NBT Bancorp (NBTB) 10-Q 9 Nov 17 2017 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2017	Oct. 31, 2017
Document And Entity Information [Abstract]
Entity Registrant Name	NBT BANCORP INC
Entity Central Index Key	790,359
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 Common Stock, Shares Outstanding		43,537,673
Document Fiscal Year Focus	2,017
Document Fiscal Period Focus	Q3
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Sep. 30, 2017

Consolidated Balance Sheets (un

Consolidated Balance Sheets (unaudited) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Assets
Cash and due from banks	$ 175,804	$ 147,789
Short-term interest bearing accounts	6,012	1,392
Securities available for sale, at fair value	1,357,614	1,338,290
Securities held to maturity (fair value $495,411 and $525,050)	494,309	527,948
Trading securities	10,883	9,259
Federal Reserve and Federal Home Loan Bank stock	45,070	47,033
Loans	6,466,934	6,198,057
Less allowance for loan losses	68,350	65,200
Net loans	6,398,584	6,132,857
Premises and equipment, net	81,421	84,187
Goodwill	268,043	265,439
Intangible assets, net	15,911	15,815
Bank owned life insurance	171,125	168,012
Other assets	130,620	129,247
Total assets	9,155,396	8,867,268
Liabilities
Demand (noninterest bearing)	2,312,715	2,195,845
Savings, NOW and money market	4,141,765	3,905,432
Time	776,756	872,411
Total deposits	7,231,236	6,973,688
Short-term borrowings	681,950	681,703
Long-term debt	88,914	104,087
Junior subordinated debt	101,196	101,196
Other liabilities	96,862	93,278
Total liabilities	8,200,158	7,953,952
Stockholders' equity
Preferred stock, $0.01 par value. Authorized 2,500,000 shares at September 30, 2017 and December 31, 2016	0	0
Common stock, $0.01 par value. Authorized 100,000,000 shares at September 30, 2017 and December 31, 2016; issued 49,651,493 at September 30, 2017 and December 31, 2016	497	497
Additional paid-in-capital	573,772	575,078
Retained earnings	536,107	501,761
Accumulated other comprehensive loss	(16,664)	(21,520)
Common stock in treasury, at cost, 6,122,595 and 6,393,743 shares at September 30, 2017 and December 31, 2016, respectively	(138,474)	(142,500)
Total stockholders' equity	955,238	913,316
Total liabilities and stockholders' equity	$ 9,155,396	$ 8,867,268

Consolidated Balance Sheets (u3

Consolidated Balance Sheets (unaudited) (Parenthetical) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Assets
Securities held to maturity fair value	$ 495,411	$ 525,050
Stockholders' equity
Preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01
Preferred stock, shares authorized (in shares)	2,500,000	2,500,000
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)	100,000,000	100,000,000
Common stock, shares issued (in shares)	49,651,493	49,651,493
Common stock in treasury, at cost (in shares)	6,122,595	6,393,743

Consolidated Statements of Inco

Consolidated Statements of Income (unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Interest, fee and dividend income
Interest and fees on loans	$ 68,086	$ 63,414	$ 197,399	$ 187,093
Securities available for sale	7,278	6,013	21,505	17,976
Securities held to maturity	2,746	2,544	8,263	7,328
Other	737	538	2,010	1,441
Total interest, fee and dividend income	78,847	72,509	229,177	213,838
Interest expense
Deposits	3,648	3,607	10,658	10,809
Short-term borrowings	1,870	761	4,375	1,668
Long-term debt	589	819	1,794	2,425
Junior subordinated debt	810	660	2,308	1,920
Total interest expense	6,917	5,847	19,135	16,822
Net interest income	71,930	66,662	210,042	197,016
Provision for loan losses	7,889	6,388	22,835	17,266
Net interest income after provision for loan losses	64,041	60,274	187,207	179,750
Noninterest income
Insurance and other financial services revenue	5,536	6,114	17,927	18,685
Service charges on deposit accounts	4,261	4,354	12,399	12,459
ATM and debit card fees	5,557	5,063	16,025	14,580
Retirement plan administration fees	5,272	4,129	14,881	11,937
Trust	4,927	4,535	14,620	13,848
Bank owned life insurance	1,284	1,336	3,913	3,898
Net securities (losses) gains	(4)	0	(2)	30
Other	3,945	4,113	10,069	12,188
Total noninterest income	30,778	29,644	89,832	87,625
Noninterest expense
Salaries and employee benefits	32,740	32,783	99,081	98,155
Occupancy	5,174	5,035	16,528	15,780
Data processing and communications	4,399	4,183	12,826	12,354
Professional fees and outside services	3,107	3,343	9,748	9,905
Equipment	3,733	3,656	11,224	10,663
Office supplies and postage	1,432	1,438	4,680	4,661
FDIC expenses	1,257	1,287	3,571	3,838
Advertising	665	634	1,711	1,733
Amortization of intangible assets	993	952	2,999	2,976
Loan collection and other real estate owned, net	1,684	985	3,627	2,535
Other	5,417	5,318	16,209	15,683
Total noninterest expense	60,601	59,614	182,204	178,283
Income before income tax expense	34,218	30,304	94,835	89,092
Income tax expense	11,342	10,303	30,321	30,291
Net income	$ 22,876	$ 20,001	$ 64,514	$ 58,801
Earnings per share
Basic (in dollars per share)	$ 0.52	$ 0.46	$ 1.48	$ 1.36
Diluted (in dollars per share)	$ 0.52	$ 0.46	$ 1.47	$ 1.35

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income (unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Consolidated Statements of Comprehensive Income (unaudited) [Abstract]
Net income	$ 22,876	$ 20,001	$ 64,514	$ 58,801
Other comprehensive income, net of tax:
Unrealized net holding gains (losses) arising during the period (pre-tax amounts of $1,355, $(2,931), $4,719 and $14,010)	837	(1,790)	2,896	8,560
Reclassification adjustment for net losses (gains) related to securities available for sale included in net income (pre-tax amounts of $(4), $-, $(2) and $30)	2	0	1	(19)
Reclassification adjustment for an impairment write-down of equity security (pre-tax amounts of $-, $-, $1,312 and $-)	0	0	811	0
Unrealized (loss) gain on derivatives (cash flow hedges) (pre-tax amounts of $(63), $782, $(167) and $719)	(40)	478	(103)	439
Amortization of unrealized net gains related to the reclassification of available for sale investment securities to held to maturity (pre-tax amounts of $212, $267, $675 and $843)	131	162	417	515
Pension and other benefits:
Amortization of prior service cost and actuarial loss (pre-tax amounts of $480, $519, $1,350, $1,544)	297	317	834	943
Total other comprehensive income (loss)	1,227	(833)	4,856	10,438
Comprehensive income	$ 24,103	$ 19,168	$ 69,370	$ 69,239

Consolidated Statements of Com6

Consolidated Statements of Comprehensive Income (unaudited) (Parenthetical) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Other comprehensive income, net of tax:
Unrealized net holding gains (losses) arising during the period , pre-tax amounts	$ 1,355	$ (2,931)	$ 4,719	$ 14,010
Reclassification adjustment for net losses (gains) related to securities available for sale included in net income, pre-tax amounts	(4)	0	(2)	30
Reclassification adjustment for an impairment write-down of equity security, pre-tax amounts	0	0	1,312	0
Unrealized (loss) gain on derivatives (cash flow hedges), pre-tax amounts	(63)	782	(167)	719
Amortization of unrealized net gains related to the reclassification of available for sale investment securities to held to maturity, pre-tax amounts	212	267	675	843
Amortization of prior service cost and actuarial loss, pre-tax amounts	$ 480	$ 519	$ 1,350	$ 1,544

Consolidated Statements of Stoc

Consolidated Statements of Stockholders' Equity (unaudited) - 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, 2015	$ 497	$ 576,726	$ 462,232	$ (22,418)	$ (135,033)	$ 882,004
Net income	0	0	58,801	0	0	58,801
Cash dividends	0	0	(28,903)	0	0	(28,903)
Purchase of treasury shares	0	0	0	0	(17,193)	(17,193)
Net issuance of shares to employee benefit plans and other stock plans, including tax benefit	0	(6,164)	0	0	7,270	1,106
Stock-based compensation	0	3,096	0	0	0	3,096
Other comprehensive income	0	0	0	10,438	0	10,438
Balance at Sep. 30, 2016	497	573,658	492,130	(11,980)	(144,956)	909,349
Balance at Dec. 31, 2016	497	575,078	501,761	(21,520)	(142,500)	913,316
Net income	0	0	64,514	0	0	64,514
Cash dividends	0	0	(30,073)	0	0	(30,073)
Net issuance of shares to employee benefit plans and other stock plans, including tax benefit	0	(4,596)	0	0	4,026	(570)
Stock-based compensation	0	3,290	(95)	0	0	3,195
Other comprehensive income	0	0	0	4,856	0	4,856
Balance at Sep. 30, 2017	$ 497	$ 573,772	$ 536,107	$ (16,664)	$ (138,474)	$ 955,238

Consolidated Statements of Sto8

Consolidated Statements of Stockholders' Equity (unaudited) (Parenthetical) - $ / shares	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016
Consolidated Statements of Stockholders' Equity (unaudited) [Abstract]
Cash dividends - per share (in dollars per share)	$ 0.69	$ 0.67
Purchase of treasury shares (in shares)		675,535
Net issuance of shares to employee benefit plans and other stock plans, including tax benefit (in shares)	271,148	389,058

Consolidated Statements of Cash

Consolidated Statements of Cash Flows (unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016
Operating activities
Net income	$ 64,514	$ 58,801
Adjustments to reconcile net income to net cash provided by operating activities
Provision for loan losses	22,835	17,266
Depreciation and amortization of premises and equipment	6,759	6,765
Net accretion on securities	3,628	3,781
Amortization of intangible assets	2,999	2,976
Excess tax benefit on stock-based compensation	1,697	0
Stock based compensation	3,195	3,096
Bank owned life insurance income	(3,913)	(3,898)
Trading securities purchases	(1,470)	(34)
Gains on trading securities	(154)	(441)
Proceeds from sales of loans held for sale	87,095	71,170
Originations and purchases of loans held for sale	(87,246)	(73,393)
Net gains on sales of loans held for sale	(292)	(459)
Net security losses (gains)	2	(30)
Net (gain) on sales of other real estate owned	(189)	(625)
Gain on asset sold	0	(2,462)
Impairment write-down of equity security	1,312	2,565
Net (increase) in other assets	(6,076)	(16,599)
Net increase in other liabilities	1,872	11,395
Net cash provided by operating activities	96,568	79,874
Investing activities
Net cash used in acquisitions	(4,000)	(2,000)
Securities available for sale:
Proceeds from maturities, calls and principal paydowns	205,327	250,441
Proceeds from sales	9,997	48
Purchases	(232,850)	(352,056)
Securities held to maturity:
Proceeds from maturities, calls and principal paydowns	86,055	76,676
Proceeds from sales	764	0
Purchases	(53,212)	(90,476)
Other:
Net increase in loans	(293,346)	(291,349)
Proceeds from Federal Home Loan Bank stock redemption	177,803	108,227
Purchases of Federal Reserve and Federal Home Loan Bank stock	(175,840)	(113,872)
Proceeds from settlement of bank owned life insurance	800	1,478
Purchase of bank owned life insurance	0	(45,000)
Purchases of premises and equipment, net	(4,177)	(4,652)
Proceeds from the sales of other real estate owned	6,767	5,153
Net cash used in investing activities	(275,912)	(457,382)
Financing activities
Net increase in deposits	257,548	344,395
Net increase in short-term borrowings	248	142,546
Proceeds from issuance of long-term debt	0	3,880
Repayments of long-term debt	(15,174)	(20,183)
Proceeds from the issuance of shares to employee benefit plans and other stock plans	3,012	4,234
Cash paid by employer for tax-withholding on stock issuance	(3,582)	(3,128)
Purchase of treasury stock	0	(17,193)
Cash dividends	(30,073)	(28,903)
Net cash provided by financing activities	211,979	425,648
Net increase in cash and cash equivalents	32,635	48,140
Cash and cash equivalents at beginning of period	149,181	140,297
Cash and cash equivalents at end of period	181,816	188,437
Cash paid during the period for:
Interest	19,771	17,269
Income taxes paid	22,230	29,173
Noncash investing activities:
Loans transferred to other real estate owned	5,227	2,363
Acquisitions:
Fair value of assets acquired	$ 3,096	$ 1,703

Description of Business

Description of Business	9 Months Ended
	Sep. 30, 2017
Description of Business [Abstract]
Description of Business	1. Description of Business NBT Bancorp Inc. (the “Registrant” or the “Company”) is a registered financial holding company incorporated in the state of Delaware in 1986, with its principal headquarters located in Norwich, New York. The principal assets of the Registrant consist of all of the outstanding shares of common stock of its subsidiaries, including: NBT Bank, National Association (the “Bank”), NBT Financial Services, Inc. (“NBT Financial”), NBT Holdings, Inc. (“NBT Holdings”), Hathaway Agency, Inc. and CNBF Capital Trust I, NBT Statutory Trust I, NBT Statutory Trust II, Alliance Financial Capital Trust I and Alliance Financial Capital Trust II (collectively, the “Trusts”). The Company’s principal sources of revenue are the management fees and dividends it receives from the Bank, NBT Financial and NBT Holdings. The Company’s business, primarily conducted through the Bank but also through its other subsidiaries, consists of providing commercial banking and financial services to customers in its market area, which includes central and upstate New York, northeastern Pennsylvania, southern New Hampshire, western Massachusetts, Vermont and the greater Portland, Maine area. The Company has been and intends to continue to be, a community-oriented financial institution offering a variety of financial services. The Company’s business philosophy is to operate as a community bank with local decision-making, principally in non-metropolitan markets, providing a broad array of banking and financial services to retail, commercial and municipal customers.

Basis of Presentation

Basis of Presentation	9 Months Ended
	Sep. 30, 2017
Basis of Presentation [Abstract]
Basis of Presentation	2. Basis of Presentation The accompanying unaudited interim consolidated financial statements include the accounts of the Registrant and its wholly owned subsidiaries, the Bank, NBT Financial and NBT Holdings. Collectively, the Registrant and its subsidiaries are referred to herein as “the Company.” The interim data includes all adjustments, consisting only of normal recurring adjustments, necessary for a fair statement of the results for the interim periods in accordance with generally accepted accounting principles in the United States of America (“GAAP”). These unaudited interim consolidated financial statements should be read in conjunction with the audited consolidated financial statements and notes thereto included in our 2016 Annual Report on Form 10-K. The results of operations for the interim periods are not necessarily indicative of the results that may be expected for the full year or any other interim period. All intercompany transactions have been eliminated in consolidation. Amounts in the prior period financial statements are reclassified whenever necessary to conform to current period presentation. The Company has evaluated subsequent events for potential recognition and/or disclosure and there were none identified.

Securities

Securities	9 Months Ended
	Sep. 30, 2017
Securities [Abstract]
Securities	3. Securities The amortized cost, estimated fair value and unrealized gains and losses of available for sale (“AFS”) securities are as follows: (In thousands) Amortized cost Unrealized gains Unrealized losses Estimated fair value September 30, 2017 Federal agency $ 139,935 $ 27 $ 544 $ 139,418 State & municipal 42,880 127 88 42,919 Mortgage-backed: Government-sponsored enterprises 554,466 3,879 1,115 557,230 U.S. government agency securities 26,760 404 168 26,996 Collateralized mortgage obligations: Government-sponsored enterprises 523,682 626 5,592 518,716 U.S. government agency securities 53,089 169 662 52,596 Other securities 13,537 6,332 130 19,739 Total securities AFS $ 1,354,349 $ 11,564 $ 8,299 $ 1,357,614 December 31, 2016 Federal agency $ 175,135 $ 78 $ 805 $ 174,408 State & municipal 47,053 153 480 46,726 Mortgage-backed: Government-sponsored enterprises 513,814 3,345 2,492 514,667 U.S. government agency securities 14,955 411 189 15,177 Collateralized mortgage obligations: Government-sponsored enterprises 513,431 532 7,688 506,275 U.S. government agency securities 60,822 184 708 60,298 Other securities 15,849 6,394 1,504 20,739 Total securities AFS $ 1,341,059 $ 11,097 $ 13,866 $ 1,338,290 The amortized cost, estimated fair value and unrealized gains and losses of held to maturity (“HTM”) securities are as follows: (In thousands) Amortized cost Unrealized gains Unrealized losses Estimated fair value September 30, 2017 Mortgage-backed: Government-sponsored enterprises $ 99,502 $ 239 $ 685 $ 99,056 U.S. government agency securities 447 67 - 514 Collateralized mortgage obligations: Government-sponsored enterprises 195,388 1,135 1,103 195,420 State & municipal 198,972 1,983 534 200,421 Total securities HTM $ 494,309 $ 3,424 $ 2,322 $ 495,411 December 31, 2016 Mortgage-backed: Government-sponsored enterprises $ 96,668 $ - $ 1,176 $ 95,492 U.S. government agency securities 533 87 - 620 Collateralized mortgage obligations: Government-sponsored enterprises 225,213 1,060 1,508 224,765 State & municipal 205,534 434 1,795 204,173 Total securities HTM $ 527,948 $ 1,581 $ 4,479 $ 525,050 Securities with amortized costs totaling $1.2 billion at September 30, 2017 and $1.5 billion at December 31, 2016 were pledged to secure public deposits and for other purposes required or permitted by law. At September 30, 2017 and December 31, 2016, securities with an amortized cost of $242.6 million and $235.6 million, respectively, were pledged as collateral for securities sold under repurchase agreements. The following table sets forth information with regard to investment securities with unrealized losses, segregated according to the length of time the securities had been in a continuous unrealized loss position: (Dollars in thousands) 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 September 30, 2017 AFS securities: Federal agency $ 45,209 $ (49 ) 3 $ 54,465 $ (495 ) 5 $ 99,674 $ (544 ) 8 State & municipal 14,720 (39 ) 24 6,015 (49 ) 8 20,735 (88 ) 32 Mortgage-backed 181,600 (1,176 ) 42 6,577 (107 ) 5 188,177 (1,283 ) 47 Collateralized mortgage obligations 339,415 (3,175 ) 50 119,108 (3,079 ) 16 458,523 (6,254 ) 66 Other securities 1,997 (3 ) 1 2,979 (127 ) 1 4,976 (130 ) 2 Total securities with unrealized losses $ 582,941 $ (4,442 ) 120 $ 189,144 $ (3,857 ) 35 $ 772,085 $ (8,299 ) 155 HTM securities: Mortgage-backed $ 51,166 $ (685 ) 4 $ - $ - - $ 51,166 $ (685 ) 4 Collateralized mortgage obligations 49,394 (160 ) 7 31,627 (943 ) 4 81,021 (1,103 ) 11 State & municipal 16,811 (188 ) 21 12,591 (346 ) 21 29,402 (534 ) 42 Total securities with unrealized losses $ 117,371 $ (1,033 ) 32 $ 44,218 $ (1,289 ) 25 $ 161,589 $ (2,322 ) 57 December 31, 2016 AFS securities: Federal agency $ 119,363 $ (805 ) 10 $ - $ - - $ 119,363 $ (805 ) 10 State & municipal 31,873 (478 ) 55 483 (2 ) 1 32,356 (480 ) 56 Mortgage-backed 277,524 (2,668 ) 49 985 (13 ) 4 278,509 (2,681 ) 53 Collateralized mortgage obligations 473,746 (8,396 ) 57 - - - 473,746 (8,396 ) 57 Other securities - - - 4,363 (1,504 ) 2 4,363 (1,504 ) 2 Total securities with unrealized losses $ 902,506 $ (12,347 ) 171 $ 5,831 $ (1,519 ) 7 $ 908,337 $ (13,866 ) 178 HTM securities: Mortgage-backed $ 95,492 $ (1,176 ) 5 $ - $ - - $ 95,492 $ (1,176 ) 5 Collateralized mortgage obligations 108,587 (319 ) 12 35,209 (1,189 ) 4 143,796 (1,508 ) 16 State & municipal 81,984 (1,795 ) 155 - - - 81,984 (1,795 ) 155 Total securities with unrealized losses $ 286,063 $ (3,290 ) 172 $ 35,209 $ (1,189 ) 4 $ 321,272 $ (4,479 ) 176 Declines in the fair value of HTM and AFS 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, the other-than-temporary impairment (“OTTI”) 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 Company will be required to sell the security before recovery of its amortized cost basis less any current-period credit loss, the OTTI 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 OTTI related to the credit loss shall be recognized in earnings. The amount of the total OTTI related to other factors shall be recognized in other comprehensive income, net of applicable taxes. In estimating OTTI 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. Management has the intent to hold the securities classified as HTM until they mature, at which time it is believed the Company will receive full value for the securities. The unrealized losses on HTM debt securities are due to increases in market interest rates over yields 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 bond approaches their maturity date or repricing date or if market yields for such investments decline. Management also has the intent to hold and will not be required to sell, the securities classified as AFS for a period of time sufficient for a recovery of cost, which may be until maturity. The unrealized losses on AFS debt securities 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. For AFS debt and equity securities, OTTI losses are recognized in earnings if the Company intends to sell the security. In other cases the Company considers the relevant factors noted above, as well as the Company’s intent and ability to retain its investment for a period of time sufficient to allow for any anticipated recovery in market value and whether evidence exists to support a realizable value equal to or greater than the cost basis. Any impairment loss on an equity security is equal to the full difference between the cost basis and the fair value of the security. As of September 30, 2017 and December 31, 2016, management believes the impairments detailed in the table above are temporary. There were no impairments realized in the three months ended September 30, 2017. For the nine months ended September 30, 2017, $1.3 million of an OTTI loss on an AFS equity investment was realized in the Company’s unaudited interim consolidated statements of income. There were no OTTI losses realized in the Company’s unaudited interim consolidated statements of income for the three and nine months ended September 30, 2016. During the three and nine months ended September 30, 2017, the Company sold HTM securities with an amortized cost of $0.8 million and an unrealized loss of $2 thousand. Due to significant deterioration in the creditworthiness of the issuers of the HTM securities, the circumstances caused the Company to change its intent to hold the HTM securities sold to maturity, which did not affect the Company’s intent to hold the remainder of the HTM portfolio to maturity. There were no sales of HTM securities in the three and nine month periods ended September 30, 2016. The following tables set forth information with regard to contractual maturities of debt securities at September 30, 2017: (In thousands) Amortized cost Estimated fair value AFS debt securities: Within one year $ 92,405 $ 92,429 From one to five years 84,442 84,598 From five to ten years 179,854 180,667 After ten years 984,111 980,181 $ 1,340,812 $ 1,337,875 HTM debt securities: Within one year $ 28,489 $ 28,493 From one to five years 38,321 38,702 From five to ten years 144,621 145,547 After ten years 282,878 282,669 $ 494,309 $ 495,411 Maturities of mortgage-backed, collateralized mortgage obligations and asset-backed securities are stated based on their estimated average lives. Actual maturities may differ from estimated average lives or contractual maturities because, in certain cases, borrowers have the right to call or prepay obligations with or without call or prepayment penalties. Except for U.S. Government securities, there were no holdings, when taken in the aggregate, of any single issuer that exceeded 10% of consolidated stockholders’ equity at September 30, 2017 and December 31, 2016.

Allowance for Loan Losses and C

Allowance for Loan Losses and Credit Quality of Loans	9 Months Ended
	Sep. 30, 2017
Allowance for Loan Losses and Credit Quality of Loans [Abstract]
Allowance for Loan Losses and Credit Quality of Loans	4. Allowance for Loan Losses and Credit Quality of Loans Allowance for Loan Losses The allowance for loan losses is maintained at a level estimated by management to provide adequately for probable incurred losses inherent in the current loan portfolio. The appropriateness of the allowance for loan losses is continuously monitored. It is assessed for appropriateness using a methodology designed to ensure the level of the allowance reasonably reflects the loan portfolio’s risk profile. It is evaluated to ensure that it is sufficient to absorb all reasonably estimable credit losses inherent in the current loan portfolio. To develop and document a systematic methodology for determining the allowance for loan losses, the Company has divided the loan portfolio into three segments, each with different risk characteristics and methodologies for assessing risk. Those segments are further segregated between our loans accounted for under the amortized cost method (referred to as “originated” loans) and loans acquired in a business combination (referred to as “acquired” loans). Each portfolio segment is broken down into class segments where appropriate. Class segments contain unique measurement attributes, risk characteristics and methods for monitoring and assessing risk that are necessary to develop the allowance for loan losses. Unique characteristics such as borrower type, loan type, collateral type and risk characteristics define each class segment. The following table illustrates the portfolio and class segments for the Company’s loan portfolio: Portfolio Class Commercial Loans Commercial Commercial Real Estate Agricultural Agricultural Real Estate Business Banking Consumer Loans Indirect Home Equity Direct Residential Real Estate Mortgages Commercial Loans The Company offers a variety of commercial loan products including commercial (non-real estate), commercial real estate, agricultural, agricultural real estate and business banking loans. The Company’s underwriting analysis for commercial loans typically includes credit verification, independent appraisals, a review of the borrower’s financial condition and a detailed analysis of the borrower’s underlying cash flows. Commercial – Commercial Real Estate – Agricultural Agricultural Real Estate Business Banking Consumer Loans The Company offers a variety of consumer loan products including indirect, home equity and direct loans. Indirect – Home Equity Direct – Residential Real Estate Mortgages 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. This practice allows the Company to manage interest rate, liquidity risk and credit risk. Loans on one-to-four-family residential real estate are generally originated in amounts of no more than 85% of the purchase price or appraised value (whichever is lower) or have private mortgage insurance. Mortgage title insurance and hazard insurance are normally required. Construction loans have a unique risk, because they are secured by an incomplete dwelling. This risk is reduced through periodic site inspections, including one at each loan draw period. Allowance for Loan Loss Calculation For purposes of evaluating the adequacy of the allowance, the Company considers a number of significant factors that affect the collectability of the portfolio. For individually analyzed loans, these include estimates of loss exposure, which reflect the facts and circumstances that affect the likelihood of repayment of such loans as of the evaluation date. For homogeneous pools of loans, estimates of the Company’s exposure to credit loss reflect a current assessment of a number of factors, which could affect collectability. These factors include: past loss experience, size, trend, composition and nature of loans; changes in lending policies and procedures, including underwriting standards and collection, charge-offs and recoveries; trends experienced in nonperforming and delinquent loans; current economic conditions in the Company’s market; portfolio concentrations that may affect loss experienced across one or more components of the portfolio; the effect of external factors such as competition, legal and regulatory requirements; and the experience, ability and depth of lending management and staff. In addition, various regulatory agencies, as an integral component of their examination process, periodically review the Company’s allowance for loan losses. Such agencies may require the Company to make loan grade changes as well as recognize additions to the allowance based on their examinations. After a thorough consideration of the factors discussed above, any required additions or reductions to the allowance for loan losses are made periodically by charges or credits to the provision for loan losses. These charges are necessary to maintain the allowance at a level that management believes is reflective of overall inherent risk of probable loss in the portfolio. While management uses available information to recognize losses on loans, additions and reductions of 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 tables illustrate the changes in the allowance for loan losses by our portfolio segments: Three months ended September 30, (In thousands) Commercial Loans Consumer Loans Residential Real Estate Mortgages Unallocated Total Balance as of June 30, 2017 $ 24,428 $ 35,523 $ 6,649 $ - $ 66,600 Charge-offs (574 ) (6,979 ) (421 ) - (7,974 ) Recoveries 266 1,446 123 - 1,835 Provision 1,434 6,197 258 - 7,889 Ending Balance as of September 30, 2017 $ 25,554 $ 36,187 $ 6,609 $ - $ 68,350 Balance as of June 30, 2016 $ 25,222 $ 31,471 $ 7,875 $ - $ 64,568 Charge-offs (637 ) (6,046 ) (142 ) - (6,825 ) Recoveries 512 898 127 - 1,537 Provision 1,514 6,078 (1,481 ) 277 6,388 Ending Balance as of September 30, 2016 $ 26,611 $ 32,401 $ 6,379 $ 277 $ 65,668 Nine months ended September 30, Commercial Loans Consumer Loans Residential Real Estate Mortgages Unallocated Total Balance as of December 31, 2016 $ 25,444 $ 33,375 $ 6,381 $ - $ 65,200 Charge-offs (2,991 ) (19,742 ) (1,717 ) - (24,450 ) Recoveries 919 3,680 166 - 4,765 Provision 2,182 18,874 1,779 - 22,835 Ending Balance as of September 30, 2017 $ 25,554 $ 36,187 $ 6,609 $ - $ 68,350 Balance as of December 31, 2015 $ 25,545 $ 29,253 $ 7,960 $ 260 $ 63,018 Charge-offs (1,723 ) (16,409 ) (1,119 ) - (19,251 ) Recoveries 1,616 2,779 240 - 4,635 Provision 1,173 16,778 (702 ) 17 17,266 Ending Balance as of September 30, 2016 $ 26,611 $ 32,401 $ 6,379 $ 277 $ 65,668 For acquired loans, to the extent that we experience deterioration in borrower credit quality resulting in a decrease in our expected cash flows subsequent to the acquisition of the loans, an allowance for loan losses would be established based on our estimate of future credit losses over the remaining life of the loan. There was no allowance for loan losses for the acquired loan portfolio as of September 30, 2017 and $0.7 million as of September 30, 2016. There were no charge-offs related to acquired loans during the three months ended September 30, 2017 and totaled $0.1 million during the three months ended September 30, 2016. Net charge-offs related to acquired loans were $0.7 million and $0.4 million during the nine months ended September 30, 2017 and 2016, respectively and are included in the table above. The following tables illustrate the allowance for loan losses and the recorded investment by portfolio segments: As of September 30, 2017 (In thousands) Commercial Loans Consumer Loans Residential Real Estate Mortgages Total Allowance for loan losses $ 25,554 $ 36,187 $ 6,609 $ 68,350 Allowance for loans individually evaluated for impairment 30 - - 30 Allowance for loans collectively evaluated for impairment $ 25,524 $ 36,187 $ 6,609 $ 68,320 Ending balance of loans $ 2,962,287 $ 2,202,070 $ 1,302,577 $ 6,466,934 Ending balance of originated loans individually evaluated for impairment $ 4,855 $ 8,307 $ 6,574 $ 19,736 Ending balance of acquired loans collectively evaluated for impairment $ 196,444 $ 47,986 $ 177,393 $ 421,823 Ending balance of originated loans collectively evaluated for impairment $ 2,760,988 $ 2,145,777 $ 1,118,610 $ 6,025,375 As of December 31, 2016 Allowance for loan losses $ 25,444 $ 33,375 $ 6,381 $ 65,200 Allowance for loans individually evaluated for impairment 1,517 - - 1,517 Allowance for loans collectively evaluated for impairment $ 23,927 $ 33,375 $ 6,381 $ 63,683 Ending balance of loans $ 2,786,002 $ 2,149,441 $ 1,262,614 $ 6,198,057 Ending balance of originated loans individually evaluated for impairment $ 13,070 $ 8,488 $ 6,111 $ 27,669 Ending balance of acquired loans individually evaluated for impairment $ 1,205 $ - $ - $ 1,205 Ending balance of acquired loans collectively evaluated for impairment $ 236,413 $ 63,005 $ 199,471 $ 498,889 Ending balance of originated loans collectively evaluated for impairment $ 2,535,314 $ 2,077,948 $ 1,057,032 $ 5,670,294 Credit Quality of Loans For all loan classes within the Company’s loan portfolio, loans are placed on nonaccrual status when timely collection of principal and interest in accordance with contractual terms is doubtful. Loans are transferred to nonaccrual status generally when principal or interest payments become ninety days delinquent, unless the loan is well-secured and in the process of collection or sooner when management concludes or circumstances indicate that borrowers may be unable to meet contractual principal or interest payments. When a loan is transferred to a nonaccrual status, all interest previously accrued in the current period but not collected is reversed against interest income in that period. Any payment received on a nonaccrual loan is applied to principal. 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. The following tables set forth information with regard to past due and nonperforming loans by loan class: As of September 30, 2017 (In thousands) 31-60 Days Past Due Accruing 61-90 Days Past Due Accruing Greater Than 90 Days Past Due Accruing Total Past Due Accruing Nonaccrual Current Recorded Total Loans Originated Commercial Loans: Commercial $ 1 $ 156 $ - $ 157 $ 430 $ 732,535 $ 733,122 Commercial Real Estate 1,274 - - 1,274 2,020 1,477,265 1,480,559 Agricultural - - - - 391 34,448 34,839 Agricultural Real Estate 234 - - 234 1,658 33,499 35,391 Business Banking 2,057 91 - 2,148 4,640 475,144 481,932 Total Commercial Loans $ 3,566 $ 247 $ - $ 3,813 $ 9,139 $ 2,752,891 $ 2,765,843 Consumer Loans: Indirect $ 18,755 $ 5,112 $ 2,452 $ 26,319 $ 2,069 $ 1,602,890 $ 1,631,278 Home Equity 2,933 628 213 3,774 2,790 452,189 458,753 Direct 319 47 79 445 78 63,530 64,053 Total Consumer Loans $ 22,007 $ 5,787 $ 2,744 $ 30,538 $ 4,937 $ 2,118,609 $ 2,154,084 Residential Real Estate Mortgages $ 3,812 $ 246 $ 597 $ 4,655 $ 6,180 $ 1,114,349 $ 1,125,184 Total Originated Loans $ 29,385 $ 6,280 $ 3,341 $ 39,006 $ 20,256 $ 5,985,849 $ 6,045,111 Acquired Commercial Loans: Commercial $ - $ - $ - $ - $ - $ 39,037 $ 39,037 Commercial Real Estate - - - - 501 112,810 113,311 Business Banking 355 275 - 630 773 42,693 44,096 Total Commercial Loans $ 355 $ 275 $ - $ 630 $ 1,274 $ 194,540 $ 196,444 Consumer Loans: Indirect $ 29 $ 8 $ 3 $ 40 $ 30 $ 2,084 $ 2,154 Home Equity 307 - - 307 160 42,510 42,977 Direct 32 26 7 65 8 2,782 2,855 Total Consumer Loans $ 368 $ 34 $ 10 $ 412 $ 198 $ 47,376 $ 47,986 Residential Real Estate Mortgages $ 660 $ 100 $ 37 $ 797 $ 1,725 $ 174,871 $ 177,393 Total Acquired Loans $ 1,383 $ 409 $ 47 $ 1,839 $ 3,197 $ 416,787 $ 421,823 Total Loans $ 30,768 $ 6,689 $ 3,388 $ 40,845 $ 23,453 $ 6,402,636 $ 6,466,934 As of December 31, 2016 (In thousands) 31-60 Days Past Due Accruing 61-90 Days Past Due Accruing Greater Than 90 Days Past Due Accruing Total Past Due Accruing Nonaccrual Current Recorded Total Loans Originated Commercial Loans: Commercial $ 33 $ 5 $ - $ 38 $ 2,964 $ 650,568 $ 653,570 Commercial Real Estate - - - - 7,935 1,343,854 1,351,789 Agricultural - - - - 730 37,186 37,916 Agricultural Real Estate - - - - 1,803 30,619 32,422 Business Banking 1,609 318 - 1,927 4,860 465,900 472,687 Total Commercial Loans $ 1,642 $ 323 $ - $ 1,965 $ 18,292 $ 2,528,127 $ 2,548,384 Consumer Loans: Indirect $ 19,253 $ 4,185 $ 2,499 $ 25,937 $ 2,145 $ 1,538,593 $ 1,566,675 Home Equity 3,416 1,065 528 5,009 2,851 448,797 456,657 Direct 452 125 20 597 107 62,400 63,104 Total Consumer Loans $ 23,121 $ 5,375 $ 3,047 $ 31,543 $ 5,103 $ 2,049,790 $ 2,086,436 Residential Real Estate Mortgages $ 2,725 $ 172 $ 1,406 $ 4,303 $ 6,682 $ 1,052,158 $ 1,063,143 Total Originated Loans $ 27,488 $ 5,870 $ 4,453 $ 37,811 $ 30,077 $ 5,630,075 $ 5,697,963 Acquired Commercial Loans: Commercial $ - $ - $ - $ - $ - $ 49,447 $ 49,447 Commercial Real Estate - - - - 1,891 135,398 137,289 Business Banking 236 - - 236 804 49,842 50,882 Total Commercial Loans $ 236 $ - $ - $ 236 $ 2,695 $ 234,687 $ 237,618 Consumer Loans: Indirect 100 5 - 105 47 8,541 8,693 Home Equity 254 53 30 337 237 50,553 51,127 Direct 30 2 - 32 20 3,133 3,185 Total Consumer Loans $ 384 $ 60 $ 30 $ 474 $ 304 $ 62,227 $ 63,005 Residential Real Estate Mortgages $ 609 $ 28 $ 327 $ 964 $ 2,636 $ 195,871 $ 199,471 Total Acquired Loans $ 1,229 $ 88 $ 357 $ 1,674 $ 5,635 $ 492,785 $ 500,094 Total Loans $ 28,717 $ 5,958 $ 4,810 $ 39,485 $ 35,712 $ 6,122,860 $ 6,198,057 There were no material commitments to extend further credit to borrowers with nonperforming loans as of September 30, 2017 and December 31, 2016. Impaired Loans The methodology used to establish the allowance for loan losses on impaired loans incorporates specific allocations on loans analyzed individually. Classified loans, including all trouble debt restructured loans (“TDRs”) and nonaccrual commercial loans that are graded Substandard or below, with outstanding balances equal to or greater than $0.8 million are evaluated for impairment through the Company’s quarterly status review process. In determining whether we are able 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 level of impairment. Any change to the previously recognized impairment loss is recognized as a change to the allowance account and recorded in the unaudited interim consolidated statements of income as a component of the provision for loan losses. The following table provides information on loans specifically evaluated for impairment: September 30, 2017 December 31, 2016 (In thousands) Recorded Investment Balance (Book) Unpaid Principal Balance (Legal) Related Allowance Recorded Investment Balance (Book) Unpaid Principal Balance (Legal) Related Allowance Originated With no related allowance recorded: Commercial Loans: Commercial $ - $ 251 $ 1,278 $ 1,697 Commercial Real Estate 2,239 3,996 3,816 3,841 Agricultural 100 112 130 137 Agricultural Real Estate 1,491 1,663 1,434 1,567 Business Banking 947 1,687 655 728 Total Commercial Loans $ 4,777 $ 7,709 $ 7,313 $ 7,970 Consumer Loans: Indirect 36 47 5 16 Home Equity 8,153 10,063 8,483 9,429 Direct 118 118 - - Total Consumer Loans $ 8,307 $ 10,228 $ 8,488 $ 9,445 Residential Real Estate Mortgages 6,574 8,335 6,111 6,906 Total $ 19,658 $ 26,272 $ 21,912 $ 24,321 With an allowance recorded: Commercial Loans: Commercial Real Estate $ 78 $ 83 $ 30 $ 5,553 $ 5,736 $ 735 Agricultural - - - 49 49 37 Agricultural Real Estate - - - 155 155 54 Total Commercial Loans $ 78 $ 83 $ 30 $ 5,757 $ 5,940 $ 826 Acquired With an allowance recorded: Commercial Loans: Commercial Real Estate $ - $ - $ - $ 1,205 $ 1,321 $ 691 Total Commercial Loans $ - $ - $ - $ 1,205 $ 1,321 $ 691 Total: $ 19,736 $ 26,355 $ 30 $ 28,874 $ 31,582 $ 1,517 The following tables summarize the average recorded investments on impaired loans specifically evaluated for impairment and the interest income recognized: For the three months ended September 30, 2017 September 30, 2016 (In thousands) Average Recorded Investment Interest Income Recognized Average Recorded Investment Interest Income Recognized Originated Commercial Loans: Commercial $ 1,000 $ - $ 3,204 $ - Commercial Real Estate 2,415 48 15,799 48 Agricultural 115 - 85 - Agricultural Real Estate 1,505 11 935 11 Business Banking 955 2 743 - Consumer Loans: Indirect 35 1 8 - Home Equity 8,159 111 8,401 116 Direct 119 2 - - Residential Real Estate Mortgage 6,633 82 6,141 76 Total Originated $ 20,936 $ 257 $ 35,316 $ 251 Acquired Commercial Loans: Commercial Real Estate $ - $ - $ 1,205 $ - Total Acquired $ - $ - $ 1,205 $ - Total Loans $ 20,936 $ 257 $ 36,521 $ 251 For the nine months ended September 30, 2017 September 30, 2016 Average Recorded Investment Interest Income Recognized Average Recorded Investment Interest Income Recognized Originated Commercial Loans: Commercial $ 2,393 $ - $ 3,041 $ - Commercial Real Estate 3,906 93 14,782 122 Agricultural 147 1 101 1 Agricultural Real Estate 1,545 32 742 33 Business Banking 837 7 882 7 Consumer Loans: Indirect 22 2 9 - Home Equity 8,274 331 8,207 357 Direct 119 2 - - Residential Real Estate Mortgage 6,425 211 6,147 211 Total Originated $ 23,668 $ 679 $ 33,911 $ 731 Acquired Commercial Loans: Commercial Real Estate $ 121 $ - $ 1,205 $ - Total Acquired $ 121 $ - $ 1,205 $ - Total Loans $ 23,789 $ 679 $ 35,116 $ 731 Credit Quality Indicators The Company has developed an internal loan grading system to evaluate and quantify the Company’s loan portfolio with respect to quality and risk. The system focuses on, among other things, financial strength of borrowers, experience and depth of borrower’s management, primary and secondary sources of repayment, payment history, nature of the business and outlook on particular industries. The internal grading system enables the Company to monitor the quality of the entire loan portfolio on a consistent basis and provide management with an early warning system, 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. Classified loans are graded Doubtful, Substandard, Special Mention and Pass. ● Doubtful A Doubtful loan has a high probability of total or substantial loss, but because of specific pending events that may strengthen the asset, its classification as a loss is deferred. Doubtful borrowers are usually in default, lack adequate liquidity or capital and lack the resources necessary to remain an operating entity. Pending events can include mergers, acquisitions, liquidations, capital injections, the perfection of liens on additional collateral, the valuation of collateral and refinancing. Generally, pending events should be resolved within a relatively short period and the ratings will be adjusted based on the new information. Nonaccrual treatment is required for Doubtful assets because of the high probability of loss. ● Substandard Substandard loans have a high probability of payment default or they have other well-defined weaknesses. They require more intensive supervision by bank management. Substandard loans are generally characterized by current or expected unprofitable operations, inadequate debt service coverage, inadequate liquidity or marginal capitalization. Repayment may depend on collateral or other credit risk mitigants. For some Substandard loans, the likelihood of full collection of interest and principal may be in doubt and those loans should be placed on nonaccrual. Although Substandard assets in the aggregate will have a distinct potential for loss, an individual asset’s loss potential does not have to be distinct for the asset to be rated Substandard. ● Special Mention Special Mention loans have potential weaknesses that may, if not checked or corrected, weaken the asset or inadequately protect the Company’s position at some future date. These loans pose elevated risk, but their weakness does not yet justify a Substandard classification. Borrowers may be experiencing adverse operating trends (i.e., declining revenues or margins) or may be struggling with an ill-proportioned balance sheet (i.e., increasing inventory without an increase in sales, high leverage, tight liquidity). Adverse economic or market conditions, such as interest rate increases or the entry of a new competitor, may also support a Special Mention rating. Although a Special Mention loan has a higher probability of default than a Pass asset, its default is not imminent. ● Pass Loans graded as Pass encompass all loans not graded as Doubtful, Substandard or Special Mention. Pass loans are in compliance with loan covenants and payments are generally made as agreed. Pass loans range from superior quality to fair quality. 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 Nonperforming loans are loans that are 1) over 90 days past due and interest is still accruing or 2) on nonaccrual status. ● Performing All loans not meeting any of these criteria are considered Performing. The following tables illustrate the Company’s credit quality by loan class: As of September 30, 2017 (In thousands) Originated Commercial Credit Exposure By Internally Assigned Grade: Commercial Commercial Real Estate Agricultural Agricultural Real Estate Total Pass $ 677,943 $ 1,424,353 $ 30,233 $ 25,546 $ 2,158,075 Special Mention 40,123 29,785 3,033 3,343 76,284 Substandard 15,056 26,421 1,573 6,502 49,552 Total $ 733,122 $ 1,480,559 $ 34,839 $ 35,391 $ 2,283,911 Business Banking Credit Exposure By Internally Assigned Grade: Business Banking Total Non-classified $ 469,025 $ 469,025 Classified 12,907 12,907 Total $ 481,932 $ 481,932 Consumer Credit Exposure By Payment Activity: Indirect Home Equity Direct Total Performing $ 1,626,757 $ 455,750 $ 63,896 $ 2,146,403 Nonperforming 4,521 3,003 157 7,681 Total $ 1,631,278 $ 458,753 $ 64,053 $ 2,154,084 Residential Mortgage Credit Exposure By Payment Activity: Residential Mortgage Total Performing $ 1,118,407 $ 1,118,407 Nonperforming 6,777 6,777 Total $ 1,125,184 $ 1,125,184 As of September 30, 2017 (In thousands) Acquired Commercial Credit Exposure By Internally Assigned Grade: Commercial Commercial Real Estate Total Pass $ 37,271 $ 106,261 $ 143,532 Special Mention 327 512 839 Substandard 1,439 6,538 7,977 Total $ 39,037 $ 113,311 $ 152,348 Business Banking Credit Exposure By Internally Assigned Grade: Business Banking Total Non-classified $ 40,636 $ 40,636 Classified 3,460 3,460 Total $ 44,096 $ 44,096 Consumer Credit Exposure By Payment Activity: Indirect Home Equity Direct Total Performing $ 2,121 $ 42,817 $ 2,840 $ 47,778 Nonperforming 33 160 15 208 Total $ 2,154 $ 42,977 $ 2,855 $ 47,986 Residential Mortgage Credit Exposure By Payment Activity: Residential Mortgage Total Performing $ 175,631 $ 175,631 Nonperforming 1,762 1,762 Total $ 177,393 $ 177,393 As of December 31, 2016 (In thousands) Originated Commercial Credit Exposure By Internally Assigned Grade: Commercial Commercial Real Estate Agricultural Agricultural Real Estate Total Pass $ 616,829 $ 1,288,409 $ 36,762 $ 28,912 $ 1,970,912 Special Mention 7,750 31,053 25 1,896 40,724 Substandard 28,991 32,327 1,124 1,614 64,056 Doubtful - - 5 - 5 Total $ 653,570 $ 1,351,789 $ 37,916 $ 32,422 $ 2,075,697 Business Banking Credit Exposure By Internally Assigned Grade: Business Banking Total Non-classified $ 458,864 $ 458,864 Classified 13,823 13,823 Total $ 472,687 $ 472,687 Consumer Credit Exposure By Payment Activity: Indirect Home Equity Direct Total Performing $ 1,562,031 $ 453,278 $ 62,977 $ 2,078,286 Nonperforming 4,644 3,379 127 8,150 Total $ 1,566,675 $ 456,657 $ 63,104 $ 2,086,436 Residential Mortgage Credit Exposure By Payment Activity: Residential Mortgage Total Performing $ 1,055,055 $ 1,055,055 Nonperforming 8,088 8,088 Total $ 1,063,143 $ 1,063,143 As of December 31, 2016 (In thousands) Acquired Commercial Credit Exposure By Internally Assigned Grade: Commercial Commercial Real Estate Total Pass $ 48,194 $ 127,660 $ 175,854 Special Mention 76 1,231 1,307 Substandard 1,177 7,193 8,370 Doubtful - 1,205 1,205 Total $ 49,447 $ 137,289 $ 186,736 Business Banking Credit Exposure By Internally Assigned Grade: Business Banking Total Non-classified $ 47,347 $ 47,347 Classified 3,535 3,535 Total $ 50,882 $ 50,882 Consumer Credit Exposure By Payment Activity: Indirect Home Equity Direct Total Performing $ 8,646 $ 50,860 $ 3,165 $ 62,671 Nonperforming 47 267 20 334 Total $ 8,693 $ 51,127 $ 3,185 $ 63,005 Residential Mortgage Credit Exposure By Payment Activity: Residential Mortgage Total Performing $ 196,508 $ 196,508 Nonperforming 2,963 2,963 Total $ 199,471 $ 199,471 Troubled Debt Restructured Loans Substantially all of these modifications included one or a combination of the following: an extension of the maturity date at a stated rate of interest lower than the current market rate for new debt with similar risk; temporary reduction in the interest rate; or change in scheduled payment amount. 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. The following tables illustrate the recorded investment and number of modifications for modified loans, including the recorded investment in the loans prior to a modification and the recorded investment in the loans after restructuring: Three months ended September 30, 2017 (Dollars in thousands) Number of Contracts Pre-Modification Outstanding Recorded Investment Post-Modification Outstanding Recorded Investment Consumer Indirect 1 $ 7 $ 7 Home Equity 4 189 222 Total Consumer 5 196 229 Residential Real Estate 1 518 518 Total Troubled Debt Restructurings 6 $ 714 $ 747 Three months ended September 30, 2016 Number of Contracts Pre-Modification Outstanding Recorded Investment Post-Modification Outstanding Recorded Investment Consumer Home Equity 10 $ 580 $ 556 Total Consumer 10 580 556 Residential Real Estate 4 230 126 Total Troubled Debt Restructurings 14 $ 810 $ 682 Nine months ended September 30, 2017 (Dollars in thousands) Number of Contracts Pre-Modification Outstanding Recorded Investment Post-Modification Outstanding Recorded Investment Commercial Commercial 1 $ 3,300 $ 3,239 Business Banking 1 337 333 Total Commercial 2 3,637 3,572 Consumer Indirect 4 39 37 Home Equity 8 373 414 Direct 1 120 120 Total Consumer 13 532 571 Residential Real Estate 8 1,066 1,068 Total Troubled Debt Restructurings 23 $ 5,235 $ 5,211 Nine months ended September 30, 2016 Number of Contracts Pre-Modification Outstanding Recorded Investment Post-Modification Outstanding Recorded Investment Consumer Home Equity 24 $ 1,690 $ 1,567 Total Consumer 24 1,690 1,567 Residential Real Estate 10 914 692 Total Troubled Debt Restructurings 34 $ 2,604 $ 2,259 TDRs occurring during the three and nine months ended September 30, 2017 and 2016 were due to the reduction in the interest rate or extension of the term. The following table illustrates the recorded investment and number of modifications for TDRs where a concession has been made and subsequently defaulted during the period: Three months ended September 30, 2017 Three months ended September 30, 2016 (Dollars in thousands) Number of Contracts Recorded Investment Number of Contracts Recorded Investment Commercial Commercial - $ - 1 $ 169 Total Commercial - - 1 169 Consumer Indirect 1 13 - - Home Equity 12 622 17 847 Total Consumer 13 635 17 847 Residential Real Estate 6 546 8 485 Total Troubled Debt Restructurings 19 $ 1,181 26 $ 1,501 Nine months ended September 30, 2017 Nine months ended September 30, 2016 Number of Contracts Recorded Investment Number of Contracts Recorded Investment Commercial Commercial 1 $ 145 1 $ 169 Business Banking 1 329 1 67 Total Commercial 2 474 2 236 Consumer Indirect 2 19 - - Home Equity 30 1,381 30 1,634 Total Consumer 32 1,400 30 1,634 Residential Real Estate 12 817 15 1,075 Total Troubled Debt Restructurings 46 $ 2,691 47 $ 2,945

Defined Benefit Post-retirement

Defined Benefit Post-retirement Plans	9 Months Ended
	Sep. 30, 2017
Defined Benefit Post-retirement Plans [Abstract]
Defined Benefit Post-retirement Plans	5. Defined Benefit Post-retirement Plans The Company has a qualified, noncontributory, defined benefit pension plan (“the Plan”) covering substantially all of its employees at September 30, 2017. 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 Employee Retirement Income Security Act of 1974 standards. Assets of the Plan are invested in publicly traded stocks and mutual funds. The Company is not required to make contributions to the Plan in 2017 and did not do so during the three and nine months ended September 30, 2017. The Company was not required to make contributions during the three and nine months ended September 30, 2016. However, the Company made contributions to the plan totaling $5.6 million during the three months ended September 30, 2016. In addition to the Plan, the Company also provides supplemental employee retirement plans to certain current and former executives. The Company also assumed supplemental retirement plans for certain current and former executives in the Alliance Financial Corporation (“Alliance”) acquisition. These supplemental employee retirement plans and the Plan are collectively referred to herein as “Pension Benefits.” In addition, the Company provides certain health care benefits for retired employees. Benefits are accrued over the employees’ active service period. Only employees that were employed by the Company on or before January 1, 2000 are eligible to receive post-retirement health care benefits. In addition, the Company assumed post-retirement medical life insurance benefits for certain Alliance employees, retirees and their spouses, if applicable, in the Alliance acquisition. These post-retirement benefits are referred to herein as “Other Benefits.” The components of expense for Pension Benefits and Other Benefits are set forth below: Pension Benefits Other Benefits (In thousands) Three months ended September 30, Three months ended September 30, Components of net periodic (benefit) cost: 2017 2016 2017 2016 Service cost $ 329 $ 534 $ 3 $ 3 Interest cost 1,043 1,050 88 89 Expected return on plan assets (1,976 ) (1,857 ) - - Net amortization 454 504 26 15 Total (benefit) cost $ (150 ) $ 231 $ 117 $ 107 Pension Benefits Other Benefits Nine months ended September 30, Nine months ended September 30, Components of net periodic (benefit) cost: 2017 2016 2017 2016 Service cost $ 1,133 $ 1,654 $ 9 $ 10 Interest cost 3,127 3,151 259 277 Expected return on plan assets (5,946 ) (5,527 ) - - Net amortization 1,284 1,471 66 73 Total (benefit) cost $ (402 ) $ 749 $ 334 $ 360

Earnings Per Share

Earnings Per Share	9 Months Ended
	Sep. 30, 2017
Earnings Per Share [Abstract]
Earnings Per Share	6. Earnings Per Share Basic earnings per share (“EPS”) excludes dilution and is computed by dividing income available to common shareholders by the weighted average number of common shares outstanding for the period. Diluted EPS reflects the potential dilution that could occur if securities or other contracts to issue common stock were exercised or converted into common stock or resulted in the issuance of common stock that then shared in the earnings of the entity (such as the Company’s dilutive stock options and restricted stock units). The following is a reconciliation of basic and diluted EPS for the periods presented in the unaudited interim consolidated statements of income: Three months ended September 30, 2017 2016 (In thousands, except per share data) Basic EPS: Weighted average common shares outstanding 43,595 43,200 Net income available to common stockholders $ 22,876 $ 20,001 Basic EPS $ 0.52 $ 0.46 Diluted EPS: Weighted average common shares outstanding 43,595 43,200 Dilutive effect of common stock options and restricted stock 320 362 Weighted average common shares and common share equivalents 43,915 43,562 Net income available to common stockholders $ 22,876 $ 20,001 Diluted EPS $ 0.52 $ 0.46 Nine months ended September 30, 2017 2016 (In thousands, except per share data) Basic EPS: Weighted average common shares outstanding 43,563 43,214 Net income available to common stockholders $ 64,514 $ 58,801 Basic EPS $ 1.48 $ 1.36 Diluted EPS: Weighted average common shares outstanding 43,563 43,214 Dilutive effect of common stock options and restricted stock 329 366 Weighted average common shares and common share equivalents 43,892 43,580 Net income available to common stockholders $ 64,514 $ 58,801 Diluted EPS $ 1.47 $ 1.35 There were 3,250 stock options for the quarter ended September 30, 2017 and no stock options for the quarter ended September 30, 2016, that were not considered in the calculation of diluted EPS since the stock options’ exercise price was greater than the average market price during these periods. There were 3,014 and 36,865 stock options for the nine months ended September 30, 2017 and September 30, 2016, respectively, that were not considered in the calculation of diluted EPS since the stock options’ exercise price was greater than the average market price during these periods.

Reclassification Adjustments Ou

Reclassification Adjustments Out of Other Comprehensive Income	9 Months Ended
	Sep. 30, 2017
Reclassification Adjustments Out of Other Comprehensive Income [Abstract]
Reclassification Adjustments Out of Other Comprehensive Income	7. Reclassification Adjustments Out of Other Comprehensive Income The following table summarizes the reclassification adjustments out of accumulated other comprehensive income (loss): Detail About Accumulated Other Comprehensive Income Components Amount Reclassified From Accumulated Other Comprehensive Income Affected Line item in the Consolidated Statement of Comprehensive Income (In thousands) Three months ended September 30, 2017 September 30, 2016 AFS Securities: Losses on AFS securities $ 4 $ - Net securities gains Amortization of unrealized gains and losses related to securities transfer 212 267 Interest income Income tax (expense) (83 ) (105 ) Income tax (expense) Net of tax $ 133 $ 162 Pension and other benefits: Amortization of net losses $ 481 $ 565 Salaries and employee benefits Amortization of prior service costs (1 ) (46 ) Salaries and employee benefits Income tax (expense) (183 ) (202 ) Income tax (expense) Net of tax $ 297 $ 317 Total reclassifications during the period, net of tax $ 430 $ 479 Detail About Accumulated Other Comprehensive Income Components Amount Reclassified From Accumulated Other Comprehensive Income Affected Line item in the Consolidated Statement of Comprehensive Income Nine months ended September 30, 2017 September 30, 2016 AFS Securities: (Gains) losses on AFS securities $ 2 (30 ) Net securities gains Amortization of unrealized gains and losses related to securities transfer 675 843 Interest income Impairment write-down of equity security 1,312 - Other noninterest income Income tax (expense) (760 ) (317 ) Income tax (expense) Net of tax $ 1,229 $ 496 Pension and other benefits: Amortization of net losses $ 1,351 $ 1,595 Salaries and employee benefits Amortization of prior service costs (1 ) (51 ) Salaries and employee benefits Income tax (expense) (516 ) (601 ) Income tax (expense) Net of tax $ 834 $ 943 Total reclassifications during the period, net of tax $ 2,063 $ 1,439

Fair Value Measurements and Fai

Fair Value Measurements and Fair Value of Financial Instruments	9 Months Ended
	Sep. 30, 2017
Fair Value Measurements and Fair Value of Financial Instruments [Abstract]
Fair Value Measurements and Fair Value of Financial Instruments	8. Fair Value Measurements and Fair Value of Financial Instruments GAAP states that fair value is an exit price, representing the amount that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants. Fair value measurements are not adjusted for transaction costs. A fair value hierarchy exists within GAAP that prioritizes the inputs to valuation techniques used to measure fair value. The hierarchy gives the highest priority to unadjusted quoted prices in active markets for identical assets or liabilities (Level 1 measurements) and the lowest priority to unobservable inputs (Level 3 measurements). The three levels of the fair value hierarchy are described below: Level 1 - Unadjusted quoted prices in active markets that are accessible at the measurement date for identical, unrestricted assets or liabilities; Level 2 - Quoted prices for similar assets or liabilities in active markets, quoted prices in markets that are not active or inputs that are observable, either directly or indirectly, for substantially the full term of the asset or liability; Level 3 - Prices or valuation techniques that require inputs that are both significant to the fair value measurement and unobservable (i.e., supported by little or no market activity). A financial instrument’s level within the fair value hierarchy is based on the lowest level of input that is significant to the fair value measurement. The types of instruments valued based on quoted market prices in active markets include most U.S. government and agency securities, many other sovereign government obligations, liquid mortgage products, active listed equities and most money market securities. Such instruments are generally classified within Level 1 or Level 2 of the fair value hierarchy. The Company does not adjust the quoted prices for such instruments. The types of instruments valued based on quoted prices in markets that are not active, broker or dealer quotations or alternative pricing sources with reasonable levels of price transparency include most investment-grade and high-yield corporate bonds, less liquid mortgage products, less liquid agency securities, less liquid listed equities, state, municipal and provincial obligations and certain physical commodities. Such instruments are generally classified within Level 2 of the fair value hierarchy. Certain common equity securities are reported at fair value utilizing Level 1 inputs (exchange quoted prices). Other investment securities are reported at fair value utilizing Level 1 and Level 2 inputs. The prices for Level 2 instruments are obtained through an independent pricing service or dealer market participants with whom the Company has historically transacted both purchases and sales of investment securities. Prices obtained from these sources include prices derived from market quotations and matrix pricing. The fair value measurements consider observable data that may include dealer quotes, market spreads, cash flows, the U.S. Treasury yield curve, live trading levels, trade execution data, market consensus prepayment speeds, credit information and the bond’s terms and conditions, amount other things. Management reviews the methodologies used in pricing the securities by its third party providers. 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. For the three and nine month periods ended September 30, 2017, the Company has made no transfers of assets between Level 1 and Level 2 and has had no Level 3 activity. The following tables set forth the Company’s financial assets and liabilities measured on a recurring basis that were accounted for at fair value. Assets and liabilities are classified in their entirety based on the lowest level of input that is significant to the fair value measurement: (In thousands) Level 1 Level 2 Level 3 Balance as of September 30, 2017 Assets: AFS securities: Federal agency $ - $ 139,418 $ - $ 139,418 State & municipal - 42,919 - 42,919 Mortgage-backed - 584,226 - 584,226 Collateralized mortgage obligations - 571,312 - 571,312 Other securities 11,438 8,301 - 19,739 Total AFS securities $ 11,438 $ 1,346,176 $ - $ 1,357,614 Trading securities 10,883 - - 10,883 Derivatives - 6,653 - 6,653 Total $ 22,321 $ 1,352,829 $ - $ 1,375,150 Liabilities: Derivatives $ - $ 4,128 $ - $ 4,128 Total $ - $ 4,128 $ - $ 4,128 (In thousands) Level 1 Level 2 Level 3 Balance as of December 31, 2016 Assets: AFS securities: Federal agency $ - $ 174,408 $ - $ 174,408 State & municipal - 46,726 - 46,726 Mortgage-backed - 529,844 - 529,844 Collateralized mortgage obligations - 566,573 - 566,573 Other securities 11,493 9,246 - 20,739 Total AFS securities $ 11,493 $ 1,326,797 $ - $ 1,338,290 Trading securities 9,259 - - 9,259 Derivatives - 3,210 - 3,210 Total $ 20,752 $ 1,330,007 $ - $ 1,350,759 Liabilities: Derivatives $ - $ 506 $ - $ 506 Total $ - $ 506 $ - $ 506 GAAP requires disclosure of assets and liabilities measured and recorded at fair value on a non-recurring basis such as loans held for sale, other real estate owned, collateral-dependent impaired loans, mortgage servicing rights and held to maturity securities. The only non-recurring fair value measurements recorded during the three and nine month periods ended September 30, 2017 and September 30, 2016 were related to impaired loans and a write-down of other real estate owned. The Company uses the fair value of underlying collateral, less costs to sell, to estimate the specific reserves for collateral dependent impaired loans. The appraisals may be adjusted by management for qualitative factors such as economic conditions and estimated liquidation expenses ranging from 10% to 35%. Based on the valuation techniques used, the fair value measurements for collateral dependent impaired loans are classified as Level 3. As of September 30, 2017 and December 31, 2016, the Company had $0.1 million and $7.0 million, respectively, of loans recorded at fair value with specific allowance reserves of $30 thousand and $1.5 million, respectively. The following table sets forth information with regard to estimated fair values of financial instruments. This table excludes financial instruments for which the carrying amount approximates fair value. Financial instruments for which the fair value approximates carrying value include cash and cash equivalents, securities AFS, trading securities, accrued interest receivable, non-maturity deposits, short-term borrowings, accrued interest payable and interest rate swaps. September 30, 2017 December 31, 2016 (In thousands) Fair Value Hierarchy Carrying amount Estimated fair value Carrying amount Estimated fair value Financial assets HTM securities 2 $ 494,309 $ 495,411 $ 527,948 $ 525,050 Net loans 3 6,398,584 6,557,674 6,132,857 6,273,233 Financial liabilities Time deposits 2 $ 776,756 $ 773,160 $ 872,411 $ 868,153 Long-term debt 2 88,914 88,948 104,087 104,113 Junior subordinated debt 2 101,196 104,584 101,196 102,262 Fair value estimates are made at a specific point in time, based on relevant market information and information about the financial instrument. These estimates do not reflect any premium or discount that could result from offering for sale at one time the Company’s entire holdings of a particular financial instrument. Because no market exists for a significant portion of the Company’s financial instruments, fair value estimates are based on judgments regarding future expected loss experience, current economic conditions, risk characteristics of various financial instruments and other factors. These estimates are subjective in nature, and involve uncertainties and matters of significant judgment, and therefore cannot be determined with precision. Changes in assumptions could significantly affect the estimates. Fair value estimates are based on existing on and off balance sheet financial instruments without attempting to estimate the value of anticipated future business and the value of assets and liabilities that are not considered financial instruments. For example, the Company has a substantial trust and investment management operation that contributes net fee income annually. The trust and investment management operation is not considered a financial instrument and its value has not been incorporated into the fair value estimates. Other significant assets and liabilities include the benefits resulting from the low-cost funding of deposit liabilities as compared to the cost of borrowing funds in the market and premises and equipment. In addition, the tax ramifications related to the realization of the unrealized gains and losses can have a significant effect on fair value estimates and have not been considered in the estimate of fair value. Securities Held to Maturity The fair value of the Company’s investment securities held to maturity is primarily measured using information from a third party pricing service. The fair value measurements consider observable data that may include dealer quotes, market spreads, cash flows, the U.S. Treasury yield curve, live trading levels, trade execution data, market consensus prepayment speeds, credit information and the bond’s terms and conditions, among other things. Net Loans The fair value of the Company’s loans was estimated by discounting the expected future cash flows using the current interest rates at which similar loans would be made for the same remaining maturities. Loans were first segregated by type and then further segmented into fixed and variable rate and loan quality categories. Expected future cash flows were projected based on contractual cash flows, adjusted for estimated prepayments. Time Deposits The fair value of time deposits was estimated using a discounted cash flow approach that applies prevailing market interest rates for similar maturity instruments. The fair values of the Company’s time deposit liabilities do not take into consideration the value of the Company’s long-term relationships with depositors, which may have significant value. Long-Term Debt The fair value of long-term debt was estimated using a discounted cash flow approach that applies prevailing market interest rates for similar maturity instruments. Junior Subordinated Debt The fair value of junior subordinated debt has been estimated using a discounted cash flow analysis. Interest Rate Swaps The Company enters into interest rate swaps to facilitate customer transactions and meet their financing needs. These swaps are considered derivatives, but are not designated in hedging relationships. These instruments have interest rate and credit risk associated with them. To mitigate the interest rate risk, the Company enters into offsetting interest rate swaps with counterparties. The counterparty swaps are also considered derivatives and are also not designated in hedging relationships. Interest rate swaps are recorded within other assets or other liabilities on the unaudited interim consolidated balance sheet at their estimated fair value. Changes to the fair value of assets and liabilities arising from these derivatives are included, net, in other operating income in the unaudited interim consolidated statement of income. At September 30, 2017 the notional amount of these customer derivative agreements and the offsetting derivative counterparty positions each totaled $469.8 million and the fair values included in other assets and other liabilities on the unaudited interim consolidated balance sheet applicable to these agreements amounted to $3.9 million. At December 31, 2016, the notional amount of these customer derivative agreements and the offsetting derivative counterparty positions each totaled $371.1 million and the fair values included in other assets and other liabilities on the unaudited interim consolidated balance sheet applicable to these agreements amounted to $0.3 million. In 2016, the Company entered into interest rate swaps to modify the interest rate characteristics of certain short-term Federal Home Loan Bank advances from variable rate to fixed rate in order to reduce the impact of changes in future cash flows due to market interest rate changes. These agreements are designated as cash flow hedges. The notional amount of these interest rate derivative agreements total $250.0 million at September 30, 2017. Fair values included in other assets on the unaudited interim consolidated balance sheet applicable to these agreements amounted to $2.7 million at September 30, 2017 and $2.9 million at December 31, 2016. Fair values included in other liabilities on the unaudited interim consolidated balance sheet applicable to these agreements amounted to $0.2 million at September 30, 2017 and December 31, 2016, respectively.

Commitments and Contingencies

Commitments and Contingencies	9 Months Ended
	Sep. 30, 2017
Commitments and Contingencies [Abstract]
Commitments and Contingencies	9. Commitments and Contingencies The Company is a party to financial instruments in the normal course of business to meet the financing needs of its customers and to reduce its own exposure to fluctuating interest rates. These financial instruments include commitments to extend credit, unused lines of credit and standby letters of credit. Exposure to credit loss in the event of nonperformance by the other party to the financial instrument for commitments to make loans and standby letters of credit is represented by the contractual amount of those instruments. The Company uses the same credit origination guidelines, portfolio maintenance and management procedures as other credit and off-balance sheet products. Commitments to extend credit and unused lines of credit totaled $1.6 billion at September 30, 2017 and $1.5 billion at December 31, 2016. Since commitments to extend credit and unused lines of credit may expire without being fully drawn upon, this amount does not necessarily represent future cash commitments. Collateral obtained upon exercise of the commitment is determined using management’s credit evaluation of the borrower and may include accounts receivable, inventory, property, land and other items. The Company guarantees the obligations or performance of customers by issuing standby letters of credit to third parties. These standby letters of credit are frequently issued in support of third party debt, such as corporate debt issuances, industrial revenue bonds and municipal securities. The credit risk involved in issuing standby letters of credit is essentially the same as the credit risk involved in extending loan facilities to customers and they are subject to the same credit origination guidelines, portfolio maintenance and management procedures as 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 commitments. Standby letters of credit totaled $40.9 million at September 30, 2017 and $36.8 million at December 31, 2016. As of September 30, 2017, the fair value of standby letters of credit was not significant to the Company’s unaudited interim consolidated financial statements.

Recent Accounting Pronouncement

Recent Accounting Pronouncements	9 Months Ended
	Sep. 30, 2017
Recent Accounting Pronouncements [Abstract]
Recent Accounting Pronouncements	10. Recent Accounting Pronouncements Recently Adopted Accounting Standards Effective January 1, 2017, the Company adopted the provision of Financial Accounting Standards Board (“FASB”) Accounting Standards Update (“ASU”) No. 2016-09, Compensation – Stock Compensation (Topic 718): Improvements to Employee Share-Based Payment Accounting Transition to the new guidance was accomplished through a combination of cumulative-effect adjustment to equity (forfeitures) and prospective methodologies (cash flows, tax windfalls and shortfalls). The actual effects of adoption in 2017 will primarily depend upon the share price of the common stock, which affects the vesting of certain performance awards, probability of exercise of certain stock options and the magnitude of windfalls for all awards upon either vesting or exercise. The effect on earnings per share calculations and election to account for forfeitures as incurred have not been significant. Effective July 1, 2017, the Company early adopted the provision of FASB issued ASU No. 2017-04, Intangibles - Goodwill and Other (Topic 350): Simplifying the Test for Goodwill Impairment Accounting Standards Issued Not Yet Adopted In August 2017, the FASB issued ASU 2017-12, Derivatives and Hedging (Topic 815): Targeted Improvements to Accounting for Hedging Activities In May 2017, the FASB issued ASU 2017-09, Compensation-Stock Compensation (Topic 718). In March 2017, the FASB issued ASU No. 2017-08, Receivables – Nonrefundable Fees and Other Costs (Subtopic 310-20) In March 2017, the FASB issued ASU No. 2017-07, Compensation – Retirement Benefits (Topic 715) In February 2017, the FASB issued ASU No. 2017-05, Other Income – Gains and Losses from the Derecognition of Nonfinancial Assets (Subtopic 610-20) in substance nonfinancial assets In January 2017, the FASB issued ASU No. 2017-01, Business Combinations (Topic 805): Clarifying the Definition of a Business In November 2016, the FASB issued ASU No. 2016-18, Statement of Cash Flows (Topic 230): Restricted Cash In August 2016, the FASB issued ASU No. 2016-15, Statement of Cash Flows (Topic 230): Classification of Certain Cash Receipts and Cash Payments) In June 2016, the FASB issued ASU No. 2016-13, Financial Instruments - Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments In February 2016, the FASB issued ASU No. 2016-02, Leases (Topic 842) In January 2016, the FASB issued ASU No. 2016-01, Financial Instruments - Overall (Subtopic 825-10) – Recognition and Measurement of Financial Assets and Financial Liabilities In May 2014, the FASB issued ASU No. 2014-09 - Revenue from Contracts with Customers (Topic 606) Revenue from Contracts with Customers - Deferral of the Effective Date Principal versus Agent Considerations (Reporting Revenue Gross versus Net), Identifying Performance Obligations and Licensing, Narrow-Scope Improvements and Practical Expedients Technical Corrections and Improvements to Top 606 - Revenue from Contract with Customers

Description of Business (Polici

Description of Business (Policies)	9 Months Ended
	Sep. 30, 2017
Description of Business [Abstract]
Nature of Operations	NBT Bancorp Inc. (the “Registrant” or the “Company”) is a registered financial holding company incorporated in the state of Delaware in 1986, with its principal headquarters located in Norwich, New York. The principal assets of the Registrant consist of all of the outstanding shares of common stock of its subsidiaries, including: NBT Bank, National Association (the “Bank”), NBT Financial Services, Inc. (“NBT Financial”), NBT Holdings, Inc. (“NBT Holdings”), Hathaway Agency, Inc. and CNBF Capital Trust I, NBT Statutory Trust I, NBT Statutory Trust II, Alliance Financial Capital Trust I and Alliance Financial Capital Trust II (collectively, the “Trusts”). The Company’s principal sources of revenue are the management fees and dividends it receives from the Bank, NBT Financial and NBT Holdings. The Company’s business, primarily conducted through the Bank but also through its other subsidiaries, consists of providing commercial banking and financial services to customers in its market area, which includes central and upstate New York, northeastern Pennsylvania, southern New Hampshire, western Massachusetts, Vermont and the greater Portland, Maine area. The Company has been and intends to continue to be, a community-oriented financial institution offering a variety of financial services. The Company’s business philosophy is to operate as a community bank with local decision-making, principally in non-metropolitan markets, providing a broad array of banking and financial services to retail, commercial and municipal customers.

Securities (Policies)

Securities (Policies)	9 Months Ended
	Sep. 30, 2017
Securities [Abstract]
Investment, Policy	Declines in the fair value of HTM and AFS 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, the other-than-temporary impairment (“OTTI”) 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 Company will be required to sell the security before recovery of its amortized cost basis less any current-period credit loss, the OTTI 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 OTTI related to the credit loss shall be recognized in earnings. The amount of the total OTTI related to other factors shall be recognized in other comprehensive income, net of applicable taxes. In estimating OTTI 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. Management has the intent to hold the securities classified as HTM until they mature, at which time it is believed the Company will receive full value for the securities. The unrealized losses on HTM debt securities are due to increases in market interest rates over yields 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 bond approaches their maturity date or repricing date or if market yields for such investments decline. Management also has the intent to hold and will not be required to sell, the securities classified as AFS for a period of time sufficient for a recovery of cost, which may be until maturity. The unrealized losses on AFS debt securities 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. For AFS debt and equity securities, OTTI losses are recognized in earnings if the Company intends to sell the security. In other cases the Company considers the relevant factors noted above, as well as the Company’s intent and ability to retain its investment for a period of time sufficient to allow for any anticipated recovery in market value and whether evidence exists to support a realizable value equal to or greater than the cost basis. Any impairment loss on an equity security is equal to the full difference between the cost basis and the fair value of the security. Maturities of mortgage-backed, collateralized mortgage obligations and asset-backed securities are stated based on their estimated average lives. Actual maturities may differ from estimated average lives or contractual maturities because, in certain cases, borrowers have the right to call or prepay obligations with or without call or prepayment penalties.

Allowance for Loan Losses and22

Allowance for Loan Losses and Credit Quality of Loans (Policies)	9 Months Ended
	Sep. 30, 2017
Allowance for Loan Losses and Credit Quality of Loans [Abstract]
Portfolio and Class Segments	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
Allowance for Loan Losses	Allowance for Loan Losses The allowance for loan losses is maintained at a level estimated by management to provide adequately for probable incurred losses inherent in the current loan portfolio. The appropriateness of the allowance for loan losses is continuously monitored. It is assessed for appropriateness using a methodology designed to ensure the level of the allowance reasonably reflects the loan portfolio’s risk profile. It is evaluated to ensure that it is sufficient to absorb all reasonably estimable credit losses inherent in the current loan portfolio. To develop and document a systematic methodology for determining the allowance for loan losses, the Company has divided the loan portfolio into three segments, each with different risk characteristics and methodologies for assessing risk. Those segments are further segregated between our loans accounted for under the amortized cost method (referred to as “originated” loans) and loans acquired in a business combination (referred to as “acquired” loans). Each portfolio segment is broken down into class segments where appropriate. Class segments contain unique measurement attributes, risk characteristics and methods for monitoring and assessing risk that are necessary to develop the allowance for loan losses. Unique characteristics such as borrower type, loan type, collateral type and risk characteristics define each class segment. Commercial Loans The Company offers a variety of commercial loan products including commercial (non-real estate), commercial real estate, agricultural, agricultural real estate and business banking loans. The Company’s underwriting analysis for commercial loans typically includes credit verification, independent appraisals, a review of the borrower’s financial condition and a detailed analysis of the borrower’s underlying cash flows. Commercial – Commercial Real Estate – Agricultural Agricultural Real Estate Business Banking Consumer Loans The Company offers a variety of consumer loan products including indirect, home equity and direct loans. Indirect – Home Equity Direct – Residential Real Estate Mortgages 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. This practice allows the Company to manage interest rate, liquidity risk and credit risk. Loans on one-to-four-family residential real estate are generally originated in amounts of no more than 85% of the purchase price or appraised value (whichever is lower) or have private mortgage insurance. Mortgage title insurance and hazard insurance are normally required. Construction loans have a unique risk, because they are secured by an incomplete dwelling. This risk is reduced through periodic site inspections, including one at each loan draw period. Allowance for Loan Loss Calculation For purposes of evaluating the adequacy of the allowance, the Company considers a number of significant factors that affect the collectability of the portfolio. For individually analyzed loans, these include estimates of loss exposure, which reflect the facts and circumstances that affect the likelihood of repayment of such loans as of the evaluation date. For homogeneous pools of loans, estimates of the Company’s exposure to credit loss reflect a current assessment of a number of factors, which could affect collectability. These factors include: past loss experience, size, trend, composition and nature of loans; changes in lending policies and procedures, including underwriting standards and collection, charge-offs and recoveries; trends experienced in nonperforming and delinquent loans; current economic conditions in the Company’s market; portfolio concentrations that may affect loss experienced across one or more components of the portfolio; the effect of external factors such as competition, legal and regulatory requirements; and the experience, ability and depth of lending management and staff. In addition, various regulatory agencies, as an integral component of their examination process, periodically review the Company’s allowance for loan losses. Such agencies may require the Company to make loan grade changes as well as recognize additions to the allowance based on their examinations. After a thorough consideration of the factors discussed above, any required additions or reductions to the allowance for loan losses are made periodically by charges or credits to the provision for loan losses. These charges are necessary to maintain the allowance at a level that management believes is reflective of overall inherent risk of probable loss in the portfolio. While management uses available information to recognize losses on loans, additions and reductions of 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. For acquired loans, to the extent that we experience deterioration in borrower credit quality resulting in a decrease in our expected cash flows subsequent to the acquisition of the loans, an allowance for loan losses would be established based on our estimate of future credit losses over the remaining life of the loan. Credit Quality of Loans For all loan classes within the Company’s loan portfolio, loans are placed on nonaccrual status when timely collection of principal and interest in accordance with contractual terms is doubtful. Loans are transferred to nonaccrual status generally when principal or interest payments become ninety days delinquent, unless the loan is well-secured and in the process of collection or sooner when management concludes or circumstances indicate that borrowers may be unable to meet contractual principal or interest payments. When a loan is transferred to a nonaccrual status, all interest previously accrued in the current period but not collected is reversed against interest income in that period. Any payment received on a nonaccrual loan is applied to principal. 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. Impaired Loans The methodology used to establish the allowance for loan losses on impaired loans incorporates specific allocations on loans analyzed individually. Classified loans, including all trouble debt restructured loans (“TDRs”) and nonaccrual commercial loans that are graded Substandard or below, with outstanding balances equal to or greater than $0.8 million are evaluated for impairment through the Company’s quarterly status review process. In determining whether we are able 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 level of impairment. Any change to the previously recognized impairment loss is recognized as a change to the allowance account and recorded in the unaudited interim consolidated statements of income as a component of the provision for loan losses. Credit Quality Indicators The Company has developed an internal loan grading system to evaluate and quantify the Company’s loan portfolio with respect to quality and risk. The system focuses on, among other things, financial strength of borrowers, experience and depth of borrower’s management, primary and secondary sources of repayment, payment history, nature of the business and outlook on particular industries. The internal grading system enables the Company to monitor the quality of the entire loan portfolio on a consistent basis and provide management with an early warning system, 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. Classified loans are graded Doubtful, Substandard, Special Mention and Pass. ● Doubtful A Doubtful loan has a high probability of total or substantial loss, but because of specific pending events that may strengthen the asset, its classification as a loss is deferred. Doubtful borrowers are usually in default, lack adequate liquidity or capital and lack the resources necessary to remain an operating entity. Pending events can include mergers, acquisitions, liquidations, capital injections, the perfection of liens on additional collateral, the valuation of collateral and refinancing. Generally, pending events should be resolved within a relatively short period and the ratings will be adjusted based on the new information. Nonaccrual treatment is required for Doubtful assets because of the high probability of loss. ● Substandard Substandard loans have a high probability of payment default or they have other well-defined weaknesses. They require more intensive supervision by bank management. Substandard loans are generally characterized by current or expected unprofitable operations, inadequate debt service coverage, inadequate liquidity or marginal capitalization. Repayment may depend on collateral or other credit risk mitigants. For some Substandard loans, the likelihood of full collection of interest and principal may be in doubt and those loans should be placed on nonaccrual. Although Substandard assets in the aggregate will have a distinct potential for loss, an individual asset’s loss potential does not have to be distinct for the asset to be rated Substandard. ● Special Mention Special Mention loans have potential weaknesses that may, if not checked or corrected, weaken the asset or inadequately protect the Company’s position at some future date. These loans pose elevated risk, but their weakness does not yet justify a Substandard classification. Borrowers may be experiencing adverse operating trends (i.e., declining revenues or margins) or may be struggling with an ill-proportioned balance sheet (i.e., increasing inventory without an increase in sales, high leverage, tight liquidity). Adverse economic or market conditions, such as interest rate increases or the entry of a new competitor, may also support a Special Mention rating. Although a Special Mention loan has a higher probability of default than a Pass asset, its default is not imminent. ● Pass Loans graded as Pass encompass all loans not graded as Doubtful, Substandard or Special Mention. Pass loans are in compliance with loan covenants and payments are generally made as agreed. Pass loans range from superior quality to fair quality. 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 Nonperforming loans are loans that are 1) over 90 days past due and interest is still accruing or 2) on nonaccrual status. ● Performing All loans not meeting any of these criteria are considered Performing.
Troubled Debt Restructuring	Troubled Debt Restructured Loans Substantially all of these modifications included one or a combination of the following: an extension of the maturity date at a stated rate of interest lower than the current market rate for new debt with similar risk; temporary reduction in the interest rate; or change in scheduled payment amount. 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.

Defined Benefit Post-retireme23

Defined Benefit Post-retirement Plans (Policies)	9 Months Ended
	Sep. 30, 2017
Defined Benefit Post-retirement Plans [Abstract]
Postemployment Benefit Plans, Policy	The Company has a qualified, noncontributory, defined benefit pension plan (“the Plan”) covering substantially all of its employees at September 30, 2017. 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 Employee Retirement Income Security Act of 1974 standards. Assets of the Plan are invested in publicly traded stocks and mutual funds. In addition to the Plan, the Company also provides supplemental employee retirement plans to certain current and former executives. The Company also assumed supplemental retirement plans for certain current and former executives in the Alliance Financial Corporation (“Alliance”) acquisition. These supplemental employee retirement plans and the Plan are collectively referred to herein as “Pension Benefits.” In addition, the Company provides certain health care benefits for retired employees. Benefits are accrued over the employees’ active service period. Only employees that were employed by the Company on or before January 1, 2000 are eligible to receive post-retirement health care benefits. In addition, the Company assumed post-retirement medical life insurance benefits for certain Alliance employees, retirees and their spouses, if applicable, in the Alliance acquisition. These post-retirement benefits are referred to herein as “Other Benefits.”

Earnings Per Share (Policies)

Earnings Per Share (Policies)	9 Months Ended
	Sep. 30, 2017
Earnings Per Share [Abstract]
Earnings Per Share	Basic earnings per share (“EPS”) excludes dilution and is computed by dividing income available to common shareholders by the weighted average number of common shares outstanding for the period. Diluted EPS reflects the potential dilution that could occur if securities or other contracts to issue common stock were exercised or converted into common stock or resulted in the issuance of common stock that then shared in the earnings of the entity (such as the Company’s dilutive stock options and restricted stock units).

Fair Value Measurements and F25

Fair Value Measurements and Fair Value of Financial Instruments (Policies)	9 Months Ended
	Sep. 30, 2017
Fair Value Measurements and Fair Value of Financial Instruments [Abstract]
Fair Value of Financial Instruments, Policy	GAAP states that fair value is an exit price, representing the amount that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants. Fair value measurements are not adjusted for transaction costs. A fair value hierarchy exists within GAAP that prioritizes the inputs to valuation techniques used to measure fair value. The hierarchy gives the highest priority to unadjusted quoted prices in active markets for identical assets or liabilities (Level 1 measurements) and the lowest priority to unobservable inputs (Level 3 measurements). The three levels of the fair value hierarchy are described below: Level 1 - Unadjusted quoted prices in active markets that are accessible at the measurement date for identical, unrestricted assets or liabilities; Level 2 - Quoted prices for similar assets or liabilities in active markets, quoted prices in markets that are not active or inputs that are observable, either directly or indirectly, for substantially the full term of the asset or liability; Level 3 - Prices or valuation techniques that require inputs that are both significant to the fair value measurement and unobservable (i.e., supported by little or no market activity). A financial instrument’s level within the fair value hierarchy is based on the lowest level of input that is significant to the fair value measurement. The types of instruments valued based on quoted market prices in active markets include most U.S. government and agency securities, many other sovereign government obligations, liquid mortgage products, active listed equities and most money market securities. Such instruments are generally classified within Level 1 or Level 2 of the fair value hierarchy. The Company does not adjust the quoted prices for such instruments. The types of instruments valued based on quoted prices in markets that are not active, broker or dealer quotations or alternative pricing sources with reasonable levels of price transparency include most investment-grade and high-yield corporate bonds, less liquid mortgage products, less liquid agency securities, less liquid listed equities, state, municipal and provincial obligations and certain physical commodities. Such instruments are generally classified within Level 2 of the fair value hierarchy. Certain common equity securities are reported at fair value utilizing Level 1 inputs (exchange quoted prices). Other investment securities are reported at fair value utilizing Level 1 and Level 2 inputs. The prices for Level 2 instruments are obtained through an independent pricing service or dealer market participants with whom the Company has historically transacted both purchases and sales of investment securities. Prices obtained from these sources include prices derived from market quotations and matrix pricing. The fair value measurements consider observable data that may include dealer quotes, market spreads, cash flows, the U.S. Treasury yield curve, live trading levels, trade execution data, market consensus prepayment speeds, credit information and the bond’s terms and conditions, amount other things. Management reviews the methodologies used in pricing the securities by its third party providers. Level 3 is for positions that are not traded in active markets or are subject to transfer restrictions, valuations are adjusted to reflect illiquidity and/or non-transferability and such adjustments are generally based on available market evidence. In the absence of such evidence, management’s best estimate will be used. Management’s best estimate consists of both internal and external support on certain Level 3 investments. Subsequent to inception, management only changes Level 3 inputs and assumptions when corroborated by evidence such as transactions in similar instruments, completed or pending third-party transactions in the underlying investment or comparable entities, subsequent rounds of financing, recapitalizations and other transactions across the capital structure, offerings in the equity or debt markets and changes in financial ratios or cash flows. GAAP requires disclosure of assets and liabilities measured and recorded at fair value on a non-recurring basis such as loans held for sale, other real estate owned, collateral-dependent impaired loans, mortgage servicing rights and held to maturity securities. The only non-recurring fair value measurements recorded during the three and nine month periods ended September 30, 2017 and September 30, 2016 were related to impaired loans and a write-down of other real estate owned. The Company uses the fair value of underlying collateral, less costs to sell, to estimate the specific reserves for collateral dependent impaired loans. The appraisals may be adjusted by management for qualitative factors such as economic conditions and estimated liquidation expenses ranging from 10% to 35%. Based on the valuation techniques used, the fair value measurements for collateral dependent impaired loans are classified as Level 3. Fair value estimates are made at a specific point in time, based on relevant market information and information about the financial instrument. These estimates do not reflect any premium or discount that could result from offering for sale at one time the Company’s entire holdings of a particular financial instrument. Because no market exists for a significant portion of the Company’s financial instruments, fair value estimates are based on judgments regarding future expected loss experience, current economic conditions, risk characteristics of various financial instruments and other factors. These estimates are subjective in nature, and involve uncertainties and matters of significant judgment, and therefore cannot be determined with precision. Changes in assumptions could significantly affect the estimates. Fair value estimates are based on existing on and off balance sheet financial instruments without attempting to estimate the value of anticipated future business and the value of assets and liabilities that are not considered financial instruments. For example, the Company has a substantial trust and investment management operation that contributes net fee income annually. The trust and investment management operation is not considered a financial instrument and its value has not been incorporated into the fair value estimates. Other significant assets and liabilities include the benefits resulting from the low-cost funding of deposit liabilities as compared to the cost of borrowing funds in the market and premises and equipment. In addition, the tax ramifications related to the realization of the unrealized gains and losses can have a significant effect on fair value estimates and have not been considered in the estimate of fair value. Securities Held to Maturity The fair value of the Company’s investment securities held to maturity is primarily measured using information from a third party pricing service. The fair value measurements consider observable data that may include dealer quotes, market spreads, cash flows, the U.S. Treasury yield curve, live trading levels, trade execution data, market consensus prepayment speeds, credit information and the bond’s terms and conditions, among other things. Net Loans The fair value of the Company’s loans was estimated by discounting the expected future cash flows using the current interest rates at which similar loans would be made for the same remaining maturities. Loans were first segregated by type and then further segmented into fixed and variable rate and loan quality categories. Expected future cash flows were projected based on contractual cash flows, adjusted for estimated prepayments. Time Deposits The fair value of time deposits was estimated using a discounted cash flow approach that applies prevailing market interest rates for similar maturity instruments. The fair values of the Company’s time deposit liabilities do not take into consideration the value of the Company’s long-term relationships with depositors, which may have significant value. Long-Term Debt The fair value of long-term debt was estimated using a discounted cash flow approach that applies prevailing market interest rates for similar maturity instruments. Junior Subordinated Debt The fair value of junior subordinated debt has been estimated using a discounted cash flow analysis. Interest Rate Swaps The Company enters into interest rate swaps to facilitate customer transactions and meet their financing needs. These swaps are considered derivatives, but are not designated in hedging relationships. These instruments have interest rate and credit risk associated with them. To mitigate the interest rate risk, the Company enters into offsetting interest rate swaps with counterparties. The counterparty swaps are also considered derivatives and are also not designated in hedging relationships. Interest rate swaps are recorded within other assets or other liabilities on the unaudited interim consolidated balance sheet at their estimated fair value. Changes to the fair value of assets and liabilities arising from these derivatives are included, net, in other operating income in the unaudited interim consolidated statement of income.

Recent Accounting Pronounceme26

Recent Accounting Pronouncements (Policies)	9 Months Ended
	Sep. 30, 2017
Recent Accounting Pronouncements [Abstract]
Recent Accounting Pronouncements	Recently Adopted Accounting Standards Effective January 1, 2017, the Company adopted the provision of Financial Accounting Standards Board (“FASB”) Accounting Standards Update (“ASU”) No. 2016-09, Compensation – Stock Compensation (Topic 718): Improvements to Employee Share-Based Payment Accounting Transition to the new guidance was accomplished through a combination of cumulative-effect adjustment to equity (forfeitures) and prospective methodologies (cash flows, tax windfalls and shortfalls). The actual effects of adoption in 2017 will primarily depend upon the share price of the common stock, which affects the vesting of certain performance awards, probability of exercise of certain stock options and the magnitude of windfalls for all awards upon either vesting or exercise. The effect on earnings per share calculations and election to account for forfeitures as incurred have not been significant. Effective July 1, 2017, the Company early adopted the provision of FASB issued ASU No. 2017-04, Intangibles - Goodwill and Other (Topic 350): Simplifying the Test for Goodwill Impairment
Accounting Standards Issued Not Yet Adopted	Accounting Standards Issued Not Yet Adopted In August 2017, the FASB issued ASU 2017-12, Derivatives and Hedging (Topic 815): Targeted Improvements to Accounting for Hedging Activities In May 2017, the FASB issued ASU 2017-09, Compensation-Stock Compensation (Topic 718). In March 2017, the FASB issued ASU No. 2017-08, Receivables – Nonrefundable Fees and Other Costs (Subtopic 310-20) In March 2017, the FASB issued ASU No. 2017-07, Compensation – Retirement Benefits (Topic 715) In February 2017, the FASB issued ASU No. 2017-05, Other Income – Gains and Losses from the Derecognition of Nonfinancial Assets (Subtopic 610-20) in substance nonfinancial assets In January 2017, the FASB issued ASU No. 2017-01, Business Combinations (Topic 805): Clarifying the Definition of a Business In November 2016, the FASB issued ASU No. 2016-18, Statement of Cash Flows (Topic 230): Restricted Cash In August 2016, the FASB issued ASU No. 2016-15, Statement of Cash Flows (Topic 230): Classification of Certain Cash Receipts and Cash Payments) In June 2016, the FASB issued ASU No. 2016-13, Financial Instruments - Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments In February 2016, the FASB issued ASU No. 2016-02, Leases (Topic 842) In January 2016, the FASB issued ASU No. 2016-01, Financial Instruments - Overall (Subtopic 825-10) – Recognition and Measurement of Financial Assets and Financial Liabilities In May 2014, the FASB issued ASU No. 2014-09 - Revenue from Contracts with Customers (Topic 606) Revenue from Contracts with Customers - Deferral of the Effective Date Principal versus Agent Considerations (Reporting Revenue Gross versus Net), Identifying Performance Obligations and Licensing, Narrow-Scope Improvements and Practical Expedients Technical Corrections and Improvements to Top 606 - Revenue from Contract with Customers

Securities (Tables)

Securities (Tables)	9 Months Ended
	Sep. 30, 2017
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 available for sale (“AFS”) securities are as follows: (In thousands) Amortized cost Unrealized gains Unrealized losses Estimated fair value September 30, 2017 Federal agency $ 139,935 $ 27 $ 544 $ 139,418 State & municipal 42,880 127 88 42,919 Mortgage-backed: Government-sponsored enterprises 554,466 3,879 1,115 557,230 U.S. government agency securities 26,760 404 168 26,996 Collateralized mortgage obligations: Government-sponsored enterprises 523,682 626 5,592 518,716 U.S. government agency securities 53,089 169 662 52,596 Other securities 13,537 6,332 130 19,739 Total securities AFS $ 1,354,349 $ 11,564 $ 8,299 $ 1,357,614 December 31, 2016 Federal agency $ 175,135 $ 78 $ 805 $ 174,408 State & municipal 47,053 153 480 46,726 Mortgage-backed: Government-sponsored enterprises 513,814 3,345 2,492 514,667 U.S. government agency securities 14,955 411 189 15,177 Collateralized mortgage obligations: Government-sponsored enterprises 513,431 532 7,688 506,275 U.S. government agency securities 60,822 184 708 60,298 Other securities 15,849 6,394 1,504 20,739 Total securities AFS $ 1,341,059 $ 11,097 $ 13,866 $ 1,338,290
Amortized Cost, Estimated Fair Value, and Unrealized Gains and Losses of Securities Held to Maturity	The amortized cost, estimated fair value and unrealized gains and losses of held to maturity (“HTM”) securities are as follows: (In thousands) Amortized cost Unrealized gains Unrealized losses Estimated fair value September 30, 2017 Mortgage-backed: Government-sponsored enterprises $ 99,502 $ 239 $ 685 $ 99,056 U.S. government agency securities 447 67 - 514 Collateralized mortgage obligations: Government-sponsored enterprises 195,388 1,135 1,103 195,420 State & municipal 198,972 1,983 534 200,421 Total securities HTM $ 494,309 $ 3,424 $ 2,322 $ 495,411 December 31, 2016 Mortgage-backed: Government-sponsored enterprises $ 96,668 $ - $ 1,176 $ 95,492 U.S. government agency securities 533 87 - 620 Collateralized mortgage obligations: Government-sponsored enterprises 225,213 1,060 1,508 224,765 State & municipal 205,534 434 1,795 204,173 Total securities HTM $ 527,948 $ 1,581 $ 4,479 $ 525,050
Investment Securities with Unrealized Losses	The following table sets forth information with regard to investment securities with unrealized losses, segregated according to the length of time the securities had been in a continuous unrealized loss position: (Dollars in thousands) 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 September 30, 2017 AFS securities: Federal agency $ 45,209 $ (49 ) 3 $ 54,465 $ (495 ) 5 $ 99,674 $ (544 ) 8 State & municipal 14,720 (39 ) 24 6,015 (49 ) 8 20,735 (88 ) 32 Mortgage-backed 181,600 (1,176 ) 42 6,577 (107 ) 5 188,177 (1,283 ) 47 Collateralized mortgage obligations 339,415 (3,175 ) 50 119,108 (3,079 ) 16 458,523 (6,254 ) 66 Other securities 1,997 (3 ) 1 2,979 (127 ) 1 4,976 (130 ) 2 Total securities with unrealized losses $ 582,941 $ (4,442 ) 120 $ 189,144 $ (3,857 ) 35 $ 772,085 $ (8,299 ) 155 HTM securities: Mortgage-backed $ 51,166 $ (685 ) 4 $ - $ - - $ 51,166 $ (685 ) 4 Collateralized mortgage obligations 49,394 (160 ) 7 31,627 (943 ) 4 81,021 (1,103 ) 11 State & municipal 16,811 (188 ) 21 12,591 (346 ) 21 29,402 (534 ) 42 Total securities with unrealized losses $ 117,371 $ (1,033 ) 32 $ 44,218 $ (1,289 ) 25 $ 161,589 $ (2,322 ) 57 December 31, 2016 AFS securities: Federal agency $ 119,363 $ (805 ) 10 $ - $ - - $ 119,363 $ (805 ) 10 State & municipal 31,873 (478 ) 55 483 (2 ) 1 32,356 (480 ) 56 Mortgage-backed 277,524 (2,668 ) 49 985 (13 ) 4 278,509 (2,681 ) 53 Collateralized mortgage obligations 473,746 (8,396 ) 57 - - - 473,746 (8,396 ) 57 Other securities - - - 4,363 (1,504 ) 2 4,363 (1,504 ) 2 Total securities with unrealized losses $ 902,506 $ (12,347 ) 171 $ 5,831 $ (1,519 ) 7 $ 908,337 $ (13,866 ) 178 HTM securities: Mortgage-backed $ 95,492 $ (1,176 ) 5 $ - $ - - $ 95,492 $ (1,176 ) 5 Collateralized mortgage obligations 108,587 (319 ) 12 35,209 (1,189 ) 4 143,796 (1,508 ) 16 State & municipal 81,984 (1,795 ) 155 - - - 81,984 (1,795 ) 155 Total securities with unrealized losses $ 286,063 $ (3,290 ) 172 $ 35,209 $ (1,189 ) 4 $ 321,272 $ (4,479 ) 176
Contractual Maturities of Debt Securities	The following tables set forth information with regard to contractual maturities of debt securities at September 30, 2017: (In thousands) Amortized cost Estimated fair value AFS debt securities: Within one year $ 92,405 $ 92,429 From one to five years 84,442 84,598 From five to ten years 179,854 180,667 After ten years 984,111 980,181 $ 1,340,812 $ 1,337,875 HTM debt securities: Within one year $ 28,489 $ 28,493 From one to five years 38,321 38,702 From five to ten years 144,621 145,547 After ten years 282,878 282,669 $ 494,309 $ 495,411

Allowance for Loan Losses and28

Allowance for Loan Losses and Credit Quality of Loans (Tables)	9 Months Ended
	Sep. 30, 2017
Allowance for Loan Losses and Credit Quality of Loans [Abstract]
Portfolio and Class Segments	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
Allowance for Loan Losses by Portfolio	The following tables illustrate the changes in the allowance for loan losses by our portfolio segments: Three months ended September 30, (In thousands) Commercial Loans Consumer Loans Residential Real Estate Mortgages Unallocated Total Balance as of June 30, 2017 $ 24,428 $ 35,523 $ 6,649 $ - $ 66,600 Charge-offs (574 ) (6,979 ) (421 ) - (7,974 ) Recoveries 266 1,446 123 - 1,835 Provision 1,434 6,197 258 - 7,889 Ending Balance as of September 30, 2017 $ 25,554 $ 36,187 $ 6,609 $ - $ 68,350 Balance as of June 30, 2016 $ 25,222 $ 31,471 $ 7,875 $ - $ 64,568 Charge-offs (637 ) (6,046 ) (142 ) - (6,825 ) Recoveries 512 898 127 - 1,537 Provision 1,514 6,078 (1,481 ) 277 6,388 Ending Balance as of September 30, 2016 $ 26,611 $ 32,401 $ 6,379 $ 277 $ 65,668 Nine months ended September 30, Commercial Loans Consumer Loans Residential Real Estate Mortgages Unallocated Total Balance as of December 31, 2016 $ 25,444 $ 33,375 $ 6,381 $ - $ 65,200 Charge-offs (2,991 ) (19,742 ) (1,717 ) - (24,450 ) Recoveries 919 3,680 166 - 4,765 Provision 2,182 18,874 1,779 - 22,835 Ending Balance as of September 30, 2017 $ 25,554 $ 36,187 $ 6,609 $ - $ 68,350 Balance as of December 31, 2015 $ 25,545 $ 29,253 $ 7,960 $ 260 $ 63,018 Charge-offs (1,723 ) (16,409 ) (1,119 ) - (19,251 ) Recoveries 1,616 2,779 240 - 4,635 Provision 1,173 16,778 (702 ) 17 17,266 Ending Balance as of September 30, 2016 $ 26,611 $ 32,401 $ 6,379 $ 277 $ 65,668 The following tables illustrate the allowance for loan losses and the recorded investment by portfolio segments: As of September 30, 2017 (In thousands) Commercial Loans Consumer Loans Residential Real Estate Mortgages Total Allowance for loan losses $ 25,554 $ 36,187 $ 6,609 $ 68,350 Allowance for loans individually evaluated for impairment 30 - - 30 Allowance for loans collectively evaluated for impairment $ 25,524 $ 36,187 $ 6,609 $ 68,320 Ending balance of loans $ 2,962,287 $ 2,202,070 $ 1,302,577 $ 6,466,934 Ending balance of originated loans individually evaluated for impairment $ 4,855 $ 8,307 $ 6,574 $ 19,736 Ending balance of acquired loans collectively evaluated for impairment $ 196,444 $ 47,986 $ 177,393 $ 421,823 Ending balance of originated loans collectively evaluated for impairment $ 2,760,988 $ 2,145,777 $ 1,118,610 $ 6,025,375 As of December 31, 2016 Allowance for loan losses $ 25,444 $ 33,375 $ 6,381 $ 65,200 Allowance for loans individually evaluated for impairment 1,517 - - 1,517 Allowance for loans collectively evaluated for impairment $ 23,927 $ 33,375 $ 6,381 $ 63,683 Ending balance of loans $ 2,786,002 $ 2,149,441 $ 1,262,614 $ 6,198,057 Ending balance of originated loans individually evaluated for impairment $ 13,070 $ 8,488 $ 6,111 $ 27,669 Ending balance of acquired loans individually evaluated for impairment $ 1,205 $ - $ - $ 1,205 Ending balance of acquired loans collectively evaluated for impairment $ 236,413 $ 63,005 $ 199,471 $ 498,889 Ending balance of originated loans collectively evaluated for impairment $ 2,535,314 $ 2,077,948 $ 1,057,032 $ 5,670,294
Past Due and Nonperforming Loans by Loan Class	The following tables set forth information with regard to past due and nonperforming loans by loan class: As of September 30, 2017 (In thousands) 31-60 Days Past Due Accruing 61-90 Days Past Due Accruing Greater Than 90 Days Past Due Accruing Total Past Due Accruing Nonaccrual Current Recorded Total Loans Originated Commercial Loans: Commercial $ 1 $ 156 $ - $ 157 $ 430 $ 732,535 $ 733,122 Commercial Real Estate 1,274 - - 1,274 2,020 1,477,265 1,480,559 Agricultural - - - - 391 34,448 34,839 Agricultural Real Estate 234 - - 234 1,658 33,499 35,391 Business Banking 2,057 91 - 2,148 4,640 475,144 481,932 Total Commercial Loans $ 3,566 $ 247 $ - $ 3,813 $ 9,139 $ 2,752,891 $ 2,765,843 Consumer Loans: Indirect $ 18,755 $ 5,112 $ 2,452 $ 26,319 $ 2,069 $ 1,602,890 $ 1,631,278 Home Equity 2,933 628 213 3,774 2,790 452,189 458,753 Direct 319 47 79 445 78 63,530 64,053 Total Consumer Loans $ 22,007 $ 5,787 $ 2,744 $ 30,538 $ 4,937 $ 2,118,609 $ 2,154,084 Residential Real Estate Mortgages $ 3,812 $ 246 $ 597 $ 4,655 $ 6,180 $ 1,114,349 $ 1,125,184 Total Originated Loans $ 29,385 $ 6,280 $ 3,341 $ 39,006 $ 20,256 $ 5,985,849 $ 6,045,111 Acquired Commercial Loans: Commercial $ - $ - $ - $ - $ - $ 39,037 $ 39,037 Commercial Real Estate - - - - 501 112,810 113,311 Business Banking 355 275 - 630 773 42,693 44,096 Total Commercial Loans $ 355 $ 275 $ - $ 630 $ 1,274 $ 194,540 $ 196,444 Consumer Loans: Indirect $ 29 $ 8 $ 3 $ 40 $ 30 $ 2,084 $ 2,154 Home Equity 307 - - 307 160 42,510 42,977 Direct 32 26 7 65 8 2,782 2,855 Total Consumer Loans $ 368 $ 34 $ 10 $ 412 $ 198 $ 47,376 $ 47,986 Residential Real Estate Mortgages $ 660 $ 100 $ 37 $ 797 $ 1,725 $ 174,871 $ 177,393 Total Acquired Loans $ 1,383 $ 409 $ 47 $ 1,839 $ 3,197 $ 416,787 $ 421,823 Total Loans $ 30,768 $ 6,689 $ 3,388 $ 40,845 $ 23,453 $ 6,402,636 $ 6,466,934 As of December 31, 2016 (In thousands) 31-60 Days Past Due Accruing 61-90 Days Past Due Accruing Greater Than 90 Days Past Due Accruing Total Past Due Accruing Nonaccrual Current Recorded Total Loans Originated Commercial Loans: Commercial $ 33 $ 5 $ - $ 38 $ 2,964 $ 650,568 $ 653,570 Commercial Real Estate - - - - 7,935 1,343,854 1,351,789 Agricultural - - - - 730 37,186 37,916 Agricultural Real Estate - - - - 1,803 30,619 32,422 Business Banking 1,609 318 - 1,927 4,860 465,900 472,687 Total Commercial Loans $ 1,642 $ 323 $ - $ 1,965 $ 18,292 $ 2,528,127 $ 2,548,384 Consumer Loans: Indirect $ 19,253 $ 4,185 $ 2,499 $ 25,937 $ 2,145 $ 1,538,593 $ 1,566,675 Home Equity 3,416 1,065 528 5,009 2,851 448,797 456,657 Direct 452 125 20 597 107 62,400 63,104 Total Consumer Loans $ 23,121 $ 5,375 $ 3,047 $ 31,543 $ 5,103 $ 2,049,790 $ 2,086,436 Residential Real Estate Mortgages $ 2,725 $ 172 $ 1,406 $ 4,303 $ 6,682 $ 1,052,158 $ 1,063,143 Total Originated Loans $ 27,488 $ 5,870 $ 4,453 $ 37,811 $ 30,077 $ 5,630,075 $ 5,697,963 Acquired Commercial Loans: Commercial $ - $ - $ - $ - $ - $ 49,447 $ 49,447 Commercial Real Estate - - - - 1,891 135,398 137,289 Business Banking 236 - - 236 804 49,842 50,882 Total Commercial Loans $ 236 $ - $ - $ 236 $ 2,695 $ 234,687 $ 237,618 Consumer Loans: Indirect 100 5 - 105 47 8,541 8,693 Home Equity 254 53 30 337 237 50,553 51,127 Direct 30 2 - 32 20 3,133 3,185 Total Consumer Loans $ 384 $ 60 $ 30 $ 474 $ 304 $ 62,227 $ 63,005 Residential Real Estate Mortgages $ 609 $ 28 $ 327 $ 964 $ 2,636 $ 195,871 $ 199,471 Total Acquired Loans $ 1,229 $ 88 $ 357 $ 1,674 $ 5,635 $ 492,785 $ 500,094 Total Loans $ 28,717 $ 5,958 $ 4,810 $ 39,485 $ 35,712 $ 6,122,860 $ 6,198,057
Impaired Loans and Specific Reserve Allocations	The following table provides information on loans specifically evaluated for impairment: September 30, 2017 December 31, 2016 (In thousands) Recorded Investment Balance (Book) Unpaid Principal Balance (Legal) Related Allowance Recorded Investment Balance (Book) Unpaid Principal Balance (Legal) Related Allowance Originated With no related allowance recorded: Commercial Loans: Commercial $ - $ 251 $ 1,278 $ 1,697 Commercial Real Estate 2,239 3,996 3,816 3,841 Agricultural 100 112 130 137 Agricultural Real Estate 1,491 1,663 1,434 1,567 Business Banking 947 1,687 655 728 Total Commercial Loans $ 4,777 $ 7,709 $ 7,313 $ 7,970 Consumer Loans: Indirect 36 47 5 16 Home Equity 8,153 10,063 8,483 9,429 Direct 118 118 - - Total Consumer Loans $ 8,307 $ 10,228 $ 8,488 $ 9,445 Residential Real Estate Mortgages 6,574 8,335 6,111 6,906 Total $ 19,658 $ 26,272 $ 21,912 $ 24,321 With an allowance recorded: Commercial Loans: Commercial Real Estate $ 78 $ 83 $ 30 $ 5,553 $ 5,736 $ 735 Agricultural - - - 49 49 37 Agricultural Real Estate - - - 155 155 54 Total Commercial Loans $ 78 $ 83 $ 30 $ 5,757 $ 5,940 $ 826 Acquired With an allowance recorded: Commercial Loans: Commercial Real Estate $ - $ - $ - $ 1,205 $ 1,321 $ 691 Total Commercial Loans $ - $ - $ - $ 1,205 $ 1,321 $ 691 Total: $ 19,736 $ 26,355 $ 30 $ 28,874 $ 31,582 $ 1,517 The following tables summarize the average recorded investments on impaired loans specifically evaluated for impairment and the interest income recognized: For the three months ended September 30, 2017 September 30, 2016 (In thousands) Average Recorded Investment Interest Income Recognized Average Recorded Investment Interest Income Recognized Originated Commercial Loans: Commercial $ 1,000 $ - $ 3,204 $ - Commercial Real Estate 2,415 48 15,799 48 Agricultural 115 - 85 - Agricultural Real Estate 1,505 11 935 11 Business Banking 955 2 743 - Consumer Loans: Indirect 35 1 8 - Home Equity 8,159 111 8,401 116 Direct 119 2 - - Residential Real Estate Mortgage 6,633 82 6,141 76 Total Originated $ 20,936 $ 257 $ 35,316 $ 251 Acquired Commercial Loans: Commercial Real Estate $ - $ - $ 1,205 $ - Total Acquired $ - $ - $ 1,205 $ - Total Loans $ 20,936 $ 257 $ 36,521 $ 251 For the nine months ended September 30, 2017 September 30, 2016 Average Recorded Investment Interest Income Recognized Average Recorded Investment Interest Income Recognized Originated Commercial Loans: Commercial $ 2,393 $ - $ 3,041 $ - Commercial Real Estate 3,906 93 14,782 122 Agricultural 147 1 101 1 Agricultural Real Estate 1,545 32 742 33 Business Banking 837 7 882 7 Consumer Loans: Indirect 22 2 9 - Home Equity 8,274 331 8,207 357 Direct 119 2 - - Residential Real Estate Mortgage 6,425 211 6,147 211 Total Originated $ 23,668 $ 679 $ 33,911 $ 731 Acquired Commercial Loans: Commercial Real Estate $ 121 $ - $ 1,205 $ - Total Acquired $ 121 $ - $ 1,205 $ - Total Loans $ 23,789 $ 679 $ 35,116 $ 731
Financing Receivable Credit Quality by Loan Class	The following tables illustrate the Company’s credit quality by loan class: As of September 30, 2017 (In thousands) Originated Commercial Credit Exposure By Internally Assigned Grade: Commercial Commercial Real Estate Agricultural Agricultural Real Estate Total Pass $ 677,943 $ 1,424,353 $ 30,233 $ 25,546 $ 2,158,075 Special Mention 40,123 29,785 3,033 3,343 76,284 Substandard 15,056 26,421 1,573 6,502 49,552 Total $ 733,122 $ 1,480,559 $ 34,839 $ 35,391 $ 2,283,911 Business Banking Credit Exposure By Internally Assigned Grade: Business Banking Total Non-classified $ 469,025 $ 469,025 Classified 12,907 12,907 Total $ 481,932 $ 481,932 Consumer Credit Exposure By Payment Activity: Indirect Home Equity Direct Total Performing $ 1,626,757 $ 455,750 $ 63,896 $ 2,146,403 Nonperforming 4,521 3,003 157 7,681 Total $ 1,631,278 $ 458,753 $ 64,053 $ 2,154,084 Residential Mortgage Credit Exposure By Payment Activity: Residential Mortgage Total Performing $ 1,118,407 $ 1,118,407 Nonperforming 6,777 6,777 Total $ 1,125,184 $ 1,125,184 As of September 30, 2017 (In thousands) Acquired Commercial Credit Exposure By Internally Assigned Grade: Commercial Commercial Real Estate Total Pass $ 37,271 $ 106,261 $ 143,532 Special Mention 327 512 839 Substandard 1,439 6,538 7,977 Total $ 39,037 $ 113,311 $ 152,348 Business Banking Credit Exposure By Internally Assigned Grade: Business Banking Total Non-classified $ 40,636 $ 40,636 Classified 3,460 3,460 Total $ 44,096 $ 44,096 Consumer Credit Exposure By Payment Activity: Indirect Home Equity Direct Total Performing $ 2,121 $ 42,817 $ 2,840 $ 47,778 Nonperforming 33 160 15 208 Total $ 2,154 $ 42,977 $ 2,855 $ 47,986 Residential Mortgage Credit Exposure By Payment Activity: Residential Mortgage Total Performing $ 175,631 $ 175,631 Nonperforming 1,762 1,762 Total $ 177,393 $ 177,393 As of December 31, 2016 (In thousands) Originated Commercial Credit Exposure By Internally Assigned Grade: Commercial Commercial Real Estate Agricultural Agricultural Real Estate Total Pass $ 616,829 $ 1,288,409 $ 36,762 $ 28,912 $ 1,970,912 Special Mention 7,750 31,053 25 1,896 40,724 Substandard 28,991 32,327 1,124 1,614 64,056 Doubtful - - 5 - 5 Total $ 653,570 $ 1,351,789 $ 37,916 $ 32,422 $ 2,075,697 Business Banking Credit Exposure By Internally Assigned Grade: Business Banking Total Non-classified $ 458,864 $ 458,864 Classified 13,823 13,823 Total $ 472,687 $ 472,687 Consumer Credit Exposure By Payment Activity: Indirect Home Equity Direct Total Performing $ 1,562,031 $ 453,278 $ 62,977 $ 2,078,286 Nonperforming 4,644 3,379 127 8,150 Total $ 1,566,675 $ 456,657 $ 63,104 $ 2,086,436 Residential Mortgage Credit Exposure By Payment Activity: Residential Mortgage Total Performing $ 1,055,055 $ 1,055,055 Nonperforming 8,088 8,088 Total $ 1,063,143 $ 1,063,143 As of December 31, 2016 (In thousands) Acquired Commercial Credit Exposure By Internally Assigned Grade: Commercial Commercial Real Estate Total Pass $ 48,194 $ 127,660 $ 175,854 Special Mention 76 1,231 1,307 Substandard 1,177 7,193 8,370 Doubtful - 1,205 1,205 Total $ 49,447 $ 137,289 $ 186,736 Business Banking Credit Exposure By Internally Assigned Grade: Business Banking Total Non-classified $ 47,347 $ 47,347 Classified 3,535 3,535 Total $ 50,882 $ 50,882 Consumer Credit Exposure By Payment Activity: Indirect Home Equity Direct Total Performing $ 8,646 $ 50,860 $ 3,165 $ 62,671 Nonperforming 47 267 20 334 Total $ 8,693 $ 51,127 $ 3,185 $ 63,005 Residential Mortgage Credit Exposure By Payment Activity: Residential Mortgage Total Performing $ 196,508 $ 196,508 Nonperforming 2,963 2,963 Total $ 199,471 $ 199,471
Troubled Debt Restructurings on Financing Receivables	The following tables illustrate the recorded investment and number of modifications for modified loans, including the recorded investment in the loans prior to a modification and the recorded investment in the loans after restructuring: Three months ended September 30, 2017 (Dollars in thousands) Number of Contracts Pre-Modification Outstanding Recorded Investment Post-Modification Outstanding Recorded Investment Consumer Indirect 1 $ 7 $ 7 Home Equity 4 189 222 Total Consumer 5 196 229 Residential Real Estate 1 518 518 Total Troubled Debt Restructurings 6 $ 714 $ 747 Three months ended September 30, 2016 Number of Contracts Pre-Modification Outstanding Recorded Investment Post-Modification Outstanding Recorded Investment Consumer Home Equity 10 $ 580 $ 556 Total Consumer 10 580 556 Residential Real Estate 4 230 126 Total Troubled Debt Restructurings 14 $ 810 $ 682 Nine months ended September 30, 2017 (Dollars in thousands) Number of Contracts Pre-Modification Outstanding Recorded Investment Post-Modification Outstanding Recorded Investment Commercial Commercial 1 $ 3,300 $ 3,239 Business Banking 1 337 333 Total Commercial 2 3,637 3,572 Consumer Indirect 4 39 37 Home Equity 8 373 414 Direct 1 120 120 Total Consumer 13 532 571 Residential Real Estate 8 1,066 1,068 Total Troubled Debt Restructurings 23 $ 5,235 $ 5,211 Nine months ended September 30, 2016 Number of Contracts Pre-Modification Outstanding Recorded Investment Post-Modification Outstanding Recorded Investment Consumer Home Equity 24 $ 1,690 $ 1,567 Total Consumer 24 1,690 1,567 Residential Real Estate 10 914 692 Total Troubled Debt Restructurings 34 $ 2,604 $ 2,259 TDRs occurring during the three and nine months ended September 30, 2017 and 2016 were due to the reduction in the interest rate or extension of the term. The following table illustrates the recorded investment and number of modifications for TDRs where a concession has been made and subsequently defaulted during the period: Three months ended September 30, 2017 Three months ended September 30, 2016 (Dollars in thousands) Number of Contracts Recorded Investment Number of Contracts Recorded Investment Commercial Commercial - $ - 1 $ 169 Total Commercial - - 1 169 Consumer Indirect 1 13 - - Home Equity 12 622 17 847 Total Consumer 13 635 17 847 Residential Real Estate 6 546 8 485 Total Troubled Debt Restructurings 19 $ 1,181 26 $ 1,501 Nine months ended September 30, 2017 Nine months ended September 30, 2016 Number of Contracts Recorded Investment Number of Contracts Recorded Investment Commercial Commercial 1 $ 145 1 $ 169 Business Banking 1 329 1 67 Total Commercial 2 474 2 236 Consumer Indirect 2 19 - - Home Equity 30 1,381 30 1,634 Total Consumer 32 1,400 30 1,634 Residential Real Estate 12 817 15 1,075 Total Troubled Debt Restructurings 46 $ 2,691 47 $ 2,945

Defined Benefit Post-retireme29

Defined Benefit Post-retirement Plans (Tables)	9 Months Ended
	Sep. 30, 2017
Defined Benefit Post-retirement Plans [Abstract]
Components of Net Periodic Pension Benefits and Other Benefit Costs	The components of expense for Pension Benefits and Other Benefits are set forth below: Pension Benefits Other Benefits (In thousands) Three months ended September 30, Three months ended September 30, Components of net periodic (benefit) cost: 2017 2016 2017 2016 Service cost $ 329 $ 534 $ 3 $ 3 Interest cost 1,043 1,050 88 89 Expected return on plan assets (1,976 ) (1,857 ) - - Net amortization 454 504 26 15 Total (benefit) cost $ (150 ) $ 231 $ 117 $ 107 Pension Benefits Other Benefits Nine months ended September 30, Nine months ended September 30, Components of net periodic (benefit) cost: 2017 2016 2017 2016 Service cost $ 1,133 $ 1,654 $ 9 $ 10 Interest cost 3,127 3,151 259 277 Expected return on plan assets (5,946 ) (5,527 ) - - Net amortization 1,284 1,471 66 73 Total (benefit) cost $ (402 ) $ 749 $ 334 $ 360

Earnings Per Share (Tables)

Earnings Per Share (Tables)	9 Months Ended
	Sep. 30, 2017
Earnings Per Share [Abstract]
Reconciliation of Basic and Diluted Earnings per Share	The following is a reconciliation of basic and diluted EPS for the periods presented in the unaudited interim consolidated statements of income: Three months ended September 30, 2017 2016 (In thousands, except per share data) Basic EPS: Weighted average common shares outstanding 43,595 43,200 Net income available to common stockholders $ 22,876 $ 20,001 Basic EPS $ 0.52 $ 0.46 Diluted EPS: Weighted average common shares outstanding 43,595 43,200 Dilutive effect of common stock options and restricted stock 320 362 Weighted average common shares and common share equivalents 43,915 43,562 Net income available to common stockholders $ 22,876 $ 20,001 Diluted EPS $ 0.52 $ 0.46 Nine months ended September 30, 2017 2016 (In thousands, except per share data) Basic EPS: Weighted average common shares outstanding 43,563 43,214 Net income available to common stockholders $ 64,514 $ 58,801 Basic EPS $ 1.48 $ 1.36 Diluted EPS: Weighted average common shares outstanding 43,563 43,214 Dilutive effect of common stock options and restricted stock 329 366 Weighted average common shares and common share equivalents 43,892 43,580 Net income available to common stockholders $ 64,514 $ 58,801 Diluted EPS $ 1.47 $ 1.35

Reclassification Adjustments 31

Reclassification Adjustments Out of Other Comprehensive Income (Tables)	9 Months Ended
	Sep. 30, 2017
Reclassification Adjustments Out of Other Comprehensive Income [Abstract]
Reclassification Out of Accumulated Other Comprehensive Income	The following table summarizes the reclassification adjustments out of accumulated other comprehensive income (loss): Detail About Accumulated Other Comprehensive Income Components Amount Reclassified From Accumulated Other Comprehensive Income Affected Line item in the Consolidated Statement of Comprehensive Income (In thousands) Three months ended September 30, 2017 September 30, 2016 AFS Securities: Losses on AFS securities $ 4 $ - Net securities gains Amortization of unrealized gains and losses related to securities transfer 212 267 Interest income Income tax (expense) (83 ) (105 ) Income tax (expense) Net of tax $ 133 $ 162 Pension and other benefits: Amortization of net losses $ 481 $ 565 Salaries and employee benefits Amortization of prior service costs (1 ) (46 ) Salaries and employee benefits Income tax (expense) (183 ) (202 ) Income tax (expense) Net of tax $ 297 $ 317 Total reclassifications during the period, net of tax $ 430 $ 479 Detail About Accumulated Other Comprehensive Income Components Amount Reclassified From Accumulated Other Comprehensive Income Affected Line item in the Consolidated Statement of Comprehensive Income Nine months ended September 30, 2017 September 30, 2016 AFS Securities: (Gains) losses on AFS securities $ 2 (30 ) Net securities gains Amortization of unrealized gains and losses related to securities transfer 675 843 Interest income Impairment write-down of equity security 1,312 - Other noninterest income Income tax (expense) (760 ) (317 ) Income tax (expense) Net of tax $ 1,229 $ 496 Pension and other benefits: Amortization of net losses $ 1,351 $ 1,595 Salaries and employee benefits Amortization of prior service costs (1 ) (51 ) Salaries and employee benefits Income tax (expense) (516 ) (601 ) Income tax (expense) Net of tax $ 834 $ 943 Total reclassifications during the period, net of tax $ 2,063 $ 1,439

Fair Value Measurements and F32

Fair Value Measurements and Fair Value of Financial Instruments (Tables)	9 Months Ended
	Sep. 30, 2017
Fair Value Measurements and Fair Value of Financial Instruments [Abstract]
Fair Value of Financial Assets and Liabilities Measured on a Recurring Basis	The following tables set forth the Company’s financial assets and liabilities measured on a recurring basis that were accounted for at fair value. Assets and liabilities are classified in their entirety based on the lowest level of input that is significant to the fair value measurement: (In thousands) Level 1 Level 2 Level 3 Balance as of September 30, 2017 Assets: AFS securities: Federal agency $ - $ 139,418 $ - $ 139,418 State & municipal - 42,919 - 42,919 Mortgage-backed - 584,226 - 584,226 Collateralized mortgage obligations - 571,312 - 571,312 Other securities 11,438 8,301 - 19,739 Total AFS securities $ 11,438 $ 1,346,176 $ - $ 1,357,614 Trading securities 10,883 - - 10,883 Derivatives - 6,653 - 6,653 Total $ 22,321 $ 1,352,829 $ - $ 1,375,150 Liabilities: Derivatives $ - $ 4,128 $ - $ 4,128 Total $ - $ 4,128 $ - $ 4,128 (In thousands) Level 1 Level 2 Level 3 Balance as of December 31, 2016 Assets: AFS securities: Federal agency $ - $ 174,408 $ - $ 174,408 State & municipal - 46,726 - 46,726 Mortgage-backed - 529,844 - 529,844 Collateralized mortgage obligations - 566,573 - 566,573 Other securities 11,493 9,246 - 20,739 Total AFS securities $ 11,493 $ 1,326,797 $ - $ 1,338,290 Trading securities 9,259 - - 9,259 Derivatives - 3,210 - 3,210 Total $ 20,752 $ 1,330,007 $ - $ 1,350,759 Liabilities: Derivatives $ - $ 506 $ - $ 506 Total $ - $ 506 $ - $ 506
Fair Value of Financial Instruments by Balance Sheet Grouping	The following table sets forth information with regard to estimated fair values of financial instruments. This table excludes financial instruments for which the carrying amount approximates fair value. Financial instruments for which the fair value approximates carrying value include cash and cash equivalents, securities AFS, trading securities, accrued interest receivable, non-maturity deposits, short-term borrowings, accrued interest payable and interest rate swaps. September 30, 2017 December 31, 2016 (In thousands) Fair Value Hierarchy Carrying amount Estimated fair value Carrying amount Estimated fair value Financial assets HTM securities 2 $ 494,309 $ 495,411 $ 527,948 $ 525,050 Net loans 3 6,398,584 6,557,674 6,132,857 6,273,233 Financial liabilities Time deposits 2 $ 776,756 $ 773,160 $ 872,411 $ 868,153 Long-term debt 2 88,914 88,948 104,087 104,113 Junior subordinated debt 2 101,196 104,584 101,196 102,262

Securities, Available for Sale

Securities, Available for Sale (Details) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017USD ($)Position	Sep. 30, 2016USD ($)	Sep. 30, 2017USD ($)Position	Sep. 30, 2016USD ($)	Dec. 31, 2016USD ($)Position
Schedule of Available-for-sale Securities [Line Items]
Amortized cost	$ 1,354,349		$ 1,354,349		$ 1,341,059
Unrealized gains	11,564		11,564		11,097
Unrealized losses	8,299		8,299		13,866
Estimated fair value	1,357,614		1,357,614		1,338,290
Unrealized Loss Position, Fair Value [Abstract]
Less than 12 months	582,941		582,941		902,506
12 months or longer	189,144		189,144		5,831
Total	772,085		772,085		908,337
Unrealized Loss Position, Unrealized Losses [Abstract]
Less than 12 months	(4,442)		(4,442)		(12,347)
12 months or longer	(3,857)		(3,857)		(1,519)
Total	$ (8,299)		$ (8,299)		$ (13,866)
Unrealized Loss Position, Number of Positions [Abstract]
Less than 12 months | Position	120		120		171
12 months or longer | Position	35		35		7
Total | Position	155		155		178
OTTI loss realized on equity investment	$ 0	$ 0	$ 1,300	$ 0
Available-for-sale Securities, Debt Maturities, Amortized Cost [Abstract]
Within one year	92,405		92,405
From one to five years	84,442		84,442
From five to ten years	179,854		179,854
After ten years	984,111		984,111
Amortized cost	1,340,812		1,340,812
Available-for-sale Securities, Debt Maturities, Estimated Fair Value [Abstract]
Within one year	92,429		92,429
From one to five years	84,598		84,598
From five to ten years	180,667		180,667
After ten years	980,181		980,181
Fair value	1,337,875		1,337,875
Federal Agency [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized cost	139,935		139,935		$ 175,135
Unrealized gains	27		27		78
Unrealized losses	544		544		805
Estimated fair value	139,418		139,418		174,408
Unrealized Loss Position, Fair Value [Abstract]
Less than 12 months	45,209		45,209		119,363
12 months or longer	54,465		54,465		0
Total	99,674		99,674		119,363
Unrealized Loss Position, Unrealized Losses [Abstract]
Less than 12 months	(49)		(49)		(805)
12 months or longer	(495)		(495)		0
Total	$ (544)		$ (544)		$ (805)
Unrealized Loss Position, Number of Positions [Abstract]
Less than 12 months | Position	3		3		10
12 months or longer | Position	5		5		0
Total | Position	8		8		10
State & Municipal [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized cost	$ 42,880		$ 42,880		$ 47,053
Unrealized gains	127		127		153
Unrealized losses	88		88		480
Estimated fair value	42,919		42,919		46,726
Unrealized Loss Position, Fair Value [Abstract]
Less than 12 months	14,720		14,720		31,873
12 months or longer	6,015		6,015		483
Total	20,735		20,735		32,356
Unrealized Loss Position, Unrealized Losses [Abstract]
Less than 12 months	(39)		(39)		(478)
12 months or longer	(49)		(49)		(2)
Total	$ (88)		$ (88)		$ (480)
Unrealized Loss Position, Number of Positions [Abstract]
Less than 12 months | Position	24		24		55
12 months or longer | Position	8		8		1
Total | Position	32		32		56
Mortgage-Backed [Member]
Unrealized Loss Position, Fair Value [Abstract]
Less than 12 months	$ 181,600		$ 181,600		$ 277,524
12 months or longer	6,577		6,577		985
Total	188,177		188,177		278,509
Unrealized Loss Position, Unrealized Losses [Abstract]
Less than 12 months	(1,176)		(1,176)		(2,668)
12 months or longer	(107)		(107)		(13)
Total	$ (1,283)		$ (1,283)		$ (2,681)
Unrealized Loss Position, Number of Positions [Abstract]
Less than 12 months | Position	42		42		49
12 months or longer | Position	5		5		4
Total | Position	47		47		53
Mortgage-Backed, Government Sponsored Enterprises [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized cost	$ 554,466		$ 554,466		$ 513,814
Unrealized gains	3,879		3,879		3,345
Unrealized losses	1,115		1,115		2,492
Estimated fair value	557,230		557,230		514,667
Mortgage-Backed, U.S. Government Agency Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized cost	26,760		26,760		14,955
Unrealized gains	404		404		411
Unrealized losses	168		168		189
Estimated fair value	26,996		26,996		15,177
Collateralized Mortgage Obligations [Member]
Unrealized Loss Position, Fair Value [Abstract]
Less than 12 months	339,415		339,415		473,746
12 months or longer	119,108		119,108		0
Total	458,523		458,523		473,746
Unrealized Loss Position, Unrealized Losses [Abstract]
Less than 12 months	(3,175)		(3,175)		(8,396)
12 months or longer	(3,079)		(3,079)		0
Total	$ (6,254)		$ (6,254)		$ (8,396)
Unrealized Loss Position, Number of Positions [Abstract]
Less than 12 months | Position	50		50		57
12 months or longer | Position	16		16		0
Total | Position	66		66		57
Collateralized Mortgage Obligations, Government-Sponsored Enterprises [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized cost	$ 523,682		$ 523,682		$ 513,431
Unrealized gains	626		626		532
Unrealized losses	5,592		5,592		7,688
Estimated fair value	518,716		518,716		506,275
Collateralized Mortgage Obligations, U.S. Government Agency Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized cost	53,089		53,089		60,822
Unrealized gains	169		169		184
Unrealized losses	662		662		708
Estimated fair value	52,596		52,596		60,298
Other Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized cost	13,537		13,537		15,849
Unrealized gains	6,332		6,332		6,394
Unrealized losses	130		130		1,504
Estimated fair value	19,739		19,739		20,739
Unrealized Loss Position, Fair Value [Abstract]
Less than 12 months	1,997		1,997		0
12 months or longer	2,979		2,979		4,363
Total	4,976		4,976		4,363
Unrealized Loss Position, Unrealized Losses [Abstract]
Less than 12 months	(3)		(3)		0
12 months or longer	(127)		(127)		(1,504)
Total	$ (130)		$ (130)		$ (1,504)
Unrealized Loss Position, Number of Positions [Abstract]
Less than 12 months | Position	1		1		0
12 months or longer | Position	1		1		2
Total | Position	2		2		2

Securities, Held to Maturity (D

Securities, Held to Maturity (Details) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2017USD ($)Position	Sep. 30, 2017USD ($)Position	Dec. 31, 2016USD ($)Position	Sep. 30, 2016USD ($)
Schedule of Held-to-maturity Securities [Line Items]
Amortized cost	$ 494,309	$ 494,309	$ 527,948
Unrealized gains	3,424	3,424	1,581
Unrealized losses	2,322	2,322	4,479
Estimated fair value	495,411	495,411	525,050
Unrealized Loss Position, Fair Value [Abstract]
Less than 12 months	117,371	117,371	286,063
12 months or longer	44,218	44,218	35,209
Total	161,589	161,589	321,272
Unrealized Loss Position, Unrealized Losses [Abstract]
Less than 12 months	(1,033)	(1,033)	(3,290)
12 months or longer	(1,289)	(1,289)	(1,189)
Total	$ (2,322)	$ (2,322)	$ (4,479)
Unrealized Loss Position, Number of Positions [Abstract]
Less than 12 months | Position	32	32	172
12 months or longer | Position	25	25	4
Total | Position	57	57	176
Held-to-maturity securities sold, amortized cost	$ 800	$ 800		$ 0
Held-to-maturity securities sold, unrealized loss	(2)	(2)
Amortized costs of securities held to maturity pledged to secure public deposits	1,200,000	1,200,000	$ 1,500,000
Amortized costs of securities held to maturity pledged as collateral for repurchase agreements	242,600	242,600	235,600
Held-to-maturity Securities, Debt Maturities, Amortized Cost [Abstract]
Within one year	28,489	28,489
From one to five years	38,321	38,321
From five to ten years	144,621	144,621
After ten years	282,878	282,878
Amortized cost	494,309	494,309	527,948
Held-to-maturity Securities, Debt Maturities, Estimated Fair Value [Abstract]
Within one year	28,493	28,493
From one to five years	38,702	38,702
From five to ten years	145,547	145,547
After ten years	282,669	282,669
Fair value	495,411	495,411	525,050
Mortgage-Backed [Member]
Unrealized Loss Position, Fair Value [Abstract]
Less than 12 months	51,166	51,166	95,492
12 months or longer	0	0	0
Total	51,166	51,166	95,492
Unrealized Loss Position, Unrealized Losses [Abstract]
Less than 12 months	(685)	(685)	(1,176)
12 months or longer	0	0	0
Total	$ (685)	$ (685)	$ (1,176)
Unrealized Loss Position, Number of Positions [Abstract]
Less than 12 months | Position	4	4	5
12 months or longer | Position	0	0	0
Total | Position	4	4	5
Mortgage-Backed, Government Sponsored Enterprises [Member]
Schedule of Held-to-maturity Securities [Line Items]
Amortized cost	$ 99,502	$ 99,502	$ 96,668
Unrealized gains	239	239	0
Unrealized losses	685	685	1,176
Estimated fair value	99,056	99,056	95,492
Held-to-maturity Securities, Debt Maturities, Amortized Cost [Abstract]
Amortized cost	99,502	99,502	96,668
Held-to-maturity Securities, Debt Maturities, Estimated Fair Value [Abstract]
Fair value	99,056	99,056	95,492
Mortgage-Backed, U.S. Government Agency Securities [Member]
Schedule of Held-to-maturity Securities [Line Items]
Amortized cost	447	447	533
Unrealized gains	67	67	87
Unrealized losses	0	0	0
Estimated fair value	514	514	620
Held-to-maturity Securities, Debt Maturities, Amortized Cost [Abstract]
Amortized cost	447	447	533
Held-to-maturity Securities, Debt Maturities, Estimated Fair Value [Abstract]
Fair value	514	514	620
Collateralized Mortgage Obligations [Member]
Unrealized Loss Position, Fair Value [Abstract]
Less than 12 months	49,394	49,394	108,587
12 months or longer	31,627	31,627	35,209
Total	81,021	81,021	143,796
Unrealized Loss Position, Unrealized Losses [Abstract]
Less than 12 months	(160)	(160)	(319)
12 months or longer	(943)	(943)	(1,189)
Total	$ (1,103)	$ (1,103)	$ (1,508)
Unrealized Loss Position, Number of Positions [Abstract]
Less than 12 months | Position	7	7	12
12 months or longer | Position	4	4	4
Total | Position	11	11	16
Collateralized Mortgage Obligations, Government-Sponsored Enterprises [Member]
Schedule of Held-to-maturity Securities [Line Items]
Amortized cost	$ 195,388	$ 195,388	$ 225,213
Unrealized gains	1,135	1,135	1,060
Unrealized losses	1,103	1,103	1,508
Estimated fair value	195,420	195,420	224,765
Held-to-maturity Securities, Debt Maturities, Amortized Cost [Abstract]
Amortized cost	195,388	195,388	225,213
Held-to-maturity Securities, Debt Maturities, Estimated Fair Value [Abstract]
Fair value	195,420	195,420	224,765
State & Municipal [Member]
Schedule of Held-to-maturity Securities [Line Items]
Amortized cost	198,972	198,972	205,534
Unrealized gains	1,983	1,983	434
Unrealized losses	534	534	1,795
Estimated fair value	200,421	200,421	204,173
Unrealized Loss Position, Fair Value [Abstract]
Less than 12 months	16,811	16,811	81,984
12 months or longer	12,591	12,591	0
Total	29,402	29,402	81,984
Unrealized Loss Position, Unrealized Losses [Abstract]
Less than 12 months	(188)	(188)	(1,795)
12 months or longer	(346)	(346)	0
Total	$ (534)	$ (534)	$ (1,795)
Unrealized Loss Position, Number of Positions [Abstract]
Less than 12 months | Position	21	21	155
12 months or longer | Position	21	21	0
Total | Position	42	42	155
Held-to-maturity Securities, Debt Maturities, Amortized Cost [Abstract]
Amortized cost	$ 198,972	$ 198,972	$ 205,534
Held-to-maturity Securities, Debt Maturities, Estimated Fair Value [Abstract]
Fair value	$ 200,421	$ 200,421	$ 204,173

Allowance for Loan Losses and35

Allowance for Loan Losses and Credit Quality of Loans (Details) $ in Millions	9 Months Ended
	Sep. 30, 2017USD ($)Segment	Dec. 31, 2016USD ($)
Financing Receivable, Allowance for Credit Losses [Line Items]
Loan portfolio segments | Segment	3
Commercial Loans [Member] | Commercial Real Estate [Member] | Maximum [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Loan amount, percentage of appraised value or purchase price of the property	80.00%
Commercial Loans [Member] | Agricultural Real Estate [Member] | Maximum [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Loan amount, percentage of appraised value or purchase price of the property	75.00%
Commercial Loans [Member] | Business Banking [Member] | Maximum [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Business banking loans, amount available	$ 0.8
Consumer Loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Unsecured consumer loans originated through relationship with leading national technology-driven consumer lending company	$ 400.9	$ 374.9
Consumer Loans [Member] | Indirect [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Percentage of automobile financing to indirect relationships with dealers	70.00%
Consumer Loans [Member] | Indirect [Member] | Minimum [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Principal repayment term of loan	3 years
Consumer Loans [Member] | Indirect [Member] | Maximum [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Principal repayment term of loan	6 years
Consumer Loans [Member] | Home Equity [Member] | Maximum [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Loan amount, percentage of equity in property	85.00%
Consumer Loans [Member] | Direct [Member] | Minimum [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Principal repayment term of loan	1 year
Consumer Loans [Member] | Direct [Member] | Maximum [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Principal repayment term of loan	10 years
Residential Real Estate Mortgages [Member] | Maximum [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Loan amount, percentage of appraised value or purchase price of the property	85.00%

Allowance for Loan Losses and36

Allowance for Loan Losses and Credit Quality of Loans, Allowance for Loan Losses by Portfolio Segments (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Changes in allowance for loan losses by portfolio segment [Roll Forward]
Balance, beginning of period	$ 66,600	$ 64,568	$ 65,200	$ 63,018
Charge-offs	(7,974)	(6,825)	(24,450)	(19,251)
Recoveries	1,835	1,537	4,765	4,635
Provision	7,889	6,388	22,835	17,266
Balance, end of period	68,350	65,668	68,350	65,668
Allowance for loan losses for acquired loan portfolio	0	700	0	700
Provision expense and net charge-offs related to acquired loans	0	100	700	400
Commercial Loans [Member]
Changes in allowance for loan losses by portfolio segment [Roll Forward]
Balance, beginning of period	24,428	25,222	25,444	25,545
Charge-offs	(574)	(637)	(2,991)	(1,723)
Recoveries	266	512	919	1,616
Provision	1,434	1,514	2,182	1,173
Balance, end of period	25,554	26,611	25,554	26,611
Consumer Loans [Member]
Changes in allowance for loan losses by portfolio segment [Roll Forward]
Balance, beginning of period	35,523	31,471	33,375	29,253
Charge-offs	(6,979)	(6,046)	(19,742)	(16,409)
Recoveries	1,446	898	3,680	2,779
Provision	6,197	6,078	18,874	16,778
Balance, end of period	36,187	32,401	36,187	32,401
Residential Real Estate Mortgages [Member]
Changes in allowance for loan losses by portfolio segment [Roll Forward]
Balance, beginning of period	6,649	7,875	6,381	7,960
Charge-offs	(421)	(142)	(1,717)	(1,119)
Recoveries	123	127	166	240
Provision	258	(1,481)	1,779	(702)
Balance, end of period	6,609	6,379	6,609	6,379
Unallocated [Member]
Changes in allowance for loan losses by portfolio segment [Roll Forward]
Balance, beginning of period	0	0	0	260
Charge-offs	0	0	0	0
Recoveries	0	0	0	0
Provision	0	277	0	17
Balance, end of period	$ 0	$ 277	$ 0	$ 277

Allowance for Loan Losses and37

Allowance for Loan Losses and Credit Quality of Loans, Allowance for Loan Losses and Recorded Investment in Loans (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Jun. 30, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Dec. 31, 2015
Allowance for loan losses and recorded investment by portfolio segment [Abstract]
Allowance for loan losses	$ 68,350	$ 66,600	$ 65,200	$ 65,668	$ 64,568	$ 63,018
Allowance for loans individually evaluated for impairment	30		1,517
Allowance for loans collectively evaluated for impairment	68,320		63,683
Ending balance of loans	6,466,934		6,198,057
Commercial Loans [Member]
Allowance for loan losses and recorded investment by portfolio segment [Abstract]
Allowance for loan losses	25,554	24,428	25,444	26,611	25,222	25,545
Allowance for loans individually evaluated for impairment	30		1,517
Allowance for loans collectively evaluated for impairment	25,524		23,927
Ending balance of loans	2,962,287		2,786,002
Consumer Loans [Member]
Allowance for loan losses and recorded investment by portfolio segment [Abstract]
Allowance for loan losses	36,187	35,523	33,375	32,401	31,471	29,253
Allowance for loans individually evaluated for impairment	0		0
Allowance for loans collectively evaluated for impairment	36,187		33,375
Ending balance of loans	2,202,070		2,149,441
Residential Real Estate Mortgages [Member]
Allowance for loan losses and recorded investment by portfolio segment [Abstract]
Allowance for loan losses	6,609	$ 6,649	6,381	$ 6,379	$ 7,875	$ 7,960
Allowance for loans individually evaluated for impairment	0		0
Allowance for loans collectively evaluated for impairment	6,609		6,381
Ending balance of loans	1,302,577		1,262,614
Originated Loans [Member]
Allowance for loan losses and recorded investment by portfolio segment [Abstract]
Ending balance of loans	6,045,111		5,697,963
Ending balance of loans individually evaluated for impairment	19,736		27,669
Ending balance of loans collectively evaluated for impairment	6,025,375		5,670,294
Originated Loans [Member] | Commercial Loans [Member]
Allowance for loan losses and recorded investment by portfolio segment [Abstract]
Ending balance of loans	2,765,843		2,548,384
Ending balance of loans individually evaluated for impairment	4,855		13,070
Ending balance of loans collectively evaluated for impairment	2,760,988		2,535,314
Originated Loans [Member] | Consumer Loans [Member]
Allowance for loan losses and recorded investment by portfolio segment [Abstract]
Ending balance of loans	2,154,084		2,086,436
Ending balance of loans individually evaluated for impairment	8,307		8,488
Ending balance of loans collectively evaluated for impairment	2,145,777		2,077,948
Originated Loans [Member] | Residential Real Estate Mortgages [Member]
Allowance for loan losses and recorded investment by portfolio segment [Abstract]
Ending balance of loans	1,125,184		1,063,143
Ending balance of loans individually evaluated for impairment	6,574		6,111
Ending balance of loans collectively evaluated for impairment	1,118,610		1,057,032
Acquired Loans [Member]
Allowance for loan losses and recorded investment by portfolio segment [Abstract]
Ending balance of loans	421,823		500,094
Ending balance of loans individually evaluated for impairment			1,205
Ending balance of loans collectively evaluated for impairment	421,823		498,889
Acquired Loans [Member] | Commercial Loans [Member]
Allowance for loan losses and recorded investment by portfolio segment [Abstract]
Ending balance of loans	196,444		237,618
Ending balance of loans individually evaluated for impairment			1,205
Ending balance of loans collectively evaluated for impairment	196,444		236,413
Acquired Loans [Member] | Consumer Loans [Member]
Allowance for loan losses and recorded investment by portfolio segment [Abstract]
Ending balance of loans	47,986		63,005
Ending balance of loans individually evaluated for impairment			0
Ending balance of loans collectively evaluated for impairment	47,986		63,005
Acquired Loans [Member] | Residential Real Estate Mortgages [Member]
Allowance for loan losses and recorded investment by portfolio segment [Abstract]
Ending balance of loans	177,393		199,471
Ending balance of loans individually evaluated for impairment			0
Ending balance of loans collectively evaluated for impairment	$ 177,393		$ 199,471

Allowance for Loan Losses and38

Allowance for Loan Losses and Credit Quality of Loans, Past Due Loans (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2017	Dec. 31, 2016
Financing Receivable, Recorded Investment, Aging [Abstract]
Minimum number of days past due for nonaccrual loan status	90 days
Total past due accruing	$ 40,845	$ 39,485
Nonaccrual	23,453	35,712
Current	6,402,636	6,122,860
Recorded total loans	6,466,934	6,198,057
31-60 Days Past Due Accruing [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing	30,768	28,717
61-90 Days Past Due Accruing [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing	6,689	5,958
Greater Than 90 Days Past Due Accruing [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing	3,388	4,810
Commercial Loans [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Recorded total loans	2,962,287	2,786,002
Consumer Loans [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Recorded total loans	2,202,070	2,149,441
Residential Real Estate Mortgages [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Recorded total loans	1,302,577	1,262,614
Originated Loans [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing	39,006	37,811
Nonaccrual	20,256	30,077
Current	5,985,849	5,630,075
Recorded total loans	6,045,111	5,697,963
Originated Loans [Member] | 31-60 Days Past Due Accruing [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing	29,385	27,488
Originated Loans [Member] | 61-90 Days Past Due Accruing [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing	6,280	5,870
Originated Loans [Member] | Greater Than 90 Days Past Due Accruing [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing	3,341	4,453
Originated Loans [Member] | Commercial Loans [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing	3,813	1,965
Nonaccrual	9,139	18,292
Current	2,752,891	2,528,127
Recorded total loans	2,765,843	2,548,384
Originated Loans [Member] | Commercial Loans [Member] | 31-60 Days Past Due Accruing [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing	3,566	1,642
Originated Loans [Member] | Commercial Loans [Member] | 61-90 Days Past Due Accruing [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing	247	323
Originated Loans [Member] | Commercial Loans [Member] | Greater Than 90 Days Past Due Accruing [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing	0	0
Originated Loans [Member] | Commercial Loans [Member] | Commercial [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing	157	38
Nonaccrual	430	2,964
Current	732,535	650,568
Recorded total loans	733,122	653,570
Originated Loans [Member] | Commercial Loans [Member] | Commercial [Member] | 31-60 Days Past Due Accruing [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing	1	33
Originated Loans [Member] | Commercial Loans [Member] | Commercial [Member] | 61-90 Days Past Due Accruing [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing	156	5
Originated Loans [Member] | Commercial Loans [Member] | Commercial [Member] | Greater Than 90 Days Past Due Accruing [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing	0	0
Originated Loans [Member] | Commercial Loans [Member] | Commercial Real Estate [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing	1,274	0
Nonaccrual	2,020	7,935
Current	1,477,265	1,343,854
Recorded total loans	1,480,559	1,351,789
Originated Loans [Member] | Commercial Loans [Member] | Commercial Real Estate [Member] | 31-60 Days Past Due Accruing [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing	1,274	0
Originated Loans [Member] | Commercial Loans [Member] | Commercial Real Estate [Member] | 61-90 Days Past Due Accruing [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing	0	0
Originated Loans [Member] | Commercial Loans [Member] | Commercial Real Estate [Member] | Greater Than 90 Days Past Due Accruing [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing	0	0
Originated Loans [Member] | Commercial Loans [Member] | Agricultural [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing	0	0
Nonaccrual	391	730
Current	34,448	37,186
Recorded total loans	34,839	37,916
Originated Loans [Member] | Commercial Loans [Member] | Agricultural [Member] | 31-60 Days Past Due Accruing [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing	0	0
Originated Loans [Member] | Commercial Loans [Member] | Agricultural [Member] | 61-90 Days Past Due Accruing [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing	0	0
Originated Loans [Member] | Commercial Loans [Member] | Agricultural [Member] | Greater Than 90 Days Past Due Accruing [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing	0	0
Originated Loans [Member] | Commercial Loans [Member] | Agricultural Real Estate [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing	234	0
Nonaccrual	1,658	1,803
Current	33,499	30,619
Recorded total loans	35,391	32,422
Originated Loans [Member] | Commercial Loans [Member] | Agricultural Real Estate [Member] | 31-60 Days Past Due Accruing [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing	234	0
Originated Loans [Member] | Commercial Loans [Member] | Agricultural Real Estate [Member] | 61-90 Days Past Due Accruing [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing	0	0
Originated Loans [Member] | Commercial Loans [Member] | Agricultural Real Estate [Member] | Greater Than 90 Days Past Due Accruing [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing	0	0
Originated Loans [Member] | Commercial Loans [Member] | Business Banking [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing	2,148	1,927
Nonaccrual	4,640	4,860
Current	475,144	465,900
Recorded total loans	481,932	472,687
Originated Loans [Member] | Commercial Loans [Member] | Business Banking [Member] | 31-60 Days Past Due Accruing [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing	2,057	1,609
Originated Loans [Member] | Commercial Loans [Member] | Business Banking [Member] | 61-90 Days Past Due Accruing [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing	91	318
Originated Loans [Member] | Commercial Loans [Member] | Business Banking [Member] | Greater Than 90 Days Past Due Accruing [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing	0	0
Originated Loans [Member] | Consumer Loans [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing	30,538	31,543
Nonaccrual	4,937	5,103
Current	2,118,609	2,049,790
Recorded total loans	2,154,084	2,086,436
Originated Loans [Member] | Consumer Loans [Member] | 31-60 Days Past Due Accruing [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing	22,007	23,121
Originated Loans [Member] | Consumer Loans [Member] | 61-90 Days Past Due Accruing [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing	5,787	5,375
Originated Loans [Member] | Consumer Loans [Member] | Greater Than 90 Days Past Due Accruing [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing	2,744	3,047
Originated Loans [Member] | Consumer Loans [Member] | Indirect [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing	26,319	25,937
Nonaccrual	2,069	2,145
Current	1,602,890	1,538,593
Recorded total loans	1,631,278	1,566,675
Originated Loans [Member] | Consumer Loans [Member] | Indirect [Member] | 31-60 Days Past Due Accruing [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing	18,755	19,253
Originated Loans [Member] | Consumer Loans [Member] | Indirect [Member] | 61-90 Days Past Due Accruing [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing	5,112	4,185
Originated Loans [Member] | Consumer Loans [Member] | Indirect [Member] | Greater Than 90 Days Past Due Accruing [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing	2,452	2,499
Originated Loans [Member] | Consumer Loans [Member] | Home Equity [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing	3,774	5,009
Nonaccrual	2,790	2,851
Current	452,189	448,797
Recorded total loans	458,753	456,657
Originated Loans [Member] | Consumer Loans [Member] | Home Equity [Member] | 31-60 Days Past Due Accruing [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing	2,933	3,416
Originated Loans [Member] | Consumer Loans [Member] | Home Equity [Member] | 61-90 Days Past Due Accruing [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing	628	1,065
Originated Loans [Member] | Consumer Loans [Member] | Home Equity [Member] | Greater Than 90 Days Past Due Accruing [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing	213	528
Originated Loans [Member] | Consumer Loans [Member] | Direct [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing	445	597
Nonaccrual	78	107
Current	63,530	62,400
Recorded total loans	64,053	63,104
Originated Loans [Member] | Consumer Loans [Member] | Direct [Member] | 31-60 Days Past Due Accruing [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing	319	452
Originated Loans [Member] | Consumer Loans [Member] | Direct [Member] | 61-90 Days Past Due Accruing [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing	47	125
Originated Loans [Member] | Consumer Loans [Member] | Direct [Member] | Greater Than 90 Days Past Due Accruing [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing	79	20
Originated Loans [Member] | Residential Real Estate Mortgages [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing	4,655	4,303
Nonaccrual	6,180	6,682
Current	1,114,349	1,052,158
Recorded total loans	1,125,184	1,063,143
Originated Loans [Member] | Residential Real Estate Mortgages [Member] | 31-60 Days Past Due Accruing [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing	3,812	2,725
Originated Loans [Member] | Residential Real Estate Mortgages [Member] | 61-90 Days Past Due Accruing [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing	246	172
Originated Loans [Member] | Residential Real Estate Mortgages [Member] | Greater Than 90 Days Past Due Accruing [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing	597	1,406
Acquired Loans [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing	1,839	1,674
Nonaccrual	3,197	5,635
Current	416,787	492,785
Recorded total loans	421,823	500,094
Acquired Loans [Member] | 31-60 Days Past Due Accruing [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing	1,383	1,229
Acquired Loans [Member] | 61-90 Days Past Due Accruing [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing	409	88
Acquired Loans [Member] | Greater Than 90 Days Past Due Accruing [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing	47	357
Acquired Loans [Member] | Commercial Loans [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing	630	236
Nonaccrual	1,274	2,695
Current	194,540	234,687
Recorded total loans	196,444	237,618
Acquired Loans [Member] | Commercial Loans [Member] | 31-60 Days Past Due Accruing [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing	355	236
Acquired Loans [Member] | Commercial Loans [Member] | 61-90 Days Past Due Accruing [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing	275	0
Acquired Loans [Member] | Commercial Loans [Member] | Greater Than 90 Days Past Due Accruing [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing	0	0
Acquired Loans [Member] | Commercial Loans [Member] | Commercial [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing	0	0
Nonaccrual	0	0
Current	39,037	49,447
Recorded total loans	39,037	49,447
Acquired Loans [Member] | Commercial Loans [Member] | Commercial [Member] | 31-60 Days Past Due Accruing [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing	0	0
Acquired Loans [Member] | Commercial Loans [Member] | Commercial [Member] | 61-90 Days Past Due Accruing [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing	0	0
Acquired Loans [Member] | Commercial Loans [Member] | Commercial [Member] | Greater Than 90 Days Past Due Accruing [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing	0	0
Acquired Loans [Member] | Commercial Loans [Member] | Commercial Real Estate [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing	0	0
Nonaccrual	501	1,891
Current	112,810	135,398
Recorded total loans	113,311	137,289
Acquired Loans [Member] | Commercial Loans [Member] | Commercial Real Estate [Member] | 31-60 Days Past Due Accruing [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing	0	0
Acquired Loans [Member] | Commercial Loans [Member] | Commercial Real Estate [Member] | 61-90 Days Past Due Accruing [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing	0	0
Acquired Loans [Member] | Commercial Loans [Member] | Commercial Real Estate [Member] | Greater Than 90 Days Past Due Accruing [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing	0	0
Acquired Loans [Member] | Commercial Loans [Member] | Business Banking [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing	630	236
Nonaccrual	773	804
Current	42,693	49,842
Recorded total loans	44,096	50,882
Acquired Loans [Member] | Commercial Loans [Member] | Business Banking [Member] | 31-60 Days Past Due Accruing [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing	355	236
Acquired Loans [Member] | Commercial Loans [Member] | Business Banking [Member] | 61-90 Days Past Due Accruing [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing	275	0
Acquired Loans [Member] | Commercial Loans [Member] | Business Banking [Member] | Greater Than 90 Days Past Due Accruing [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing	0	0
Acquired Loans [Member] | Consumer Loans [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing	412	474
Nonaccrual	198	304
Current	47,376	62,227
Recorded total loans	47,986	63,005
Acquired Loans [Member] | Consumer Loans [Member] | 31-60 Days Past Due Accruing [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing	368	384
Acquired Loans [Member] | Consumer Loans [Member] | 61-90 Days Past Due Accruing [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing	34	60
Acquired Loans [Member] | Consumer Loans [Member] | Greater Than 90 Days Past Due Accruing [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing	10	30
Acquired Loans [Member] | Consumer Loans [Member] | Indirect [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing	40	105
Nonaccrual	30	47
Current	2,084	8,541
Recorded total loans	2,154	8,693
Acquired Loans [Member] | Consumer Loans [Member] | Indirect [Member] | 31-60 Days Past Due Accruing [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing	29	100
Acquired Loans [Member] | Consumer Loans [Member] | Indirect [Member] | 61-90 Days Past Due Accruing [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing	8	5
Acquired Loans [Member] | Consumer Loans [Member] | Indirect [Member] | Greater Than 90 Days Past Due Accruing [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing	3	0
Acquired Loans [Member] | Consumer Loans [Member] | Home Equity [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing	307	337
Nonaccrual	160	237
Current	42,510	50,553
Recorded total loans	42,977	51,127
Acquired Loans [Member] | Consumer Loans [Member] | Home Equity [Member] | 31-60 Days Past Due Accruing [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing	307	254
Acquired Loans [Member] | Consumer Loans [Member] | Home Equity [Member] | 61-90 Days Past Due Accruing [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing	0	53
Acquired Loans [Member] | Consumer Loans [Member] | Home Equity [Member] | Greater Than 90 Days Past Due Accruing [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing	0	30
Acquired Loans [Member] | Consumer Loans [Member] | Direct [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing	65	32
Nonaccrual	8	20
Current	2,782	3,133
Recorded total loans	2,855	3,185
Acquired Loans [Member] | Consumer Loans [Member] | Direct [Member] | 31-60 Days Past Due Accruing [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing	32	30
Acquired Loans [Member] | Consumer Loans [Member] | Direct [Member] | 61-90 Days Past Due Accruing [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing	26	2
Acquired Loans [Member] | Consumer Loans [Member] | Direct [Member] | Greater Than 90 Days Past Due Accruing [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing	7	0
Acquired Loans [Member] | Residential Real Estate Mortgages [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing	797	964
Nonaccrual	1,725	2,636
Current	174,871	195,871
Recorded total loans	177,393	199,471
Acquired Loans [Member] | Residential Real Estate Mortgages [Member] | 31-60 Days Past Due Accruing [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing	660	609
Acquired Loans [Member] | Residential Real Estate Mortgages [Member] | 61-90 Days Past Due Accruing [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing	100	28
Acquired Loans [Member] | Residential Real Estate Mortgages [Member] | Greater Than 90 Days Past Due Accruing [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing	$ 37	$ 327

Allowance for Loan Losses and39

Allowance for Loan Losses and Credit Quality of Loans, Impaired Loans (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Allowance for Loan Losses and Credit Quality of Loans [Abstract]
Threshold balance for classified loans to be evaluated individually for impairment	$ 800
Total [Abstract]
Recorded investment balance (book)	19,736	$ 28,874
Unpaid principal balance (legal)	26,355	31,582
Related allowance	30	1,517
Originated Loans [Member]
With no related allowance recorded [Abstract]
Recorded investment balance (book)	19,658	21,912
Unpaid principal balance (legal)	26,272	24,321
Originated Loans [Member] | Commercial Loans [Member]
With no related allowance recorded [Abstract]
Recorded investment balance (book)	4,777	7,313
Unpaid principal balance (legal)	7,709	7,970
With an allowance recorded [Abstract]
Recorded investment balance (book)	78	5,757
Unpaid principal balance (legal)	83	5,940
Total [Abstract]
Related allowance	30	826
Originated Loans [Member] | Commercial Loans [Member] | Commercial [Member]
With no related allowance recorded [Abstract]
Recorded investment balance (book)	0	1,278
Unpaid principal balance (legal)	251	1,697
Originated Loans [Member] | Commercial Loans [Member] | Commercial Real Estate [Member]
With no related allowance recorded [Abstract]
Recorded investment balance (book)	2,239	3,816
Unpaid principal balance (legal)	3,996	3,841
With an allowance recorded [Abstract]
Recorded investment balance (book)	78	5,553
Unpaid principal balance (legal)	83	5,736
Total [Abstract]
Related allowance	30	735
Originated Loans [Member] | Commercial Loans [Member] | Agricultural [Member]
With no related allowance recorded [Abstract]
Recorded investment balance (book)	100	130
Unpaid principal balance (legal)	112	137
With an allowance recorded [Abstract]
Recorded investment balance (book)	0	49
Unpaid principal balance (legal)	0	49
Total [Abstract]
Related allowance	0	37
Originated Loans [Member] | Commercial Loans [Member] | Agricultural Real Estate [Member]
With no related allowance recorded [Abstract]
Recorded investment balance (book)	1,491	1,434
Unpaid principal balance (legal)	1,663	1,567
With an allowance recorded [Abstract]
Recorded investment balance (book)	0	155
Unpaid principal balance (legal)	0	155
Total [Abstract]
Related allowance	0	54
Originated Loans [Member] | Commercial Loans [Member] | Business Banking [Member]
With no related allowance recorded [Abstract]
Recorded investment balance (book)	947	655
Unpaid principal balance (legal)	1,687	728
Originated Loans [Member] | Consumer Loans [Member]
With no related allowance recorded [Abstract]
Recorded investment balance (book)	8,307	8,488
Unpaid principal balance (legal)	10,228	9,445
Originated Loans [Member] | Consumer Loans [Member] | Indirect [Member]
With no related allowance recorded [Abstract]
Recorded investment balance (book)	36	5
Unpaid principal balance (legal)	47	16
Originated Loans [Member] | Consumer Loans [Member] | Home Equity [Member]
With no related allowance recorded [Abstract]
Recorded investment balance (book)	8,153	8,483
Unpaid principal balance (legal)	10,063	9,429
Originated Loans [Member] | Consumer Loans [Member] | Direct [Member]
With no related allowance recorded [Abstract]
Recorded investment balance (book)	118	0
Unpaid principal balance (legal)	118	0
Originated Loans [Member] | Residential Real Estate Mortgages [Member]
With no related allowance recorded [Abstract]
Recorded investment balance (book)	6,574	6,111
Unpaid principal balance (legal)	8,335	6,906
Acquired Loans [Member] | Commercial Loans [Member]
With an allowance recorded [Abstract]
Recorded investment balance (book)	0	1,205
Unpaid principal balance (legal)	0	1,321
Total [Abstract]
Related allowance	0	691
Acquired Loans [Member] | Commercial Loans [Member] | Commercial Real Estate [Member]
With an allowance recorded [Abstract]
Recorded investment balance (book)	0	1,205
Unpaid principal balance (legal)	0	1,321
Total [Abstract]
Related allowance	$ 0	$ 691

Allowance for Loan Losses and40

Allowance for Loan Losses and Credit Quality of Loans, Average Recorded Investments on Loans Specifically Evaluated for Impairment and Interest Income Recognized (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Financing Receivable, Impaired [Line Items]
Average recorded investment	$ 20,936	$ 36,521	$ 23,789	$ 35,116
Interest income recognized	257	251	679	731
Originated Loans [Member]
Financing Receivable, Impaired [Line Items]
Average recorded investment	20,936	35,316	23,668	33,911
Interest income recognized	257	251	679	731
Originated Loans [Member] | Commercial Loans [Member] | Commercial [Member]
Financing Receivable, Impaired [Line Items]
Average recorded investment	1,000	3,204	2,393	3,041
Interest income recognized	0	0	0	0
Originated Loans [Member] | Commercial Loans [Member] | Commercial Real Estate [Member]
Financing Receivable, Impaired [Line Items]
Average recorded investment	2,415	15,799	3,906	14,782
Interest income recognized	48	48	93	122
Originated Loans [Member] | Commercial Loans [Member] | Agricultural [Member]
Financing Receivable, Impaired [Line Items]
Average recorded investment	115	85	147	101
Interest income recognized	0	0	1	1
Originated Loans [Member] | Commercial Loans [Member] | Agricultural Real Estate [Member]
Financing Receivable, Impaired [Line Items]
Average recorded investment	1,505	935	1,545	742
Interest income recognized	11	11	32	33
Originated Loans [Member] | Commercial Loans [Member] | Business Banking [Member]
Financing Receivable, Impaired [Line Items]
Average recorded investment	955	743	837	882
Interest income recognized	2	0	7	7
Originated Loans [Member] | Consumer Loans [Member] | Indirect [Member]
Financing Receivable, Impaired [Line Items]
Average recorded investment	35	8	22	9
Interest income recognized	1	0	2	0
Originated Loans [Member] | Consumer Loans [Member] | Home Equity [Member]
Financing Receivable, Impaired [Line Items]
Average recorded investment	8,159	8,401	8,274	8,207
Interest income recognized	111	116	331	357
Originated Loans [Member] | Consumer Loans [Member] | Direct [Member]
Financing Receivable, Impaired [Line Items]
Average recorded investment	119	0	119	0
Interest income recognized	2	0	2	0
Originated Loans [Member] | Residential Real Estate Mortgages [Member]
Financing Receivable, Impaired [Line Items]
Average recorded investment	6,633	6,141	6,425	6,147
Interest income recognized	82	76	211	211
Acquired Loans [Member]
Financing Receivable, Impaired [Line Items]
Average recorded investment	0	1,205	121	1,205
Interest income recognized	0	0	0	0
Acquired Loans [Member] | Commercial Loans [Member] | Commercial Real Estate [Member]
Financing Receivable, Impaired [Line Items]
Average recorded investment	0	1,205	121	1,205
Interest income recognized	$ 0	$ 0	$ 0	$ 0

Allowance for Loan Losses and41

Allowance for Loan Losses and Credit Quality of Loans, Credit Quality by Loan Class (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Financing Receivable, Recorded Investment [Line Items]
Net loans	$ 6,466,934	$ 6,198,057
Commercial Credit Exposure [Member]
Financing Receivable, Recorded Investment [Line Items]
Net loans	2,962,287	2,786,002
Consumer Credit Exposure [Member]
Financing Receivable, Recorded Investment [Line Items]
Net loans	2,202,070	2,149,441
Residential Mortgage Credit Exposure [Member]
Financing Receivable, Recorded Investment [Line Items]
Net loans	1,302,577	1,262,614
Originated Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Net loans	6,045,111	5,697,963
Originated Loans [Member] | Commercial Credit Exposure [Member]
Financing Receivable, Recorded Investment [Line Items]
Net loans	2,765,843	2,548,384
Originated Loans [Member] | Commercial Credit Exposure [Member] | Total Commercial and Agricultural [Member]
Financing Receivable, Recorded Investment [Line Items]
Net loans	2,283,911	2,075,697
Originated Loans [Member] | Commercial Credit Exposure [Member] | Total Commercial and Agricultural [Member] | Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Net loans	2,158,075	1,970,912
Originated Loans [Member] | Commercial Credit Exposure [Member] | Total Commercial and Agricultural [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Net loans	76,284	40,724
Originated Loans [Member] | Commercial Credit Exposure [Member] | Total Commercial and Agricultural [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Net loans	49,552	64,056
Originated Loans [Member] | Commercial Credit Exposure [Member] | Total Commercial and Agricultural [Member] | Doubtful [Member]
Financing Receivable, Recorded Investment [Line Items]
Net loans	0	5
Originated Loans [Member] | Commercial Credit Exposure [Member] | Commercial [Member]
Financing Receivable, Recorded Investment [Line Items]
Net loans	733,122	653,570
Originated Loans [Member] | Commercial Credit Exposure [Member] | Commercial [Member] | Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Net loans	677,943	616,829
Originated Loans [Member] | Commercial Credit Exposure [Member] | Commercial [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Net loans	40,123	7,750
Originated Loans [Member] | Commercial Credit Exposure [Member] | Commercial [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Net loans	15,056	28,991
Originated Loans [Member] | Commercial Credit Exposure [Member] | Commercial [Member] | Doubtful [Member]
Financing Receivable, Recorded Investment [Line Items]
Net loans	0	0
Originated Loans [Member] | Commercial Credit Exposure [Member] | Commercial Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Net loans	1,480,559	1,351,789
Originated Loans [Member] | Commercial Credit Exposure [Member] | Commercial Real Estate [Member] | Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Net loans	1,424,353	1,288,409
Originated Loans [Member] | Commercial Credit Exposure [Member] | Commercial Real Estate [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Net loans	29,785	31,053
Originated Loans [Member] | Commercial Credit Exposure [Member] | Commercial Real Estate [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Net loans	26,421	32,327
Originated Loans [Member] | Commercial Credit Exposure [Member] | Commercial Real Estate [Member] | Doubtful [Member]
Financing Receivable, Recorded Investment [Line Items]
Net loans	0	0
Originated Loans [Member] | Commercial Credit Exposure [Member] | Agricultural [Member]
Financing Receivable, Recorded Investment [Line Items]
Net loans	34,839	37,916
Originated Loans [Member] | Commercial Credit Exposure [Member] | Agricultural [Member] | Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Net loans	30,233	36,762
Originated Loans [Member] | Commercial Credit Exposure [Member] | Agricultural [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Net loans	3,033	25
Originated Loans [Member] | Commercial Credit Exposure [Member] | Agricultural [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Net loans	1,573	1,124
Originated Loans [Member] | Commercial Credit Exposure [Member] | Agricultural [Member] | Doubtful [Member]
Financing Receivable, Recorded Investment [Line Items]
Net loans	0	5
Originated Loans [Member] | Commercial Credit Exposure [Member] | Agricultural Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Net loans	35,391	32,422
Originated Loans [Member] | Commercial Credit Exposure [Member] | Agricultural Real Estate [Member] | Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Net loans	25,546	28,912
Originated Loans [Member] | Commercial Credit Exposure [Member] | Agricultural Real Estate [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Net loans	3,343	1,896
Originated Loans [Member] | Commercial Credit Exposure [Member] | Agricultural Real Estate [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Net loans	6,502	1,614
Originated Loans [Member] | Commercial Credit Exposure [Member] | Agricultural Real Estate [Member] | Doubtful [Member]
Financing Receivable, Recorded Investment [Line Items]
Net loans	0	0
Originated Loans [Member] | Commercial Credit Exposure [Member] | Business Banking [Member]
Financing Receivable, Recorded Investment [Line Items]
Net loans	481,932	472,687
Originated Loans [Member] | Business Banking Credit Exposure [Member]
Financing Receivable, Recorded Investment [Line Items]
Net loans	481,932	472,687
Originated Loans [Member] | Business Banking Credit Exposure [Member] | Non-classified [Member]
Financing Receivable, Recorded Investment [Line Items]
Net loans	469,025	458,864
Originated Loans [Member] | Business Banking Credit Exposure [Member] | Classified [Member]
Financing Receivable, Recorded Investment [Line Items]
Net loans	12,907	13,823
Originated Loans [Member] | Business Banking Credit Exposure [Member] | Business Banking [Member]
Financing Receivable, Recorded Investment [Line Items]
Net loans	481,932	472,687
Originated Loans [Member] | Business Banking Credit Exposure [Member] | Business Banking [Member] | Non-classified [Member]
Financing Receivable, Recorded Investment [Line Items]
Net loans	469,025	458,864
Originated Loans [Member] | Business Banking Credit Exposure [Member] | Business Banking [Member] | Classified [Member]
Financing Receivable, Recorded Investment [Line Items]
Net loans	12,907	13,823
Originated Loans [Member] | Consumer Credit Exposure [Member]
Financing Receivable, Recorded Investment [Line Items]
Net loans	2,154,084	2,086,436
Originated Loans [Member] | Consumer Credit Exposure [Member] | Performing [Member]
Financing Receivable, Recorded Investment [Line Items]
Net loans	2,146,403	2,078,286
Originated Loans [Member] | Consumer Credit Exposure [Member] | Nonperforming [Member]
Financing Receivable, Recorded Investment [Line Items]
Net loans	7,681	8,150
Originated Loans [Member] | Consumer Credit Exposure [Member] | Indirect [Member]
Financing Receivable, Recorded Investment [Line Items]
Net loans	1,631,278	1,566,675
Originated Loans [Member] | Consumer Credit Exposure [Member] | Indirect [Member] | Performing [Member]
Financing Receivable, Recorded Investment [Line Items]
Net loans	1,626,757	1,562,031
Originated Loans [Member] | Consumer Credit Exposure [Member] | Indirect [Member] | Nonperforming [Member]
Financing Receivable, Recorded Investment [Line Items]
Net loans	4,521	4,644
Originated Loans [Member] | Consumer Credit Exposure [Member] | Home Equity [Member]
Financing Receivable, Recorded Investment [Line Items]
Net loans	458,753	456,657
Originated Loans [Member] | Consumer Credit Exposure [Member] | Home Equity [Member] | Performing [Member]
Financing Receivable, Recorded Investment [Line Items]
Net loans	455,750	453,278
Originated Loans [Member] | Consumer Credit Exposure [Member] | Home Equity [Member] | Nonperforming [Member]
Financing Receivable, Recorded Investment [Line Items]
Net loans	3,003	3,379
Originated Loans [Member] | Consumer Credit Exposure [Member] | Direct [Member]
Financing Receivable, Recorded Investment [Line Items]
Net loans	64,053	63,104
Originated Loans [Member] | Consumer Credit Exposure [Member] | Direct [Member] | Performing [Member]
Financing Receivable, Recorded Investment [Line Items]
Net loans	63,896	62,977
Originated Loans [Member] | Consumer Credit Exposure [Member] | Direct [Member] | Nonperforming [Member]
Financing Receivable, Recorded Investment [Line Items]
Net loans	157	127
Originated Loans [Member] | Residential Mortgage Credit Exposure [Member]
Financing Receivable, Recorded Investment [Line Items]
Net loans	1,125,184	1,063,143
Originated Loans [Member] | Residential Mortgage Credit Exposure [Member] | Performing [Member]
Financing Receivable, Recorded Investment [Line Items]
Net loans	1,118,407	1,055,055
Originated Loans [Member] | Residential Mortgage Credit Exposure [Member] | Nonperforming [Member]
Financing Receivable, Recorded Investment [Line Items]
Net loans	6,777	8,088
Originated Loans [Member] | Residential Mortgage Credit Exposure [Member] | Residential Mortgage [Member]
Financing Receivable, Recorded Investment [Line Items]
Net loans	1,125,184	1,063,143
Originated Loans [Member] | Residential Mortgage Credit Exposure [Member] | Residential Mortgage [Member] | Performing [Member]
Financing Receivable, Recorded Investment [Line Items]
Net loans	1,118,407	1,055,055
Originated Loans [Member] | Residential Mortgage Credit Exposure [Member] | Residential Mortgage [Member] | Nonperforming [Member]
Financing Receivable, Recorded Investment [Line Items]
Net loans	6,777	8,088
Acquired Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Net loans	421,823	500,094
Acquired Loans [Member] | Commercial Credit Exposure [Member]
Financing Receivable, Recorded Investment [Line Items]
Net loans	196,444	237,618
Acquired Loans [Member] | Commercial Credit Exposure [Member] | Total Commercial and Agricultural [Member]
Financing Receivable, Recorded Investment [Line Items]
Net loans	152,348	186,736
Acquired Loans [Member] | Commercial Credit Exposure [Member] | Total Commercial and Agricultural [Member] | Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Net loans	143,532	175,854
Acquired Loans [Member] | Commercial Credit Exposure [Member] | Total Commercial and Agricultural [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Net loans	839	1,307
Acquired Loans [Member] | Commercial Credit Exposure [Member] | Total Commercial and Agricultural [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Net loans	7,977	8,370
Acquired Loans [Member] | Commercial Credit Exposure [Member] | Total Commercial and Agricultural [Member] | Doubtful [Member]
Financing Receivable, Recorded Investment [Line Items]
Net loans		1,205
Acquired Loans [Member] | Commercial Credit Exposure [Member] | Commercial [Member]
Financing Receivable, Recorded Investment [Line Items]
Net loans	39,037	49,447
Acquired Loans [Member] | Commercial Credit Exposure [Member] | Commercial [Member] | Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Net loans	37,271	48,194
Acquired Loans [Member] | Commercial Credit Exposure [Member] | Commercial [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Net loans	327	76
Acquired Loans [Member] | Commercial Credit Exposure [Member] | Commercial [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Net loans	1,439	1,177
Acquired Loans [Member] | Commercial Credit Exposure [Member] | Commercial [Member] | Doubtful [Member]
Financing Receivable, Recorded Investment [Line Items]
Net loans		0
Acquired Loans [Member] | Commercial Credit Exposure [Member] | Commercial Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Net loans	113,311	137,289
Acquired Loans [Member] | Commercial Credit Exposure [Member] | Commercial Real Estate [Member] | Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Net loans	106,261	127,660
Acquired Loans [Member] | Commercial Credit Exposure [Member] | Commercial Real Estate [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Net loans	512	1,231
Acquired Loans [Member] | Commercial Credit Exposure [Member] | Commercial Real Estate [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Net loans	6,538	7,193
Acquired Loans [Member] | Commercial Credit Exposure [Member] | Commercial Real Estate [Member] | Doubtful [Member]
Financing Receivable, Recorded Investment [Line Items]
Net loans		1,205
Acquired Loans [Member] | Commercial Credit Exposure [Member] | Business Banking [Member]
Financing Receivable, Recorded Investment [Line Items]
Net loans	44,096	50,882
Acquired Loans [Member] | Business Banking Credit Exposure [Member]
Financing Receivable, Recorded Investment [Line Items]
Net loans	44,096	50,882
Acquired Loans [Member] | Business Banking Credit Exposure [Member] | Non-classified [Member]
Financing Receivable, Recorded Investment [Line Items]
Net loans	40,636	47,347
Acquired Loans [Member] | Business Banking Credit Exposure [Member] | Classified [Member]
Financing Receivable, Recorded Investment [Line Items]
Net loans	3,460	3,535
Acquired Loans [Member] | Business Banking Credit Exposure [Member] | Business Banking [Member]
Financing Receivable, Recorded Investment [Line Items]
Net loans	44,096	50,882
Acquired Loans [Member] | Business Banking Credit Exposure [Member] | Business Banking [Member] | Non-classified [Member]
Financing Receivable, Recorded Investment [Line Items]
Net loans	40,636	47,347
Acquired Loans [Member] | Business Banking Credit Exposure [Member] | Business Banking [Member] | Classified [Member]
Financing Receivable, Recorded Investment [Line Items]
Net loans	3,460	3,535
Acquired Loans [Member] | Consumer Credit Exposure [Member]
Financing Receivable, Recorded Investment [Line Items]
Net loans	47,986	63,005
Acquired Loans [Member] | Consumer Credit Exposure [Member] | Performing [Member]
Financing Receivable, Recorded Investment [Line Items]
Net loans	47,778	62,671
Acquired Loans [Member] | Consumer Credit Exposure [Member] | Nonperforming [Member]
Financing Receivable, Recorded Investment [Line Items]
Net loans	208	334
Acquired Loans [Member] | Consumer Credit Exposure [Member] | Indirect [Member]
Financing Receivable, Recorded Investment [Line Items]
Net loans	2,154	8,693
Acquired Loans [Member] | Consumer Credit Exposure [Member] | Indirect [Member] | Performing [Member]
Financing Receivable, Recorded Investment [Line Items]
Net loans	2,121	8,646
Acquired Loans [Member] | Consumer Credit Exposure [Member] | Indirect [Member] | Nonperforming [Member]
Financing Receivable, Recorded Investment [Line Items]
Net loans	33	47
Acquired Loans [Member] | Consumer Credit Exposure [Member] | Home Equity [Member]
Financing Receivable, Recorded Investment [Line Items]
Net loans	42,977	51,127
Acquired Loans [Member] | Consumer Credit Exposure [Member] | Home Equity [Member] | Performing [Member]
Financing Receivable, Recorded Investment [Line Items]
Net loans	42,817	50,860
Acquired Loans [Member] | Consumer Credit Exposure [Member] | Home Equity [Member] | Nonperforming [Member]
Financing Receivable, Recorded Investment [Line Items]
Net loans	160	267
Acquired Loans [Member] | Consumer Credit Exposure [Member] | Direct [Member]
Financing Receivable, Recorded Investment [Line Items]
Net loans	2,855	3,185
Acquired Loans [Member] | Consumer Credit Exposure [Member] | Direct [Member] | Performing [Member]
Financing Receivable, Recorded Investment [Line Items]
Net loans	2,840	3,165
Acquired Loans [Member] | Consumer Credit Exposure [Member] | Direct [Member] | Nonperforming [Member]
Financing Receivable, Recorded Investment [Line Items]
Net loans	15	20
Acquired Loans [Member] | Residential Mortgage Credit Exposure [Member]
Financing Receivable, Recorded Investment [Line Items]
Net loans	177,393	199,471
Acquired Loans [Member] | Residential Mortgage Credit Exposure [Member] | Performing [Member]
Financing Receivable, Recorded Investment [Line Items]
Net loans	175,631	196,508
Acquired Loans [Member] | Residential Mortgage Credit Exposure [Member] | Nonperforming [Member]
Financing Receivable, Recorded Investment [Line Items]
Net loans	1,762	2,963
Acquired Loans [Member] | Residential Mortgage Credit Exposure [Member] | Residential Mortgage [Member]
Financing Receivable, Recorded Investment [Line Items]
Net loans	177,393	199,471
Acquired Loans [Member] | Residential Mortgage Credit Exposure [Member] | Residential Mortgage [Member] | Performing [Member]
Financing Receivable, Recorded Investment [Line Items]
Net loans	175,631	196,508
Acquired Loans [Member] | Residential Mortgage Credit Exposure [Member] | Residential Mortgage [Member] | Nonperforming [Member]
Financing Receivable, Recorded Investment [Line Items]
Net loans	$ 1,762	$ 2,963

Allowance for Loan Losses and42

Allowance for Loan Losses and Credit Quality of Loans, Troubled Debt Restructurings (Details) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017USD ($)Contract	Sep. 30, 2016USD ($)Contract	Sep. 30, 2017USD ($)Contract	Sep. 30, 2016USD ($)Contract
Financing Receivable, Modifications [Line Items]
Number of contracts | Contract	6	14	23	34
Pre-modification outstanding recorded investment	$ 714	$ 810	$ 5,235	$ 2,604
Post-modification outstanding recorded investment	$ 747	$ 682	$ 5,211	$ 2,259
Number of TDR loans with subsequent default | Contract	19	26	46	47
Outstanding recorded investment on TDR loans with subsequent default	$ 1,181	$ 1,501	$ 2,691	$ 2,945
Commercial Loans [Member]
Financing Receivable, Modifications [Line Items]
Number of contracts | Contract			2
Pre-modification outstanding recorded investment			$ 3,637
Post-modification outstanding recorded investment			$ 3,572
Number of TDR loans with subsequent default | Contract	0	1	2	2
Outstanding recorded investment on TDR loans with subsequent default	$ 0	$ 169	$ 474	$ 236
Commercial Loans [Member] | Commercial [Member]
Financing Receivable, Modifications [Line Items]
Number of contracts | Contract			1
Pre-modification outstanding recorded investment			$ 3,300
Post-modification outstanding recorded investment			$ 3,239
Number of TDR loans with subsequent default | Contract	0	1	1	1
Outstanding recorded investment on TDR loans with subsequent default	$ 0	$ 169	$ 145	$ 169
Commercial Loans [Member] | Business Banking [Member]
Financing Receivable, Modifications [Line Items]
Number of contracts | Contract			1
Pre-modification outstanding recorded investment			$ 337
Post-modification outstanding recorded investment			$ 333
Number of TDR loans with subsequent default | Contract			1	1
Outstanding recorded investment on TDR loans with subsequent default			$ 329	$ 67
Consumer Loans [Member]
Financing Receivable, Modifications [Line Items]
Number of contracts | Contract	5	10	13	24
Pre-modification outstanding recorded investment	$ 196	$ 580	$ 532	$ 1,690
Post-modification outstanding recorded investment	$ 229	$ 556	$ 571	$ 1,567
Number of TDR loans with subsequent default | Contract	13	17	32	30
Outstanding recorded investment on TDR loans with subsequent default	$ 635	$ 847	$ 1,400	$ 1,634
Consumer Loans [Member] | Indirect [Member]
Financing Receivable, Modifications [Line Items]
Number of contracts | Contract	1		4
Pre-modification outstanding recorded investment	$ 7		$ 39
Post-modification outstanding recorded investment	$ 7		$ 37
Number of TDR loans with subsequent default | Contract	1	0	2	0
Outstanding recorded investment on TDR loans with subsequent default	$ 13	$ 0	$ 19	$ 0
Consumer Loans [Member] | Home Equity [Member]
Financing Receivable, Modifications [Line Items]
Number of contracts | Contract	4	10	8	24
Pre-modification outstanding recorded investment	$ 189	$ 580	$ 373	$ 1,690
Post-modification outstanding recorded investment	$ 222	$ 556	$ 414	$ 1,567
Number of TDR loans with subsequent default | Contract	12	17	30	30
Outstanding recorded investment on TDR loans with subsequent default	$ 622	$ 847	$ 1,381	$ 1,634
Consumer Loans [Member] | Direct [Member]
Financing Receivable, Modifications [Line Items]
Number of contracts | Contract			1
Pre-modification outstanding recorded investment			$ 120
Post-modification outstanding recorded investment			$ 120
Residential Real Estate Mortgages [Member]
Financing Receivable, Modifications [Line Items]
Number of contracts | Contract	1	4	8	10
Pre-modification outstanding recorded investment	$ 518	$ 230	$ 1,066	$ 914
Post-modification outstanding recorded investment	$ 518	$ 126	$ 1,068	$ 692
Number of TDR loans with subsequent default | Contract	6	8	12	15
Outstanding recorded investment on TDR loans with subsequent default	$ 546	$ 485	$ 817	$ 1,075

Defined Benefit Post-retireme43

Defined Benefit Post-retirement Plans (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Defined Benefit Post-retirement Plans [Abstract]
Employer contributions	$ 0	$ 5,600	$ 0
Pension Benefits [Member] | United States [Member]
Components of net periodic (benefit) cost [Abstract]
Service cost	329	534	1,133	$ 1,654
Interest cost	1,043	1,050	3,127	3,151
Expected return on plan assets	(1,976)	(1,857)	(5,946)	(5,527)
Net amortization	454	504	1,284	1,471
Total (benefit) cost	(150)	231	(402)	749
Other Benefits [Member] | United States [Member]
Components of net periodic (benefit) cost [Abstract]
Service cost	3	3	9	10
Interest cost	88	89	259	277
Expected return on plan assets	0	0	0	0
Net amortization	26	15	66	73
Total (benefit) cost	$ 117	$ 107	$ 334	$ 360

Earnings Per Share (Details)

Earnings Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Basic EPS [Abstract]
Weighted average common shares outstanding (in shares)	43,595,000	43,200,000	43,563,000	43,214,000
Net income available to common stockholders	$ 22,876	$ 20,001	$ 64,514	$ 58,801
Basic EPS (in dollars per share)	$ 0.52	$ 0.46	$ 1.48	$ 1.36
Diluted EPS [Abstract]
Weighted average common shares outstanding (in shares)	43,595,000	43,200,000	43,563,000	43,214,000
Dilutive effect of common stock options and restricted stock (in shares)	320,000	362,000	329,000	366,000
Weighted average common shares and common share equivalents (in shares)	43,915,000	43,562,000	43,892,000	43,580,000
Net income available to common stockholders	$ 22,876	$ 20,001	$ 64,514	$ 58,801
Diluted EPS (in dollars per share)	$ 0.52	$ 0.46	$ 1.47	$ 1.35
Stock Options [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Stock options excluded from calculation of diluted EPS (in shares)	3,250	0	3,014	36,865

Reclassification Adjustments 45

Reclassification Adjustments Out of Other Comprehensive Income (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Net securities gains	$ 4	$ 0	$ 2	$ (30)
Interest income	71,930	66,662	210,042	197,016
Other noninterest income	3,945	4,113	10,069	12,188
Salaries and employee benefits	32,740	32,783	99,081	98,155
Income tax (expense)	(11,342)	(10,303)	(30,321)	(30,291)
Net income	22,876	20,001	64,514	58,801
Reclassification out of Accumulated Other Comprehensive Income [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Total reclassification during the period, net of tax	430	479	2,063	1,439
AOCI Attributable to Parent [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Net income			0	0
Accumulated Net Unrealized Investment Gain (Loss) [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Income tax (expense)	(83)	(105)	(760)	(317)
Net income	133	162	1,229	496
Gains (Losses) on Available for Sale Securities [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Net securities gains	4	0	2	(30)
Amortization of Unrealized Gains and Losses Related to Securities Transfer [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Interest income	212	267	675	843
Impairment Write-Down of Equity Security [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Other noninterest income			1,312	0
Accumulated Defined Benefit Plans Adjustment [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Income tax (expense)	(183)	(202)	(516)	(601)
Net income	297	317	834	943
Amortization of Net Losses [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Salaries and employee benefits	481	565	1,351	1,595
Amortization of Prior Service Costs [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Salaries and employee benefits	$ (1)	$ (46)	$ (1)	$ (51)

Fair Value Measurements and F46

Fair Value Measurements and Fair Value of Financial Instruments (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2017	Dec. 31, 2016
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Transfers from Level 1 to Level 2	$ 0	$ 0
Transfers from Level 2 to Level 1	0	0
Transfers into Level 3	0	0
Transfers out of Level 3	0	0
AFS securities [Abstract]
AFS Securities	1,357,614	1,357,614	$ 1,338,290
Trading securities	10,883	10,883	9,259
Liabilities [Abstract]
Collateral dependent impaired financing receivable with specific reserves	100	100	7,000
Allowance for loan losses for collateral dependent impaired loans with specific reserves	30	$ 30	1,500
Minimum [Member]
Liabilities [Abstract]
Liquidation expense ratio on impaired collateral		10.00%
Maximum [Member]
Liabilities [Abstract]
Liquidation expense ratio on impaired collateral		35.00%
Federal Agency [Member]
AFS securities [Abstract]
AFS Securities	139,418	$ 139,418	174,408
State & Municipal [Member]
AFS securities [Abstract]
AFS Securities	42,919	42,919	46,726
Other Securities [Member]
AFS securities [Abstract]
AFS Securities	19,739	19,739	20,739
Recurring Basis [Member]
AFS securities [Abstract]
AFS Securities	1,357,614	1,357,614	1,338,290
Trading securities	10,883	10,883	9,259
Derivatives	6,653	6,653	3,210
Total	1,375,150	1,375,150	1,350,759
Liabilities [Abstract]
Derivatives	4,128	4,128	506
Total	4,128	4,128	506
Recurring Basis [Member] | Level 1 [Member]
AFS securities [Abstract]
AFS Securities	11,438	11,438	11,493
Trading securities	10,883	10,883	9,259
Derivatives	0	0	0
Total	22,321	22,321	20,752
Liabilities [Abstract]
Derivatives	0	0	0
Total	0	0	0
Recurring Basis [Member] | Level 2 [Member]
AFS securities [Abstract]
AFS Securities	1,346,176	1,346,176	1,326,797
Trading securities	0	0	0
Derivatives	6,653	6,653	3,210
Total	1,352,829	1,352,829	1,330,007
Liabilities [Abstract]
Derivatives	4,128	4,128	506
Total	4,128	4,128	506
Recurring Basis [Member] | Level 3 [Member]
AFS securities [Abstract]
AFS Securities	0	0	0
Trading securities	0	0	0
Derivatives	0	0	0
Total	0	0	0
Liabilities [Abstract]
Derivatives	0	0	0
Total	0	0	0
Recurring Basis [Member] | Federal Agency [Member]
AFS securities [Abstract]
AFS Securities	139,418	139,418	174,408
Recurring Basis [Member] | Federal Agency [Member] | Level 1 [Member]
AFS securities [Abstract]
AFS Securities	0	0	0
Recurring Basis [Member] | Federal Agency [Member] | Level 2 [Member]
AFS securities [Abstract]
AFS Securities	139,418	139,418	174,408
Recurring Basis [Member] | Federal Agency [Member] | Level 3 [Member]
AFS securities [Abstract]
AFS Securities	0	0	0
Recurring Basis [Member] | State & Municipal [Member]
AFS securities [Abstract]
AFS Securities	42,919	42,919	46,726
Recurring Basis [Member] | State & Municipal [Member] | Level 1 [Member]
AFS securities [Abstract]
AFS Securities	0	0	0
Recurring Basis [Member] | State & Municipal [Member] | Level 2 [Member]
AFS securities [Abstract]
AFS Securities	42,919	42,919	46,726
Recurring Basis [Member] | State & Municipal [Member] | Level 3 [Member]
AFS securities [Abstract]
AFS Securities	0	0	0
Recurring Basis [Member] | Mortgage-Backed [Member]
AFS securities [Abstract]
AFS Securities	584,226	584,226	529,844
Recurring Basis [Member] | Mortgage-Backed [Member] | Level 1 [Member]
AFS securities [Abstract]
AFS Securities	0	0	0
Recurring Basis [Member] | Mortgage-Backed [Member] | Level 2 [Member]
AFS securities [Abstract]
AFS Securities	584,226	584,226	529,844
Recurring Basis [Member] | Mortgage-Backed [Member] | Level 3 [Member]
AFS securities [Abstract]
AFS Securities	0	0	0
Recurring Basis [Member] | Collateralized Mortgage Obligations [Member]
AFS securities [Abstract]
AFS Securities	571,312	571,312	566,573
Recurring Basis [Member] | Collateralized Mortgage Obligations [Member] | Level 1 [Member]
AFS securities [Abstract]
AFS Securities	0	0	0
Recurring Basis [Member] | Collateralized Mortgage Obligations [Member] | Level 2 [Member]
AFS securities [Abstract]
AFS Securities	571,312	571,312	566,573
Recurring Basis [Member] | Collateralized Mortgage Obligations [Member] | Level 3 [Member]
AFS securities [Abstract]
AFS Securities	0	0	0
Recurring Basis [Member] | Other Securities [Member]
AFS securities [Abstract]
AFS Securities	19,739	19,739	20,739
Recurring Basis [Member] | Other Securities [Member] | Level 1 [Member]
AFS securities [Abstract]
AFS Securities	11,438	11,438	11,493
Recurring Basis [Member] | Other Securities [Member] | Level 2 [Member]
AFS securities [Abstract]
AFS Securities	8,301	8,301	9,246
Recurring Basis [Member] | Other Securities [Member] | Level 3 [Member]
AFS securities [Abstract]
AFS Securities	$ 0	$ 0	$ 0

Fair Value Measurements and F47

Fair Value Measurements and Fair Value of Financial Instruments, Estimated Fair Values of Financial Instruments (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Financial assets [Abstract]
HTM securities	$ 495,411	$ 525,050
Financial liabilities [Abstract]
Time deposits	776,756	872,411
Long-term debt	88,914	104,087
Junior subordinated debt	101,196	101,196
Carrying Amount [Member] | Level 2 [Member]
Financial assets [Abstract]
HTM securities	494,309	527,948
Financial liabilities [Abstract]
Time deposits	776,756	872,411
Long-term debt	88,914	104,087
Junior subordinated debt	101,196	101,196
Carrying Amount [Member] | Level 3 [Member]
Financial assets [Abstract]
Net loans	6,398,584	6,132,857
Estimated Fair Value [Member] | Level 2 [Member]
Financial assets [Abstract]
HTM securities	495,411	525,050
Financial liabilities [Abstract]
Time deposits	773,160	868,153
Long-term debt	88,948	104,113
Junior subordinated debt	104,584	102,262
Estimated Fair Value [Member] | Level 3 [Member]
Financial assets [Abstract]
Net loans	6,557,674	6,273,233
Not Designated as Hedging Instrument [Member] | Interest Rate Swaps [Member] | Other Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative asset, notional amount	469,800	371,100
Fair value of derivative asset	3,900	300
Not Designated as Hedging Instrument [Member] | Interest Rate Swaps [Member] | Other Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative liability, notional amount	469,800	371,100
Fair value of derivative liability	3,900	300
Designated as Hedging Instrument [Member] | Cash Flow Hedging [Member] | Interest Rate Swaps [Member]
Derivatives, Fair Value [Line Items]
Notional amount	250,000	250,000
Designated as Hedging Instrument [Member] | Cash Flow Hedging [Member] | Interest Rate Swaps [Member] | Other Assets [Member]
Derivatives, Fair Value [Line Items]
Fair value of derivative asset	2,700	2,900
Designated as Hedging Instrument [Member] | Cash Flow Hedging [Member] | Interest Rate Swaps [Member] | Other Liabilities [Member]
Derivatives, Fair Value [Line Items]
Fair value of derivative liability	$ 200	$ 200

Commitments and Contingencies (

Commitments and Contingencies (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2017	Dec. 31, 2016
Commitment to Extend Credits and Unused Lines of Credit [Member]
Guarantor Obligations [Line Items]
Commitments - maximum potential obligation	$ 1,600	$ 1,500
Standby Letters of Credit [Member]
Guarantor Obligations [Line Items]
Obligation instrument term	5 years
Commitments - maximum potential obligation	$ 40.9	$ 36.8