1,024
Fair value adjustments from acquisitions		2,227			-
Accrued liabilities		1,482			1,649
Stock-based compensation expense		4,440			3,943
Other		1,214			1,012
Total deferred tax assets		42,797			39,744
Deferred tax liabilities
Pension and executive retirement		6,916			11,922
Unrealized gains on securities available for sale		12,156			7,162
Premises and equipment, primarily due to accelerated depreciation		2,340			1,384
Equipment leasing		3,090			11,456
Deferred loan costs		767			1,395
Intangible amortization		11,081			10,270
Other		494			178
Total deferred tax liabilities		36,844			43,767
Net deferred tax asset (liability) at year-end		5,953			(4,023	)
Net deferred tax liability at beginning of year		(4,023	)		(23,245	)
Decrease in net deferred tax liability	$	(9,976	)	$	(19,222	)

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, 2011 and 2010.

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

(In thousands)	2011			2010			2009
Balance at January 1	$	3,081		$	2,287		$	2,212
Additions for tax positions of prior years		-			1,714			132
Reduction for tax positions of prior years		(2,193	)		(920	)		(57	)
Balance at December 31	$	888		$	3,081		$	2,287

The $0.9 million, $3.1 million, and $2.3 million of unrecognized tax benefits at December 31, 2011, 2010, and 2009 respectively, would impact the annual effective tax rate, if recognized. During 2011, the Company reached settlement with New York State on franchise tax examinations for the years 2003 through 2007. Also during 2011, there was a reduction of reserves for Federal tax benefits for years in which the statute of limitations has expired. As a result, unrecognized tax benefits were reduced by $1.4 million and $0.8 million related to the examination and the expiration of the statute of limitations, respectively, which resulted in a reduction of tax expense for 2011 of $1.5 million.

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 and 2010 was approximately $0.1 million and $0.7 million, respectively. Net interest impacting the Company's 2011, 2010 and 2009 tax expense was $0.3 million, $0.1 million and $0.2 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)	2011			2010			2009
Federal income tax at statutory rate	$	27,711		$	27,410		$	25,424
Tax exempt income		(2,925	)		(3,448	)		(3,811	)
Net increase in CSV of life insurance		(919	)		(939	)		(871	)
Low income housing tax credits		(782	)		(296	)		(132	)
State taxes, net of federal tax benefit		764			756			816
State audit settlements		(681	)		(1,465	)		-
Other, net		(1,895	)		(1,106	)		(795	)
Income tax expense	$	21,273		$	20,912		$	20,631

- 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
-Name Statement of Financial Accounting Standard (FAS)
-Number 109
-Paragraph 136, 172
-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 109
-Paragraph 43, 44, 45, 46, 47, 48, 49
-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 740
-SubTopic 10
-Section 50
-Paragraph 15
-URI http://asc.fasb.org/extlink&oid=6907707&loc=d3e32718-109319

Reference 5: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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-SubTopic 10
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-Paragraph 9
-URI http://asc.fasb.org/extlink&oid=6907707&loc=d3e32639-109319

Reference 6: 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.(h))
-URI http://asc.fasb.org/extlink&oid=6881521&loc=d3e23780-122690

Reference 7: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 50
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=6907707&loc=d3e32537-109319

Reference 8: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 50
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=6907707&loc=d3e32559-109319

+ Details

Stockholders Equity

12 Months Ended

Dec. 31, 2011

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)	2011			2010
Unrecognized prior service cost and net actuarial loss on pension plans	$	(24,633	)	$	(16,251	)
Unrealized net holding gains on available for sale securities		18,529			10,916
Accumulated other comprehensive income (loss)	$	(6,104	)	$	(5,335	)

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, 2011, approximately $95.9 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 Business 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
-Publisher SEC
-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
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 129
-Paragraph 2, 3, 4, 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 6: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 08
-Article 4

Reference 7: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 5
-Paragraph 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 8: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 02
-Paragraph 29, 30, 31
-Article 5

Reference 9: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Staff Accounting Bulletin (SAB)
-Number Topic 4
-Section E

Reference 10: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Staff Accounting Bulletin (SAB)
-Number Topic 4
-Section C

Reference 11: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.3-04)
-URI http://asc.fasb.org/extlink&oid=6959260&loc=d3e187085-122770

Reference 12: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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-Name Accounting Standards Codification
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Reference 17: http://www.xbrl.org/2003/role/presentationRef
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Reference 20: http://www.xbrl.org/2003/role/presentationRef
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-Name Accounting Standards Codification
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-Paragraph 2
-Subparagraph (SAB TOPIC 4.E)
-URI http://asc.fasb.org/extlink&oid=6228006&loc=d3e74512-122707

Reference 21: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Preferred Stock
-URI http://asc.fasb.org/extlink&oid=6521494

Reference 22: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
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-Paragraph 1
-Subparagraph (SX 210.5-02.29-31)
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 23: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
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-Section S99
-Paragraph 4
-Subparagraph (SAB TOPIC 4.C)
-URI http://asc.fasb.org/extlink&oid=6959260&loc=d3e187143-122770

+ Details

Regulatory Capital Requirements

12 Months Ended

Dec. 31, 2011

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, 2011 and 2010, 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, 2011, 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, 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	%

As of December 31, 2010
Total Capital (to risk weighted assets):
Company	$	537,305		13.70	%		8.00	%		10.00	%
NBT Bank		510,196		13.03	%		8.00	%		10.00	%
Tier I Capital (to risk weighted assets)
Company		487,994		12.44	%		4.00	%		6.00	%
NBT Bank		460,969		11.77	%		4.00	%		6.00	%
Tier I Capital (to average assets)
Company		487,994		9.16	%		4.00	%		5.00	%
NBT Bank		460,969		8.67	%		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
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-Name Accounting Standards Codification
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Reference 7: http://www.xbrl.org/2003/role/presentationRef
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Reference 8: http://www.xbrl.org/2003/role/presentationRef
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-Topic 942
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-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
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-URI http://asc.fasb.org/extlink&oid=6918689&loc=d3e65071-112826

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
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-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6918689&loc=SL5958568-112826

+ Details

Employee Benefit Plans

12 Months Ended

Dec. 31, 2011

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, 2011. 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, 2011 are summarized below. The Company expects that $3.3 million in net actuarial loss and $0.1 million in prior service cost will be recognized as components of net periodic benefit cost in 2012.

	Pension Benefits				Other Benefits
(In thousands)	2011		2010		2011			2010
Net actuarial loss	$	37,914	$	23,161	$	2,323		$	3,089
Prior service cost		1,430		1,739		(874	)		(1,076	)
Total amounts recognized in accumulated other comprehensive loss (pre-tax)	$	39,344	$	24,900	$	1,449		$	2,013

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)	2011			2010			2011			2010
Change in benefit obligation
Benefit obligation at beginning of year	$	70,229		$	63,408		$	4,554		$	3,838
Service cost		2,589			2,254			17			17
Interest cost		3,544			3,613			202			228
Plan participants' contributions		-			-			263			277
Actuarial loss (gain)		5,935			4,940			(562	)		955
Amendments		-			21			-			-
Benefits paid		(4,273	)		(4,007	)		(489	)		(761	)
Projected benefit obligation at end of year		78,024			70,229			3,985			4,554
Change in plan assets
Fair value of plan assets at beginning of year		97,821			90,891			-			-
Actual return (loss) on plan assets		(2,452	)		10,487			-			-
Employer contributions		479			450			226			484
Plan participants' contributions		-			-			263			277
Benefits paid		(4,273	)		(4,007	)		(489	)		(761	)
Fair value of plan assets at end of year		91,575			97,821			-			-

Funded status at year end	$	13,551		$	27,592		$	(3,985	)	$	(4,554	)

The funded status of the pension and other postretirement benefit plans has been recognized as follows in the consolidated balance sheets at December 31, 2011 and 2010. 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 $76.5 million and $68.6 million at December 31, 2011 and 2010, respectively. The accumulated benefit obligation for other postretirement benefits was $4.0 million and $4.6 million at December 31, 2011 and 2010, respectively.

	Pension Benefits						Other Benefits
(In thousands)	2011			2010			2011			2010
Other assets	$	23,973		$	35,895		$	-		$	-
Other liabilities		(10,422	)		(8,303	)		(3,985	)		(4,554	)
Funded status	$	13,551		$	27,592		$	(3,985	)	$	(4,554	)

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)	2011			2010			2009
Weighted average assumptions:
The following assumptions were used to determine benefit obligations:
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	%

The following assumptions were used to determine net periodic pension cost:
Discount rate		5.15	%		5.70	%		6.30	%
Expected long-term return on plan assets		8.00	%		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)	2011			2010			2009			2011			2010			2009
Components of net periodic benefit cost
Service cost	$	2,589		$	2,254		$	2,222		$	17		$	17		$	17
Interest cost		3,544			3,613			3,413			202			228			205
Expected return on plan assets		(7,720	)		(7,166	)		(5,591	)		-			-			-
Amortization of initial unrecognized asset		-			-			(23	)		-			-			-
Amortization of prior service cost		309			322			296			(202	)		(202	)		(202	)
Amortization of unrecognized net loss		1,353			1,447			2,374			205			201			136
Net periodic pension cost	$	75		$	470		$	2,691		$	222		$	244		$	156

Other changes in plan assets and benefit obligations recognized in other comprehensive income (pre-tax)

Net loss (gain)	$	16,108		$	1,620		$	(6,053	)	$	(562	)	$	955		$	289
Prior service cost		-			21			127			-			-			-
Amortization of initial unrecognized asset		-			-			23			-			-			-
Amortization of prior service cost		(309	)		(322	)		(296	)		202			202			202
Amortization of unrecognized net gain		(1,353	)		(1,447	)		(2,374	)		(205	)		(201	)		(136	)
Total recognized in other comprehensive loss (income)		14,446			(128	)		(8,573	)		(565	)		956			355

Total recognized in net periodic benefit cost and other comprehensive income (loss) - pre-tax	$	14,521		$	342		$	(5,882	)	$	(343	)	$	1,200		$	511

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

	Pension		Other
	Benefits		Benefits

2012		5,010		204
2013		5,236		218
2014		5,361		232
2015		7,034		244
2016		5,590		254
Thereafter		29,745		1,358

The Company is not required to make contributions to the defined benefit plan in 2012.

For measurement purposes, the annual rates of increase in the per capita cost of covered medical and prescription drug benefits for fiscal year 2011 were assumed to be 8.0 to 9.75 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, 2011:

(In thousands)	One Percentage point increase		One Percentage point decrease
Increase (decrease) on total service and interest cost components	$	29	$	(24	)
Increase (decrease) on postretirement accumulated benefit obligation		482		(410	)

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 2012			2011			2010
Cash and cash equivalents		0 - 20	%		2	%		2	%
Fixed income securities		20 - 40	%		34	%		26	%
Equities		40 - 80	%		64	%		72	%
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, 2011 and 2010 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, 2011 and 2010:

	Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)		Balance as of 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

(in thousands)	Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)		Balance as of December 31, 2010
Cash and Cash Equivalents	$	1,604	$	-	$	-	$	1,604
Foreign Equity Mutual Funds		6,577		-		-		6,577
Equity Mutual Funds		22,515		-		-		22,515
US Government Bonds		-		16,219		-		16,219
Corporate Bonds		-		5,003		-		5,003
Common Stock		31,213		-		-		31,213
Municipal bonds and Notes		-		2,294		-		2,294
Foreign Bonds and Notes		-		1,666		-		1,666
Foreign Equity		10,730		-		-		10,730
Totals	$	72,639	$	25,182	$	-	$	97,821

The Plan had no financial instruments recorded at fair value on a nonrecurring basis as of December 31, 2011.

Determination of Assumed Rate of Return

The expected long-term rate-of-return on assets is 7.5% at December 31, 2011. 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 $3.7 million in 2011, $3.5 million in 2010, and $3.4 million in 2009.

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 assumes 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 2011, 2010, and 2009 was $5.45, $5.03, and $5.71, 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,
	2011	2010	2009
Dividend yield	3.31%–3.82%	3.27%–3.96%	2.86%–3.65%
Expected volatility	33.75%–34.36%	33.00%–33.86%	30.20%–32.91%
Risk-free interest rates	1.48%–2.81%	1.90%–3.17%	1.71%–3.20%
Expected life	7 years	7 years	7 years

The following table summarizes information concerning stock options outstanding at December 31, 2011:

	Number of Shares			Weighted average exercise price		Weighted Average Remaining Contractual Term (in yrs)		Aggregate Intrinsic Value
Outstanding at December 31, 2010		2,031,578		$	22.05
Granted		50,700			22.21
Exercised		(142,178	)		16.11
Forfeited		(26,085	)		24.42
Expired		(50,425	)		24.64
Outstanding at December 31, 2011		1,863,590		$	22.41		5.37	$	3,869,134

Exercisable at December 31, 2011		1,457,710		$	22.50		4.71	$	2,872,729

Expected to Vest		399,034		$	22.08		7.73	$	979,661

Total stock-based compensation expense for stock option awards totaled $0.9 million for the year ended December 31, 2011, $1.8 million for the year ended December 31, 2010, and $1.6 million for the year ended December 31, 2009. There were no new stock option awards issued in 2011 which caused the aforementioned decrease. Cash proceeds, tax benefits and intrinsic value related to total stock options exercised is as follows:

	Years ended
(dollars in thousands)	2011		2010		2009
Proceeds from stock options exercised	$	1,793	$	1,778	$	2,728
Tax benefits related to stock options exercised		341		140		(243	)
Intrinsic value of stock options exercised		897		574		406
Fair value of shares vested during the year		1,597		1,800		1,700

The Company has outstanding restricted and deferred stock awards granted from various plans at December 31, 2011. The Company recognized $2.3 million in stock-based compensation expense related to these stock awards for the year ended December 31, 2011, $2.0 million for the year ended December 31, 2010, and $1.5 million for the year ended December 31, 2009. Tax benefits recognized with respect to restricted and deferred stock-based compensation expense were $1.2 million, $0.7 million and $0.6 million for the years ended December 31, 2011, 2010 and 2009, respectively. Unrecognized compensation cost related to restricted stock awards and stock units totaled $4.4 million at December 31, 2011 and will be recognized over 2.8 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, 2011:

	Number of Shares			Weighted- Average Grant Date Fair Value
Unvested Restricted Stock Awards
Unvested at January 1, 2011		202,039		$	24.09
Forfeited		(14,000	)		24.44
Vested		(58,110	)		24.48
Granted		25,447			24.09
Unvested at December 31, 2011		155,376		$	23.92

The following table summarizes information for unvested restricted stock units outstanding as of December 31, 2011:

	Number of Shares			Weighted- Average Grant Date Fair Value
Unvested Restricted Stock Units
Unvested at January 1, 2011		57,400		$	22.59
Forfeited		(3,520	)		-
Vested		(625	)		-
Granted		188,652			23.84
Unvested at December 31, 2011		241,907		$	23.95

The Company has 4.6 million securities remaining available to be granted as part of the Plan at December 31, 2011.

- 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)
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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 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 132R
-Paragraph 5
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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 Statement of Financial Accounting Standard (FAS)
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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 5: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 132R
-Paragraph 8
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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
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
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Reference 7: http://www.xbrl.org/2003/role/presentationRef
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-Name Statement of Financial Accounting Standard (FAS)
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Reference 11: http://www.xbrl.org/2003/role/presentationRef
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-Name Statement of Financial Accounting Standard (FAS)
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-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
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-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.

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+ Details

Commitments and Contingent Liabilities

12 Months Ended

Dec. 31, 2011

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, 2011, approximately 58% of the Company's loans were secured by real estate located in central and northern New York, northeastern Pennsylvania, western Massachusetts 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)	2011		2010
Unused lines of credit	$	161,551	$	141,579
Commitments to extend credits, primarily variable rate		603,322		501,987
Standby letters of credit		26,783		26,193
Commercial letters of credit		15,218		16,255
Loans sold with recourse		16,175		13,970

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, 2011 and 2010 was not significant.

The total amount of loans serviced by the Company for unrelated third parties was approximately $301.9 million and $323.2 million at December 31, 2011 and 2010, 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, 2011 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.

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-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
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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.

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+ Details

Parent Company Financial Information

12 Months Ended

Dec. 31, 2011

Parent Company Financial Information [Abstract]

Parent Company Financial Information

(20) Parent Company Financial Information

Condensed Balance Sheets

	December 31,
(In thousands)	2011		2010
Assets
Cash and cash equivalents	$	2,454	$	3,493
Securities available for sale, at estimated fair value		9,825		9,190
Trading securities		2,550		2,273
Investment in subsidiaries, on equity basis		622,885		609,260
Other assets		48,153		41,942
Total assets	$	685,867	$	666,158
Liabilities and Stockholders' Equity
Total liabilities	$	147,757	$	132,586
Stockholders' equity		538,110		533,572
Total liabilities and stockholders' equity	$	685,867	$	666,158

Condensed Income Statements

	Years ended December 31,
(In thousands)	2011			2010		2009
Dividends from subsidiaries	$	54,400		$	12,000	$	9,000
Management fee from subsidiaries		69,430			68,228		65,596
Securities (losses) gains		(31	)		1,814		141
Interest, dividend and other income		628			1,136		869
Total revenue		124,427			83,178		75,606
Operating expense		75,254			72,436		73,687
Income before income tax benefit and equity in undistributed income of subsidiaries		49,173			10,742		1,919
Income tax benefit		1,340			282		1,994
Equity in undistributed income of subsidiaries		7,388			46,380		48,098
Net income	$	57,901		$	57,404	$	52,011

Statements of Cash Flow

	Years ended December 31,
(In thousands)	2011			2010			2009
Operating activities
Net income	$	57,901		$	57,404		$	52,011
Adjustments to reconcile net income to net cash provided by operating activities
Stock-based compensation		3,244			3,782			3,133
Loss (Gain) on sales of available-for-sale securities		31			(1,814	)		(141	)
Equity in undistributed income of subsidiaries		(7,388	)		(46,380	)		(48,098	)
Net change in other liabilities		15,311			2,155			(3,662	)
Net change in other assets		(11,607	)		(2,605	)		3,632
Net cash provided by operating activities		57,492			12,542			6,875
Investing activities
Purchases of available-for-sale securities		(968	)		(1,745	)		(2,173	)
Sales and maturities of available-for-sale securities		71			7,807			494
Purchases of premises and equipment		(1,656	)		(321	)		(600	)
Net cash provided by (used in) investing activities		(2,553	)		5,741			(2,279	)
Financing activities
Proceeds from the issuance of shares to employee benefit plans and other stock plans		1,386			1,675			2,728
Payments on long-term debt		(140	)		(135	)		(12,625	)
Proceeds from the issuance of common stock		-			-			33,401
Purchases of treasury shares		(30,502	)		(477	)		-
Cash dividends and payments for fractional shares		(27,063	)		(27,577	)		(27,119	)
Excess tax benefit from exercise of stock options		341			140			(243	)
Net cash used in financing activities		(55,978	)		(26,374	)		(3,858	)
Net (decrease) increase in cash and cash equivalents		(1,039	)		(8,091	)		738
Cash and cash equivalents at beginning of year		3,493			11,584			10,846
Cash and cash equivalents at end of year	$	2,454		$	3,493		$	11,584

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, 2011

Fair Values of Financial Instruments [Abstract]

Fair Values of Financial Instruments

(21) Fair Values of Financial Instruments

The following methods and assumptions were used to estimate the fair value of each class of financial instruments.

Short-Term Instruments

For short-term instruments, such as cash and cash equivalents, accrued interest receivable, accrued interest payable, and short term borrowings, carrying value approximates fair value.

Securities

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 third party pricing vendors 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.

Loans

For variable rate loans that reprice frequently and have no significant credit risk, fair values are based on carrying values. The fair values for fixed rate loans are estimated through discounted cash flow analysis using interest rates currently being offered for loans with similar terms and credit quality. Nonperforming loans are valued based upon recent loss history for similar loans.

Deposits

The fair values disclosed for savings, money market, and noninterest bearing accounts are, by definition, equal to their carrying values at the reporting date. The fair value of fixed maturity time deposits is estimated using a discounted cash flow analysis that applies interest rates currently offered to a schedule of aggregated expected monthly maturities on time deposits.

Long-Term Debt

The fair value of long-term debt has been estimated using discounted cash flow analysis that applies interest rates currently offered for notes with similar terms.

Commitments to Extend Credit and Standby Letters of Credit

The fair value of commitments to extend credit and standby letters of credit are estimated using fees currently charged to enter into similar agreements, taking into account the remaining terms of the agreements and the present credit worthiness of the counterparties. Carrying amounts, which are comprised of the unamortized fee income, are not significant.

Trust Preferred Debentures

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

Estimated fair values of financial instruments at December 31 are as follows:

	2011				2010
(In thousands)	Carrying amount		Estimated fair value		Carrying amount		Estimated fair value
Financial assets
Cash and cash equivalents	$	129,381	$	129,381	$	168,792	$	168,792
Securities available for sale		1,244,619		1,244,619		1,129,368		1,129,368
Securities held to maturity		70,811		72,198		97,310		98,759
Trading securities		3,062		3,062		2,808		2,808
Net loans		3,728,869		3,821,640		3,538,772		3,626,603
Accrued interest receivable		17,800		17,800		19,130		19,130
Financial liabilities
Savings, NOW, and money market	$	2,381,116	$	2,381,116	$	2,291,833	$	2,291,833
Time deposits		933,127		942,436		930,778		943,988
Noninterest bearing		1,052,906		1,052,906		911,741		911,741
Short-term borrowings		181,592		181,592		159,434		159,434
Long-term debt		370,344		427,107		369,874		423,350
Accrued interest payable		3,942		3,942		4,356		4,356
Trust preferred debentures		75,422		75,422		75,422		71,148

1. Lease receivables, although excluded from the scope of SFAS No. 107, are included in the estimated fair value amounts at their carrying amounts.

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.

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, 2011 and December 31, 2010. 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 Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)		Balance as of 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

	Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)		Balance as of December 31, 2010
Assets:
Securities Available for Sale:
U.S. Treasury		91,280		-		-		91,280
Federal Agency		-		349,750		-		349,750
State & municipal		-		114,937		-		114,937
Mortgage-backed		-		244,808		-		244,808
Collateralized mortgage obligations		-		297,888		-		297,888
Corporate		-		20,489		-		20,489
Other securities		8,190		2,026		-		10,216
Total Securities Available for Sale	$	99,470	$	1,029,898	$	-	$	1,129,368

Trading Securities		2,808		-		-		2,808
Total	$	102,278	$	1,029,898	$	-	$	1,132,176

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 $0.5 million which had specific reserves included in the allowance for loan and lease losses of $0.2 million at December 31, 2011. The Company uses the fair value of underlying collateral to estimate the specific reserves for collateral dependent impaired loans. 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, 2011, 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
-SubTopic 10
-Section 50
-Paragraph 21
-URI http://asc.fasb.org/extlink&oid=6947722&loc=d3e13537-108611

Reference 10: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 28
-URI http://asc.fasb.org/extlink&oid=6957238&loc=d3e14064-108612

Reference 11: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 10
-URI http://asc.fasb.org/extlink&oid=6947722&loc=d3e13433-108611

Reference 12: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 30
-URI http://asc.fasb.org/extlink&oid=6957238&loc=d3e14172-108612

Reference 13: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 16
-URI http://asc.fasb.org/extlink&oid=6947722&loc=d3e13504-108611

Reference 14: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=6925170&loc=d3e19296-110258

+ Details

Significant Accounting Policies (Policies)	12 Months Ended
Significant Accounting Policies (Policies)	Dec. 31, 2011
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 northern New York, northeastern Pennsylvania, western Massachusetts and Burlington, Vermont. The Company has identified separate operating segments; however, these segments did not meet the quantitative thresholds for separate disclosure.
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 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, with the exception of small business investment company (SBIC) investments, which are carried at fair value in accordance with SBIC rules. 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 FHLB stock are required for membership in those organizations and are carried at cost since there is no market value available.
Loans and Leases	Loans and Leases 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 and leases are placed on nonaccrual status when timely collection of principal and interest in accordance with contractual terms is doubtful. Loans and leases 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 or lease 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 and lease 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 and Lease Losses	Allowance for Loan and Lease Losses The allowance for loan and lease losses is the amount which, in the opinion of management, is necessary to absorb probable losses inherent in the loan and lease 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 and lease losses are made periodically by charges to the provision for loan and lease losses. The allowance for loan and lease 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 and lease losses is adequate. While management uses available information to recognize loan and lease losses, future additions to the allowance for loan and lease 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 and lease losses. Such agencies may require the Company to recognize additions to the allowance for loan and lease 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 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 and lease losses and any subsequent valuation write-downs are charged to other expense. In connection with the determination of the allowance for loan and lease 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, 2011 and 2010 was approximately $2.2 million and $0.9 million, respectively.
Acquired Loans	Acquired Loans Loans that we acquire in acquisitions subsequent to January 1, 2009 are recorded at fair value with no carryover of the related allowance for credit losses. Determining the fair value of the loans involves estimating the amount and timing of principal and interest cash flows expected to be collected on the loans and discounting those cash flows at a market rate of interest. The excess of cash flows expected at acquisition over the estimated fair value is referred to as the accretable discount and is recognized into interest income over the remaining life of the loan. The difference between contractually required payments at acquisition and the cash flows expected to be collected at acquisition is referred to as the nonaccretable discount. The nonaccretable discount represents estimated future credit losses expected to be incurred over the life of the loan. Subsequent decreases to the expected cash flows require us to evaluate the need for an allowance for credit losses. Subsequent improvements in expected cash flows result in the reversal of a corresponding amount of the nonaccretable discount which we then reclassify as accretable discount that is recognized into interest income over the remaining life of the loan using the interest method. Our evaluation of the amount of future cash flows that we expect to collect is performed in a similar manner as that used to determine our allowance for credit losses. Charge-offs of the principal amount on acquired loans would be first applied to the nonaccretable discount portion of the fair value adjustment. Acquired loans that met the criteria for nonaccrual of interest prior to the acquisition may be considered performing upon acquisition, regardless of whether the customer is contractually delinquent, if we can reasonably estimate the timing and amount of the expected cash flows on such loans and if we expect to fully collect the new carrying value of the loans. As such, we may no longer consider the loan to be nonaccrual or nonperforming and may accrue interest on these loans, including the impact of any accretable discount. We have determined that we can reasonably estimate future cash flows on any such acquired loans that are past due 90 days or more and on which we are accruing interest and we expect to fully collect the carrying value of the loans.
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.
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.
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.

Earnings Per Share (Tables)

12 Months Ended

Dec. 31, 2011

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,
	2011						2010						2009
			Weighted						Weighted						Weighted
(In thousands, except share and per share data)	Net income		average shares		Per share amount		Net income		average shares		Per share amount		Net income		average shares		Per share amount
Basic earnings per share	$	57,901		33,662	$	1.72	$	57,404		34,275	$	1.67	$	52,011		33,723	$	1.54
Effect of dilutive securities

Stock based compensation				262						234						180
Diluted earnings per share	$	57,901		33,924	$	1.71	$	57,404		34,509	$	1.66	$	52,011		33,903	$	1.53

Securities (Tables)

12 Months Ended

Dec. 31, 2011

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, 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
December 31, 2010
U.S. Treasury	$	91,338	$	424	$	482	$	91,280
Federal Agency		350,641		1,905		2,796		349,750
State & municipal		113,821		1,771		655		114,937
Mortgage-backed		233,861		11,666		719		244,808
Collateralized mortgage obligations		293,565		6,574		2,251		297,888
Corporate		20,005		484		-		20,489
Other securities		8,059		2,162		5		10,216
Total securities available for sale	$	1,111,290	$	24,986	$	6,908	$	1,129,368

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)	2011			2010			2009
Proceeds from sales	$	2,437		$	103,253		$	2,753
Gross realized gains	$	7		$	3,170		$	154
Gross realized losses		(165	)		(25	)		(49	)
Net securities (losses) gains	$	(158	)	$	3,145		$	105

Schedule 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, 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
December 31, 2010
Mortgage-backed	$	1,719	$	200	$	-	$	1,919
State & municipal		95,591		1,249		-		96,840
Total securities held to maturity	$	97,310	$	1,449	$	-	$	98,759

Schedule of 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, 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

December 31, 2010
U.S. Treasury	$	40,741	$	(482	)		4	$	-	$	-			-	$	40,741	$	(482	)		4
Federal agency		147,012		(2,796	)		12		-		-			-		147,012		(2,796	)		12
State & municipal		22,273		(317	)		31		7,533		(338	)		19		29,806		(655	)		50
Mortgage-backed		44,340		(719	)		3		-		-			-		44,340		(719	)		3
Collateralized mortgage obligations		72,595		(2,251	)		3		-		-			-		72,595		(2,251	)		3
Other securities		95		(5	)		1		-		-			-		95		(5	)		1
Total securities with unrealized losses	$	327,056	$	(6,570	)		54	$	7,533	$	(338	)		19	$	334,589	$	(6,908	)		73

Schedule of contractual maturities of debt securities

The following tables set forth information with regard to contractual maturities of debt securities at December 31, 2011:

(In thousands)	Amortized cost		Estimated fair value
Debt securities classified as available for sale
Within one year	$	23,867	$	23,941
From one to five years		302,772		305,366
From five to ten years		245,058		254,864
After ten years		633,302		649,568
	$	1,204,999	$	1,233,739

Debt securities classified as held to maturity
Within one year	$	26,315	$	26,383
From one to five years		34,032		35,058
From five to ten years		7,073		7,153
After ten years		3,391		3,604
	$	70,811	$	72,198

- 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.

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- 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.

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+ Details

Loans and Leases (Tables)

12 Months Ended

Dec. 31, 2011

Loans and Leases [Abstract]

Loans and leases, net of deferred fees and origination costs

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

	At December 31,
(In thousands)	2011		2010
Residential real estate mortgages	$	581,511	$	548,394
Commercial		611,298		577,731
Commercial real estate		888,879		844,458
Real estate construction and development		93,977		45,444
Agricultural and agricultural real estate mortgages		108,423		112,738
Consumer		946,470		905,563
Home equity		569,645		575,678
Total loans and leases	$	3,800,203	$	3,610,006

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

12 Months Ended

Dec. 31, 2011

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

Allowance for loan and lease losses by portfolio

The following table illustrates the changes in the allowance for loan and lease losses by portfolio segment for the years ended December 31, 2011 and 2010:

Allowance for Loan and Lease Losses

(in thousands)

Years ended December 31							Residential
	Commercial			Consumer			Real Estate
	Loans			Loans			Mortgages			Unallocated			Total
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 and lease losses and the recorded investment by portfolio segment as of December 31, 2011 and 2010:

Allowance for Loan and Lease Losses and Recorded Investment in Loans and Leases

(in thousands)

					Residential
	Commercial		Consumer		Real Estate
	Loans		Loans		Mortgages		Unallocated		Total
As of December 31, 2011
Allowance for loan and lease losses	$	38,831	$	26,049	$	6,249	$	205	$	71,334

Allowance for loans and leases individually evaluated for impairment	$	175	$	-	$	-			$	175

Allowance for loans and leases collectively evaluated for impairment	$	38,656	$	26,049	$	6,249	$	205	$	71,159

Ending balance of loans and leases	$	1,702,577	$	1,516,115	$	581,511			$	3,800,203

Ending balance of loans and leases individually evaluated for impairment	$	6,219	$	-	$	-			$	6,219

Ending balance of loans and leases collectively evaluated for impairment	$	1,696,358	$	1,516,115	$	581,511			$	3,793,984

As of December 31, 2010
Allowance for loan and lease losses	$	40,101	$	26,126	$	4,627	$	380	$	71,234

Allowance for loans and leases individually evaluated for impairment	$	2,211	$	-	$	-			$	2,211

Allowance for loans and leases collectively evaluated for impairment	$	37,890	$	26,126	$	4,627	$	380	$	69,023

Ending balance of loans and leases	$	1,580,371	$	1,481,241	$	548,394			$	3,610,006

Ending balance of loans and leases individually evaluated for impairment	$	11,419	$	-	$	-			$	11,419

Ending balance of loans and leases collectively evaluated for impairment	$	1,568,952	$	1,481,241	$	548,394			$	3,598,587

Credit Quality of Loans and Leases

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

The following table illustrates the Company's nonaccrual loans by loan class as of December 31, 2011 and 2010:

Loans on Nonaccrual Status

(In thousands)	December 31, 2011		December 31, 2010
Commercial Loans
Commercial	$	1,699	$	5,837
Commercial Real Estate		4,868		5,687
Agricultural		3,307		4,065
Agricultural Real Estate		2,067		2,429
Business Banking		7,446		7,033
		19,387		25,051

Consumer Loans
Indirect		1,550		1,971
Home Equity		7,931		6,395
Direct		378		399
		9,859		8,765

Residential Real Estate Mortgages		9,044		8,651

Total Nonaccrual	$	38,290	$	42,467

Past Due Financing Receivables

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

Age Analysis of Past Due Financing Receivables

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

Age Analysis of Past Due Loans and Leases

As of December 31, 2010

(in thousands)


					Greater Than								Recorded
	31-60 Days		61-90 Days		91 Days		Total						Total
	Past Due		Past Due		Past Due		Past Due						Loans and
	Accruing		Accruing		Accruing		Accruing		Non-Accrual		Current		Leases
Commercial
Commercial	$	136	$	55	$	94	$	285	$	5,837	$	461,633	$	467,755
Commercial Real Estate		1,263		-		-		1,263		5,687		730,285		737,235
Agricultural		63		92		-		155		4,065		63,336		67,556
Agricultural Real Estate		108		-		-		108		2,429		33,400		35,937
Business Banking		2,570		1,183		-		3,753		7,033		261,102		271,888
		4,140		1,330		94		5,564		25,051		1,549,756		1,580,371

Consumer
Indirect		9,307		2,193		862		12,362		1,971		814,594		828,927
Home Equity		5,740		1,756		396		7,892		6,395		561,391		575,678
Direct		927		158		54		1,139		399		75,098		76,636
		15,974		4,107		1,312		21,393		8,765		1,451,083		1,481,241

Residential Real Estate Mortgages		3,002		126		919		4,047		8,651		535,696		548,394
	$	23,116	$	5,563	$	2,325	$	31,004	$	42,467	$	3,536,535	$	3,610,006

Impaired loans and specific reserve allocations

The following provides additional information on impaired loans for the years ended December 31, 2011 and 2010:

Impaired Loans
	December 31, 2011						December 31, 2010
	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	$	1,243	$	2,723			$	2,112	$	2,459
Commercial Real Estate		4,868		7,165				5,687		6,654
Agricultural		3,307		4,166				2,394		2,865
Agricultural Real Estate		2,067		2,288				1,701		1,883
Business Banking		7,446		9,976				7,033		9,395
Total Commercial Loans		18,931		26,318				18,927		23,256

Consumer Loans
Home Equity		2,000		2,103				-		-

Residential Real Estate Mortgages		1,040		1,125				313		339
		21,971		29,546				19,240		23,595

With an allowance recorded:
Commercial Loans
Commercial	$	456	$	808	$	175	$	3,725	$	4,762	$	1,907
Commercial Real Estate		-		-		-		-		-		-
Agricultural		-		-		-		1,671		1,918		281
Agricultural Real Estate		-		-		-		728		784		23
		456		808		175		6,124		7,464		2,211

Total:	$	22,427	$	30,354	$	175	$	25,364	$	31,059	$	2,211

Financing Receivable Credit Quality by Loan Class

The following table summarizes the average recorded investments on impaired loans and the interest income recognized for the years ended December 31, 2011, 2010 and 2009:

	December 31, 2011						December 31, 2010						December 31, 2009
	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	$	2,322	$	94	$	94	$	1,898	$	113	$	113	$	1,118	$	1,429	$	1,429
Commercial Real Estate		4,794		163		163		4,219		317		317		5,702		2,744		2,744
Agricultural		3,013		133		133		2,990		82		82		1,606		531		531
Agricultural Real Estate		1,719		109		109		1,929		150		150		1,853		589		589
Business Banking		6,121		266		266		4,959		234		234		6,231		917		917
Consumer Loans
Home Equity		1,904		91		91		-		-		-		-		-		-
Res Real Estate Mortgages		926		58		58		132		6		6		-		-		-
	$	20,798	$	914	$	914	$	16,127	$	902	$	902	$	16,509	$	6,210	$	6,210

With an allowance recorded:
Commercial Loans
Commercial	$	861	$	86	$	86	$	2,366	$	118	$	118	$	2,984	$	57	$	57
Commercial Real Estate		287		-		-		1,234		-		-		1,551		-		-
Agricultural		791		68		68		1,386		150		150		2,046		63		63
Agricultural Real Estate		357		18		18		816		67		67		560		5		5
	$	2,295	$	172	$	172	$	5,802	$	335	$	335	$	7,141	$	125	$	125

Total:	$	23,094	$	1,086	$	1,086	$	21,929	$	1,237	$	1,237	$	23,650	$	6,335	$	6,335

Commercial Grading System

4 – Doubtful

3 – Substandard

2 – Special Mention

1 – Pass

Business Banking Grading System

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

Classified

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

The following tables illustrates the Company's credit quality by loan class for the years ended December 31, 2011 and 2010:

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

Credit Quality Indicators

As of December 31, 2010

(in thousands)

Commercial Credit Exposure			Commercial				Agricultural
By Internally Assigned Grade:	Commercial		Real Estate		Agricultural		Real Estate		Total
1 - Pass	$	441,834	$	654,974	$	61,195	$	30,483	$	1,188,486
2 - Special Mention		4,830		35,461		660		936		41,887
3 - Substandard		21,091		46,800		5,606		4,518		78,015
4 - Doubtful		-		-		95		-		95
Total	$	467,755	$	737,235	$	67,556	$	35,937	$	1,308,483

Business Banking Credit Exposure	Business
By Internally Assigned Grade:	Banking								Total
Non-classified	$	253,120							$	253,120
Classified		18,768								18,768
Total	$	271,888							$	271,888

Consumer Credit Exposure
By Payment Activity:	Indirect		Home Equity		Direct				Total
Performing	$	826,956	$	569,283	$	76,237			$	1,472,476
Nonperforming		1,971		6,395		399				8,765
Total	$	828,927	$	575,678	$	76,636			$	1,481,241

Residential Mortgage Credit Exposure	Residential
By Payment Activity:	Mortgage								Total
Performing	$	539,743							$	539,743
Nonperforming		8,651								8,651
Total	$	548,394							$	548,394

Related Party Transactions (Tables)

12 Months Ended

Dec. 31, 2011

Related Party Loans

The aggregate amount of loans outstanding to qualifying related parties and changes during the years are summarized as follows:

(In thousands)	2011			2010
Balance at January 1	$	2,914		$	1,843
New loans		25			1,174
Adjustment due to change in composition of related parties		328			216
Repayments		(730	)		(319	)
Balance at December 31	$	2,537		$	2,914

Premises and Equipment, Net (Tables)

12 Months Ended

Dec. 31, 2011

Premises and Equipment, Net [Abstract]

Summary of premises and equipment

A summary of premises and equipment follows:

	December 31,
(In thousands)	2011		2010
Land, buildings, and improvements	$	103,399	$	95,970
Equipment		47,646		72,326
Construction in progress		75		342
Premises and equipment before accumulated depreciation		151,120		168,638
Accumulated depreciation		76,579		101,234
Total premises and equipment	$	74,541	$	67,404

Future minimum rental payments related to noncancelable operating leases

The future minimum rental payments related to noncancelable operating leases with original terms of one year or more are as follows at December 31, 2011 (in thousands):

Future Minimum Rental Payments

2012	$	5,337
2013		5,200
2014		4,786
2015		4,365
2016		4,121
Thereafter		25,081
Total	$	48,890

- 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, 2011

Goodwill and Other Intangible Assets [Abstract]

Summary of goodwill

A summary of goodwill is as follows:

(In thousands)
January 1, 2011		114,841
Goodwill resulting from acquisitions		17,188
December 31, 2011	$	132,029

January 1, 2010		114,938
Goodwill resulting from acquisitions		-
Goodwill reclassification		(97	)
December 31, 2010	$	114,841

Summary of core deposit and other intangible assets

A summary of core deposit and other intangible assets follows:

	December 31,
(In thousands)	2011		2010
Core deposit intangibles
Gross carrying amount	$	11,966	$	10,762
Less: accumulated amortization		6,401		5,517
Net carrying amount		5,565		5,245

Identified intangible assets
Gross carrying amount		20,919		18,556
Less: accumulated amortization		8,290		6,259
Net carrying amount		12,629		12,297

Total intangibles
Gross carrying amount		32,885		29,318
Less: accumulated amortization		14,691		11,776
Net carrying amount	$	18,194	$	17,542

- 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, 2011

Deposits [Abstract]

Maturity distribution of time deposits

The following table sets forth the maturity distribution of time deposits at December 31, 2011 (in thousands):

Time deposits
Within one year	$	444,870
After one but within two years		162,049
After two but within three years		240,228
After three but within four years		50,954
After four but within five years		28,528
After five years		6,498
Total	$	933,127

Short-Term Borrowings (Tables)

12 Months Ended

Dec. 31, 2011

Short-Term Borrowings [Abstract]

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

(In thousands)	2011			2010			2009
Federal funds purchased
Balance at year-end	$	27,000		$	-		$	-
Average during the year		3,017			-			5,957
Maximum month end balance		28,000			-			50,000
Weighted average rate during the year		0.11	%		-			0.30	%
Weighted average rate at December 31		0.13	%		-			-

Securities sold under repurchase agreements
Balance at year-end	$	154,592		$	159,184		$	155,727
Average during the year		150,663			157,964			133,859
Maximum month end balance		178,414			169,278			166,208
Weighted average rate during the year		0.13	%		0.25	%		0.40	%
Weighted average rate at December 31		0.10	%		0.15	%		0.32	%

Other short-term borrowings
Balance at year-end	$	-		$	250		$	250
Average during the year		249			250			250
Maximum month end balance		250			250			250
Weighted average rate during the year		-			-			0.03	%
Weighted average rate at December 31		-			-			-

Long-Term Debt (Tables)

12 Months Ended

Dec. 31, 2011

Long-Term Debt [Abstract]

Schedule of Long-term Debt

A summary as of December 31, 2011 and 2010 is as follows:

	As of December 31, 2011										As of December 31, 2010
Maturity	Amount		Weighted Average Rate			Callable Amount		Weighted Average Rate			Amount		Weighted Average Rate			Callable Amount		Weighted Average Rate
2011		-		-			-		-			1,994		4.73	%		1,994		4.73	%
2013		119,400		3.87	%		100,000		3.71	%		119,400		3.87	%		100,000		3.71	%
2014		2,604		2.00	%		-		-			-		-			-		-
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	%
2025		3,340		2.75	%		-		-			3,480		2.75	%		-		-
	$	370,344				$	345,000				$	369,874				$	346,994

Income Taxes (Tables)

12 Months Ended

Dec. 31, 2011

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,
	2011			2010			2009
Current
Federal	$	29,274		$	34,124		$	21,046
State		1,477			1,743			1,086
		30,751			35,867			22,132

Deferred
Federal		(8,129	)		(12,121	)		(1,669	)
State		(1,349	)		(2,834	)		168
		(9,478	)		(14,955	)		(1,501	)
Total income tax expense	$	21,273		$	20,912		$	20,631

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)	2011			2010
Deferred tax assets
Allowance for loan and lease losses	$	27,487		$	27,463
Deferred compensation		4,911			4,653
Postretirement benefit obligation		1,036			1,024
Fair value adjustments from acquisitions		2,227			-
Accrued liabilities		1,482			1,649
Stock-based compensation expense		4,440			3,943
Other		1,214			1,012
Total deferred tax assets		42,797			39,744
Deferred tax liabilities
Pension and executive retirement		6,916			11,922
Unrealized gains on securities available for sale		12,156			7,162
Premises and equipment, primarily due to accelerated depreciation		2,340			1,384
Equipment leasing		3,090			11,456
Deferred loan costs		767			1,395
Intangible amortization		11,081			10,270
Other		494			178
Total deferred tax liabilities		36,844			43,767
Net deferred tax asset (liability) at year-end		5,953			(4,023	)
Net deferred tax liability at beginning of year		(4,023	)		(23,245	)
Decrease in net deferred tax liability	$	(9,976	)	$	(19,222	)

Reconciliation of gross unrecognized tax benefits

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

(In thousands)	2011			2010			2009
Balance at January 1	$	3,081		$	2,287		$	2,212
Additions for tax positions of prior years		-			1,714			132
Reduction for tax positions of prior years		(2,193	)		(920	)		(57	)
Balance at December 31	$	888		$	3,081		$	2,287

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)	2011			2010			2009
Federal income tax at statutory rate	$	27,711		$	27,410		$	25,424
Tax exempt income		(2,925	)		(3,448	)		(3,811	)
Net increase in CSV of life insurance		(919	)		(939	)		(871	)
Low income housing tax credits		(782	)		(296	)		(132	)
State taxes, net of federal tax benefit		764			756			816
State audit settlements		(681	)		(1,465	)		-
Other, net		(1,895	)		(1,106	)		(795	)
Income tax expense	$	21,273		$	20,912		$	20,631

- 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, 2011

Stockholders Equity [Abstract]

Components of Accumulated other comprehensive (loss) income

For the years ended December 31, components of accumulated other comprehensive loss are:

(In thousands)	2011			2010
Unrecognized prior service cost and net actuarial loss on pension plans	$	(24,633	)	$	(16,251	)
Unrealized net holding gains on available for sale securities		18,529			10,916
Accumulated other comprehensive income (loss)	$	(6,104	)	$	(5,335	)

Regulatory Capital Requirements (Tables)

12 Months Ended

Dec. 31, 2011

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, 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	%

As of December 31, 2010
Total Capital (to risk weighted assets):
Company	$	537,305		13.70	%		8.00	%		10.00	%
NBT Bank		510,196		13.03	%		8.00	%		10.00	%
Tier I Capital (to risk weighted assets)
Company		487,994		12.44	%		4.00	%		6.00	%
NBT Bank		460,969		11.77	%		4.00	%		6.00	%
Tier I Capital (to average assets)
Company		487,994		9.16	%		4.00	%		5.00	%
NBT Bank		460,969		8.67	%		4.00	%		5.00	%

Employee Benefit Plans (Tables)

12 Months Ended

Dec. 31, 2011

Employee Benefit Plans [Abstract]

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)	2011			2010			2009			2011			2010			2009
Components of net periodic benefit cost
Service cost	$	2,589		$	2,254		$	2,222		$	17		$	17		$	17
Interest cost		3,544			3,613			3,413			202			228			205
Expected return on plan assets		(7,720	)		(7,166	)		(5,591	)		-			-			-
Amortization of initial unrecognized asset		-			-			(23	)		-			-			-
Amortization of prior service cost		309			322			296			(202	)		(202	)		(202	)
Amortization of unrecognized net loss		1,353			1,447			2,374			205			201			136
Net periodic pension cost	$	75		$	470		$	2,691		$	222		$	244		$	156

Other changes in plan assets and benefit obligations recognized in other comprehensive income (pre-tax)

Net loss (gain)	$	16,108		$	1,620		$	(6,053	)	$	(562	)	$	955		$	289
Prior service cost		-			21			127			-			-			-
Amortization of initial unrecognized asset		-			-			23			-			-			-
Amortization of prior service cost		(309	)		(322	)		(296	)		202			202			202
Amortization of unrecognized net gain		(1,353	)		(1,447	)		(2,374	)		(205	)		(201	)		(136	)
Total recognized in other comprehensive loss (income)		14,446			(128	)		(8,573	)		(565	)		956			355

Total recognized in net periodic benefit cost and other comprehensive income (loss) - pre-tax	$	14,521		$	342		$	(5,882	)	$	(343	)	$	1,200		$	511

Components of Accumulated other comprehensive income (loss), Net periodic benefit cost

The Company expects that $3.3 million in net actuarial loss and $0.1 million in prior service cost will be recognized as components of net periodic benefit cost in 2012.

	Pension Benefits				Other Benefits
(In thousands)	2011		2010		2011			2010
Net actuarial loss	$	37,914	$	23,161	$	2,323		$	3,089
Prior service cost		1,430		1,739		(874	)		(1,076	)
Total amounts recognized in accumulated other comprehensive loss (pre-tax)	$	39,344	$	24,900	$	1,449		$	2,013

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

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)	2011			2010			2011			2010
Change in benefit obligation
Benefit obligation at beginning of year	$	70,229		$	63,408		$	4,554		$	3,838
Service cost		2,589			2,254			17			17
Interest cost		3,544			3,613			202			228
Plan participants' contributions		-			-			263			277
Actuarial loss (gain)		5,935			4,940			(562	)		955
Amendments		-			21			-			-
Benefits paid		(4,273	)		(4,007	)		(489	)		(761	)
Projected benefit obligation at end of year		78,024			70,229			3,985			4,554
Change in plan assets
Fair value of plan assets at beginning of year		97,821			90,891			-			-
Actual return (loss) on plan assets		(2,452	)		10,487			-			-
Employer contributions		479			450			226			484
Plan participants' contributions		-			-			263			277
Benefits paid		(4,273	)		(4,007	)		(489	)		(761	)
Fair value of plan assets at end of year		91,575			97,821			-			-

Funded status at year end	$	13,551		$	27,592		$	(3,985	)	$	(4,554	)

Amounts recognized in Balance Sheet

The accumulated benefit obligation for other postretirement benefits was $4.0 million and $4.6 million at December 31, 2011 and 2010, respectively.

	Pension Benefits						Other Benefits
(In thousands)	2011			2010			2011			2010
Other assets	$	23,973		$	35,895		$	-		$	-
Other liabilities		(10,422	)		(8,303	)		(3,985	)		(4,554	)
Funded status	$	13,551		$	27,592		$	(3,985	)	$	(4,554	)

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)	2011			2010			2009
Weighted average assumptions:
The following assumptions were used to determine benefit obligations:
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	%

The following assumptions were used to determine net periodic pension cost:
Discount rate		5.15	%		5.70	%		6.30	%
Expected long-term return on plan assets		8.00	%		8.00	%		8.00	%
Rate of compensation increase		3.00	%		3.00	%		3.00	%

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

2012		5,010		204
2013		5,236		218
2014		5,361		232
2015		7,034		244
2016		5,590		254
Thereafter		29,745		1,358

Effect of One-Percentage Point Change in Assumed Health Care Cost Trend Rates

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, 2011:

(In thousands)	One Percentage point increase		One Percentage point decrease
Increase (decrease) on total service and interest cost components	$	29	$	(24	)
Increase (decrease) on postretirement accumulated benefit obligation		482		(410	)

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

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

	Target 2012			2011			2010
Cash and cash equivalents		0 - 20	%		2	%		2	%
Fixed income securities		20 - 40	%		34	%		26	%
Equities		40 - 80	%		64	%		72	%
Total					100	%		100	%

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

The following table presents the financial instruments recorded at fair value on a recurring basis by the Plan as of December 31, 2011 and 2010:

	Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)		Balance as of 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

(in thousands)	Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)		Balance as of December 31, 2010
Cash and Cash Equivalents	$	1,604	$	-	$	-	$	1,604
Foreign Equity Mutual Funds		6,577		-		-		6,577
Equity Mutual Funds		22,515		-		-		22,515
US Government Bonds		-		16,219		-		16,219
Corporate Bonds		-		5,003		-		5,003
Common Stock		31,213		-		-		31,213
Municipal bonds and Notes		-		2,294		-		2,294
Foreign Bonds and Notes		-		1,666		-		1,666
Foreign Equity		10,730		-		-		10,730
Totals	$	72,639	$	25,182	$	-	$	97,821

Fair value assumptions

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,
	2011	2010	2009
Dividend yield	3.31%–3.82%	3.27%–3.96%	2.86%–3.65%
Expected volatility	33.75%–34.36%	33.00%–33.86%	30.20%–32.91%
Risk-free interest rates	1.48%–2.81%	1.90%–3.17%	1.71%–3.20%
Expected life	7 years	7 years	7 years

Stock option activity

The following table summarizes information concerning stock options outstanding at December 31, 2011:

	Number of Shares			Weighted average exercise price		Weighted Average Remaining Contractual Term (in yrs)		Aggregate Intrinsic Value
Outstanding at December 31, 2010		2,031,578		$	22.05
Granted		50,700			22.21
Exercised		(142,178	)		16.11
Forfeited		(26,085	)		24.42
Expired		(50,425	)		24.64
Outstanding at December 31, 2011		1,863,590		$	22.41		5.37	$	3,869,134

Exercisable at December 31, 2011		1,457,710		$	22.50		4.71	$	2,872,729

Expected to Vest		399,034		$	22.08		7.73	$	979,661

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

Cash proceeds, tax benefits and intrinsic value related to total stock options exercised is as follows:

	Years ended
(dollars in thousands)	2011		2010		2009
Proceeds from stock options exercised	$	1,793	$	1,778	$	2,728
Tax benefits related to stock options exercised		341		140		(243	)
Intrinsic value of stock options exercised		897		574		406
Fair value of shares vested during the year		1,597		1,800		1,700

Unvested restricted awards and unvested restricted units activity

The following table summarizes information for unvested restricted stock awards outstanding as of December 31, 2011:

	Number of Shares			Weighted- Average Grant Date Fair Value
Unvested Restricted Stock Awards
Unvested at January 1, 2011		202,039		$	24.09
Forfeited		(14,000	)		24.44
Vested		(58,110	)		24.48
Granted		25,447			24.09
Unvested at December 31, 2011		155,376		$	23.92

The following table summarizes information for unvested restricted stock units outstanding as of December 31, 2011:

	Number of Shares			Weighted- Average Grant Date Fair Value
Unvested Restricted Stock Units
Unvested at January 1, 2011		57,400		$	22.59
Forfeited		(3,520	)		-
Vested		(625	)		-
Granted		188,652			23.84
Unvested at December 31, 2011		241,907		$	23.95

Commitments and Contingent Liabilities (Tables)

12 Months Ended

Dec. 31, 2011

Commitments and Contingent Liabilities [Abstract]

Schedule of maximum commitments potential obligation

Collateral may be obtained based on management's assessment of the customer's creditworthiness.

	At December 31,
(In thousands)	2011		2010
Unused lines of credit	$	161,551	$	141,579
Commitments to extend credits, primarily variable rate		603,322		501,987
Standby letters of credit		26,783		26,193
Commercial letters of credit		15,218		16,255
Loans sold with recourse		16,175		13,970

- 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, 2011

Parent Company Financial Information [Abstract]

Parent company financial information

Condensed Balance Sheets

	December 31,
(In thousands)	2011		2010
Assets
Cash and cash equivalents	$	2,454	$	3,493
Securities available for sale, at estimated fair value		9,825		9,190
Trading securities		2,550		2,273
Investment in subsidiaries, on equity basis		622,885		609,260
Other assets		48,153		41,942
Total assets	$	685,867	$	666,158
Liabilities and Stockholders' Equity
Total liabilities	$	147,757	$	132,586
Stockholders' equity		538,110		533,572
Total liabilities and stockholders' equity	$	685,867	$	666,158

Condensed Income Statements

	Years ended December 31,
(In thousands)	2011			2010		2009
Dividends from subsidiaries	$	54,400		$	12,000	$	9,000
Management fee from subsidiaries		69,430			68,228		65,596
Securities (losses) gains		(31	)		1,814		141
Interest, dividend and other income		628			1,136		869
Total revenue		124,427			83,178		75,606
Operating expense		75,254			72,436		73,687
Income before income tax benefit and equity in undistributed income of subsidiaries		49,173			10,742		1,919
Income tax benefit		1,340			282		1,994
Equity in undistributed income of subsidiaries		7,388			46,380		48,098
Net income	$	57,901		$	57,404	$	52,011

Statements of Cash Flow

	Years ended December 31,
(In thousands)	2011			2010			2009
Operating activities
Net income	$	57,901		$	57,404		$	52,011
Adjustments to reconcile net income to net cash provided by operating activities
Stock-based compensation		3,244			3,782			3,133
Loss (Gain) on sales of available-for-sale securities		31			(1,814	)		(141	)
Equity in undistributed income of subsidiaries		(7,388	)		(46,380	)		(48,098	)
Net change in other liabilities		15,311			2,155			(3,662	)
Net change in other assets		(11,607	)		(2,605	)		3,632
Net cash provided by operating activities		57,492			12,542			6,875
Investing activities
Purchases of available-for-sale securities		(968	)		(1,745	)		(2,173	)
Sales and maturities of available-for-sale securities		71			7,807			494
Purchases of premises and equipment		(1,656	)		(321	)		(600	)
Net cash provided by (used in) investing activities		(2,553	)		5,741			(2,279	)
Financing activities
Proceeds from the issuance of shares to employee benefit plans and other stock plans		1,386			1,675			2,728
Payments on long-term debt		(140	)		(135	)		(12,625	)
Proceeds from the issuance of common stock		-			-			33,401
Purchases of treasury shares		(30,502	)		(477	)		-
Cash dividends and payments for fractional shares		(27,063	)		(27,577	)		(27,119	)
Excess tax benefit from exercise of stock options		341			140			(243	)
Net cash used in financing activities		(55,978	)		(26,374	)		(3,858	)
Net (decrease) increase in cash and cash equivalents		(1,039	)		(8,091	)		738
Cash and cash equivalents at beginning of year		3,493			11,584			10,846
Cash and cash equivalents at end of year	$	2,454		$	3,493		$	11,584

Fair Values of Financial Instruments (Tables)

12 Months Ended

Dec. 31, 2011

Fair Values of Financial Instruments [Abstract]

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

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 Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)		Balance as of 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

	Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)		Balance as of December 31, 2010
Assets:
Securities Available for Sale:
U.S. Treasury		91,280		-		-		91,280
Federal Agency		-		349,750		-		349,750
State & municipal		-		114,937		-		114,937
Mortgage-backed		-		244,808		-		244,808
Collateralized mortgage obligations		-		297,888		-		297,888
Corporate		-		20,489		-		20,489
Other securities		8,190		2,026		-		10,216
Total Securities Available for Sale	$	99,470	$	1,029,898	$	-	$	1,129,368

Trading Securities		2,808		-		-		2,808
Total	$	102,278	$	1,029,898	$	-	$	1,132,176

Fair Value of Financial Instruments By Balance Sheet Grouping

Estimated fair values of financial instruments at December 31 are as follows:

	2011				2010
(In thousands)	Carrying amount		Estimated fair value		Carrying amount		Estimated fair value
Financial assets
Cash and cash equivalents	$	129,381	$	129,381	$	168,792	$	168,792
Securities available for sale		1,244,619		1,244,619		1,129,368		1,129,368
Securities held to maturity		70,811		72,198		97,310		98,759
Trading securities		3,062		3,062		2,808		2,808
Net loans		3,728,869		3,821,640		3,538,772		3,626,603
Accrued interest receivable		17,800		17,800		19,130		19,130
Financial liabilities
Savings, NOW, and money market	$	2,381,116	$	2,381,116	$	2,291,833	$	2,291,833
Time deposits		933,127		942,436		930,778		943,988
Noninterest bearing		1,052,906		1,052,906		911,741		911,741
Short-term borrowings		181,592		181,592		159,434		159,434
Long-term debt		370,344		427,107		369,874		423,350
Accrued interest payable		3,942		3,942		4,356		4,356
Trust preferred debentures		75,422		75,422		75,422		71,148

- 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)
-URI http://asc.fasb.org/extlink&oid=6947722&loc=d3e13433-108611

Reference 8: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 11
-URI http://asc.fasb.org/extlink&oid=6947722&loc=d3e13467-108611

Reference 9: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 12
-URI http://asc.fasb.org/extlink&oid=6947722&loc=d3e13476-108611

Reference 10: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 30
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=6957238&loc=d3e14172-108612

Reference 11: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=6925170&loc=d3e19207-110258

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

Significant Accounting Policies (Details) $ in Millions	12 Months Ended
Significant Accounting Policies (Details) $ in Millions	Dec. 31, 2011 USD ($)
Significant Accounting Policies [Abstract]
Balance of OREO	$ 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

Mergers and Acquisition Activity (Details) $ in Millions	Dec. 31, 2011 USD ($)
Latremore's Insurance Agency [Member]
Business Acquisition [Line Items]
Acquisition of intangible assets	$ 2.1
Acquisition of goodwill	1.3
Acquisition of fixed assets	0.1
Purchase price of intangible asset and goodwill	3.5
Legacy Bank [Member]
Business Acquisition [Line Items]
Acquisition of intangible assets	1.3
Acquisition of goodwill	12.5
Purchase price of intangible asset and goodwill	$ 8.9
Number of bank branches converted to the Company	4
Acquisition of loans	$ 39.9
Acquisition of deposits	144.8
Acquisition of other assets	$ 2.8
Berkshire Hills Bancorp and Legacy Banks [Member]
Business Acquisition [Line Items]
Number of bank branches converted to the Company	3
Number of bank branches deposits and loans converted to the Company	1

Earnings Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Basic earnings per share [abstract]
Net income available to common shareholders	$ 57,901	$ 57,404	$ 52,011
Weighted average common shares, basic (in shares)	33,662	34,275	33,723
Basic EPS (in dollars per share)	$ 1.72	$ 1.67	$ 1.54
Diluted earnings per share [abstract]
Net income available to common shareholders	$ 57,901	$ 57,404	$ 52,011
Dilutive effect of stock based compensation (in shares)	262	234	180
Weighted average common shares, diluted (in shares)	33,924	34,509	33,903
Diluted EPS (in dollars per share)	$ 1.71	$ 1.66	$ 1.53
Stock options excluded from calculation of diluted EPS (in shares)	1,258,000	1,309,000	1,245,000

- 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
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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
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-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
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-Name Regulation S-X (SX)
-Number 210
-Section 04
-Paragraph 21
-Article 9

Reference 5: http://www.xbrl.org/2003/role/presentationRef
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-Name Accounting Standards Codification
-Topic 225
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-Paragraph 2
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Reference 11: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Emerging Issues Task Force (EITF)
-Number 07-4
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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

- 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 5: 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) $ in Millions	12 Months Ended
Federal Reserve Bank Requirement (Details) $ in Millions	Dec. 31, 2011 USD ($)
Federal Reserve Bank Requirement [Abstract]
Federal Reserve Bank maintenance period (in days)	14D
Average reserve at Federal Reserve Bank for maintenance period	$ 33.4

Securities (Details) $ in Thousands	12 Months Ended
Securities (Details) $ in Thousands	Dec. 31, 2011 USD ($)	Dec. 31, 2010 USD ($)	Dec. 31, 2009 USD ($)
Schedule of Available-for-sale Securities [Line Items]
Amortized cost	$ 1,213,934	$ 1,111,290
Unrealized gains	30,839	24,986
Unrealized losses	154	6,908
Estimated fair value	1,244,619	1,129,368
Amortized Cost of mortgage-backed securities comprised of Government Sponsored Enterprise Securities	290,200	208,900
Fair value of mortgage-backed securities comprised of Government Sponsored Enterprise Securities	303,000	217,900
Amortized Cost of mortgage-backed securities comprised of US Government Agency Securities	20,500	25,000
Fair value of mortgage-backed securities comprised of US Government Agency Securities	22,400	26,900
Amortized Cost of Collateralized Mortgage Obligations comprised of Government Sponsored Enterprise Securities	398,300	206,000
Fair Value of Collateralized Mortgage Obligations comprised of Government Sponsored Enterprise Securities	402,400	207,000
Amortized Cost of Collateralized Mortgage Obligations comprised of US Government Agency Securities	60,800	87,600
Fair Value of Collateralized Mortgage Obligations comprised of US Government Agency Securities	63,100	90,800
Investment securities with unrealized losses [Abstract]
Unrealized Loss Position, Less Than 12 Months, Fair Value	63,966	327,056
Unrealized Loss Position, Less Than 12 Months, Unrealized Losses	$ (153)	$ (6,570)
Unrealized Loss Position, Less Than 12 Months, Number of Positions	11	54
Unrealized Loss Position, 12 Months or Longer, Fair Value	$ 377	$ 7,533
Unrealized Loss Position, 12 Months or Longer, Unrealized Losses	$ (1)	$ (338)
Unrealized Loss Position, 12 Months or Longer, Number of Positions	2	19
Unrealized Loss Position, Total, Fair Value	$ 64,343	$ 334,589
Unrealized Loss Position, Total, Unrealized Losses	$ (154)	$ (6,908)
Unrealized Loss Position, Total, Number of Positions	13	73
Consolidated stockholders' equity threshold percentage that no single issuer of securities exceeded except for U.S. Government securities. (in hundredths)	10.00%	10.00%
Sales transactions of securities available for sale [Abstract]
Proceeds from sales	$ 2,437	$ 103,253	$ 2,753
Gross realized gains	7	3,170	154
Gross realized losses	(165)	(25)	(49)
Net securities (losses) gains excluding gains from calls	(158)	3,145	$ 105
Gains from calls on securities available for sale	300	100
Amortized costs of securities available for sale pledged to secure public deposits	1,200,000	900,000
Amortized costs of securities available for sale pledged as collateral for repurchase agreements	141,700
Schedule of Held-to-maturity Securities [Line Items]
Amortized cost	70,811	97,310
Unrealized gains	1,387	1,449
Unrealized losses	0	0
Estimated fair value	72,198	98,759
Available-for-sale Securities, Debt Maturities, Amortized Cost Basis [Abstract]
Within one year	23,867
From one to five years	302,772
From five to ten years	245,058
After ten years	633,302
Total, Amortized Cost	1,204,999
Available-for-sale Securities, Debt Maturities, Fair Value [Abstract]
Within one year	23,941
From one to five years	305,366
From five to ten years	254,864
After ten years	649,568
Total, Fair Value	1,233,739
Debt Securities Classified as Held to Maturity [Abstract]
Within one year	26,315
From one to five years	34,032
From five to ten years	7,073
After ten years	3,391
Securities held to maturity	70,811	97,310
Held-to-maturity Securities, Debt Maturities, Fair Value [Abstract]
Within one year	26,383
From one to five years	35,058
From five to ten years	7,153
After ten years	3,604
Total, Fair Value	72,198
US Treasury [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized cost	81,006	91,338
Unrealized gains	1,228	424
Unrealized losses	0	482
Estimated fair value	82,234	91,280
Investment securities with unrealized losses [Abstract]
Unrealized Loss Position, Less Than 12 Months, Fair Value	0	40,741
Unrealized Loss Position, Less Than 12 Months, Unrealized Losses	$ 0	$ (482)
Unrealized Loss Position, Less Than 12 Months, Number of Positions	0	4
Unrealized Loss Position, 12 Months or Longer, Fair Value	$ 0	$ 0
Unrealized Loss Position, 12 Months or Longer, Unrealized Losses	$ 0	$ 0
Unrealized Loss Position, 12 Months or Longer, Number of Positions	0	0
Unrealized Loss Position, Total, Fair Value	$ 0	$ 40,741
Unrealized Loss Position, Total, Unrealized Losses	$ 0	$ (482)
Unrealized Loss Position, Total, Number of Positions	0	4
Federal Agency [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized cost	$ 254,983	$ 350,641
Unrealized gains	879	1,905
Unrealized losses	16	2,796
Estimated fair value	255,846	349,750
Investment securities with unrealized losses [Abstract]
Unrealized Loss Position, Less Than 12 Months, Fair Value	34,996	147,012
Unrealized Loss Position, Less Than 12 Months, Unrealized Losses	$ (16)	$ (2,796)
Unrealized Loss Position, Less Than 12 Months, Number of Positions	3	12
Unrealized Loss Position, 12 Months or Longer, Fair Value	$ 0	$ 0
Unrealized Loss Position, 12 Months or Longer, Unrealized Losses	$ 0	$ 0
Unrealized Loss Position, 12 Months or Longer, Number of Positions	0	0
Unrealized Loss Position, Total, Fair Value	$ 34,996	$ 147,012
Unrealized Loss Position, Total, Unrealized Losses	$ (16)	$ (2,796)
Unrealized Loss Position, Total, Number of Positions	3	12
State & municipal [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized cost	$ 99,176	$ 113,821
Unrealized gains	5,624	1,771
Unrealized losses	11	655
Estimated fair value	104,789	114,937
Investment securities with unrealized losses [Abstract]
Unrealized Loss Position, Less Than 12 Months, Fair Value	957	22,273
Unrealized Loss Position, Less Than 12 Months, Unrealized Losses	$ (10)	$ (317)
Unrealized Loss Position, Less Than 12 Months, Number of Positions	3	31
Unrealized Loss Position, 12 Months or Longer, Fair Value	$ 377	$ 7,533
Unrealized Loss Position, 12 Months or Longer, Unrealized Losses	$ (1)	$ (338)
Unrealized Loss Position, 12 Months or Longer, Number of Positions	2	19
Unrealized Loss Position, Total, Fair Value	$ 1,334	$ 29,806
Unrealized Loss Position, Total, Unrealized Losses	$ (11)	$ (655)
Unrealized Loss Position, Total, Number of Positions	5	50
Mortgage-backed [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized cost	$ 310,767	$ 233,861
Unrealized gains	14,629	11,666
Unrealized losses	0	719
Estimated fair value	325,396	244,808
Investment securities with unrealized losses [Abstract]
Unrealized Loss Position, Less Than 12 Months, Fair Value	0	44,340
Unrealized Loss Position, Less Than 12 Months, Unrealized Losses	$ 0	$ (719)
Unrealized Loss Position, Less Than 12 Months, Number of Positions	0	3
Unrealized Loss Position, 12 Months or Longer, Fair Value	$ 0	$ 0
Unrealized Loss Position, 12 Months or Longer, Unrealized Losses	$ 0	$ 0
Unrealized Loss Position, 12 Months or Longer, Number of Positions	0	0
Unrealized Loss Position, Total, Fair Value	$ 0	$ 44,340
Unrealized Loss Position, Total, Unrealized Losses	$ 0	$ (719)
Unrealized Loss Position, Total, Number of Positions	0	3
Corporate [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized cost	$ 0	$ 20,005
Unrealized gains	0	484
Unrealized losses	0	0
Estimated fair value	0	20,489
Other securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized cost	8,935	8,059
Unrealized gains	2,021	2,162
Unrealized losses	76	5
Estimated fair value	10,880	10,216
Investment securities with unrealized losses [Abstract]
Unrealized Loss Position, Less Than 12 Months, Fair Value	645	95
Unrealized Loss Position, Less Than 12 Months, Unrealized Losses	$ (76)	$ (5)
Unrealized Loss Position, Less Than 12 Months, Number of Positions	2	1
Unrealized Loss Position, 12 Months or Longer, Fair Value	$ 0	$ 0
Unrealized Loss Position, 12 Months or Longer, Unrealized Losses	$ 0	$ 0
Unrealized Loss Position, 12 Months or Longer, Number of Positions	0	0
Unrealized Loss Position, Total, Fair Value	$ 645	$ 95
Unrealized Loss Position, Total, Unrealized Losses	$ (76)	$ (5)
Unrealized Loss Position, Total, Number of Positions	2	1
Collateralized Mortgage Obligations [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized cost	$ 459,067	$ 293,565
Unrealized gains	6,458	6,574
Unrealized losses	51	2,251
Estimated fair value	465,474	297,888
Investment securities with unrealized losses [Abstract]
Unrealized Loss Position, Less Than 12 Months, Fair Value	27,368	72,595
Unrealized Loss Position, Less Than 12 Months, Unrealized Losses	$ (51)	$ (2,251)
Unrealized Loss Position, Less Than 12 Months, Number of Positions	3	3
Unrealized Loss Position, 12 Months or Longer, Fair Value	$ 0	$ 0
Unrealized Loss Position, 12 Months or Longer, Unrealized Losses	$ 0	$ 0
Unrealized Loss Position, 12 Months or Longer, Number of Positions	0	0
Unrealized Loss Position, Total, Fair Value	$ 27,368	$ 72,595
Unrealized Loss Position, Total, Unrealized Losses	$ (51)	$ (2,251)
Unrealized Loss Position, Total, Number of Positions	3	3
State & municipal [Member]
Schedule of Held-to-maturity Securities [Line Items]
Amortized cost	$ 69,364	$ 95,591
Unrealized gains	1,174	1,249
Unrealized losses	0	0
Estimated fair value	70,538	96,840
Debt Securities Classified as Held to Maturity [Abstract]
Securities held to maturity	69,364	95,591
Mortgage-backed [Member]
Schedule of Held-to-maturity Securities [Line Items]
Amortized cost	1,447	1,719
Unrealized gains	213	200
Unrealized losses	0	0
Estimated fair value	1,660	1,919
Debt Securities Classified as Held to Maturity [Abstract]
Securities held to maturity	$ 1,447	$ 1,719

Loans and Leases (Details) - USD ($) $ in Thousands	Dec. 31, 2011	Dec. 31, 2010
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases	$ 3,800,203	$ 3,610,006
Deferred loan origination costs, net	1,600	2,900
Unearned income	300	1,400
Residential loans held for sale	2,700	0
Residential Real Estate Mortgages [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases	581,511	548,394
Commercial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases	611,298	577,731
Commercial Real Estate loans or lease [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases	888,879	844,458
Real Estate Construction and Development [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases	93,977	45,444
Agricultural and agricultural real estate mortgages [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases	108,423	112,738
Consumer [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases	946,470	905,563
Home Equity Loan [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases	$ 569,645	$ 575,678

Allowance for Loan and Lease Losses and Credit Quality of Loans and Leases Disclosure (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010
Allowance for Loan and Lease Losses and Credit Quality of Loans and Leases [Abstract]
Loan portfolio segments	3
Commercial Real Estate Loan amount, percentage of appraised value of the property, maximum (in hundredths)	80.00%
Agricultural Real Estate Loan amount, percentage of appraised value of the property, maximum (in hundredths)	75.00%
Small Business Loans, Maximum Amount	$ 350
Automobile Financing Approximate percentage of Indirect loans (in hundredths)	73.00%
Automobile Financing Principal Repayment terms, Low End Of range (in years)	3Y
Automobile Financing Principal Repayment terms, High End Of range (in years)	6Y
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Balance as of Beginning of Period	$ 71,234	$ 66,550
Charge-offs	(24,488)	(29,837)
Recoveries	3,851	4,712
Provision	20,737	29,809
Balance as of Ending of Period	71,334	71,234
Allowance loan and lease losses
Allowance for loans and leases individually evaluated for impairment	175	2,211
Allowance for loans and leases collectively evaluated for impairment	71,159	69,023
Loans and leases	3,800,203	3,610,006
Ending balance of loans and leases individually evaluated for impairment	6,219	11,419
Ending balance of loans and leases collectively evaluated for impairment	$ 3,793,984	3,598,587
Nonperforming Loans Minimum Number of days Past Due For Classification (in days)	90D
Commercial Portfolio Segment [Member]
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Balance as of Beginning of Period	$ 40,101	36,599
Charge-offs	(8,969)	(12,969)
Recoveries	1,438	1,922
Provision	6,261	14,549
Balance as of Ending of Period	38,831	40,101
Allowance loan and lease losses
Allowance for loans and leases individually evaluated for impairment	175	2,211
Allowance for loans and leases collectively evaluated for impairment	38,656	37,890
Loans and leases	1,702,577	1,580,371
Ending balance of loans and leases individually evaluated for impairment	6,219	11,419
Ending balance of loans and leases collectively evaluated for impairment	1,696,358	1,568,952
Consumer Portfolio Segment [Member]
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Balance as of Beginning of Period	26,126	26,664
Charge-offs	(14,209)	(15,692)
Recoveries	2,406	2,747
Provision	11,726	12,407
Balance as of Ending of Period	26,049	26,126
Allowance loan and lease losses
Allowance for loans and leases individually evaluated for impairment	0	0
Allowance for loans and leases collectively evaluated for impairment	26,049	26,126
Loans and leases	1,516,115	1,481,241
Ending balance of loans and leases individually evaluated for impairment	0	0
Ending balance of loans and leases collectively evaluated for impairment	1,516,115	1,481,241
Residential Portfolio Segment [Member]
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Balance as of Beginning of Period	4,627	3,002
Charge-offs	(1,310)	(1,176)
Recoveries	7	43
Provision	2,925	2,758
Balance as of Ending of Period	6,249	4,627
Allowance loan and lease losses
Allowance for loans and leases individually evaluated for impairment	0	0
Allowance for loans and leases collectively evaluated for impairment	6,249	4,627
Loans and leases	581,511	548,394
Ending balance of loans and leases individually evaluated for impairment	0	0
Ending balance of loans and leases collectively evaluated for impairment	581,511	548,394
Unallocated Financing Receivables [Member]
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Balance as of Beginning of Period	380	285
Charge-offs	0	0
Recoveries	0	0
Provision	(175)	95
Balance as of Ending of Period	205	380
Allowance loan and lease losses
Allowance for loans and leases individually evaluated for impairment		0
Allowance for loans and leases collectively evaluated for impairment	$ 205	380
Loans and leases		0
Ending balance of loans and leases individually evaluated for impairment		0
Ending balance of loans and leases collectively evaluated for impairment		$ 0

Allowance for Loan and Lease Losses and Credit Quality of Loans and Leases Credit Quality of Loans and Leases (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010
Financing Receivable, Recorded Investment, Aging [Abstract]
31 - 60 Days Past Due Accruing	$ 25,351	$ 23,116
61 - 90 Days Past Due Accruing	5,278	5,563
Greater Than 91 Days Past Due Accruing	3,190	2,325
Total Past Due Accruing	33,819	31,004
Non-Accrual	38,290	42,467
Current	3,728,094	3,536,535
Loans and leases	$ 3,800,203	3,610,006
Home Equity Loan amount, Percentage of Equity in Home, Maximum (in hundredths)	85.00%
Principal repayment terms on direct financing, minimum (in years)	1Y
Principal repayment terms on direct financing, maximum (in years)	10Y
Residential Real Estate Loan amount, percentage of appraised value or purchase price of the property, minimum (in hundredths)	85.00%
Residential Real Estate Loan amount, percentage of appraised value or purchase price of the property, maximum (in hundredths)	95.00%
Commercial Portfolio Segment [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Loans and leases	$ 1,702,577	1,580,371
Commercial Portfolio Segment [Member] \| Commercial Financing Receivable [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
31 - 60 Days Past Due Accruing	663	136
61 - 90 Days Past Due Accruing	50	55
Greater Than 91 Days Past Due Accruing	0	94
Total Past Due Accruing	713	285
Non-Accrual	1,699	5,837
Current	508,662	461,633
Loans and leases	511,074	467,755
Commercial Portfolio Segment [Member] \| Commercial Real Estate Other Receivable [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
31 - 60 Days Past Due Accruing	1,942	1,263
61 - 90 Days Past Due Accruing	0	0
Greater Than 91 Days Past Due Accruing	0	0
Total Past Due Accruing	1,942	1,263
Non-Accrual	4,868	5,687
Current	828,089	730,285
Loans and leases	834,899	737,235
Commercial Portfolio Segment [Member] \| Agricultural Financing Receivable [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
31 - 60 Days Past Due Accruing	77	63
61 - 90 Days Past Due Accruing	13	92
Greater Than 91 Days Past Due Accruing	0	0
Total Past Due Accruing	90	155
Non-Accrual	3,307	4,065
Current	63,140	63,336
Loans and leases	66,537	67,556
Commercial Portfolio Segment [Member] \| Agricultural Real Estate Financing Receivable [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
31 - 60 Days Past Due Accruing	0	108
61 - 90 Days Past Due Accruing	0	0
Greater Than 91 Days Past Due Accruing	50	0
Total Past Due Accruing	50	108
Non-Accrual	2,067	2,429
Current	31,809	33,400
Loans and leases	33,926	35,937
Commercial Portfolio Segment [Member] \| Small Business Financing Receivable [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
31 - 60 Days Past Due Accruing	1,871	2,570
61 - 90 Days Past Due Accruing	1,024	1,183
Greater Than 91 Days Past Due Accruing	0	0
Total Past Due Accruing	2,895	3,753
Non-Accrual	7,446	7,033
Current	245,800	261,102
Loans and leases	256,141	271,888
Commercial Portfolio Segment [Member] \| Total Commercial Loan Financing Receivable [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
31 - 60 Days Past Due Accruing	4,553	4,140
61 - 90 Days Past Due Accruing	1,087	1,330
Greater Than 91 Days Past Due Accruing	50	94
Total Past Due Accruing	5,690	5,564
Non-Accrual	19,387	25,051
Current	1,677,499	1,549,756
Loans and leases	1,702,577	1,580,371
Consumer Portfolio Segment [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Loans and leases	1,516,115	1,481,241
Consumer Portfolio Segment [Member] \| Indirect Financing Receivable [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
31 - 60 Days Past Due Accruing	12,141	9,307
61 - 90 Days Past Due Accruing	2,584	2,193
Greater Than 91 Days Past Due Accruing	1,283	862
Total Past Due Accruing	16,008	12,362
Non-Accrual	1,550	1,971
Current	855,545	814,594
Loans and leases	873,103	828,927
Consumer Portfolio Segment [Member] \| Home Equity Financing Receivables [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
31 - 60 Days Past Due Accruing	5,823	5,740
61 - 90 Days Past Due Accruing	1,277	1,756
Greater Than 91 Days Past Due Accruing	954	396
Total Past Due Accruing	8,054	7,892
Non-Accrual	7,931	6,395
Current	553,660	561,391
Loans and leases	569,645	575,678
Consumer Portfolio Segment [Member] \| Direct Financing Receivable [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
31 - 60 Days Past Due Accruing	831	927
61 - 90 Days Past Due Accruing	191	158
Greater Than 91 Days Past Due Accruing	140	54
Total Past Due Accruing	1,162	1,139
Non-Accrual	378	399
Current	71,827	75,098
Loans and leases	73,367	76,636
Consumer Portfolio Segment [Member] \| Total Consumer Loan Financing Receivable [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
31 - 60 Days Past Due Accruing	18,795	15,974
61 - 90 Days Past Due Accruing	4,052	4,107
Greater Than 91 Days Past Due Accruing	2,377	1,312
Total Past Due Accruing	25,224	21,393
Non-Accrual	9,859	8,765
Current	1,481,032	1,451,083
Loans and leases	1,516,115	1,481,241
Residential Portfolio Segment [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
31 - 60 Days Past Due Accruing	2,003	3,002
61 - 90 Days Past Due Accruing	139	126
Greater Than 91 Days Past Due Accruing	763	919
Total Past Due Accruing	2,905	4,047
Non-Accrual	9,044	8,651
Current	569,562	535,696
Loans and leases	$ 581,511	$ 548,394

Allowance for Loan and Lease Losses and Credit Quality of Loans and Leases Impaired Loans and Reserve Allocations (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2011 USD ($)	Dec. 31, 2010 USD ($)	Dec. 31, 2009 USD ($)
Financing Receivable, Impaired [Line Items]
Recorded Investment Balance (Book)	$ 500
Related Allowance	200	$ 2,200
Average Recorded Investment	23,094	21,929	$ 23,650
Interest Income Recognized Total	1,086	1,237	6,335
Interest Income Recognized Cash	1,086	1,237	6,335
Troubled Debt Restructured Loans Amount	4,000	1,000
Commercial Financing Receivable [Member]
Financing Receivable, Impaired [Line Items]
Troubled Debt Restructured Loans Amount	700
Modifications made to loans	$ 700	$ 300
Number of loans with modifications	3	1
Number of loans classified as troubled debt restructuring	2
Home Equity Financing Receivable [Member]
Financing Receivable, Impaired [Line Items]
Troubled Debt Restructured Loans Amount	$ 600
Modifications made to loans	$ 2,400
Number of loans with modifications	25
Number of loans classified as troubled debt restructuring	7
Commercial Portfolio Segment [Member]
Financing Receivable, Impaired [Line Items]
Recorded Investment Balance (Book)		$ 25,364
Unpaid Principal Balance (Legal)		31,059
Financing Receivable	$ 1,446,436	1,308,483
Commercial Portfolio Segment [Member] \| Commercial Financing Receivable [Member]
Financing Receivable, Impaired [Line Items]
Financing Receivable	511,074	467,755
Commercial Portfolio Segment [Member] \| Commercial Real Estate Other Receivable [Member]
Financing Receivable, Impaired [Line Items]
Financing Receivable	834,899	737,235
Commercial Portfolio Segment [Member] \| Agricultural Financing Receivable [Member]
Financing Receivable, Impaired [Line Items]
Financing Receivable	66,537	67,556
Commercial Portfolio Segment [Member] \| Agricultural Real Estate Financing Receivable [Member]
Financing Receivable, Impaired [Line Items]
Financing Receivable	33,926	35,937
Commercial Portfolio Segment [Member] \| Small Business Financing Receivable [Member]
Financing Receivable, Impaired [Line Items]
Financing Receivable	256,141	271,888
Consumer Loans and Leases [Member]
Financing Receivable, Impaired [Line Items]
Recorded Investment Balance (Book)	22,427
Unpaid Principal Balance (Legal)	30,354
Related Allowance	175	2,211
Residential Real Estate Mortgages [Member]
Financing Receivable, Impaired [Line Items]
Financing Receivable	581,511	548,394
Troubled Debt Restructured Loans Amount	400
Modifications made to loans	$ 800
Number of loans with modifications	4
Number of loans classified as troubled debt restructuring	2
With No Allowance Recorded [Member]
Financing Receivable, Impaired [Line Items]
Recorded Investment Balance (Book)	$ 21,971	19,240
Unpaid Principal Balance (Legal)	29,546	23,595
Average Recorded Investment	20,798	16,127	16,509
Interest Income Recognized Total	914	902	6,210
Interest Income Recognized Cash	914	902	6,210
With No Allowance Recorded [Member] \| Total Commercial Loans Receivable No Allowance [Member]
Financing Receivable, Impaired [Line Items]
Recorded Investment Balance (Book)	18,931	18,927
Unpaid Principal Balance (Legal)	26,318	23,256
With No Allowance Recorded [Member] \| Commercial Portfolio Segment [Member] \| Commercial Financing Receivable [Member]
Financing Receivable, Impaired [Line Items]
Recorded Investment Balance (Book)	1,243	2,112
Unpaid Principal Balance (Legal)	2,723	2,459
Average Recorded Investment	2,322	1,898	1,118
Interest Income Recognized Total	94	113	1,429
Interest Income Recognized Cash	94	113	1,429
With No Allowance Recorded [Member] \| Commercial Portfolio Segment [Member] \| Commercial Real Estate Other Receivable [Member]
Financing Receivable, Impaired [Line Items]
Recorded Investment Balance (Book)	4,868	5,687
Unpaid Principal Balance (Legal)	7,165	6,654
Average Recorded Investment	4,794	4,219	5,702
Interest Income Recognized Total	163	317	2,744
Interest Income Recognized Cash	163	317	2,744
With No Allowance Recorded [Member] \| Commercial Portfolio Segment [Member] \| Agricultural Financing Receivable [Member]
Financing Receivable, Impaired [Line Items]
Recorded Investment Balance (Book)	3,307	2,394
Unpaid Principal Balance (Legal)	4,166	2,865
Average Recorded Investment	3,013	2,990	1,606
Interest Income Recognized Total	133	82	531
Interest Income Recognized Cash	133	82	531
With No Allowance Recorded [Member] \| Commercial Portfolio Segment [Member] \| Agricultural Real Estate Financing Receivable [Member]
Financing Receivable, Impaired [Line Items]
Recorded Investment Balance (Book)	2,067	1,701
Unpaid Principal Balance (Legal)	2,288	1,883
Average Recorded Investment	1,719	1,929	1,853
Interest Income Recognized Total	109	150	589
Interest Income Recognized Cash	109	150	589
With No Allowance Recorded [Member] \| Commercial Portfolio Segment [Member] \| Small Business Financing Receivable [Member]
Financing Receivable, Impaired [Line Items]
Recorded Investment Balance (Book)	7,446	7,033
Unpaid Principal Balance (Legal)	9,976	9,395
Average Recorded Investment	6,121	4,959	6,231
Interest Income Recognized Total	266	234	917
Interest Income Recognized Cash	266	234	917
With No Allowance Recorded [Member] \| Consumer Loans and Leases [Member] \| Home Equity Financing Receivable [Member]
Financing Receivable, Impaired [Line Items]
Recorded Investment Balance (Book)	2,000	0
Unpaid Principal Balance (Legal)	2,103	0
Average Recorded Investment	1,904	0	0
Interest Income Recognized Total	91	0	0
Interest Income Recognized Cash	91	0	0
With No Allowance Recorded [Member] \| Residential Real Estate Mortgages [Member]
Financing Receivable, Impaired [Line Items]
Recorded Investment Balance (Book)	1,040	313
Unpaid Principal Balance (Legal)	1,125	339
Average Recorded Investment	926	132	0
Interest Income Recognized Total	58	6	0
Interest Income Recognized Cash	58	6	0
With An Allowance Recorded [Member]
Financing Receivable, Impaired [Line Items]
Related Allowance	175	2,211
With An Allowance Recorded [Member] \| Commercial Portfolio Segment [Member]
Financing Receivable, Impaired [Line Items]
Recorded Investment Balance (Book)	456	6,124
Unpaid Principal Balance (Legal)	808	7,464
Average Recorded Investment	2,295	5,802	7,141
Interest Income Recognized Total	172	335	125
Interest Income Recognized Cash	172	335	125
With An Allowance Recorded [Member] \| Commercial Portfolio Segment [Member] \| Commercial Financing Receivable [Member]
Financing Receivable, Impaired [Line Items]
Recorded Investment Balance (Book)	456	3,725
Unpaid Principal Balance (Legal)	808	4,762
Related Allowance	175	1,907
Average Recorded Investment	861	2,366	2,984
Interest Income Recognized Total	86	118	57
Interest Income Recognized Cash	86	118	57
With An Allowance Recorded [Member] \| Commercial Portfolio Segment [Member] \| Commercial Real Estate Other Receivable [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	287	1,234	1,551
Interest Income Recognized Total	0	0	0
Interest Income Recognized Cash	0	0	0
With An Allowance Recorded [Member] \| Commercial Portfolio Segment [Member] \| Agricultural Financing Receivable [Member]
Financing Receivable, Impaired [Line Items]
Recorded Investment Balance (Book)	0	1,671
Unpaid Principal Balance (Legal)	0	1,918
Related Allowance	0	281
Average Recorded Investment	791	1,386	2,046
Interest Income Recognized Total	68	150	63
Interest Income Recognized Cash	68	150	63
With An Allowance Recorded [Member] \| Commercial Portfolio Segment [Member] \| Agricultural Real Estate Financing Receivable [Member]
Financing Receivable, Impaired [Line Items]
Recorded Investment Balance (Book)	0	728
Unpaid Principal Balance (Legal)	0	784
Related Allowance	0	23
Average Recorded Investment	357	816	560
Interest Income Recognized Total	18	67	5
Interest Income Recognized Cash	$ 18	$ 67	$ 5

Allowance for Loan and Lease Losses and Credit Quality of Loans and Leases Quality Indicators (Details) - USD ($) $ in Thousands	Dec. 31, 2011	Dec. 31, 2010
Financing Receivable, Recorded Investment [Line Items]
Minimum Balance For Classified Loans to be Evaluated for Impairment	$ 500
Recorded investment, Related allowance	200	$ 2,200
Recorded investment with specific reserve allocation	500	6,100
Performing Financing Receivable [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	571,704	539,743
Nonperforming Financing Receivable [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	9,807	8,651
Total Consumer Loan Financing Receivable [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	1,516,115	1,481,241
Total Consumer Loan Financing Receivable [Member] \| Performing Financing Receivable [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	1,503,604	1,472,476
Total Consumer Loan Financing Receivable [Member] \| Nonperforming Financing Receivable [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	12,236	8,765
Commercial Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	1,446,436	1,308,483
Commercial Loans [Member] \| Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	1,316,413	1,188,486
Commercial Loans [Member] \| Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	34,876	41,887
Commercial Loans [Member] \| Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	94,622	78,015
Commercial Loans [Member] \| Doubtful [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	525	95
Commercial Loans [Member] \| Commercial Financing Receivable [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	511,074	467,755
Commercial Loans [Member] \| Commercial Financing Receivable [Member] \| Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	470,332	441,834
Commercial Loans [Member] \| Commercial Financing Receivable [Member] \| Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	10,346	4,830
Commercial Loans [Member] \| Commercial Financing Receivable [Member] \| Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	29,940	21,091
Commercial Loans [Member] \| Commercial Financing Receivable [Member] \| Doubtful [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	456	0
Commercial Loans [Member] \| Commercial Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	834,899	737,235
Commercial Loans [Member] \| Commercial Real Estate [Member] \| Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	758,673	654,974
Commercial Loans [Member] \| Commercial Real Estate [Member] \| Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	24,478	35,461
Commercial Loans [Member] \| Commercial Real Estate [Member] \| Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	51,748	46,800
Commercial Loans [Member] \| Commercial Real Estate [Member] \| Doubtful [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	0	0
Commercial Loans [Member] \| Agricultural Financing Receivable [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	66,537	67,556
Commercial Loans [Member] \| Agricultural Financing Receivable [Member] \| Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	58,481	61,195
Commercial Loans [Member] \| Agricultural Financing Receivable [Member] \| Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	42	660
Commercial Loans [Member] \| Agricultural Financing Receivable [Member] \| Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	7,945	5,606
Commercial Loans [Member] \| Agricultural Financing Receivable [Member] \| Doubtful [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	69	95
Commercial Loans [Member] \| Agricultural Real Estate Financing Receivable [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	33,926	35,937
Commercial Loans [Member] \| Agricultural Real Estate Financing Receivable [Member] \| Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	28,927	30,483
Commercial Loans [Member] \| Agricultural Real Estate Financing Receivable [Member] \| Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	10	936
Commercial Loans [Member] \| Agricultural Real Estate Financing Receivable [Member] \| Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	4,989	4,518
Commercial Loans [Member] \| Agricultural Real Estate Financing Receivable [Member] \| Doubtful [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	0	0
Commercial Loans [Member] \| Small Business Financing Receivable [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	256,141	271,888
Commercial Loans [Member] \| Small Business Financing Receivable [Member] \| Non-classified [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	237,887	253,120
Commercial Loans [Member] \| Small Business Financing Receivable [Member] \| Classified [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	18,254	18,768
Commercial Loans [Member] \| Total Small Business Receivable [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	256,141	271,888
Consumer Loans and Leases [Member]
Financing Receivable, Recorded Investment [Line Items]
Recorded investment, Related allowance	175	2,211
Consumer Loans and Leases [Member] \| Indirect Financing Receivable [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	873,103	828,927
Consumer Loans and Leases [Member] \| Indirect Financing Receivable [Member] \| Performing Financing Receivable [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	870,270	826,956
Consumer Loans and Leases [Member] \| Indirect Financing Receivable [Member] \| Nonperforming Financing Receivable [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	2,833	1,971
Consumer Loans and Leases [Member] \| Direct Financing Receivable Member [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	73,367	76,636
Consumer Loans and Leases [Member] \| Direct Financing Receivable Member [Member] \| Performing Financing Receivable [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	72,849	76,237
Consumer Loans and Leases [Member] \| Direct Financing Receivable Member [Member] \| Nonperforming Financing Receivable [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	518	399
Consumer Loans and Leases [Member] \| Home Equity Financing Receivables [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	569,645	575,678
Consumer Loans and Leases [Member] \| Home Equity Financing Receivables [Member] \| Performing Financing Receivable [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	560,760	569,283
Consumer Loans and Leases [Member] \| Home Equity Financing Receivables [Member] \| Nonperforming Financing Receivable [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	8,885	6,395
Residential Real Estate Mortgages [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	581,511	548,394
Residential Real Estate Mortgages [Member] \| Performing Financing Receivable [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	571,704	539,743
Residential Real Estate Mortgages [Member] \| Nonperforming Financing Receivable [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	$ 9,807	$ 8,651

Related Party Transactions (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010
Loans and Leases Receivable, Related Parties [Roll Forward]
Balance at January 1	$ 2,914	$ 1,843
New loans	25	1,174
Adjustment due to change in composition of related parties	328	216
Repayments	(730)	(319)
Balance at December 31	$ 2,537	$ 2,914

Premises and Equipment, Net (Details) $ in Thousands	12 Months Ended
Premises and Equipment, Net (Details) $ in Thousands	Dec. 31, 2011 USD ($)	Dec. 31, 2010 USD ($)	Dec. 31, 2009 USD ($)
Property, Plant and Equipment [Line Items]
Premises and equipment before accumulated depreciation	$ 151,120	$ 168,638
Accumulated depreciation	76,579	101,234
Total premises and equipment	74,541	67,404
Rental expense	5,900	5,500	$ 5,300
Operating Leases, Future Minimum Payments Due [Abstract]
2012	5,337
2013	5,200
2014	4,786
2015	4,365
2016	4,121
Thereafter	25,081
Total	48,890
Depreciated asset removal	27,100
Land, Buildings and Improvements [Member]
Property, Plant and Equipment [Line Items]
Premises and equipment before accumulated depreciation	103,399	95,970
Pledged to secure long-term borrowings	2,900	3,000
Equipment [Member]
Property, Plant and Equipment [Line Items]
Premises and equipment before accumulated depreciation	$ 47,646	72,326
Property, Plant and Equipment, Useful Life, Minimum (in years)	3
Property, Plant and Equipment, Useful Life, Maximum (in years)	10
Construction in Progress [Member]
Property, Plant and Equipment [Line Items]
Premises and equipment before accumulated depreciation	$ 75	$ 342
Building and Building Improvements [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Useful Life, Minimum (in years)	15
Property, Plant and Equipment, Useful Life, Maximum (in years)	40

Goodwill and Other Intangible Assets (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2011 USD ($)	Dec. 31, 2010 USD ($)	Dec. 31, 2009 USD ($)
Goodwill [Roll Forward]
Beginning Balance	$ 114,841	$ 114,938
Goodwill Acquired	17,188	0
Goodwill Reclassification	0	(97)
Ending Balance	132,029	114,841	$ 114,938
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	32,885	29,318
Less: accumulated amortization	14,691	11,775
Net carrying amount	$ 18,194	17,543
Finite-Lived Intangible Assets, Future Amortization Expense [Abstract]
Intangible assets estimated useful lives, minimum (in years)	1
Intangible assets estimated useful lives, maximum (in years)	12
Amortization expense on intangible assets with definite useful lives	$ 3,000	3,100	$ 3,200
2012	3,200
2013	3,000
2014	2,800
2015	2,600
2016	1,600
Thereafter	3,000
Indefinite-Lived Intangible Assets (Excluding Goodwill)	2,000
Core Deposits [Member]
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	11,966	10,762
Less: accumulated amortization	6,401	5,517
Net carrying amount	5,565	5,245
Other Intangible Assets [Member]
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	20,919	18,556
Less: accumulated amortization	8,290	6,258
Net carrying amount	$ 12,629	$ 12,298

Deposits (Details) - USD ($) $ in Thousands	Dec. 31, 2011	Dec. 31, 2010
Maturities of Time Deposits [Abstract]
Within one year	$ 444,870
After one but within two years	162,049
After two but within three years	240,228
After three but within four years	50,954
After four but within five years	28,528
After five years	6,498
Total	933,127	$ 930,778
Time Deposits, $100,000 or More [Abstract]
Time deposits of $100,000 or more	$ 305,700	$ 264,400

Short-Term Borrowings (Details) - USD ($) $ in Thousands	12 Months Ended
Short-Term Borrowings (Details) - USD ($) $ in Thousands	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Short-term Debt [Line Items]
Balance at year-end	$ 181,592	$ 159,434
FHLB, unused lines of credit available for short-term financing	323,000	284,000
Federal Funds Purchased [Member]
Short-term Debt [Line Items]
Balance at year-end	27,000	0	$ 0
Average during the year	3,017	0	5,957
Maximum month end balance	$ 28,000	$ 0	$ 50,000
Weighted average rate during the year (in hundredths)	0.11%	0.00%	0.30%
Weighted average rate at December 31 (in hundredths)	0.13%	0.00%	0.00%
Securities Sold under Agreements to Repurchase [Member]
Short-term Debt [Line Items]
Balance at year-end	$ 154,592	$ 159,184	$ 155,727
Average during the year	150,663	157,964	133,859
Maximum month end balance	$ 178,414	$ 169,278	$ 166,208
Weighted average rate during the year (in hundredths)	0.13%	0.25%	0.40%
Weighted average rate at December 31 (in hundredths)	0.10%	0.15%	0.32%
Other Short-Term Borrowings [Member]
Short-term Debt [Line Items]
Balance at year-end	$ 0	$ 250	$ 250
Average during the year	249	250	250
Maximum month end balance	$ 250	$ 250	$ 250
Weighted average rate during the year (in hundredths)	0.00%	0.00%	0.03%
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, 2011	Dec. 31, 2010
Long-Term Debt by Maturity Periods [Abstract]
Amount	$ 370,344	$ 369,874
Callable Amount	$ 345,000	$ 346,994
2011 [Member]
Long-Term Debt by Maturity Periods [Abstract]
Maturity year	2011	2011
Amount	$ 0	$ 1,994
Weighted Average Rate (in hundredths)	0.00%	4.73%
Callable Amount	$ 0	$ 1,994
Weighted Average Rate (in hundredths)	0.00%	4.73%
2013 [Member]
Long-Term Debt by Maturity Periods [Abstract]
Maturity year	2013	2013
Amount	$ 119,400	$ 119,400
Weighted Average Rate (in hundredths)	3.87%	3.87%
Callable Amount	$ 100,000	$ 100,000
Weighted Average Rate (in hundredths)	3.71%	3.71%
2014 [Member]
Long-Term Debt by Maturity Periods [Abstract]
Maturity year	2014	2014
Amount	$ 2,604	$ 0
Weighted Average Rate (in hundredths)	2.00%	0.00%
Callable Amount	$ 0	$ 0
Weighted Average Rate (in hundredths)		0.00%
2016 [Member]
Long-Term Debt by Maturity Periods [Abstract]
Maturity year	2016	2016
Amount	$ 70,000	$ 70,000
Weighted Average Rate (in hundredths)	4.21%	4.21%
Callable Amount	$ 70,000	$ 70,000
Weighted Average Rate (in hundredths)	4.21%	4.21%
2017 [Member]
Long-Term Debt by Maturity Periods [Abstract]
Maturity year	2017	2017
Amount	$ 100,000	$ 100,000
Weighted Average Rate (in hundredths)	3.89%	3.89%
Callable Amount	$ 100,000	$ 100,000
Weighted Average Rate (in hundredths)	3.89%	3.89%
2018 [Member]
Long-Term Debt by Maturity Periods [Abstract]
Maturity year	2018	2018
Amount	$ 75,000	$ 75,000
Weighted Average Rate (in hundredths)	3.61%	3.61%
Callable Amount	$ 75,000	$ 75,000
Weighted Average Rate (in hundredths)	3.61%	3.61%
2025 [Member]
Long-Term Debt by Maturity Periods [Abstract]
Maturity year	2025	2025
Amount	$ 3,340	$ 3,480
Weighted Average Rate (in hundredths)	2.75%	2.75%
Callable Amount	$ 0	$ 0
Weighted Average Rate (in hundredths)	0.00%	0.00%

Trust Preferred Debentures (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2009	Dec. 31, 2010
Variable Interest Entity [Line Items]
Trust preferred debt owed to trust	$ 75,422		$ 75,422
Wholly owned Delaware statutory business trusts - variable interest entities	three wholly owned Delaware statutory business trusts
Common equity securities issued by Variable Interest Entity to NBT		$ 33,401
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	$ 74,000
Minimum assets for bank holding companies to be subject to the same capital requirements as insured depository institutions	500,000
CNBF Capital Trust I VIE Entity Not Primary Beneficiary [Member] \| CNBF Capital Trust I Debenture [Member]
Variable Interest Entity [Line Items]
Trust preferred debt owed to trust	18,720
Trust Preferred Securities Outstanding	$ 18,000
Issuance Date	June 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	$ 700
CNBF Trust I securities owned by bank	1,000
NBT Statutory Trust I VIE Entity Not Primary Beneficiary [Member] \| NBT Statutory Trust I Debenture [Member]
Variable Interest Entity [Line Items]
Trust preferred debt owed to trust	5,155
Trust Preferred Securities Outstanding	$ 5,000
Issuance Date	November 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	$ 200
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]
Variable Interest Entity [Line Items]
Trust preferred debt owed to trust	$ 51,547
Trust Preferred Securities Outstanding	$ 50,000
Issuance Date	February 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	$ 1,500
Original issuance fixed interest rate (in hundredths)	6.195%
Fixed rate to convert to a floating rate (in years)	5Y

Income Taxes (Details) - USD ($) $ in Thousands	12 Months Ended
Income Taxes (Details) - USD ($) $ in Thousands	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Current [Abstract]
Federal	$ 29,274	$ 34,124	$ 21,046
State	1,477	1,743	1,086
Current tax expense (benefit)	30,751	35,867	22,132
Deferred [Abstract]
Federal	(8,129)	(12,121)	(1,669)
State	(1,349)	(2,834)	168
Deferred tax expense (benefit)	(9,478)	(14,955)	(1,501)
Income tax expense	21,273	20,912	20,631
Income tax recorded to stockholders' equity	(500)	(4,300)	6,100
Deferred tax assets [Abstract]
Allowance for loan and lease losses	27,487	27,463
Deferred compensation	4,911	4,653
Postretirement benefit obligation	1,036	1,024
Purchase accounting fair value adjustments	2,227	0
Accrued liabilities	1,482	1,649
Stock-based compensation expense	4,440	3,943
Other	1,214	1,012
Total deferred tax assets	42,797	39,744
Deferred tax liabilities [Abstract]
Pension and executive retirement	6,916	11,922
Unrealized gains on securities available for sale	12,156	7,162
Premises and equipment, primarily due to accelerated depreciation	2,340	1,384
Equipment leasing	3,090	11,456
Deferred loan costs	767	1,395
Intangible amortization	11,081	10,270
Other	494	178
Total deferred tax liabilities	36,844	43,767
Net deferred tax liability at period-end	5,953	(4,023)	(23,245)
Net deferred tax liability at beginning of period	(4,023)	(23,245)
(Decrease) increase in net deferred tax liability	(9,976)	(19,222)
Reconciliation of gross unrecognized tax benefits [Roll Forward]
Balance, beginning of period	3,081	2,287	2,212
Additions for tax positions of prior years	0	1,714	132
Reduction for tax positions of prior years	(2,193)	(920)	(57)
Balance, end of period	888	3,081	2,287
Unrecognized tax benefits that would impact effective tax rate, if recognized	900	3,100	2,300
Decreases in unrecognized tax benefits resulting from settlements with taxing authorities	1,400	800
Decrease in tax expense resulting from lapse of statute of limitations	1,500
Accrued interest	100	700
Net interest	$ 300	100	200
Federal statutory income tax rate (in hundredths)	35.00%
Income tax reconciliation [Abstract]
Federal income tax at statutory rate	$ 27,711	27,410	25,424
Tax exempt income	(2,925)	(3,448)	(3,811)
Net increase in CSV of life insurance	(919)	(939)	(871)
Low income housing tax credits	(782)	(296)	(132)
State taxes, net of federal tax benefit	764	756	816
State audit settlements and law change	(681)	(1,465)	0
Other, net	(1,895)	(1,106)	(795)
Income tax expense	$ 21,273	$ 20,912	$ 20,631

Stockholders Equity (Details) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2011 USD ($) $ / shares shares	Dec. 31, 2010 USD ($)
Stockholders Equity [Abstract]
Unrecognized prior service cost and net actuarial loss on pension plans	$ (24,633)	$ (16,251)
Unrealized net holding gains on available for sale securities	18,529	10,916
Accumulated other comprehensive (loss) income	$ (6,104)	$ (5,335)
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	$ 95,900
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
Stockholder Rights Plan [Member] \| 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

Regulatory Capital Requirements (Details) - USD ($) $ in Thousands	Dec. 31, 2011	Dec. 31, 2010
Total Capital (to risk weighted assets) [Abstract]
Total capital to risk weighted assets	$ 528,674	$ 537,305
Total capital to risk weighted assets (in hundredths)	12.81%	13.70%
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	$ 476,837	$ 487,994
Tier I capital to risk weighted assets (in hundredths)	11.56%	12.44%
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	$ 476,837	$ 487,994
Tier I capital to average assets (in hundredths)	8.74%	9.16%
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	$ 506,246	$ 510,196
Total capital to risk weighted assets (in hundredths)	12.28%	13.03%
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	$ 454,476	$ 460,969
Tier I capital to risk weighted assets (in hundredths)	11.03%	11.77%
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	$ 454,476	$ 460,969
Tier I capital to average assets (in hundredths)	8.35%	8.67%
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, 2011 USD ($) $ / shares shares	Dec. 31, 2010 USD ($) $ / shares shares	Dec. 31, 2009 USD ($) $ / shares	Dec. 31, 2011 USD ($) $ / shares shares	Dec. 31, 2010 USD ($)	Dec. 31, 2009 USD ($)
Other changes in plan assets and benefit obligation recognized in other comprehensive income (pre-tax) [Abstract]
Amortization of prior service cost	$ 1,665,000	$ 1,767,000	$ 2,581,000
Transition obligation period of recognition (in years)	20Y
Net actuarial loss that will be amortized from Accumulated other comprehensive income (loss) in next fiscal year	$ 3,300,000
Prior service cost that will be amortized from Accumulated other comprehensive income (loss) in next fiscal year	100,000
Change in benefit obligation [Roll Forward]
Actuarial loss	9,381,000	1,560,000	(3,415,000)
Change in plan assets [Roll Forward]
Fair value of plan assets at beginning of period	97,821,000
Fair value of plan assets at end of period	$ 91,575,000	97,821,000
Assumptions used to determine net periodic pension cost [Abstract]
Expected long-term return on plan assets (in hundredths)	7.50%
Estimate future benefit payments [Abstract]
Annual rates of increase in the per capita cost of covered medical and prescription drug benefits, minimum (in hundredths)	8.00%
Annual rates of increase in the per capita cost of covered medical and prescription drug benefits, maximum (in hundredths)	9.75%
Ultimate health care cost trend rate (in hundredths)	5.00%
Fair value of plan assets	$ 91,575,000	97,821,000		$ 91,575,000	$ 97,821,000
Employer contributions to 401 (k) plan	3,700,000	3,500,000	3,400,000
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	29,000
One-percentage point (decrease) on total service and interest cost components	(24,000)
One-percentage point Increase on postretirement accumulated benefit obligation	482,000
One-percentage point (decrease) on postretirement accumulated benefit obligation	$ (410,000)
Target asset allocations [Abstract]
Target allocation percentage of assets, Cash and cash equivalents, range minimum (in hundredths)	0.00%
Target allocation percentage of assets, Cash and cash equivalents, range maximum (in hundredths)	20.00%
Target allocation percentage of assets, Fixed income securities, range minimum (in hundredths)	20.00%
Target allocation percentage of assets, Fixed income securities, range maximum (in hundredths)	40.00%
Target allocation percentage of assets, Equities, range minimum (in hundredths)	40.00%
Target allocation percentage of assets, Equities, range maximum (in hundredths)	80.00%
Actual plan asset allocations [Abstract]
Actual plan asset allocations, Cash and cash equivalents (in hundredths)				2.00%	2.00%
Actual plan asset allocations, Fixed income securities (in hundredths)				34.00%	26.00%
Actual plan asset allocations, Equities (in hundredths)				64.00%	72.00%
Actual plan asset allocations, Total (in hundredths)				100.00%	100.00%
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock awards termination period (in years)	10Y
Stock options additional disclosures [Abstract]
Stock-based compensation expense	$ 3,244,000	$ 3,782,000	$ 3,133,000
Number of shares available for future grant (in shares) \| shares				4,600,000
Restricted Stock and restricted stock additional disclosures [Abstract]
Expected long-term rate-of-return on assets (in hundredths)	7.50%
Fair value assumptions [Abstract]
Dividend yield, minimum (in hundredths)	3.31%	3.27%	2.86%
Dividend yield, maximum (in hundredths)	3.82%	3.96%	3.65%
Expected volatility, minimum (in hundredths)	33.75%	33.00%	30.20%
Expected volatility, maximum (in hundredths)	34.36%	33.86%	32.91%
Risk-free interest rates, minimum (in hundredths)	1.48%	1.90%	1.71%
Risk-free interest rates, maximum (in hundredths)	2.81%	3.17%	3.20%
Expected life (in years)	7	7	7
Level 1 [Member]
Change in plan assets [Roll Forward]
Fair value of plan assets at beginning of period	$ 72,639,000
Fair value of plan assets at end of period	60,043,000	$ 72,639,000
Estimate future benefit payments [Abstract]
Fair value of plan assets	60,043,000	72,639,000		$ 60,043,000	$ 72,639,000
Level 2 [Member]
Change in plan assets [Roll Forward]
Fair value of plan assets at beginning of period	25,182,000
Fair value of plan assets at end of period	31,532,000	25,182,000
Estimate future benefit payments [Abstract]
Fair value of plan assets	31,532,000	25,182,000		31,532,000	25,182,000
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
Estimate future benefit payments [Abstract]
Fair value of plan assets	0	0		0	0
Cash and Cash Equivalents [Member]
Change in plan assets [Roll Forward]
Fair value of plan assets at beginning of period	1,604,000
Fair value of plan assets at end of period	1,503,000	1,604,000
Estimate future benefit payments [Abstract]
Fair value of plan assets	1,503,000	1,604,000		1,503,000	1,604,000
Cash and Cash Equivalents [Member] \| Level 1 [Member]
Change in plan assets [Roll Forward]
Fair value of plan assets at beginning of period	1,604,000
Fair value of plan assets at end of period	1,503,000	1,604,000
Estimate future benefit payments [Abstract]
Fair value of plan assets	1,503,000	1,604,000		1,503,000	1,604,000
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
Estimate future benefit payments [Abstract]
Fair value of plan assets	0	0		0	0
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
Estimate future benefit payments [Abstract]
Fair value of plan assets	0	0		0	0
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	6,577,000	6,577,000
Estimate future benefit payments [Abstract]
Fair value of plan assets	6,577,000	6,577,000		6,577,000	6,577,000
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	6,577,000	6,577,000
Estimate future benefit payments [Abstract]
Fair value of plan assets	6,577,000	6,577,000		6,577,000	6,577,000
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
Estimate future benefit payments [Abstract]
Fair value of plan assets	0	0		0	0
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
Estimate future benefit payments [Abstract]
Fair value of plan assets	0	0		0	0
Equity Mutual Funds [Member]
Change in plan assets [Roll Forward]
Fair value of plan assets at beginning of period	22,515,000
Fair value of plan assets at end of period	9,902,000	22,515,000
Estimate future benefit payments [Abstract]
Fair value of plan assets	9,902,000	22,515,000		9,902,000	22,515,000
Equity Mutual Funds [Member] \| Level 1 [Member]
Change in plan assets [Roll Forward]
Fair value of plan assets at beginning of period	22,515,000
Fair value of plan assets at end of period	9,902,000	22,515,000
Estimate future benefit payments [Abstract]
Fair value of plan assets	9,902,000	22,515,000		9,902,000	22,515,000
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
Estimate future benefit payments [Abstract]
Fair value of plan assets	0	0		0	0
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
Estimate future benefit payments [Abstract]
Fair value of plan assets	0	0		0	0
US Government Bonds [Member]
Change in plan assets [Roll Forward]
Fair value of plan assets at beginning of period	16,219,000
Fair value of plan assets at end of period	15,683,000	16,219,000
Estimate future benefit payments [Abstract]
Fair value of plan assets	15,683,000	16,219,000		15,683,000	16,219,000
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
Estimate future benefit payments [Abstract]
Fair value of plan assets	0	0		0	0
US Government Bonds [Member] \| Level 2 [Member]
Change in plan assets [Roll Forward]
Fair value of plan assets at beginning of period	16,219,000
Fair value of plan assets at end of period	15,683,000	16,219,000
Estimate future benefit payments [Abstract]
Fair value of plan assets	15,683,000	16,219,000		15,683,000	16,219,000
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
Estimate future benefit payments [Abstract]
Fair value of plan assets	0	0		0	0
Corporate [Member]
Change in plan assets [Roll Forward]
Fair value of plan assets at beginning of period	5,003,000
Fair value of plan assets at end of period	12,954,000	5,003,000
Estimate future benefit payments [Abstract]
Fair value of plan assets	12,954,000	5,003,000		12,954,000	5,003,000
Corporate [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
Estimate future benefit payments [Abstract]
Fair value of plan assets	0	0		0	0
Corporate [Member] \| Level 2 [Member]
Change in plan assets [Roll Forward]
Fair value of plan assets at beginning of period	5,003,000
Fair value of plan assets at end of period	12,954,000	5,003,000
Estimate future benefit payments [Abstract]
Fair value of plan assets	12,954,000	5,003,000		12,954,000	5,003,000
Corporate [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
Estimate future benefit payments [Abstract]
Fair value of plan assets	0	0		0	0
Common Stock [Member]
Change in plan assets [Roll Forward]
Fair value of plan assets at beginning of period	31,213,000
Fair value of plan assets at end of period	33,850,000	31,213,000
Estimate future benefit payments [Abstract]
Fair value of plan assets	33,850,000	31,213,000		33,850,000	31,213,000
Common Stock [Member] \| Level 1 [Member]
Change in plan assets [Roll Forward]
Fair value of plan assets at beginning of period	31,213,000
Fair value of plan assets at end of period	33,850,000	31,213,000
Estimate future benefit payments [Abstract]
Fair value of plan assets	33,850,000	31,213,000		33,850,000	31,213,000
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
Estimate future benefit payments [Abstract]
Fair value of plan assets	0	0		0	0
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
Estimate future benefit payments [Abstract]
Fair value of plan assets	0	0		0	0
Foreign Bonds and Notes [Member]
Change in plan assets [Roll Forward]
Fair value of plan assets at beginning of period	1,666,000
Fair value of plan assets at end of period	1,096,000	1,666,000
Estimate future benefit payments [Abstract]
Fair value of plan assets	1,096,000	1,666,000		1,096,000	1,666,000
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
Estimate future benefit payments [Abstract]
Fair value of plan assets	0	0		0	0
Foreign Bonds and Notes [Member] \| Level 2 [Member]
Change in plan assets [Roll Forward]
Fair value of plan assets at beginning of period	1,666,000
Fair value of plan assets at end of period	1,096,000	1,666,000
Estimate future benefit payments [Abstract]
Fair value of plan assets	1,096,000	1,666,000		1,096,000	1,666,000
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
Estimate future benefit payments [Abstract]
Fair value of plan assets	0	0		0	0
Foreign Equity [Member]
Change in plan assets [Roll Forward]
Fair value of plan assets at beginning of period	10,730,000
Fair value of plan assets at end of period	8,211,000	10,730,000
Estimate future benefit payments [Abstract]
Fair value of plan assets	8,211,000	10,730,000		8,211,000	10,730,000
Foreign Equity [Member] \| Level 1 [Member]
Change in plan assets [Roll Forward]
Fair value of plan assets at beginning of period	10,730,000
Fair value of plan assets at end of period	8,211,000	10,730,000
Estimate future benefit payments [Abstract]
Fair value of plan assets	8,211,000	10,730,000		8,211,000	10,730,000
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
Estimate future benefit payments [Abstract]
Fair value of plan assets	0	0		0	0
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
Estimate future benefit payments [Abstract]
Fair value of plan assets	0	0		0	0
Municipal Bonds and Notes [Member]
Change in plan assets [Roll Forward]
Fair value of plan assets at beginning of period	2,294,000
Fair value of plan assets at end of period	1,799,000	2,294,000
Estimate future benefit payments [Abstract]
Fair value of plan assets	1,799,000	2,294,000		1,799,000	2,294,000
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
Estimate future benefit payments [Abstract]
Fair value of plan assets	0	0		0	0
Municipal Bonds and Notes [Member] \| Level 2 [Member]
Change in plan assets [Roll Forward]
Fair value of plan assets at beginning of period	2,294,000
Fair value of plan assets at end of period	1,799,000	2,294,000
Estimate future benefit payments [Abstract]
Fair value of plan assets	1,799,000	2,294,000		1,799,000	2,294,000
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
Estimate future benefit payments [Abstract]
Fair value of plan assets	$ 0	$ 0		$ 0	0
Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock awards vesting period (in years)	4Y
Weighted average fair value of stock options granted (in dollars per share) \| $ / shares	$ 5.45	$ 5.03	$ 5.71
Stock options [Roll Forward]
Outstanding, Beginning of period (in shares) \| shares	2,031,578
Granted (in shares) \| shares	50,700
Exercised (in shares) \| shares	(142,178)
Forfeited (in shares) \| shares	(26,085)
Expired (in shares) \| shares	(50,425)
Outstanding, End of period (in shares) \| shares	1,863,590	2,031,578
Exercisable, End of period (in shares) \| shares				1,457,710
Expected to Vest (in shares) \| shares				399,034
Stock options additional disclosures [Abstract]
Weighted average exercise price, Outstanding, Beginning of period (in dollars per share) \| $ / shares	$ 22.05
Weighted average exercise price, Granted (in dollars per share) \| $ / shares				$ 22.21
Weighted average exercise price, Exercised (in dollars per share) \| $ / shares				16.11
Weighted average exercise price, Forfeited (in dollars per share) \| $ / shares				24.42
Weighted average exercise price, Expired (in dollars per share) \| $ / shares				24.64
Weighted average exercise price, Outstanding, End of period (in dollars per share) \| $ / shares	$ 22.41	$ 22.05
Weighted average exercise price, Exercisable, End of period (in dollars per share) \| $ / shares				22.50
Weighted average exercise price, Expected to Vest (in dollars per share) \| $ / shares				$ 22.08
Weighted Average Remaining Contractual Term, Outstanding, End of period (in years)				5.37
Weighted Average Remaining Contractual Term, Exercisable, End of period (in years)	4.71
Weighted Average Remaining Contractual Term, Expected to Vest (in years)	7.73
Aggregate Intrinsic Value, Outstanding, End of period				$ 3,869,134
Aggregate Intrinsic Value, Exercisable, End of period				2,872,729
Aggregate Intrinsic Value, Expected to Vest				979,661
Stock-based compensation expense	$ 900,000	$ 1,800,000	$ 1,600,000
Proceeds from stock options exercised	1,793,000	1,778,000	2,728,000
Tax benefits related to stock options exercised	341,000	140,000	(243,000)
Intrinsic value of stock options exercised	897,000	574,000	406,000
Fair value of shares vested during the year	$ 1,597,000	$ 1,800,000	1,700,000
Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock awards vesting period (in years)	4Y
Restricted shares vesting period for employees, minimum (in years)	5Y
Restricted shares vesting period for non-employee directors, minimum (in years)	3Y
Stock options additional disclosures [Abstract]
Unrecognized compensation cost				$ 4,400,000
Unrecognized compensation cost, weighted average period of recognition (in years)	2.8
Restricted Stock and restricted stock [Roll Forward]
Unvested, Beginning of period (in shares) \| shares	202,039
Forfeited (in shares) \| shares	(14,000)
Vested (in shares) \| shares	(58,110)
Granted (in shares) \| shares	25,447
Unvested, End of period (in shares) \| shares	155,376	202,039
Restricted Stock and restricted stock additional disclosures [Abstract]
Weighted-average grant date fair value, Unvested, Beginning of period (in dollars per share) \| $ / shares	$ 24.09
Weighted-average grant date fair value, Forfeited (in dollars per share) \| $ / shares				$ 24.44
Weighted-average grant date fair value, Vested (in dollars per share) \| $ / shares	24.48
Weighted-average grant date fair value, Granted (in dollars per share) \| $ / shares	24.09
Weighted-average grant date fair value, Unvested, End of period (in dollars per share) \| $ / shares	$ 23.92	$ 24.09
Restricted Stock Units (RSUs) [Member]
Restricted Stock and restricted stock [Roll Forward]
Unvested, Beginning of period (in shares) \| shares	57,400
Forfeited (in shares) \| shares	(3,520)
Vested (in shares) \| shares	(625)
Granted (in shares) \| shares	188,652
Unvested, End of period (in shares) \| shares	241,907	57,400
Restricted Stock and restricted stock additional disclosures [Abstract]
Weighted-average grant date fair value, Unvested, Beginning of period (in dollars per share) \| $ / shares	$ 22.59
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	23.84
Weighted-average grant date fair value, Unvested, End of period (in dollars per share) \| $ / shares	$ 23.95	$ 22.59
Restricted and Deferred Stock Awards [Member]
Stock options additional disclosures [Abstract]
Stock-based compensation expense	$ 2,300,000	$ 2,000,000	1,500,000
Tax benefit from compensation expense	1,200,000	700,000	600,000
Pension Benefits [Member]
Accumulated other comprehensive income (loss), before tax [Abstract]
Net actuarial loss				$ 37,914,000	23,161,000
Prior service cost				1,430,000	1,739,000
Total amounts recognized in accumulated other comprehensive loss (pre-tax)				39,344,000	24,900,000
Components of net periodic benefit cost: [Abstract]
Service cost	2,589,000	2,254,000	2,222,000
Interest cost	3,544,000	3,613,000	3,413,000
Expected return on plan assets	(7,720,000)	(7,166,000)	(5,591,000)
Amortization of initial unrecognized asset	0	0	(23,000)
Amortization of prior service cost	309,000	322,000	296,000
Amortization of unrecognized net loss	1,353,000	1,447,000	2,374,000
Total cost (benefit)	75,000	470,000	2,691,000
Other changes in plan assets and benefit obligation recognized in other comprehensive income (pre-tax) [Abstract]
Net loss (gain)	16,108,000	1,620,000	(6,053,000)
Prior service cost	0	21,000	127,000
Amortization of initial unrecognized asset	0	0	23,000
Amortization of prior service cost	(309,000)	(322,000)	(296,000)
Amortization of unrecognized net loss	(1,353,000)	(1,447,000)	(2,374,000)
Total recognized in other comprehensive (income) loss	14,446,000	(128,000)	(8,573,000)
Total recognized in net periodic benefit cost and other comprehensive income (pre-tax)	14,521,000	342,000	(5,882,000)
Change in benefit obligation [Roll Forward]
Benefit obligation at beginning of period	70,229,000	63,408,000
Service cost	2,589,000	2,254,000	2,222,000
Interest cost	3,544,000	3,613,000	3,413,000
Plan participants' contributions	0	0
Actuarial loss	5,935,000	4,940,000
Amendments	0	21,000
Benefits paid	(4,273,000)	(4,007,000)
Projected benefit obligation at end of period	78,024,000	70,229,000	63,408,000
Change in plan assets [Roll Forward]
Fair value of plan assets at beginning of period	97,821,000	90,891,000
Actual return on plan assets	(2,452,000)	10,487,000
Employer contributions	479,000	450,000
Plan participants' contributions	0	0
Benefits paid	(4,273,000)	(4,007,000)
Fair value of plan assets at end of period	$ 91,575,000	$ 97,821,000	$ 90,891,000
Funded status at period end				13,551,000	27,592,000
Weighted average assumptions [Abstract]
Accumulated benefit obligation				76,500,000	68,600,000
Amounts recognized in Balance Sheet [Abstract]
Other assets				23,973,000	35,895,000
Other liabilities				(10,422,000)	(8,303,000)
Funded status				$ 13,551,000	$ 27,592,000
Assumptions used to determine benefit obligations [Abstract]
Discount rate (in hundredths)				4.10%	5.15%	5.70%
Expected long-term return on plan assets (in hundredths)				7.50%	8.00%	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)	5.15%	5.70%	6.30%
Expected long-term return on plan assets (in hundredths)	8.00%	8.00%	8.00%
Rate of compensation increase (in hundredths)	3.00%	3.00%	3.00%
Estimate future benefit payments [Abstract]
2012				$ 5,010,000
2013				5,236,000
2014				5,361,000
2015				7,034,000
2016				5,590,000
Thereafter				29,745,000
Fair value of plan assets	$ 97,821,000	$ 90,891,000	$ 90,891,000	91,575,000	$ 97,821,000	$ 90,891,000
Restricted Stock and restricted stock additional disclosures [Abstract]
Expected long-term rate-of-return on assets (in hundredths)	8.00%	8.00%	8.00%
Other Benefits [Member]
Accumulated other comprehensive income (loss), before tax [Abstract]
Net actuarial loss				2,323,000	3,089,000
Prior service cost				(874,000)	(1,076,000)
Total amounts recognized in accumulated other comprehensive loss (pre-tax)				1,449,000	2,013,000
Components of net periodic benefit cost: [Abstract]
Service cost	$ 17,000	$ 17,000	$ 17,000
Interest cost	202,000	228,000	205,000
Expected return on plan assets	0	0	0
Amortization of initial unrecognized asset	0	0	0
Amortization of prior service cost	(202,000)	(202,000)	(202,000)
Amortization of unrecognized net loss	205,000	201,000	136,000
Total cost (benefit)	222,000	244,000	156,000
Other changes in plan assets and benefit obligation recognized in other comprehensive income (pre-tax) [Abstract]
Net loss (gain)	(562,000)	955,000	289,000
Prior service cost	0	0	0
Amortization of initial unrecognized asset	0	0	0
Amortization of prior service cost	202,000	202,000	202,000
Amortization of unrecognized net loss	(205,000)	(201,000)	(136,000)
Total recognized in other comprehensive (income) loss	(565,000)	956,000	355,000
Total recognized in net periodic benefit cost and other comprehensive income (pre-tax)	(343,000)	1,200,000	511,000
Change in benefit obligation [Roll Forward]
Benefit obligation at beginning of period	4,554,000	3,838,000
Service cost	17,000	17,000	17,000
Interest cost	202,000	228,000	205,000
Plan participants' contributions	263,000	277,000
Actuarial loss	(562,000)	955,000
Amendments	0	0
Benefits paid	(489,000)	(761,000)
Projected benefit obligation at end of period	3,985,000	4,554,000	3,838,000
Change in plan assets [Roll Forward]
Fair value of plan assets at beginning of period	0	0
Actual return on plan assets	0	0
Employer contributions	226,000	484,000
Plan participants' contributions	263,000	277,000
Benefits paid	(489,000)	(761,000)
Fair value of plan assets at end of period	0	0	0
Funded status at period end				(3,985,000)	(4,554,000)
Weighted average assumptions [Abstract]
Accumulated benefit obligation				4,000,000	4,600,000
Amounts recognized in Balance Sheet [Abstract]
Other assets				0	0
Other liabilities				(3,985,000)	(4,554,000)
Funded status				(3,985,000)	(4,554,000)
Estimate future benefit payments [Abstract]
2012				204,000
2013				218,000
2014				232,000
2015				244,000
2016				254,000
Thereafter				1,358,000
Fair value of plan assets	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0

Commitments and Contingent Liabilities (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010
Commitments and Contingent Liabilities [Abstract]
Percentage of the Company's loans secured by real estate (in hundredths)	58.00%
Guarantor Obligations [Line Items]
Loans serviced by the Company for unrelated third parties	$ 301,900	$ 323,200
Standby Letters of Credit [Member]
Guarantor Obligations [Line Items]
Obligation instrument term	five years or less and expire unused
Commitments - maximum potential obligation	$ 26,783	26,193
Commercial Letters of Credit [Member]
Guarantor Obligations [Line Items]
Commitments - maximum potential obligation	15,218	16,255
Unused lines of Credit [Member]
Guarantor Obligations [Line Items]
Commitments - maximum potential obligation	161,551	141,579
Commitment To Extend Credits Credit [Member]
Guarantor Obligations [Line Items]
Commitments - maximum potential obligation	603,322	501,987
Loans Sold With Recourse [Member]
Guarantor Obligations [Line Items]
Commitments - maximum potential obligation	$ 16,175	$ 13,970

Parent Company Financial Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009	Dec. 31, 2008
Assets
Cash and cash equivalents	$ 168,792	$ 168,792	$ 187,161	$ 129,381	$ 168,792	$ 187,161	$ 110,396
Securities available for sale, at estimated fair value				1,244,619	1,129,368
Trading securities				3,062	2,808
Other assets				92,254	99,471
Total assets				5,598,406	5,338,856
Liabilities and Stockholders' Equity
Total liabilities				5,060,296	4,805,284
Stockholders' equity				538,110	533,572	505,123	431,845
Total liabilities and stockholders' equity				5,598,406	5,338,856
Condensed Income Statements [Abstract]
Securities gains	150	3,274	144
Interest, dividend and other income	239,997	255,738	273,393
Income before income tax benefit and equity in undistributed income of subsidiaries	79,174	78,316	72,642
Income tax benefit	(21,273)	(20,912)	(20,631)
Net income	57,901	57,404	52,011
Operating activities
Net income	57,901	57,404	52,011
Adjustments to reconcile net income to net cash provided by operating activities
Stock-based compensation	3,244	3,782	3,133
Gain on sales of available-for-sale securities	(7)	(3,170)	(154)
Net change in other liabilities	11,805	2,645	6,399
Net change in other assets	(3,579)	6,627	(39,324)
Net cash provided by operating activities	83,765	89,437	54,684
Investing activities
Purchases of available-for-sale securities	(648,048)	(635,319)	(426,979)
Sales and maturities of available-for-sale securities	541,555	511,394	434,127
Purchases of premises and equipment	(9,954)	(6,510)	(6,378)
Net cash (used in) provided by investing activities	(175,498)	58,494	(28,448)
Financing activities
Payments on long-term debt	(2,146)	(184,824)	(77,511)
Proceeds from the issuance of common stock	0	0	33,401
Purchases of treasury shares	30,502	477
Cash dividends and payments for fractional shares	(27,063)	(27,577)	(27,119)
Excess tax benefit from exercise of stock options	341	140	(243)
Net cash provided by (used in) financing activities	52,322	(166,300)	50,529
Net (decrease) increase in cash and cash equivalents	(39,411)	(18,369)	76,765
Cash and cash equivalents at beginning of year	168,792	187,161	110,396
Cash and cash equivalents at end of year	129,381	168,792	187,161
NBT Bancorp Inc [Member]
Assets
Cash and cash equivalents	2,454	3,493	11,584	2,454	3,493	$ 11,584	$ 10,846
Securities available for sale, at estimated fair value				9,825	9,190
Trading securities				2,550	2,273
Investment in subsidiaries, on equity basis				622,885	609,260
Other assets				48,153	41,942
Total assets				685,867	666,158
Liabilities and Stockholders' Equity
Total liabilities				147,757	132,586
Stockholders' equity				538,110	533,572
Total liabilities and stockholders' equity				$ 685,867	$ 666,158
Condensed Income Statements [Abstract]
Dividends from subsidiaries	54,400	12,000	9,000
Management fee from subsidiaries	69,430	68,228	65,596
Securities gains	(31)	1,814	141
Interest, dividend and other income	628	1,136	869
Total revenue	124,427	83,178	75,606
Operating expense	75,254	72,436	73,687
Income before income tax benefit and equity in undistributed income of subsidiaries	49,173	10,742	1,919
Income tax benefit	1,340	282	1,994
Equity in undistributed income of subsidiaries	7,388	46,380	48,098
Net income	57,901	57,404	52,011
Operating activities
Net income	57,901	57,404	52,011
Adjustments to reconcile net income to net cash provided by operating activities
Stock-based compensation	3,244	3,782	3,133
Gain on sales of available-for-sale securities	31	(1,814)	(141)
Equity in undistributed income of subsidiaries	(7,388)	(46,380)	(48,098)
Net change in other liabilities	15,311	2,155	(3,662)
Net change in other assets	(11,607)	(2,605)	3,632
Net cash provided by operating activities	57,492	12,542	6,875
Investing activities
Purchases of available-for-sale securities	(968)	(1,745)	(2,173)
Sales and maturities of available-for-sale securities	71	7,807	494
Purchases of premises and equipment	(1,656)	(321)	(600)
Net cash (used in) provided by investing activities	(2,553)	5,741	(2,279)
Financing activities
Proceeds from the issuance of shares to employee benefit plans and other stock plans	1,386	1,675	2,728
Payments on long-term debt	(140)	(135)	(12,625)
Proceeds from the issuance of common stock	0	0	33,401
Purchases of treasury shares	(30,502)	(477)	0
Cash dividends and payments for fractional shares	(27,063)	(27,577)	(27,119)
Excess tax benefit from exercise of stock options	341	140	(243)
Net cash provided by (used in) financing activities	(55,978)	(26,374)	(3,858)
Net (decrease) increase in cash and cash equivalents	(1,039)	(8,091)	738
Cash and cash equivalents at beginning of year	3,493	11,584	10,846
Cash and cash equivalents at end of year	$ 2,454	$ 3,493	$ 11,584

Fair Values of Financial Instruments (Details) - USD ($) $ in Thousands	Dec. 31, 2011	Dec. 31, 2010
Financial assets [Abstract]
Securities available for sale, at fair value	$ 1,244,619	$ 1,129,368
Securities held to maturity	70,811	97,310
Trading securities	3,062	2,808
Net loans and leases	3,728,869	3,538,772
Financial liabilities [Abstract]
Savings, NOW, and money market	2,381,116	2,291,833
Time deposits	933,127	930,778
Noninterest bearing	1,052,906	911,741
Short-term borrowings	181,592	159,434
Long-term debt	370,344	369,874
Trust preferred debentures	75,422	75,422
Securities Available for Sale: [Abstract]
Securities Available for Sale	1,244,619	1,129,368
Trading Securities	3,062	2,808
Collateral dependent impaired loans with no specific reserve	500
Reserves on collateral dependent impaired loans	200
Carrying (Reported) Amount, Fair Value Disclosure [Member]
Financial assets [Abstract]
Cash and cash equivalents	129,381	168,792
Securities available for sale, at fair value	1,244,619	1,129,368
Securities held to maturity	70,811	97,310
Trading securities	3,062	2,808
Net loans and leases	3,728,869	3,538,772
Accrued interest receivable	17,800	19,130
Financial liabilities [Abstract]
Savings, NOW, and money market	2,381,116	2,291,833
Time deposits	933,127	930,778
Noninterest bearing	1,052,906	911,741
Short-term borrowings	181,592	159,434
Long-term debt	370,344	369,874
Accrued interest payable	3,942	4,356
Trust preferred debentures	75,422	75,422
Securities Available for Sale: [Abstract]
Securities Available for Sale	1,244,619	1,129,368
Trading Securities	3,062	2,808
Estimate of Fair Value, Fair Value Disclosure [Member]
Financial assets [Abstract]
Cash and cash equivalents	129,381	168,792
Securities available for sale, at fair value	1,244,619	1,129,368
Securities held to maturity	72,198	98,759
Trading securities	3,062	2,808
Net loans and leases	3,821,640	3,626,603
Accrued interest receivable	17,800	19,130
Financial liabilities [Abstract]
Savings, NOW, and money market	2,381,116	2,291,833
Time deposits	942,436	943,988
Noninterest bearing	1,052,906	911,741
Short-term borrowings	181,592	159,434
Long-term debt	427,107	423,350
Accrued interest payable	3,942	4,356
Trust preferred debentures	75,422	71,148
Securities Available for Sale: [Abstract]
Securities Available for Sale	1,244,619	1,129,368
Trading Securities	3,062	2,808
Fair Value, Measurements, Recurring [Member] \| Fair Value, Inputs, Level 1 [Member]
Financial assets [Abstract]
Securities available for sale, at fair value	91,058	99,470
Trading securities	3,062	2,808
Securities Available for Sale: [Abstract]
U.S. Treasury	82,233	91,280
Federal Agency	0	0
State & municipal	0	0
Mortgage-backed	0	0
Collateralized mortgage obligations	0	0
Corporate	0	0
Other securities	8,825	8,190
Securities Available for Sale	91,058	99,470
Trading Securities	3,062	2,808
Total	94,120	102,278
Fair Value, Measurements, Recurring [Member] \| Fair Value, Inputs, Level 2 [Member]
Financial assets [Abstract]
Securities available for sale, at fair value	1,153,561	1,029,898
Trading securities	0	0
Securities Available for Sale: [Abstract]
U.S. Treasury	0	0
Federal Agency	255,846	349,750
State & municipal	104,789	114,937
Mortgage-backed	325,397	244,808
Collateralized mortgage obligations	465,475	297,888
Corporate	0	20,489
Other securities	2,054	2,026
Securities Available for Sale	1,153,561	1,029,898
Trading Securities	0	0
Total	1,153,561	1,029,898
Fair Value, Measurements, Recurring [Member] \| Fair Value, Inputs, Level 3 [Member]
Financial assets [Abstract]
Securities available for sale, at fair value	0	0
Trading securities	0	0
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
Corporate	0	0
Other securities	0	0
Securities Available for Sale	0	0
Trading Securities	0	0
Total	0	0
Fair Value, Measurements, Recurring [Member] \| Estimate of Fair Value, Fair Value Disclosure [Member]
Financial assets [Abstract]
Securities available for sale, at fair value	1,244,619	1,129,368
Trading securities	3,062	2,808
Securities Available for Sale: [Abstract]
U.S. Treasury	82,233	91,280
Federal Agency	255,846	349,750
State & municipal	104,789	114,937
Mortgage-backed	325,397	244,808
Collateralized mortgage obligations	465,475	297,888
Corporate	0	20,489
Other securities	10,879	10,216
Securities Available for Sale	1,244,619	1,129,368
Trading Securities	3,062	2,808
Total	$ 1,247,681	$ 1,132,176