First Merchants (FRME) 10-Q 10 May 18 2018 Q1 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	3 Months Ended
	Mar. 31, 2018	Apr. 30, 2018
Document and Entity Information [Abstract]
Entity Registrant Name	FIRST MERCHANTS CORP
Entity Central Index Key	712,534
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Document Type	10-Q
Document Period End Date	Mar. 31, 2018
Document Fiscal Year Focus	2,018
Document Fiscal Period Focus	Q1
Trading Symbol	FRME
Amendment Flag	false
Entity Common Stock, Shares Outstanding		49,522,136

CONSOLIDATED CONDENSED BALANCE

CONSOLIDATED CONDENSED BALANCE SHEETS - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
ASSETS
Cash and cash equivalents	$ 128,828	$ 154,905
Interest-bearing time deposits	24,233	35,027
Investment securities available for sale	1,003,799	999,947
Investment securities held to maturity (fair value of $538,399 and $568,208)	540,021	560,655
Loans held for sale	4,469	7,216
Loans, net of allowance for loan losses of $76,420 and $75,032	6,825,276	6,676,167
Premises and equipment	94,741	95,852
Federal Home Loan Bank stock	24,588	23,825
Interest receivable	35,223	37,130
Goodwill	445,355	445,355
Other intangibles	29,422	31,148
Cash surrender value of life insurance	221,949	223,557
Other real estate owned	9,698	10,373
Tax asset, deferred and receivable	24,177	23,983
Other assets	61,017	42,338
TOTAL ASSETS	9,472,796	9,367,478
Deposits:
Noninterest-bearing	1,698,958	1,761,553
Interest-bearing	5,628,677	5,410,977
Total Deposits	7,327,635	7,172,530
Borrowings:
Federal funds purchased	50,000	144,038
Securities sold under repurchase agreements	138,910	136,623
Federal Home Loan Bank advances	449,419	414,377
Subordinated debentures and term loans	138,297	139,349
Total Borrowings	776,626	834,387
Interest payable	5,376	4,390
Other liabilities	50,086	52,708
Total Liabilities	8,159,723	8,064,015
COMMITMENTS AND CONTINGENT LIABILITIES
STOCKHOLDERS' EQUITY
Cumulative Preferred Stock, $1,000 par value, $1,000 liquidation value: Authorized - 600 shares; Issued and outstanding - 125 shares	125	125
Common Stock, $.125 stated value: Authorized - 50,000,000 shares; Issued and outstanding - 49,140,594 and 40,912,697 shares	6,155	6,145
Additional paid-in capital	834,894	834,870
Retained earnings	493,624	465,231
Accumulated other comprehensive loss	(21,725)	(2,908)
Total Stockholders' Equity	1,313,073	1,303,463
TOTAL LIABILITIES AND STOCKHOLDERS' EQUITY	$ 9,472,796	$ 9,367,478

CONSOLIDATED CONDENSED BALANCE3

CONSOLIDATED CONDENSED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Statement of Financial Position [Abstract]
Investment securities held to maturity - fair value	$ 538,399	$ 568,208
Loans - allowance for loan losses	$ 76,420	$ 75,032
Preferred Stock, par value (in dollars per share)	$ 1,000	$ 1,000
Preferred Stock, liquidation value per share (in dollars per share)	$ 1,000	$ 1,000
Preferred Stock, authorized (in shares)	600	600
Preferred Stock, issued (in shares)	125	125
Preferred Stock, outstanding (in shares)	125	125
Common Stock, stated value (in dollars per share)	$ 0.125	$ 0.125
Common Stock, authorized (in shares)	100,000,000	100,000,000
Common Stock, issued (in shares)	49,243,096	49,158,238
Common Stock, outstanding (in shares)	49,243,096	49,158,238

CONSOLIDATED CONDENSED STATEMEN

CONSOLIDATED CONDENSED STATEMENTS OF INCOME (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Loans receivable:
Taxable	$ 78,267	$ 56,357
Tax exempt	3,596	2,333
Investment securities:
Taxable	5,096	4,308
Tax exempt	6,126	5,003
Deposits with financial institutions	131	44
Federal Home Loan Bank stock	404	189
Total Interest Income	93,620	68,234
INTEREST EXPENSE
Deposits	9,002	4,124
Federal funds purchased	380	228
Securities sold under repurchase agreements	173	88
Federal Home Loan Bank advances	2,159	978
Subordinated debentures and term loans	1,990	1,817
Total Interest Expense	13,704	7,235
NET INTEREST INCOME	79,916	60,999
Provision for loan losses	2,500	2,385
NET INTEREST INCOME AFTER PROVISION FOR LOAN LOSSES	77,416	58,614
OTHER INCOME
Service charges on deposit accounts	4,777	4,174
Fiduciary and wealth management fees	3,416	2,640
Other customer fees	5,416	4,863
Increase in cash surrender value of life insurance	1,078	898
Gains on life insurance benefits	98
Net gains and fees on sales of loans	1,821	1,275
Net realized gains on sales of available for sale securities	1,609	598
Other income	1,346	398
Total Other Income	19,561	14,846
OTHER EXPENSES
Salaries and employee benefits	32,226	25,732
Net occupancy	4,670	4,216
Equipment	3,668	2,807
Marketing	884	565
Outside data processing fees	2,964	2,616
Printing and office supplies	334	264
Intangible asset amortization	1,726	903
FDIC assessments	719	570
Other real estate owned and foreclosure expenses	402	531
Professional and other outside services	1,541	1,734
Other expenses	4,553	3,161
Total Other Expenses	53,687	43,099
INCOME BEFORE INCOME TAX	43,290	30,361
Income tax expense	6,611	7,168
NET INCOME AVAILABLE TO COMMON STOCKHOLDERS	$ 36,679	$ 23,193
Per Share Data:
Basic Net Income Available to Common Stockholders (in dollars per share)	$ 0.75	$ 0.57
Diluted Net Income Available to Common Stockholders (in dollars per share)	0.74	0.56
Cash Dividends Paid (in dollars per share)	$ 0.18	$ 0.15
Average Diluted Shares Outstanding (in shares)	49,427,972	41,220,586

CONSOLIDATED CONDENSED STATEME5

CONSOLIDATED CONDENSED STATEMENTS OF COMPREHENSIVE INCOME (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Statement of Comprehensive Income [Abstract]
Net income	$ 36,679	$ 23,193
Other comprehensive income (loss), net of tax:
Unrealized holding gain (loss) on securities available for sale arising during the period, net of tax of $4,191 and $5,444	(17,698)	10,110
Unrealized gain on cash flow hedges arising during the period, net of tax of $106 and $11	644	23
Reclassification adjustment for net gains included in net income, net of tax of $302 and $115	(1,137)	(215)
Defined benefit pension plan amortization of prior service cost, net of tax of $32	0	(59)
Total other comprehensive income (loss), net of tax	(18,191)	9,859
Comprehensive income	$ 18,488	$ 33,052

CONSOLIDATED CONDENSED STATEME6

CONSOLIDATED CONDENSED STATEMENTS OF COMPREHENSIVE INCOME (Unaudited) (Parenthetical) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Statement of Comprehensive Income [Abstract]
Unrealized holding gain (loss) on securities available for sale arising during the period, tax	$ (4,191)	$ 5,444
Unrealized gain (loss) on cash flow hedges arising during the period, tax	106	11
Reclassification adjustment for net losses (gains) included in net income, tax	302	115
Other Comprehensive (Income) Loss, Defined Benefit Plan, Prior Service Cost (Credit), Reclassification Adjustment from AOCI, Tax		$ 32

CONSOLIDATED CONDENSED STATEME7

CONSOLIDATED CONDENSED STATEMENT OF STOCKHOLDERS' EQUITY (Unaudited) - USD ($) $ in Thousands	Total	Preferred	Common Stock	Additional Paid in Capital	Retained Earnings	Accumulated Other Comprehensive Income (Loss)
Beginning balance at Dec. 31, 2016						$ (13,581)
Comprehensive income:
Net income	$ 23,193
Other comprehensive income (loss), net of tax	9,859
Ending balance at Mar. 31, 2017						(3,722)
Beginning balance (in shares) at Dec. 31, 2017		125	49,158,238
Beginning balance at Dec. 31, 2017	1,303,463	$ 125	$ 6,145	$ 834,870	$ 465,231	(2,908)
Comprehensive income:
Net income	36,679				36,679
Other comprehensive income (loss), net of tax	(18,191)					(18,191)
Cash dividends on common stock ($.18 per share)	(8,912)				(8,912)
Reclassification adjustment under ASU 2018-02	0				626	(626)
Share-based compensation (in shares)			93,076
Share-based compensation	875		$ 12	863
Stock issued under employee benefit plans (in shares)			4,363
Stock issued under employee benefit plans	159		$ 1	158
Stock issued under dividend reinvestment and stock purchase plan (in shares)			5,614
Stock issued under dividend reinvestment and stock purchase plan	$ 250		$ 1	249
Stock options exercised (in shares)	23,557		23,557
Stock options exercised	$ 535		$ 3	532
Stock redeemed (in shares)			(41,752)
Stock redeemed	(1,785)		$ (7)	(1,778)
Ending balance (in shares) at Mar. 31, 2018		125	49,243,096
Ending balance at Mar. 31, 2018	$ 1,313,073	$ 125	$ 6,155	$ 834,894	$ 493,624	$ (21,725)

CONSOLIDATED CONDENSED STATEME8

CONSOLIDATED CONDENSED STATEMENT OF STOCKHOLDERS' EQUITY (Unaudited) (Parenthetical) - $ / shares	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Statement of Stockholders' Equity [Abstract]
Cash dividends on common stock (in dollars per share)	$ 0.18	$ 0.15

CONSOLIDATED CONDENSED STATEME9

CONSOLIDATED CONDENSED STATEMENTS OF CASH FLOWS (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Cash Flow From Operating Activities:
Net income	$ 36,679	$ 23,193
Adjustments to reconcile net income to net cash provided by operating activities:
Provision for loan losses	2,500	2,385
Depreciation and amortization	2,213	1,830
Change in deferred taxes	957	3,019
Share-based compensation	875	573
Loans originated for sale	(92,887)	(46,280)
Proceeds from sales of loans held for sale	96,973	48,903
Gains on sales of loans held for sale	(1,339)	(956)
Gains on sales of securities available for sale	(1,609)	(598)
Increase in cash surrender of life insurance	(1,078)	(898)
Gains on life insurance benefits	(98)
Change in interest receivable	1,907	1,020
Change in interest payable	986	765
Other adjustments	(15,082)	2,372
Net cash provided by operating activities	30,997	35,328
Cash Flows from Investing Activities:
Net change in interest-bearing deposits	10,794	4,020
Purchases of:
Securities available for sale	(98,113)	(68,819)
Securities held to maturity		(7,438)
Proceeds from sales of securities available for sale	55,695	26,169
Proceeds from maturities of:
Securities available for sale	15,764	15,374
Securities held to maturity	20,092	18,076
Change in Federal Home Loan Bank stock	(763)
Net change in loans	(153,893)	(136,141)
Proceeds from the sale of other real estate owned	820	1,228
Proceeds from life insurance benefits	2,784
Other adjustments	1,051	1,291
Net cash used in investing activities	(145,769)	(146,240)
Net change in :
Demand and savings deposits	108,446	(1,047)
Certificates of deposit and other time deposits	46,659	79,858
Borrowings	737,347	480,059
Repayment of borrowings	(794,004)	(465,826)
Cash dividends on common stock	(8,912)	(6,191)
Stock issued under employee benefit plans	159	114
Stock issued under dividend reinvestment and stock purchase plans	250	205
Stock options exercised	535	1,314
Stock redeemed	(1,785)	(1,254)
Net cash provided by financing activities	88,695	87,232
Net Change in Cash and Cash Equivalents	(26,077)	(23,680)
Cash and Cash Equivalents at beginning of period	154,905	127,927
Cash and Cash Equivalents at end of period	128,828	104,247
Additional cash flow information:
Interest paid	12,718	6,470
Income tax paid (refunded)	(257)
Loans transferred to other real estate owned	131	680
Non-cash investing activities using trade date accounting	$ 601	$ 8,162

General

General	3 Months Ended
	Mar. 31, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
General	GENERAL Financial Statement Preparation The significant accounting policies followed by the Corporation and its wholly owned subsidiaries for interim financial reporting are consistent with the accounting policies followed for annual financial reporting. All adjustments, which are of a normal recurring nature and are in the opinion of management necessary for a fair statement of the results for the periods reported, have been included in the accompanying Consolidated Condensed Financial Statements. The Consolidated Condensed Balance Sheet of the Corporation as of December 31, 2017 , has been derived from the audited consolidated balance sheet of the Corporation as of that date. Certain information and note disclosures normally included in the Corporation’s annual financial statements, prepared in accordance with accounting principles generally accepted in the United States of America, have been condensed or omitted. These consolidated condensed financial statements should be read in conjunction with the consolidated financial statements and notes thereto included in the Corporation’s Annual Report on Form 10-K for the year ended December 31, 2017 filed with the Securities and Exchange Commission. The results of operations for the three months ended March 31, 2018 , are not necessarily indicative of the results to be expected for the year. Reclassifications have been made to prior financial statements to conform to the current financial statement presentation. These reclassifications had no effect on net income. Recent Accounting Changes ASU 2018-02 "Income Statement - Reporting Comprehensive Income (Topic 220): Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income" ("ASU 2018-02") allows a reclassification from accumulated other comprehensive income (loss) to retained earnings for the stranded tax effects caused by the revaluation of deferred taxes resulting from the newly enacted corporate tax rate in the Tax Cuts and Jobs Act. The ASU is effective in years beginning after December 15, 2018, but permits early adoption in a period for which financial statements have not yet been issued. The Corporation elected to early adopt the ASU as of January 1, 2018. The adoption of the guidance resulted in an insignificant cumulative-effect adjustment that decreased accumulated other comprehensive income (loss) and increased retained earnings in the first quarter of 2018. ASU 2017-07 " Compensation - Retirement Benefits (Topic 715): Improving the Presentation of Net Periodic Pension Cost and Net Periodic Postretirement Benefit Cost" ("ASU 2017-07") applies to all employers, including not-for-profit entities, that offer to their employees defined benefit pension plans, other postretirement benefit plans, or other types of benefits accounted for under Topic 715, Compensation - Retirement Benefits . The amendments require that an employer report the service cost component in the same line item or items as other compensation costs arising from services rendered by the pertinent employees during the period. The other components of net benefit cost are required to be presented in the income statement separately from the service cost component and outside a subtotal of income from operations, if one is presented. If a separate line item or items are used to present the other components of net benefit cost, that line item or items must be appropriately described. If a separate line item or items are not used, the line item or items used in the income statement to present the other components of net benefit cost must be disclosed. The amendments also allow only the service cost component to be eligible for capitalization when applicable (e.g., as a cost of internally manufactured inventory or a self-constructed asset). The amendments are effective for public business entities for annual periods beginning after December 15, 2017, including interim periods within those annual periods. For other entities, the amendments are effective for annual periods beginning after December 15, 2018, and interim periods within annual periods beginning after December 15, 2019. Early adoption is permitted as of the beginning of an annual period for which financial statements (interim or annual) have not been issued or made available for issuance. The Corporation adopted this ASU in the first quarter of 2018 and did not have a significant impact on the Corporation’s consolidated financial statements. ASU 2016-15 "Statement of Cash Flows (Topic 230)" ("ASU 2016-15") is intended to reduce the diversity in practice around how certain transactions are classified within the statement of cash flows. ASU 2016-15 became effective for the Corporation on January 1, 2018 and did not have a significant impact on the Corporation's financial statements. ASU 2016-01 "Financial Instruments - Overall (Subtopic 825-10): Recognition of Financial Assets and Financial Liabilities" ("ASU 2016-01") makes targeted amendments to the guidance for recognition, measurement, presentation and disclosure of financial instruments. ASU 2016-01 requires equity investments, other than equity method investments, to be measured at fair value with changes in fair value recognized in net income. The ASU requires a cumulative-effect adjustment to retained earnings as of the beginning of the reporting period of adoption to reclassify the cumulative change in fair value of equity securities previously recognized in accumulated other comprehensive income (loss). ASU 2016-01 became effective for the Corporation on January 1, 2018. The adoption of the guidance did not result in any cumulative effect adjustment in the first quarter of 2018. ASU 2016-01 also emphasizes the existing requirement to use exit prices to measure fair value for disclosure purposes and clarifies that entities should not make use of a practicability exception in determining the fair value of loans. Accordingly, the Corporation refined the calculation used to determine the disclosed fair value of loans held for investment as part of adopting this standard. The refined calculation did not have a significant impact on the fair value disclosures included in NOTE 9. DISCLOSURES ABOUT FAIR VALUE OF ASSETS AND LIABILITIES of these Notes to Consolidated Condensed Financial Statements. ASU 2014-09 "Revenue from Contracts with Customers (Topic 606)" ("ASU 2014-09") implements a common revenue standard that clarifies the principles for recognizing revenue. The core principle of ASU 2014-09 is that an entity should recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. ASU 2014-09 establishes a five-step model which entities must follow to recognize revenue and removes inconsistencies and weaknesses in existing guidance. The guidance does not apply to revenue associated with financial instruments, including loans and investment securities that are accounted for under other GAAP, which comprises a significant portion of our revenue stream. ASU 2014-09 became effective for the Corporation on January 1, 2018. The adoption of ASU 2014-09 did not result in a change to the accounting for any of the in-scope revenue streams; as such, no cumulative effect adjustment was recorded. Additional information related to revenue generated from contracts with customers is detailed below. Revenue Recognition ASU 2014-09 establishes principles for reporting information about the nature, amount, timing and uncertainty of revenue and cash flows arising from the entity's contracts to provide goods or services to customers. The core principle requires an entity to recognize revenue to depict the transfer of goods or services to customers in an amount that reflects the consideration that it expects to be entitled to receive in exchange for those goods or services recognized as performance obligations are satisfied. The majority of the Corporation's revenue-generating transactions are not subject to ASU 2014-09, including revenue generated from financial instruments, such as loans, letters of credit, derivatives and investment securities, as well as revenue related to mortgage servicing activities, as these activities are subject to other GAAP discussed elsewhere within the disclosures. The Corporation has evaluated the nature of its contracts with customers and determined that further disaggregation of revenue from contracts with customers into more granular categories beyond what is presented in the Consolidated Condensed Statements of Income was not necessary. Descriptions of revenue-generating activities that are within the scope of ASU 2014-09, which are presented in our income statements are as follows: Service charges on deposit accounts: The Corporation earns fees from its deposit customers for transaction-based, account maintenance and overdraft services. Transaction-based fees, which include services such as ATM use fees, stop payment charges, statement rendering and ACH fees, are recognized at the time the transaction is executed, which is the point in time the Corporation fulfills the customer's request. Account maintenance fees, which relate primarily to monthly maintenance, are earned monthly, representing the period which the Corporation satisfies the performance obligation. Overdraft fees are recognized at the point in time that the overdraft occurs. Service charges on deposits are withdrawn from the customer's account balance. Fiduciary activities : This represents monthly fees due from wealth management customers as consideration for managing the customers' assets. Wealth management and trust services include custody of assets, investment management, fees for trust services and similar fiduciary activities. These fees are primarily earned over time as the Corporation provides the contracted monthly or quarterly services and are generally assessed based on the market value of assets under management at month-end. Fees that are transaction-based are recognized at the point in time that the transaction is executed. Investment Brokerage Fees : The Corporation earns fees from investment brokerage services provided to its customers by a third-party service provider. The Corporation receives commissions from the third-party provider on a monthly basis based upon customer activity for the month. The fees are paid to us by the third party on a monthly basis and are recognized when received. Interchange income : The Corporation earns interchange fees from debit and credit cardholder transactions conducted through the Visa and MasterCard payment networks. Interchange fees from cardholder transactions represent a percentage of the underlying transaction value and are recognized concurrent with the transaction processing services provided to the cardholder. Gains (Losses) on Sales of OREO : The Corporation records a gain or loss from the sale of OREO when control of the property transfers to the buyer, which generally occurs at the time of an executed deed. When the Corporation finances the sale of OREO to the buyer, the Corporation assesses whether the buyer is committed to perform their obligations under the contract and whether collectability of the transaction price is probable. Once these criteria are met, the OREO asset is derecognized and the gain or loss on sale is recorded upon the transfer of control of the property to the buyer. In determining the gain or loss on the sale, the Corporation adjusts the transaction price and related gain (loss) on sale if a significant financing component is present.

Acquisitions

Acquisitions	3 Months Ended
	Mar. 31, 2018
Business Combinations [Abstract]
Acquisitions	ACQUISITIONS Independent Alliance Banks, Inc. On November 21, 2016, the Corporation purchased 495,112 shares, or 12.1 percent, of IAB's outstanding common stock from an IAB shareholder for $19.8 million , or $40.00 per share. On July 14, 2017, the Corporation acquired the remaining shares of IAB common stock. IAB, an Indiana Corporation, merged with and into the Corporation, whereupon the separate corporate existence of IAB ceased and the Corporation survived. Immediately following the merger, IAB's wholly-owned subsidiary, iAB Financial Bank, merged with and into the Bank, with the Bank continuing as the surviving bank. IAB was headquartered in Fort Wayne, Indiana and had 16 banking centers serving the Fort Wayne market. Pursuant to the merger agreement, each IAB shareholder received 1.653 shares of the Corporation's common stock for each outstanding share of IAB common stock held. The Corporation issued approximately 6.0 million shares of common stock. The transaction value for the remaining shares of common stock, not owned by the Corporation, was approximately $238.8 million , resulting in a total purchase price of $258.6 million . The Corporation engaged in this transaction with the expectation that it would be accretive to income and add a new market area with a demographic profile consistent with many of the current Indiana markets served by the Bank. Goodwill resulted from this transaction due to the expected synergies and economies of scale. In the third quarter of 2017, ASC 805-10 - Business Combinations, required the Corporation to remeasure the 12.1 percent equity interest in IAB's common stock and recognize the resulting gain or loss, if any, in earnings. The remeasurement was based upon the closing price of IAB's common stock immediately prior to the acquisition announcement, and prior to the Corporation obtaining control of IAB. The trading price of IAB's common stock subsequent to the acquisition announcement included a control or acquisition premium and was not indicative of the fair value of the Corporation's pre-existing equity interest immediately prior to the acquisition announcement. The fair value of the equity interest in IAB's common stock after the remeasurement was $19.8 million . The Corporation recorded a $50,000 loss in the third quarter of 2017 as a result of the remeasurement. Under the acquisition method of accounting, the total purchase price is allocated to net tangible and intangible assets based on their current estimated fair values on the date of the acquisition. Based on valuations of the fair value of tangible and intangible assets acquired and liabilities assumed, which are based on assumptions that are subject to change, the purchase price for the IAB acquisition is detailed in the following table. If prior to the end of the one-year measurement period for finalizing the purchase price allocation, information becomes available about facts and circumstances that existed as of the acquisition date which would indicate adjustments are required to the purchase price allocation, such adjustments will be included in the purchase price allocation retrospectively. Fair Value Cash and cash equivalents $ 6,016 Interest-bearing time deposits 248,212 Investment securities 4,078 Loans held for sale 594 Loans 725,382 Premises and equipment 10,107 Federal Home Loan Bank stock 4,810 Interest receivable 3,445 Cash surrender value of life insurance 26,964 Other assets 11,780 Deposits (862,271 ) Securities sold under repurchase agreements (17,915 ) Federal Home Loan Bank Advances (47,575 ) Subordinated debentures (10,583 ) Interest payable (1,005 ) Other liabilities (14,472 ) Net tangible assets acquired 87,567 Other Intangible assets 17,403 Goodwill 153,636 Purchase price $ 258,606 Of the total purchase price, $17,403,000 has been allocated to other intangible assets. Approximately $13.6 million was allocated to a core deposit intangible, which will be amortized over its estimated life of 10 years. Approximately $3.8 million was allocated to a non-compete intangible, which will be amortized over its estimated life of 2 years. The remaining purchase price has been allocated to goodwill, which is not deductible for tax purposes. Acquired loan data for IAB can be found in the table below: Fair Value of Acquired Loans at Acquisition Date Gross Contractual Amounts Receivable at Acquisition Date Best Estimate at Acquisition Date of Contractual Cash Flows Not Expected to be Collected Acquired receivables subject to ASC 310-30 $ 4,838 $ 14,131 $ 8,352 Acquired receivables not subject to ASC 310-30 $ 720,544 $ 864,613 $ 9,786 Purchased loans with evidence of credit deterioration since origination and for which it is probable at the date of acquisition that the acquirer will not collect all contractually required principal and interest payments are accounted for under ASC 310-30, Loans Acquired with Deteriorated Credit Quality . The difference between contractually required payments and the cash flows expected to be collected at acquisition is referred to as the nonaccretable difference. The accretable portion of the fair value discount or premium is the difference between the expected cash flows and the net present value of expected cash flows, with such difference accreted into earnings over the term of the loans. The Arlington Bank On May 19, 2017, the Corporation acquired 100 percent of Arlington Bank. Arlington Bank, an Ohio savings bank, merged with and into the Bank, with the Bank continuing as the surviving bank. Arlington Bank was headquartered in Columbus, Ohio and had 3 banking centers serving the Columbus, Ohio market. Pursuant to the merger agreement, each Arlington Bank shareholder received 2.7245 shares of the Corporation's common stock for each outstanding share of Arlington Bank common stock held. The Corporation issued approximately 2.1 million shares of common stock, which was valued at approximately $82.6 million . The Corporation engaged in this transaction with the expectation that it would be accretive to income and expand the existing footprint in Columbus, Ohio. Goodwill resulted from this transaction due to the expected synergies and economies of scale. Under the acquisition method of accounting, the total purchase price is allocated to net tangible and intangible assets based on their current estimated fair values on the date of the acquisition. Based on valuations of the fair value of tangible and intangible assets acquired and liabilities assumed, which are based on assumptions that are subject to change, the purchase price for the Arlington Bank acquisition is detailed in the following table. If prior to the end of the one-year measurement period for finalizing the purchase price allocation, information becomes available about facts and circumstances that existed as of the acquisition date which would indicate adjustments are required to the purchase price allocation, such adjustments will be included in the purchase price allocation retrospectively. Fair Value Cash and cash equivalents $ 48,532 Interest-bearing time deposits 292 Loans held for sale 7,626 Loans 224,680 Premises and equipment 1,986 Federal Home Loan Bank stock 1,091 Interest receivable 653 Other assets 1,620 Deposits (252,783 ) Interest payable (244 ) Other liabilities (3,106 ) Net tangible assets acquired 30,347 Core deposit intangible 4,526 Goodwill 47,719 Purchase price $ 82,592 Of the total purchase price, $4,526,000 has been allocated to a core deposit intangible that will be amortized over its estimated life of 10 years. The remaining purchase price has been allocated to goodwill, which is not deductible for tax purposes. Acquired loan data for Arlington Bank can be found in the table below: Fair Value of Acquired Loans at Acquisition Date Gross Contractual Amounts Receivable at Acquisition Date Best Estimate at Acquisition Date of Contractual Cash Flows Not Expected to be Collected Acquired receivables subject to ASC 310-30 $ 2,625 $ 6,183 $ 2,891 Acquired receivables not subject to ASC 310-30 $ 222,055 $ 308,857 $ 2,741 Pro Forma Financial Information The results of operations of Arlington Bank and IAB have been included in the Corporation's consolidated financial statements since the acquisition dates. The following schedule includes pro forma results for the year ended December 31, 2017, as if the Arlington Bank and IAB acquisitions occurred as of the beginning of the period presented. 2017 Total revenue (net interest income plus other income) $ 380,324 Net income $ 95,009 Net income available to common shareholders Earnings per share: Basic $ 1.94 Diluted $ 1.93 The pro forma information includes adjustments for interest income on loans, interest expense on deposits and borrowings, premises expense for banking centers acquired and amortization of intangibles arising from the transaction and the related income tax effects. The pro forma information for the year ended December 31, 2017 includes operating revenue of $9.0 million and $21.4 million from the Arlington Bank and IAB acquisitions since the date of acquisition, respectively. Additionally, $15.4 million , net of tax, of expenses directly attributable to the Arlington Bank and IAB acquisitions were included in the year ended December 31, 2017 pro forma information. The pro forma information is presented for information purposes only and is not indicative of the results of operations that actually would have been achieved had the acquisitions been consummated as of that time, nor is it intended to be a projection of future results.

Investment Securities

Investment Securities	3 Months Ended
	Mar. 31, 2018
Investments, Debt and Equity Securities [Abstract]
Investment Securities	INVESTMENT SECURITIES The amortized cost, gross unrealized gains, gross unrealized losses and approximate market value of the Corporation's investment securities at the dates indicated were: Amortized Gross Gross Fair Available for sale at March 31, 2018 U.S. Government-sponsored agency securities $ 6,491 $ 8 $ 1 $ 6,498 State and municipal 510,884 6,588 7,238 510,234 U.S. Government-sponsored mortgage-backed securities 496,824 251 10,039 487,036 Corporate obligations 31 31 Total available for sale 1,014,230 6,847 17,278 1,003,799 Held to maturity at March 31, 2018 U.S. Government-sponsored agency securities 22,619 715 21,904 State and municipal 228,620 2,784 911 230,493 U.S. Government-sponsored mortgage-backed securities 287,782 988 3,762 285,008 Foreign Investments 1,000 6 994 Total held to maturity 540,021 3,772 5,394 538,399 Total Investment Securities $ 1,554,251 $ 10,619 $ 22,672 $ 1,542,198 Amortized Gross Gross Fair Available for sale at December 31, 2017 State and municipal $ 510,852 $ 16,932 $ 1,091 $ 526,693 U.S. Government-sponsored mortgage-backed securities 473,325 964 3,423 470,866 Corporate obligations 31 31 Equity securities 2,357 2,357 Total available for sale 986,565 17,896 4,514 999,947 Held to maturity at December 31, 2017 U.S. Government-sponsored agency securities 22,618 435 22,183 State and municipal 235,594 6,295 244 241,645 U.S. Government-sponsored mortgage-backed securities 301,443 3,341 1,404 303,380 Foreign Investment 1,000 1,000 Total held to maturity 560,655 9,636 2,083 568,208 Total Investment Securities $ 1,547,220 $ 27,532 $ 6,597 $ 1,568,155 The amortized cost and fair value of available for sale and held to maturity securities at March 31, 2018 and December 31, 2017 , by contractual maturity, are shown below. Expected maturities will differ from contractual maturities because issuers may have the right to call or prepay obligations with or without call or prepayment penalties. Available for Sale Held to Maturity Amortized Cost Fair Value Amortized Cost Fair Value Maturity Distribution at March 31, 2018: Due in one year or less $ 544 $ 549 $ 18,366 $ 18,675 Due after one through five years 4,982 5,064 68,198 67,756 Due after five through ten years 81,890 83,630 52,976 53,437 Due after ten years 429,990 427,520 112,699 113,523 517,406 516,763 252,239 253,391 U.S. Government-sponsored mortgage-backed securities 496,824 487,036 287,782 285,008 Total Investment Securities $ 1,014,230 $ 1,003,799 $ 540,021 $ 538,399 Available for Sale Held to Maturity Amortized Cost Fair Value Amortized Cost Fair Value Maturity Distribution at December 31, 2017 Due in one year or less $ 425 $ 425 $ 12,015 $ 12,158 Due after one through five years 5,040 5,204 76,146 76,334 Due after five through ten years 74,921 78,806 54,441 55,679 Due after ten years 430,497 442,289 116,610 120,657 510,883 526,724 259,212 264,828 U.S. Government-sponsored mortgage-backed securities 473,325 470,866 301,443 303,380 Equity securities 2,357 2,357 Total Investment Securities $ 986,565 $ 999,947 $ 560,655 $ 568,208 The carrying value of securities pledged as collateral, to secure borrowings and for other purposes, was $552,899,000 at March 31, 2018 , and $475,999,000 at December 31, 2017 . The book value of securities sold under agreements to repurchase amounted to $141,664,000 at March 31, 2018 , and $136,639,000 at December 31, 2017 . Gross gains on the sales and redemptions of available for sale securities for the three months ended March 31, 2018 and 2017 are shown below. Three Months Ended 2018 2017 Sales and Redemptions of Available for Sale Securities: Gross gains $ 1,609 $ 598 Gross losses The following tables show the Corporation’s gross unrealized losses and fair value, aggregated by investment category and length of time the individual securities have been in a continuous unrealized loss position at March 31, 2018 , and December 31, 2017 : Less than 12 Months Total Fair Gross Fair Gross Fair Gross Temporarily Impaired Available for Sale Securities at March 31, 2018 U.S. Government-sponsored agency securities $ 371 $ 1 $ 371 $ 1 State and municipal 236,539 5,298 $ 28,126 $ 1,940 264,665 7,238 U.S. Government-sponsored mortgage-backed securities 385,626 6,956 65,490 3,083 451,116 10,039 Total Temporarily Impaired Available for Sale Securities 622,536 12,255 93,616 5,023 716,152 17,278 Temporarily Impaired Held to Maturity Securities at March 31, 2018 U.S. Government-sponsored agency securities 9,861 258 12,043 457 21,904 715 State and municipal 18,155 307 15,388 604 33,543 911 U.S. Government-sponsored mortgage-backed securities 177,080 2,154 40,866 1,608 217,946 3,762 Corporate Obligations 994 6 994 6 Total Temporarily Impaired Held to Maturity Securities 206,090 2,725 68,297 2,669 274,387 5,394 Total Temporarily Impaired Investment Securities $ 828,626 $ 14,980 $ 161,913 $ 7,692 $ 990,539 $ 22,672 Less than 12 Months Total Fair Gross Fair Gross Fair Gross Temporarily Impaired Available for Sale Securities at December 31, 2017 State and municipal $ 13,296 $ 198 $ 35,324 $ 893 $ 48,620 $ 1,091 U.S. Government-sponsored mortgage-backed securities 182,755 1,520 68,667 1,903 251,422 3,423 Total Temporarily Impaired Available for Sale Securities 196,051 1,718 103,991 2,796 300,042 4,514 Temporarily Impaired Held to Maturity Securities at December 31, 2017 U.S. Government-sponsored agency securities 9,988 131 12,196 304 22,184 435 State and municipal 2,430 36 15,805 208 18,235 244 U.S. Government-sponsored mortgage-backed securities 62,508 485 43,078 919 105,586 1,404 Total Temporarily Impaired Held to Maturity Securities 74,926 652 71,079 1,431 146,005 2,083 Total Temporarily Impaired Investment Securities $ 270,977 $ 2,370 $ 175,070 $ 4,227 $ 446,047 $ 6,597 Certain investments in debt and equity securities are reported in the financial statements at an amount less than their historical cost as indicated in the table below. March 31, 2018 December 31, 2017 Investments reported at less than historical cost: Historical cost $ 1,013,210 $ 452,644 Fair value $ 990,539 $ 446,047 Percent of the Corporation's investment portfolio 64.2 % 28.6 % Except as discussed below, management believes the decline in fair value for these securities was temporary. Should the impairment of any of these securities become other-than-temporary, the cost basis of the investment will be reduced and the resulting loss recognized in net income during the period the OTTI is identified. The Corporation’s management has evaluated all securities with unrealized losses for OTTI as of March 31, 2018 . The evaluations are based on the nature of the securities, the extent and duration of the loss and the intent and ability of the Corporation to hold these securities either to maturity or through the expected recovery period. In determining the fair value of the investment securities portfolio, the Corporation utilizes a third party for portfolio accounting services, including market value input, for those securities classified as Level 1 and Level 2 in the fair value hierarchy. The Corporation has obtained an understanding of what inputs are being used by the vendor in pricing the portfolio and how the vendor classified these securities based upon these inputs. From these discussions, the Corporation’s management is comfortable that the classifications are proper. The Corporation has gained trust in the data for two reasons: (a) independent spot testing of the data is conducted by the Corporation through obtaining market quotes from various brokers on a periodic basis; and (b) actual gains or loss resulting from the sale of certain securities has proven the data to be accurate over time. Fair value of securities classified as Level 3 in the valuation hierarchy was determined using a discounted cash flow model that incorporated market estimates of interest rates and volatility in markets that have not been active. State and Municipal and U.S. Government-Sponsored Agency Securities The unrealized losses on the Corporation's investments in securities of state and political subdivisions and U.S. Government-Sponsored Agency securities were caused by interest rate increases. The contractual terms of those investments do not permit the issuer to settle the securities at a price less than the amortized cost basis of the investments. Because the Corporation does not intend to sell the investments and it is not more likely than not that the Corporation will be required to sell the investments before recovery of their amortized cost basis, which may be maturity, the Corporation does not consider those investments to be other-than-temporarily impaired at March 31, 2018 . The state and municipal securities portfolio contains unrealized losses of $7,238,000 on two hundred eight securities and $911,000 on forty-six securities in the available for sale and held to maturity portfolios, respectively. The U.S. Government-Sponsored Agency securities portfolio contains unrealized losses of $1,000 on one security and $715,000 on five securities in the available for sale and held to maturity portfolios, respectively. U.S. Government-Sponsored Mortgage-Backed Securities The unrealized losses on the Corporation's investment in mortgage-backed securities were a result of interest rate changes. The Corporation expects to recover the amortized cost basis over the term of the securities. Because the decline in market value is attributable to changes in interest rates and not credit quality, and because the Corporation does not intend to sell the investments and it is not more likely than not that the Corporation will be required to sell the investments before recovery of their amortized cost basis, which may be maturity, the Corporation does not consider those investments to be other-than-temporarily impaired at March 31, 2018 . The mortgage-backed securities portfolio contains unrealized losses of $10,039,000 on one hundred one securities and $3,762,000 on seventy-six securities in the available for sale and held to maturity portfolios, respectively. All these securities are issued by a U.S. government-sponsored entity.

Loans and Allowance

Loans and Allowance	3 Months Ended
	Mar. 31, 2018
Receivables [Abstract]
Loans and Allowance	90 Days Non-Accrual Total Past Due Total Commercial and industrial loans $ 1,549,330 $ 1,062 $ 49 $ 490 $ 3,238 $ 4,839 $ 1,554,169 Agriculture production financing and other loans to farmers 89,198 8,479 638 9,117 98,315 Real estate loans: Construction 588,424 188 1,481 1,669 590,093 Commercial and farmland 2,693,020 5,589 1,378 63 13,944 20,974 2,713,994 Residential 938,960 2,577 305 37 6,765 9,684 948,644 Home equity 506,922 1,638 481 119 1,385 3,623 510,545 Individuals' loans for household and other personal expenditures 87,933 170 57 29 46 302 88,235 Lease financing receivables, net of unearned income 2,193 2,193 Other commercial loans 395,508 395,508 Loans $ 6,851,488 $ 19,703 $ 2,270 $ 738 $ 27,497 $ 50,208 $ 6,901,696 December 31, 2017 Current 30-59 Days 60-89 Days Loans > 90 Days Non-Accrual Total Past Due Total Commercial and industrial loans $ 1,487,221 $ 2,967 $ 30 $ 3,275 $ 6,272 $ 1,493,493 Agriculture production financing and other loans to farmers 120,720 10 1,027 1,037 121,757 Real estate loans: Construction 610,896 1,193 $ 65 65 1,323 612,219 Commercial and farmland 2,542,048 6,923 166 603 12,951 20,643 2,562,691 Residential 948,947 4,010 308 56 9,444 13,818 962,765 Home equity 510,362 1,372 184 175 1,928 3,659 514,021 Individuals' loans for household and other personal expenditures 85,744 298 834 25 34 1,191 86,935 Lease financing receivables, net of unearned income 2,527 2,527 Other commercial loans 394,791 394,791 Loans $ 6,703,256 $ 16,773 $ 1,522 $ 924 $ 28,724 $ 47,943 $ 6,751,199 See the information regarding the analysis of loan loss experience in the "LOAN QUALITY/PROVISION FOR LOAN LOSSES" section of Management’s Discussion and Analysis of Financial Condition and Results of Operations included as Item 2 of this Quarterly Report on Form 10-Q. On occasion, borrowers experience declines in income and cash flow. As a result, these borrowers seek to reduce contractual cash outlays including debt payments. Concurrently, in an effort to preserve and protect its earning assets, specifically troubled loans, the Corporation works to maintain its relationship with certain customers who are experiencing financial difficulty by contractually modifying the borrower's debt agreement with the Corporation. In certain loan restructuring situations, the Corporation may grant a concession to a debtor experiencing financial difficulty, resulting in a trouble debt restructuring. A concession is deemed to be granted when, as a result of the restructuring, the Corporation does not expect to collect all original amounts due, including interest accrued at the original contract rate. If the payment of principal at original maturity is primarily dependent on the value of collateral, the current value of the collateral is considered in determining whether the principal will be paid. The following tables summarize troubled debt restructures in the Corporation's loan portfolio that occurred during the periods indicated: Three Months Ended March 31, 2018 Pre-Modification Post-Modification Number Real estate loans: Residential $ 214 $ 222 5 Home equity 16 16 2 Individuals' loans for household and other personal expenditures 7 8 1 Total $ 237 $ 246 8 Three Months Ended March 31, 2017 Pre-Modification Post-Modification Number Real estate loans: Commercial and farmland $ 107 $ 241 3 Residential 121 122 2 Home equity 122 Total $ 350 $ 363 5 The following tables summarize the recorded investment of troubled debt restructures as of March 31, 2018 and 2017 , by modification type, that occurred during the periods indicated: Three Months Ended March 31, 2018 Term Rate Combination Total Real estate loans: Residential $ 38 $ 74 $ 106 $ 218 Home equity 16 10 26 Individuals' loans for household and other personal expenditures 7 7 Total $ 54 $ 91 $ 106 $ 251 Three Months Ended March 31, 2017 Term Rate Combination Total Real estate loans: Commercial and farmland $ 241 $ 241 Residential $ 122 122 Total $ 122 $ 241 $ 363 Loans secured by residential real estate made up 91 percent of the post-modification balance of troubled debt restructured loans made in the three months ended March 31, 2018 . The following tables summarize troubled debt restructures that occurred during the twelve months ended March 31, 2018 and 2017, that subsequently defaulted during the period indicated and remained in default at period end. For purposes of this schedule, a loan is considered in default if it is 30 or more days past due. Three Months Ended March 31, 2018 Number of Loans Recorded Balance Real estate loans: Commercial and farmland 1 $ 324 Residential 3 108 Total 4 $ 432 Three Months Ended March 31, 2017 Number of Loans Recorded Balance Real estate loans: Commercial and farmland 1 $ 223 Total 1 $ 223 For potential consumer loan restructures, impairment evaluation occurs prior to modification. Any subsequent impairment is typically addressed through the charge-off process, or may be addressed through a specific reserve. Consumer troubled debt loan restructures are generally included in the general historical allowance for loan loss at the post modification balance. Consumer non-accrual and delinquent troubled debt loan restructures are also considered in the calculation of the non-accrual and delinquency trend environmental allowance allocation. Consumer mortgage loans secured by residential real estate properties for which formal foreclosure proceedings are in process totaled $1,465,000 and $2,302,000 at March 31, 2018 and December 31, 2017, respectively. Commercial troubled debt restructured loans risk graded special mention, substandard, doubtful and loss are individually evaluated for impairment under ASC 310. Any resulting specific reserves are included in the allowance for loan losses. Commercial troubled debt loan restructures 30 - 89 days delinquent are included in the calculation of the delinquency trend environmental allocation in the allowance for loan losses. With the exception of the acquired loans excluded from the allowance for loan losses, all commercial non-impaired loans, including non-accrual and 90+ day delinquents, are included in the ASC 450 loss estimate." id="sjs-B4">LOANS AND ALLOWANCE The Corporation’s primary lending focus is small business and middle market commercial, commercial real estate and residential real estate, which results in portfolio diversification. The following tables show the composition of the loan portfolio, the allowance for loan losses and credit quality characteristics by collateral classification, excluding loans held for sale. Loans held for sale as of March 31, 2018 , and December 31, 2017 , were $4,469,000 and $7,216,000 , respectively. The following table illustrates the composition of the Corporation’s loan portfolio by loan class for the periods indicated: March 31, 2018 December 31, 2017 Commercial and industrial loans $ 1,554,169 $ 1,493,493 Agricultural production financing and other loans to farmers 98,315 121,757 Real estate loans: Construction 590,093 612,219 Commercial and farmland 2,713,994 2,562,691 Residential 948,644 962,765 Home equity 510,545 514,021 Individuals' loans for household and other personal expenditures 88,235 86,935 Lease financing receivables, net of unearned income 2,193 2,527 Other commercial loans 395,508 394,791 Loans $ 6,901,696 $ 6,751,199 Allowance for loan losses (76,420 ) (75,032 ) Net Loans $ 6,825,276 $ 6,676,167 Allowance, Credit Quality and Loan Portfolio The Corporation maintains an allowance for loan losses to cover probable credit losses identified during its loan review process. Management believes the allowance for loan losses is adequate to cover probable losses inherent in the loan portfolio at March 31, 2018 . The process for determining the adequacy of the allowance for loan losses is critical to the Corporation’s financial results. It requires management to make difficult, subjective and complex judgments to estimate the effect of uncertain matters. The allowance for loan losses considers current factors, including economic conditions and ongoing internal and external examinations, and will increase or decrease as deemed necessary to ensure it remains adequate. In addition, the allowance as a percentage of charge-offs and nonperforming loans will change at different points in time based on credit performance, portfolio mix and collateral values. The allowance for loan losses is maintained through the provision for loan losses, which is a charge against earnings. The allowance is increased by provision expense and decreased by charge-offs less recoveries. All charge-offs are approved by the Bank's senior credit officers and in accordance with established policies. The Bank charges off a loan when a determination is made that all or a portion of the loan is uncollectable. The amount provided for loan losses in a given period may be greater than or less than net loan losses experienced during the period, and is based on management’s judgment as to the appropriate level of the allowance for loan losses. The determination of the provision amount is based on management’s ongoing review and evaluation of the loan portfolio, including an internally administered loan "watch" list and independent loan reviews. The evaluation takes into consideration identified credit problems, the possibility of losses inherent in the loan portfolio that are not specifically identified and management’s judgment as to the impact of the current environment and economic conditions on the portfolio. The allowance consists of specific impairment reserves as required by ASC 310-10-35, a component for historical losses in accordance with ASC 450 and the consideration of current environmental factors in accordance with ASC 450. A loan is deemed impaired when, based on current information or events, it is probable that all amounts due of principal and interest according to the contractual terms of the loan agreement will not be collected. The historical loss allocation for loans not deemed impaired according to ASC 450 is the product of the volume of loans within the non-impaired criticized and non-criticized risk grade classifications, each segmented by call code, and the historical loss factor for each respective classification and call code segment. The historical loss factors are based upon actual loss experience within each risk and call code classification. The historical look back period for non-criticized loans looks to the most recent rolling-four-quarter average and aligns with the look back period for non-impaired criticized loans. Each of the rolling four quarter periods used to obtain the average, include all charge-offs for the previous twelve-month period, therefore the historical look back period includes seven quarters. The resulting allocation is reflective of current conditions. Criticized loans are grouped based on the risk grade assigned to the loan. Loans with a special mention grade are assigned a loss factor, and loans with a classified grade but not impaired are assigned a separate loss factor. The loss factor computation for this allocation includes a segmented historical loss migration analysis of risk grades to charge-off. In addition to the specific reserves and historical loss components of the allowance, consideration is given to various environmental factors to ensure that losses inherent in the portfolio are reflected in the allowance for loan losses. The environmental component adjusts the historical loss allocations for non-impaired loans to reflect relevant current conditions that, in management's opinion, have an impact on loss recognition. Environmental factors that management reviews in the analysis include: national and local economic trends and conditions; trends in growth in the loan portfolio and growth in higher risk areas; levels of, and trends in, delinquencies and non-accruals; experience and depth of lending management and staff; adequacy of, and adherence to, lending policies and procedures including those for underwriting; industry concentrations of credit; and adequacy of risk identification systems and controls through the internal loan review and internal audit processes. In conformance with ASC 805 and ASC 820, purchased loans are recorded at the acquisition date fair value. Such loans are included in the allowance to the extent a specific impairment is identified that exceeds the fair value adjustment on an impaired loan or the historical loss and environmental factor analysis indicates losses inherent in a purchased portfolio exceeds the fair value adjustment on the portion of the purchased portfolio not deemed impaired. The following tables summarize changes in the allowance for loan losses by loan segment for the three months ended March 31, 2018 and March 31, 2017 : Three Months Ended March 31, 2018 Commercial Commercial Consumer Residential Finance Total Allowance for loan losses: Balances, December 31, 2017 $ 30,418 $ 27,343 $ 3,732 $ 13,537 $ 2 $ 75,032 Provision for losses 840 84 274 1,302 2,500 Recoveries on loans 119 339 89 154 701 Loans charged off (609 ) (61 ) (199 ) (944 ) (1,813 ) Balances, March 31, 2018 $ 30,768 $ 27,705 $ 3,896 $ 14,049 $ 2 $ 76,420 Three Months Ended March 31, 2017 Commercial Commercial Consumer Residential Finance Total Allowance for loan losses: Balances, December 31, 2016 $ 27,696 $ 23,661 $ 2,923 $ 11,755 $ 2 $ 66,037 Provision for losses 1,197 247 249 692 2,385 Recoveries on loans 366 564 101 237 1,268 Loans charged off (735 ) (152 ) (153 ) (425 ) (1,465 ) Balances, March 31, 2017 $ 28,524 $ 24,320 $ 3,120 $ 12,259 $ 2 $ 68,225 The tables below show the Corporation’s allowance for loan losses and loan portfolio by loan segment as of the periods indicated. There was no related allowance for loan losses for loans acquired with deteriorated credit quality at March 31, 2018 or December 31, 2017. March 31, 2018 Commercial Commercial Consumer Residential Finance Total Allowance Balances: Individually evaluated for impairment $ 143 $ 758 $ 416 $ 1,317 Collectively evaluated for impairment 30,625 26,947 $ 3,896 13,633 $ 2 75,103 Total Allowance for Loan Losses $ 30,768 $ 27,705 $ 3,896 $ 14,049 $ 2 $ 76,420 Loan Balances: Individually evaluated for impairment $ 2,914 $ 16,501 $ 11 $ 2,738 $ 22,164 Collectively evaluated for impairment 2,042,193 3,268,036 88,224 1,454,894 $ 2,193 6,855,540 Loans acquired with deteriorated credit quality 2,885 19,550 1,557 23,992 Loans $ 2,047,992 $ 3,304,087 $ 88,235 $ 1,459,189 $ 2,193 $ 6,901,696 December 31, 2017 Commercial Commercial Consumer Residential Finance Total Allowance Balances: Individually evaluated for impairment $ 666 $ 567 $ 404 $ 1,637 Collectively evaluated for impairment 29,752 26,776 $ 3,732 13,133 $ 2 73,395 Total Allowance for Loan Losses $ 30,418 $ 27,343 $ 3,732 $ 13,537 $ 2 $ 75,032 Loan Balances: Individually evaluated for impairment $ 3,345 $ 17,432 $ 5 $ 2,429 $ 23,211 Collectively evaluated for impairment 2,005,275 3,135,481 86,930 1,472,821 $ 2,527 6,703,034 Loans acquired with deteriorated credit quality 1,421 21,997 1,536 24,954 Loans $ 2,010,041 $ 3,174,910 $ 86,935 $ 1,476,786 $ 2,527 $ 6,751,199 Loans individually evaluated for impairment are comprised of commercial and consumer loans deemed impaired in accordance with ASC 310-10 and include loans acquired with deteriorated credit quality totaling $289,000 and $315,000 at March 31, 2018 and December 31, 2017, respectively. The risk characteristics of the Corporation’s material portfolio segments are as follows: Commercial Commercial lending is primarily based on the identified cash flows of the borrower and secondarily on the underlying collateral provided by the borrower. The cash flows of borrowers, however, may not be as expected and the collateral securing these loans may fluctuate in value. Most commercial loans are secured by the tangible assets being financed such as equipment or real estate or other business assets such as accounts receivable or inventory and may incorporate a personal guarantee. Other loans may be unsecured, secured but under-collateralized or otherwise made on the basis of the enterprise value of an organization. In the case of loans secured by accounts receivable, the availability of funds for the repayment of these loans may be substantially dependent on the ability of the borrower to collect amounts due from its customers. Commercial real estate These loans are viewed primarily as cash flow loans and secondarily as loans secured by real estate. Commercial real estate lending typically involves higher loan principal amounts and the repayment of these loans is generally dependent on the successful operation of the property securing the loan or the business conducted on the property securing the loan. Commercial real estate loans may be more adversely affected by conditions in the real estate markets or in the general economy. Management monitors and evaluates commercial real estate loans based on collateral and risk grade criteria. In addition, management tracks the level of owner-occupied commercial real estate loans versus non-owner occupied loans. Consumer and Residential With respect to residential loans that are secured by 1-4 family residences and are typically owner occupied, the Corporation generally establishes a maximum loan-to-value ratio and requires private mortgage insurance if that ratio is exceeded. Home equity loans are secured by a subordinate interest in 1-4 family residences, and consumer loans are secured by consumer assets such as automobiles or recreational vehicles. Some consumer loans are unsecured such as small installment loans and certain lines of credit. Repayment of these loans is primarily dependent on the personal income and credit rating of the borrowers, which can be impacted by economic conditions in their market areas such as unemployment levels. Repayment on loans secured by 1-4 family residences can be impacted by changes in property values. Risk is mitigated by the fact that the loans are of smaller individual amounts and spread over a large number of borrowers. Loans are reclassified to a non-accruing status when, in management’s judgment, the collateral value and financial condition of the borrower do not justify accruing i n terest. When the interest accrual is discontinued, all unpaid accrued interest is reversed against earnings when considered uncollectable. Payments subsequently received on non-accrual loans are applied to principal. A loan is returned to accrual status when principal and interest are no longer past due and collectability is probable, typically after a minimum of six consecutive months of performance. Payments received on impaired accruing or delinquent loans are applied to interest income as accrued. The following table summarizes the Corporation’s non-accrual loans by loan class as of the periods indicated: March 31, 2018 December 31, 2017 Commercial and industrial loans $ 3,238 $ 3,275 Agriculture production financing and other loans to farmers 638 1,027 Real estate loans: Construction 1,481 65 Commercial and farmland 13,944 12,951 Residential 6,765 9,444 Home equity 1,385 1,928 Individuals' loans for household and other personal expenditures 46 34 Total $ 27,497 $ 28,724 Impaired loans include loans deemed impaired according to the guidance set forth in ASC 310-10. Commercial loans under $250,000 and consumer loans, with the exception of troubled debt restructures, are not individually evaluated for impairment. Allowable methods for determining the amount of impairment include estimating fair value using the fair value of the collateral for collateral dependent loans. If the impaired loan is identified as collateral dependent, then the fair value method for measuring the amount of impairment is utilized. This method requires obtaining a current independent appraisal of the collateral and applying a discount factor, which includes selling costs if applicable, to the value. The fair value of real estate is generally based on appraisals by qualified licensed appraisers. The appraisers typically determine the value of the real estate by utilizing an income or market valuation approach. If an appraisal is not available, the fair value may be determined by using a cash flow analysis. Fair value on other collateral such as business assets is typically ascertained by assessing, either singularly or some combination of, asset appraisals, accounts receivable aging reports, inventory listings and or customer financial statements. Both appraised values and values based on borrower’s financial information are discounted as considered appropriate based on age and quality of the information and current market conditions. The following tables show the composition of the Corporation’s impaired loans, related allowance and interest income recognized while impaired by loan class as of the periods indicated: March 31, 2018 Unpaid Recorded Related Impaired loans with no related allowance: Commercial and industrial loans $ 7,863 $ 1,812 Agriculture production financing and other loans to farmers 660 640 Real estate Loans: Commercial and farmland 16,581 14,388 Residential 1,146 790 Home equity 40 8 Individuals' loans for household and other personal expenditures 11 11 Total $ 26,301 $ 17,649 Impaired loans with related allowance: Commercial and industrial loans $ 474 $ 462 $ 143 Real estate Loans: Construction 1,352 1,352 307 Commercial and farmland 823 761 451 Residential 1,697 1,636 341 Home equity 324 304 75 Total $ 4,670 $ 4,515 $ 1,317 Total Impaired Loans $ 30,971 $ 22,164 $ 1,317 December 31, 2017 Unpaid Recorded Related Impaired loans with no related allowance: Commercial and industrial loans $ 7,611 $ 1,536 Agriculture production financing and other loans to farmers 732 700 Real estate Loans: Commercial and farmland 16,758 15,162 Residential 833 519 Home equity 40 8 Individuals' loans for household and other personal expenditures 5 5 Total $ 25,979 $ 17,930 Impaired loans with related allowance: Commercial and industrial loans $ 812 $ 782 $ 552 Agriculture production financing and other loans to farmers 357 327 114 Real estate Loans: Commercial and farmland 2,989 2,270 567 Residential 1,616 1,572 327 Home equity 349 330 77 Total $ 6,123 $ 5,281 $ 1,637 Total Impaired Loans $ 32,102 $ 23,211 $ 1,637 Three Months Ended March 31, 2018 Three Months Ended March 31, 2017 Average Interest Average Interest Impaired loans with no related allowance: Commercial and industrial loans $ 1,845 $ 1,066 Agriculture production financing and other loans to farmers 640 Real estate Loans: Commercial and farmland 14,450 $ 48 14,963 $ 80 Residential 759 6 935 1 Home equity 8 26 Individuals' loans for household and other personal expenditures 12 7 Total $ 17,714 $ 54 $ 16,997 $ 81 Impaired loans with related allowance: Commercial and industrial loans $ 465 Agriculture production financing and other loans to farmers $ 657 Real estate Loans: Construction 1,352 Commercial and farmland 767 2,848 Residential 1,709 $ 12 1,062 $ 6 Home equity 305 2 260 2 Total $ 4,598 $ 14 $ 4,827 $ 8 Total Impaired Loans $ 22,312 $ 68 $ 21,824 $ 89 Impaired loans in the December 31, 2017 table do not include loans accounted for under ASC 310-30, or any other loan, unless deemed impaired in accordance with ASC 310-10. As part of the ongoing monitoring of the credit quality of the Corporation's loan portfolio, management tracks certain credit quality indicators including trends related to: (i) the level of criticized commercial loans, (ii) net charge-offs, (iii) non-performing loans, (iv) covenant failures and (v) the general national and local economic conditions. The Corporation utilizes a risk grading of pass, special mention, substandard, doubtful and loss to assess the overall credit quality of large commercial loans. All large commercial credit grades are reviewed at a minimum of once a year for pass grade loans. Loans with grades below pass are reviewed more frequently depending on the grade. A description of the general characteristics of these grades is as follows: • Pass - Loans that are considered to be of acceptable credit quality. • Special Mention - Loans which possess some credit deficiency or potential weakness, which deserves close attention. If left uncorrected, these potential weaknesses may result in deterioration of the repayment prospects for the asset or in the Corporation's credit position at some future date. Special mention assets are not adversely classified and do not expose the Corporation to sufficient risk to warrant adverse classification. The key distinctions of this category's classification are that it is indicative of an unwarranted level of risk; and weaknesses are considered “potential”, not “defined”, impairments to the primary source of repayment. Examples include businesses that may be suffering from inadequate management, loss of key personnel or significant customer or litigation. • Substandard - A substandard loan is inadequately protected by the current net worth and paying capacity of the obligor or of the collateral pledged, if any. Assets so classified have a well-defined weakness that jeopardizes the liquidation of the debt. They are characterized by the distinct possibility that the Corporation will sustain some loss if the deficiencies are not corrected. Other characteristics may include: o the likelihood that a loan will be paid from the primary source of repayment is uncertain or financial deterioration is underway and very close attention is warranted to ensure that the loan is collected without loss, o the primary source of repayment is gone, and the Corporation is forced to rely on a secondary source of repayment, such as collateral liquidation or guarantees, o loans have a distinct possibility that the Corporation will sustain some loss if deficiencies are not corrected, o unusual courses of action are needed to maintain a high probability of repayment, o the borrower is not generating enough cash flow to repay loan principal; however, it continues to make interest payments, o the Corporation is forced into a subordinated or unsecured position due to flaws in documentation, o loans have been restructured so that payment schedules, terms and collateral represent concessions to the borrower when compared to the normal loan terms, o the Corporation is seriously contemplating foreclosure or legal action due to the apparent deterioration of the loan, and o there is significant deterioration in market conditions to which the borrower is highly vulnerable. • Doubtful - Loans that have all of the weaknesses of those classified as Substandard. However, based on currently existing facts, conditions and values, these weaknesses make full collection of principal highly questionable and improbable. Other credit characteristics may include considerable doubt as to the quality of the secondary sources of repayment. The possibility of loss is high, but because of certain important pending factors that may strengthen the loan, loss classification is deferred until the exact status of repayment is known. • Loss – Loans that are considered uncollectable and of such little value that continuing to carry them as an asset is not warranted. Loans will be classified as Loss when it is neither practical not desirable to defer writing off or reserving all or a portion of a basically worthless asset, even though partial recovery may be possible at some time in the future. The following tables summarize the credit quality of the Corporation’s loan portfolio, by loan class for the periods indicated. Consumer non-performing loans include accruing consumer loans 90 plus days delinquent and consumer non-accrual loans. The entire balance of a loan is considered delinquent if the minimum payment contractually required to be made is not received by the specified date. Loans that evidenced deterioration of credit quality since origination and it was probable, at acquisition, that all contractually required payments would not be collected are included in the applicable categories below. March 31, 2018 Commercial Commercial Commercial Substandard Commercial Commercial Loss Consumer Performing Consumer Total Commercial and industrial loans $ 1,465,692 $ 58,916 $ 29,561 $ 1,554,169 Agriculture production financing and other loans to farmers 57,888 16,599 23,828 98,315 Real estate Loans: Construction 553,131 1,363 11,918 $ 23,552 $ 129 590,093 Commercial and farmland 2,557,293 64,356 88,312 $ 1,117 2,914 2 2,713,994 Residential 179,135 5,198 5,340 31 753,126 5,814 948,644 Home equity 27,372 532 344 480,830 1,467 510,545 Individuals' loans for household and other personal expenditures 88,159 76 88,235 Lease financing receivables, net of unearned income 2,193 2,193 Other commercial loans 395,155 353 395,508 Loans $ 5,237,859 $ 146,964 $ 159,656 $ 1,148 $ 1,348,581 $ 7,488 $ 6,901,696 December 31, 2017 Commercial Commercial Commercial Substandard Commercial Commercial Loss Consumer Performing Consumer Total Commercial and industrial loans $ 1,418,401 $ 51,336 $ 23,386 $ 370 $ 1,493,493 Agriculture production financing and other loans to farmers 73,800 27,502 20,018 387 $ 50 121,757 Real estate Loans: Construction 587,906 828 981 $ 22,374 $ 130 612,219 Commercial and farmland 2,408,329 70,074 79,769 1,536 2,980 3 2,562,691 Residential 185,725 4,376 4,209 114 759,900 8,441 962,765 Home equity 28,554 457 286 482,661 2,063 514,021 Individuals' loans for household and other personal expenditures 86,875 60 86,935 Lease financing receivables, net of unearned income 2,527 2,527 Other commercial loans 394,222 569 394,791 Loans $ 5,099,464 $ 154,573 $ 129,218 $ 2,407 $ 50 $ 1,354,790 $ 10,697 $ 6,751,199 The tables below show a past due aging of the Corporation’s loan portfolio, by loan class, as of March 31, 2018 , and December 31, 2017 : March 31, 2018 Current 30-59 Days 60-89 Days Loans > 90 Days Non-Accrual Total Past Due Total Commercial and industrial loans $ 1,549,330 $ 1,062 $ 49 $ 490 $ 3,238 $ 4,839 $ 1,554,169 Agriculture production financing and other loans to farmers 89,198 8,479 638 9,117 98,315 Real estate loans: Construction 588,424 188 1,481 1,669 590,093 Commercial and farmland 2,693,020 5,589 1,378 63 13,944 20,974 2,713,994 Residential 938,960 2,577 305 37 6,765 9,684 948,644 Home equity 506,922 1,638 481 119 1,385 3,623 510,545 Individuals' loans for household and other personal expenditures 87,933 170 57 29 46 302 88,235 Lease financing receivables, net of unearned income 2,193 2,193 Other commercial loans 395,508 395,508 Loans $ 6,851,488 $ 19,703 $ 2,270 $ 738 $ 27,497 $ 50,208 $ 6,901,696 December 31, 2017 Current 30-59 Days 60-89 Days Loans > 90 Days Non-Accrual Total Past Due Total Commercial and industrial loans $ 1,487,221 $ 2,967 $ 30 $ 3,275 $ 6,272 $ 1,493,493 Agriculture production financing and other loans to farmers 120,720 10 1,027 1,037 121,757 Real estate loans: Construction 610,896 1,193 $ 65 65 1,323 612,219 Commercial and farmland 2,542,048 6,923 166 603 12,951 20,643 2,562,691 Residential 948,947 4,010 308 56 9,444 13,818 962,765 Home equity 510,362 1,372 184 175 1,928 3,659 514,021 Individuals' loans for household and other personal expenditures 85,744 298 834 25 34 1,191 86,935 Lease financing receivables, net of unearned income 2,527 2,527 Other commercial loans 394,791 394,791 Loans $ 6,703,256 $ 16,773 $ 1,522 $ 924 $ 28,724 $ 47,943 $ 6,751,199 See the information regarding the analysis of loan loss experience in the "LOAN QUALITY/PROVISION FOR LOAN LOSSES" section of Management’s Discussion and Analysis of Financial Condition and Results of Operations included as Item 2 of this Quarterly Report on Form 10-Q. On occasion, borrowers experience declines in income and cash flow. As a result, these borrowers seek to reduce contractual cash outlays including debt payments. Concurrently, in an effort to preserve and protect its earning assets, specifically troubled loans, the Corporation works to maintain its relationship with certain customers who are experiencing financial difficulty by contractually modifying the borrower's debt agreement with the Corporation. In certain loan restructuring situations, the Corporation may grant a concession to a debtor experiencing financial difficulty, resulting in a trouble debt restructuring. A concession is deemed to be granted when, as a result of the restructuring, the Corporation does not expect to collect all original amounts due, including interest accrued at the original contract rate. If the payment of principal at original maturity is primarily dependent on the value of collateral, the current value of the collateral is considered in determining whether the principal will be paid. The following tables summarize troubled debt restructures in the Corporation's loan portfolio that occurred during the periods indicated: Three Months Ended March 31, 2018 Pre-Modification Post-Modification Number Real estate loans: Residential $ 214 $ 222 5 Home equity 16 16 2 Individuals' loans for household and other personal expenditures 7 8 1 Total $ 237 $ 246 8 Three Months Ended March 31, 2017 Pre-Modification Post-Modification Number Real estate loans: Commercial and farmland $ 107 $ 241 3 Residential 121 122 2 Home equity 122 Total $ 350 $ 363 5 The following tables summarize the recorded investment of troubled debt restructures as of March 31, 2018 and 2017 , by modification type, that occurred during the periods indicated: Three Months Ended March 31, 2018 Term Rate Combination Total Real estate loans: Residential $ 38 $ 74 $ 106 $ 218 Home equity 16 10 26 Individuals' loans for household and other personal expenditures 7 7 Total $ 54 $ 91 $ 106 $ 251 Three Months Ended March 31, 2017 Term Rate Combination Total Real estate loans: Commercial and farmland $ 241 $ 241 Residential $ 122 122 Total $ 122 $ 241 $ 363 Loans secured by residential real estate made up 91 percent of the post-modification balance of troubled debt restructured loans made in the three months ended March 31, 2018 . The following tables summarize troubled debt restructures that occurred during the twelve months ended March 31, 2018 and 2017, that subsequently defaulted during the period indicated and remained in default at period end. For purposes of this schedule, a loan is considered in default if it is 30 or more days past due. Three Months Ended March 31, 2018 Number of Loans Recorded Balance Real estate loans: Commercial and farmland 1 $ 324 Residential 3 108 Total 4 $ 432 Three Months Ended March 31, 2017 Number of Loans Recorded Balance Real estate loans: Commercial and farmland 1 $ 223 Total 1 $ 223 For potential consumer loan restructures, impairment evaluation occurs prior to modification. Any subsequent impairment is typically addressed through the charge-off process, or may be addressed through a specific reserve. Consumer troubled debt loan restructures are generally included in the general historical allowance for loan loss at the post modification balance. Consumer non-accrual and delinquent troubled debt loan restructures are also considered in the calculation of the non-accrual and delinquency trend environmental allowance allocation. Consumer mortgage loans secured by residential real estate properties for which formal foreclosure proceedings are in process totaled $1,465,000 and $2,302,000 at March 31, 2018 and December 31, 2017, respectively. Commercial troubled debt restructured loans risk graded special mention, substandard, doubtful and loss are individually evaluated for impairment under ASC 310. Any resulting specific reserves are included in the allowance for loan losses. Commercial troubled debt loan restructures 30 - 89 days delinquent are included in the calculation of the delinquency trend environmental allocation in the allowance for loan losses. With the exception of the acquired loans excluded from the allowance for loan losses, all commercial non-impaired loans, including non-accrual and 90+ day delinquents, are included in the ASC 450 loss estimate.

Purchased Credit Impaired Loans

Purchased Credit Impaired Loans	3 Months Ended
	Mar. 31, 2018
Receivables [Abstract]
Purchased Credit Impaired Loans	PURCHASED CREDIT IMPAIRED LOANS Purchased Credit Impaired Loans are included in NOTE 4. LOANS AND ALLOWANCE, in the Notes to Consolidated Condensed Financial Statements of this Quarterly Report on Form 10-Q. As described in NOTE 4, purchased loans are recorded at the acquisition date fair value, which could result in a fair value discount or premium. Purchased loans with evidence of credit deterioration since origination and for which it is probable at the date of acquisition that the acquirer will not collect all contractually required principal and interest payments are accounted for under ASC 310-30, Loans Acquired with Deteriorated Credit Quality . The difference between contractually required payments and the cash flows expected to be collected at acquisition is referred to as the nonaccretable difference. The accretable portion of the fair value discount or premium is the difference between the expected cash flows and the net present value of expected cash flows, with such difference accreted into earnings over the term of the loans. The carrying amount of Purchased Credit Impaired Loans as of March 31, 2018 and December 31, 2017 was $24.3 million and $25.3 million , respectively; with no required allowance for loan losses. As customer cash flow expectations improve, nonaccretable yield can be reclassified to accretable yield. The accretable yield, or income expected to be collected, and reclassifications from nonaccretable, are identified in the table below. Three Months Ended March 31, 2018 Three Months Ended March 31, 2017 Beginning balance $ 2,890 $ 3,950 Additions Accretion (510 ) (3,238 ) Reclassification from nonaccretable 295 2,370 Disposals Ending balance $ 2,675 $ 3,082 There were no loans acquired during the three month periods ended March 31, 2018 and 2017, for which it was probable that all contractually required payments would not be collected.

Goodwill

Goodwill	3 Months Ended
	Mar. 31, 2018
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill	GOODWILL Goodwill is recorded on the acquisition date of an entity. During the measurement period, the Corporation may record subsequent adjustments to goodwill for provisional amounts recorded at the acquisition date. The IAB acquisition on July, 14, 2017 resulted in $153,636,000 of goodwill. The Arlington Bank acquisition on May 19, 2017 resulted in $47,719,000 of goodwill, which includes a reduction of $469,000 . This reduction was recorded in the third quarter of 2017 as a measurement period adjustment. Details regarding the IAB and Arlington Bank acquisitions are discussed in NOTE 2. ACQUISITIONS of these Notes to Consolidated Condensed Financial Statements. There have been no changes in goodwill since December 31, 2017 , resulting in a goodwill balance of $445,355,000 as of March 31, 2018 . 2017 Balance, January 1 $ 244,000 Goodwill acquired 201,824 Measurement period adjustment (469 ) Balance, December 31 $ 445,355

Other Intangibles

Other Intangibles	3 Months Ended
	Mar. 31, 2018
Goodwill and Intangible Assets Disclosure [Abstract]
Other Intangibles	OTHER INTANGIBLES Core deposit intangibles and other intangibles are recorded on the acquisition date of an entity. During the measurement period, the Corporation may record subsequent adjustments to these intangibles for provisional amounts recorded at the acquisition date. The IAB acquisition on July 14, 2017 resulted in a core deposit intangible of $13,638,000 and other intangibles, consisting of non-compete intangibles, of $3,765,000 . The Arlington Bank acquisition on May 19, 2017 resulted in a core deposit intangible of $4,526,000 . Details regarding the IAB acquisition are discussed in NOTE 2. ACQUISITIONS of these Notes to Consolidated Condensed Financial Statements. The carrying basis and accumulated amortization of recognized core deposit intangibles and other intangibles are noted below. March 31, 2018 December 31, 2017 Gross carrying amount $ 85,869 $ 63,940 Core deposit intangibles acquired 18,164 Other intangibles acquired 3,765 Accumulated amortization (56,447 ) (54,721 ) Total other intangibles $ 29,422 $ 31,148 The core deposit intangibles and other intangibles are being amortized primarily on an accelerated basis over their estimated useful lives, generally over a period of two to ten years. Estimated future amortization expense is summarized as follows: Amortization Expense 2018 $ 4,993 2019 5,169 2020 3,632 2021 3,427 2022 3,325 After 2022 8,876 $ 29,422

Derivative Financial Instrument

Derivative Financial Instruments	3 Months Ended
	Mar. 31, 2018
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivative Financial Instruments	DERIVATIVE FINANCIAL INSTRUMENTS Risk Management Objective of Using Derivatives The Corporation is exposed to certain risks arising from both its business operations and economic conditions. The Corporation principally manages its exposures to a wide variety of business and operational risks through management of its core business activities. The Corporation manages economic risks, including interest rate, liquidity, and credit risk, primarily by managing the amount, sources, and duration of its assets and liabilities and through the use of derivative financial instruments. Specifically, the Corporation enters into derivative financial instruments to manage exposures that arise from business activities that result in the receipt or payment of future known and uncertain cash amounts, the value of which are determined by interest rates. The Corporation’s derivative financial instruments are used to manage differences in the amount, timing, and duration of the Corporation’s known or expected cash payments principally related to certain variable-rate liabilities. The Corporation also has derivatives that are a result of a service the Corporation provides to certain qualifying customers, and, therefore, are not used to manage interest rate risk in the Corporation’s assets or liabilities. The Corporation manages a matched book with respect to its derivative instruments offered as a part of this service to its customers in order to minimize its net risk exposure resulting from such transactions. Cash Flow Hedges of Interest Rate Risk The Corporation’s objectives in using interest rate derivatives are to add stability to interest expense and to manage its exposure to interest rate movements. To accomplish these objectives, the Corporation primarily uses interest rate swaps and interest rate caps as part of its interest rate risk management strategy. Interest rate swaps designated as cash flow hedges involve the payment of fixed amounts to a counterparty in exchange for the Corporation receiving variable payments over the life of the agreements without exchange of the underlying notional amount. Interest rate caps designated as cash flow hedges involve the receipt of variable amounts from a counterparty if interest rates rise above the strike rate on the contract in exchange for an up-front premium. As of March 31, 2018 and December 31, 2017 , the Corporation had five interest rate swaps with a notional amount of $56.0 million and one interest rate cap with a notional amount of $13.0 million that were designated as cash flow hedges. The effective portion of changes in the fair value of derivatives designated and that qualify as cash flow hedges is recorded in accumulated other comprehensive income and is subsequently reclassified into earnings in the period that the hedged forecasted transaction affects earnings. During 2018 , $26.0 million of the interest rate swaps and the $13.0 million interest rate cap were used to hedge the variable cash outflows (LIBOR-based) associated with existing trust preferred securities when the outflows converted from a fixed rate to variable rate in September of 2012. In addition, the remaining $30.0 million of interest rate swaps were used to hedge the variable cash outflows (LIBOR-based) associated with three Federal Home Loan Bank advances. The ineffective portion of the change in fair value of the derivatives is recognized directly in earnings. During the three months ended March 31, 2018 , and 2017 , the Corporation did not recognize any ineffectiveness. Amounts reported in accumulated other comprehensive income related to derivatives will be reclassified to interest expense as interest payments are made on the Corporation's variable-rate liabilities. During the next twelve months, the Corporation expects to reclassify $393,000 from accumulated other comprehensive income to interest expense. Non-designated Hedges The Corporation does not use derivatives for trading or speculative purposes. Derivatives not designated as hedges are not speculative and result from a service the Corporation provides to certain customers. The Corporation executes interest rate swaps with commercial banking customers to facilitate their respective risk management strategies. Those interest rate swaps are simultaneously hedged by offsetting interest rate swaps that the Corporation executes with a third party, such that the Corporation minimizes its net risk exposure resulting from such transactions. As the interest rate swaps associated with this program do not meet the strict hedge accounting requirements, changes in the fair value of both the customer swaps and the offsetting swaps are recognized directly in earnings. As of March 31, 2018 , the notional amount of customer-facing swaps was approximately $429,360,000 . This amount is offset with third party counterparties, as described above. Fair Values of Derivative Instruments on the Balance Sheet The table below presents the fair value of the Corporation’s derivative financial instruments, as well as their classification on the Balance Sheet, as of March 31, 2018 , and December 31, 2017 . Asset Derivatives Liability Derivatives March 31, 2018 December 31, 2017 March 31, 2018 December 31, 2017 Balance Fair Balance Fair Balance Fair Balance Fair Derivatives designated as hedging instruments: Interest rate contracts Other Assets $ 258 Other Assets $ 18 Other Liabilities $ 689 Other Liabilities $ 1,383 Derivatives not designated as hedging instruments: Interest rate contracts Other Assets $ 11,376 Other Assets $ 7,305 Other Liabilities $ 11,376 Other Liabilities $ 7,305 The amount of gain (loss) recognized in other comprehensive income is included in the table below for the periods indicated. Derivatives in Cash Flow Hedging Relationships Amount of Gain (Loss) Recognized in Other Comprehensive Income on Derivative Three Months Ended March 31, 2018 March 31, 2017 Interest Rate Products $ 508 $ 34 Effect of Derivative Instruments on the Income Statement The Corporation did not recognize any gains or losses from derivative financial instruments in the Income Statement for the three months ended March 31, 2018 and 2017 . The amount of gain (loss) reclassified from other comprehensive income into income is included in the table below for the periods indicated. Derivatives Designated as Location of Gain (Loss) Amount of Gain (Loss) Reclassed from Other Comprehensive Income into Income (Effective Portion) Three Months Ended Three Months Ended Interest rate contracts Interest Expense $ (170 ) $ (268 ) The Corporation’s exposure to credit risk occurs because of nonperformance by its counterparties. The counterparties approved by the Corporation are usually financial institutions, which are well capitalized and have credit ratings through Moody’s and/or Standard & Poor’s at or above investment grade. The Corporation’s control of such risk is through quarterly financial reviews, comparing mark-to-market values with policy limitations, credit ratings and collateral pledging. Credit-risk-related Contingent Features The Corporation has agreements with certain of its derivative counterparties that contain a provision where if the Corporation fails to maintain its status as a well or adequately capitalized institution, then the Corporation could be required to terminate or fully collateralize all outstanding derivative contracts. Additionally, the Corporation has agreements with certain of its derivative counterparties that contain a provision where if the Corporation defaults on any of its indebtedness, including default where repayment of the indebtedness has not been accelerated by the lender, then the Corporation could also be declared in default on its derivative obligations. As of March 31, 2018 , the termination value of derivatives in a net liability position related to these agreements was $1,068,000 . As of March 31, 2018 , the Corporation has minimum collateral posting thresholds with certain of its derivative counterparties and has posted collateral of $3,315,000 . If the Corporation had breached any of these provisions at March 31, 2018 , it could have been required to settle its obligations under the agreements at their termination value.

Disclosures About Fair Value of

Disclosures About Fair Value of Assets and Liabilities	3 Months Ended
	Mar. 31, 2018
Fair Value Disclosures [Abstract]
Disclosures About Fair Value of Assets and Liabilities	DISCLOSURES ABOUT FAIR VALUE OF ASSETS AND LIABILITIES The Corporation used fair value measurements to record fair value adjustments to certain assets and liabilities and to determine fair value disclosures. The accounting guidance defines fair value, establishes a framework for measuring fair value and expands disclosures about fair value measurements. ASC 820 applies only when other guidance requires or permits assets or liabilities to be measured at fair value; it does not expand the use of fair value in any new circumstances. As defined in ASC 820, fair value is the price to sell an asset or transfer a liability in an orderly transaction between market participants. It represents an exit price at the measurement date. Market participants are buyers and sellers, who are independent, knowledgeable, and willing and able to transact in the principal (or most advantageous) market for the asset or liability being measured. Current market conditions, including imbalances between supply and demand, are considered in determining fair value. The Corporation values its assets and liabilities in the principal market where it sells the particular asset or transfers the liability with the greatest volume and level of activity. In the absence of a principal market, the valuation is based on the most advantageous market for the asset or liability (i.e., the market where the asset could be sold or the liability transferred at a price that maximizes the amount to be received for the asset or minimizes the amount to be paid to transfer the liability). Valuation inputs refer to the assumptions market participants would use in pricing a given asset or liability. Inputs can be observable or unobservable. Observable inputs are those assumptions which market participants would use in pricing the particular asset or liability. These inputs are based on market data and are obtained from a source independent of the Corporation. Unobservable inputs are assumptions based on the Corporation’s own information or estimate of assumptions used by market participants in pricing the asset or liability. Unobservable inputs are based on the best and most current information available on the measurement date. All inputs, whether observable or unobservable, are ranked in accordance with a prescribed fair value hierarchy which gives the highest ranking to quoted prices (unadjusted) in active markets for identical assets or liabilities (Level 1) and the lowest ranking to unobservable inputs for which there is little or no market activity (Level 3). Fair values for assets or liabilities classified as Level 2 are based on one or a combination of the following factors: (i) quoted prices for similar assets; (ii) observable inputs for the asset or liability, such as interest rates or yield curves; or (iii) inputs derived principally from or corroborated by observable market data. The level in the fair value hierarchy within which the fair value measurement in its entirety falls is determined based on the lowest level input that is significant to the fair value measurement in its entirety. The Corporation considers an input to be significant if it drives 10 percent or more of the total fair value of a particular asset or liability. RECURRING MEASUREMENTS Assets and liabilities are considered to be measured at fair value on a recurring basis if fair value is measured regularly (i.e., daily, weekly, monthly or quarterly). Recurring valuation occurs at a minimum on the measurement date. Assets and liabilities are considered to be measured at fair value on a nonrecurring basis if the fair value measurement of the instrument does not necessarily result in a change in the amount recorded on the balance sheet. Generally, nonrecurring valuation is the result of the application of other accounting pronouncements which require assets or liabilities to be assessed for impairment or recorded at the lower of cost or fair value. The fair value of assets or liabilities transferred in or out of Level 3 is measured on the transfer date, with any additional changes in fair value subsequent to the transfer considered to be realized or unrealized gains or losses. Following is a description of the valuation methodologies used for instruments measured at fair value on a recurring basis and recognized in the accompanying Consolidated Condensed Balance Sheets, as well as the general classification of such instruments pursuant to the valuation hierarchy. Investment Securities Where quoted prices are available in an active market, securities are classified within Level 1 of the valuation hierarchy. The Corporation currently has no securities classified within Level 1 of the hierarchy. Where significant observable inputs, other than Level 1 quoted prices, are available, securities are classified within Level 2 of the valuation hierarchy. Level 2 securities include government-sponsored mortgage backs and state and municipal securities. In certain cases where Level 1 or Level 2 inputs are not available, securities are classified within Level 3 of the hierarchy and include state and municipal, government-sponsored mortgage backs and corporate obligations securities. Level 3 fair value for securities was determined using a discounted cash flow model that incorporated market estimates of interest rates and volatility in markets that have not been active. Third party vendors compile prices from various sources and may apply such techniques as matrix pricing to determine the value of identical or similar investment securities (Level 2). Matrix pricing is a mathematical technique widely used in the banking industry to value investment securities without relying exclusively on quoted prices for specific investment securities but rather relying on the investment securities’ relationship to other benchmark quoted investment securities. Any investment security not valued based upon the methods above are considered Level 3. Interest Rate Derivative Agreements See information regarding the Corporation’s interest rate derivative products in NOTE 8. DERIVATIVE FINANCIAL INSTRUMENTS of these Notes to Consolidated Condensed Financial Statements. The following table presents the fair value measurements of assets and liabilities recognized in the accompanying balance sheets measured at fair value on a recurring basis and the level within the ASC 820-10 fair value hierarchy in which the fair value measurements fall at March 31, 2018 , and December 31, 2017 . Fair Value Measurements Using: March 31, 2018 Fair Value Quoted Prices in Active Markets for Identical Assets Significant Other Significant Available for sale securities: U.S. Government-sponsored agency securities $ 6,498 $ 6,498 State and municipal 510,234 506,303 $ 3,931 U.S. Government-sponsored mortgage-backed securities 487,036 487,032 4 Corporate obligations 31 31 Interest rate swap asset 11,376 11,376 Interest rate cap 258 258 Interest rate swap liability 12,065 12,065 Fair Value Measurements Using: December 31, 2017 Fair Value Quoted Prices in Significant Other Observable Inputs Significant Available for sale securities: State and municipal $ 526,693 $ 522,750 $ 3,943 U.S. Government-sponsored mortgage-backed securities 470,866 470,866 Corporate obligations 31 31 Equity securities 2,357 2,353 4 Interest rate swap asset 7,305 7,305 Interest rate cap 18 18 Interest rate swap liability 8,688 8,688 Level 3 Reconciliation The following is a reconciliation of the beginning and ending balances of recurring fair value measurements recognized in the Consolidated Condensed Balance Sheets using significant unobservable (Level 3) inputs for the three months ended March 31, 2018 and 2017 . Available for Sale Securities Three Months Ended March 31, 2018 March 31, 2017 Balance at beginning of the period $ 3,978 $ 5,169 Included in other comprehensive income (25 ) 11 Principal payments 13 (1,901 ) Ending balance $ 3,966 $ 3,279 There were no gains or losses for the period included in earnings that were attributable to the changes in unrealized gains or losses related to assets or liabilities held at March 31, 2018 or December 31, 2017 . Transfers Between Levels There were no transfers in or out of Level 3 for the three months ended March 31, 2018 and 2017 . Nonrecurring Measurements Following is a description of valuation methodologies used for instruments measured at fair value on a non-recurring basis and recognized in the accompanying balance sheets, as well as the general classification of such instruments pursuant to the valuation hierarchy for March 31, 2018 , and December 31, 2017 . Fair Value Measurements Using March 31, 2018 Fair Value Quoted Prices in Significant Other Significant Unobservable Impaired loans (collateral dependent) $ 7,833 $ 7,833 Other real estate owned 119 119 Fair Value Measurements Using December 31, 2017 Fair Value Quoted Prices in Significant Other Significant Unobservable Impaired loans (collateral dependent) $ 9,576 $ 9,576 Other real estate owned 859 859 Impaired Loans (collateral dependent) Loans for which it is probable that the Corporation will not collect all principal and interest due according to contractual terms are measured for impairment. Allowable methods for determining the amount of impairment include estimating fair value of the collateral for collateral dependent loans. If the impaired loan is identified as collateral dependent, then the fair value method of measuring the amount of impairment is utilized. This method requires obtaining a current independent appraisal of the collateral and applying a discount factor to the value. A portion of the allowance for loan losses is allocated to impaired loans if the value of such loans is deemed to be less than the unpaid balance. If these allocations cause the allowance for loan losses to increase, such increase is reported as a component of the provision for loan losses. Loan losses are charged against the allowance when management believes the uncollectability of the loan is confirmed. During 2017 and 2018 , certain impaired loans were partially charged off or re-evaluated. Impaired loans that are collateral dependent are classified within Level 3 of the fair value hierarchy when impairment is determined using the fair value method. Other Real Estate Owned The fair value for impaired loans and other real estate owned is measured based on the value of the collateral securing those loans or real estate and is determined using several methods. The fair value of real estate is generally determined based on appraisals by qualified licensed appraisers. The appraisers typically determine the value of the real estate by utilizing an income or market valuation approach. If an appraisal is not available, the fair value may be determined by using a discounted cash flow analysis. Fair value on other collateral such as business assets is typically ascertained by assessing, either singularly or some combination of, asset appraisals, accounts receivable aging reports, inventory listings and or customer financial statements. Both appraised values and values based on borrower’s financial information are discounted as considered appropriate based on age and quality of the information and current market conditions. Unobservable (Level 3) Inputs The following table presents quantitative information about unobservable inputs used in recurring and nonrecurring Level 3 fair value measurements, other than goodwill, at March 31, 2018 and December 31, 2017 . March 31, 2018 Fair Value Valuation Technique Unobservable Inputs Range (Weighted-Average) State and municipal securities $ 3,931 Discounted cash flow Maturity/Call date 1 month to 20 yrs US Muni BQ curve A- to BBB- Discount rate 1% - 5% Corporate obligations and U.S. Government-sponsored mortgage backed securities $ 35 Discounted cash flow Risk free rate 3 month LIBOR plus premium for illiquidity plus 200bps Impaired loans (collateral dependent) $ 7,833 Collateral based measurements Discount to reflect current market conditions and ultimate collectability 0% - 10% (1%) Other real estate owned $ 119 Appraisals Discount to reflect current market conditions 0% - 24% (24%) December 31, 2017 Fair Value Valuation Technique Unobservable Inputs Range (Weighted-Average) State and municipal securities $ 3,943 Discounted cash flow Maturity/Call date 1 month to 20 yrs US Muni BQ curve A- to BBB- Discount rate .69% - 5% Corporate obligations and equity securities $ 35 Discounted cash flow Risk free rate 3 month LIBOR plus premium for illiquidity plus 200bps Impaired loans (collateral dependent) $ 9,576 Collateral based measurements Discount to reflect current market conditions and ultimate collectability 0% - 10% (1%) Other real estate owned $ 859 Appraisals Discount to reflect current market conditions 0% - 10% (2%) The following is a discussion of the sensitivity of significant unobservable inputs, the interrelationships between those inputs and other unobservable inputs used in recurring fair value measurement and how those inputs might magnify or mitigate the effect of changes in the unobservable inputs on the fair value measurement. State and Municipal Securities, Corporate Obligations, U.S. Government-sponsored Mortgage Backed and Equity Securities The significant unobservable inputs used in the fair value measurement of the Corporation's state and municipal securities, corporate obligations and U.S. Government-sponsored mortgage backed securities are premiums for unrated securities and marketability discounts. Significant increases or decreases in either of those inputs in isolation would result in a significantly lower or higher fair value measurement. Generally, changes in either of those inputs will not affect the other input. Fair Value of Financial Instruments The following table presents estimated fair values of the Corporation’s financial instruments and the level within the fair value hierarchy in which the fair value measurements fall at March 31, 2018 , and December 31, 2017 . March 31, 2018 Quoted Prices in Active Markets Significant Significant Unobservable Carrying Amount (Level 1) (Level 2) (Level 3) Assets: Cash and cash equivalents $ 128,828 $ 128,828 Interest-bearing time deposits 24,233 24,233 Investment securities available for sale 1,003,799 $ 999,833 $ 3,966 Investment securities held to maturity 540,021 527,253 11,146 Loans held for sale 4,469 4,469 Loans 6,825,276 6,649,237 Federal Home Loan Bank stock 24,588 24,588 Interest rate swap and cap asset 11,634 11,634 Interest receivable 35,223 35,223 Liabilities: Deposits $ 7,327,635 $ 5,849,466 $ 1,450,066 Borrowings: Federal funds purchased 50,000 50,000 Securities sold under repurchase agreements 138,910 138,770 Federal Home Loan Bank advances 449,419 443,804 Subordinated debentures and term loans 138,297 123,485 Interest rate swap liability 12,065 12,065 Interest payable 5,376 5,376 December 31, 2017 Quoted Prices in Active Markets Significant Significant Unobservable Carrying Amount (Level 1) (Level 2) (Level 3) Assets: Cash and cash equivalents $ 154,905 $ 154,905 Interest-bearing time deposits 35,027 35,027 Investment securities available for sale 999,947 $ 995,969 $ 3,978 Investment securities held to maturity 560,655 556,305 11,903 Loans held for sale 7,216 7,216 Loans 6,676,167 6,534,877 Federal Home Loan Bank stock 23,825 23,825 Interest rate swap and cap asset 7,323 7,323 Interest receivable 37,130 37,130 Liabilities: Deposits $ 7,172,530 $ 5,741,019 $ 1,406,526 Borrowings: Federal funds purchased 144,038 144,038 Securities sold under repurchase agreements 136,623 136,562 Federal Home Loan Bank advances 414,377 361,085 Subordinated debentures and term loans 139,349 120,085 Interest rate swap liability 8,688 8,688 Interest payable 4,390 4,390 The following methods were used to estimate the fair value of all other financial instruments recognized in the Consolidated Condensed Balance Sheets at amounts other than fair value. Cash and cash equivalents: The fair value of cash and cash equivalents approximates carrying value. Interest-bearing time deposits: The fair value of interest-bearing time deposits approximates carrying value. Investment securities: Fair value is based on quoted market prices, if available. If a quoted market price is not available, fair value is estimated using quoted prices for similar securities. The fair values of certain Level 3 securities were estimated using discounted cash flow analyses, using interest rates currently being offered on investments with similar maturities and investment quality. Loans held for sale: The carrying amount approximates fair value due to the short duration between origination and date of sale. Loans: For March 31, 2018, fair values of loans are estimated on an exit price basis incorporating discounts for credit, liquidity and marketability factors. This is not comparable with the fair values disclosed for December 31, 2017, which were based on an entrance price basis. For that date, fair values of variable rate loans that reprice frequently and with no significant change in credit risk were based on carrying values. The fair values of other loans as of that date were estimated using discounted cash flow analyses which used interest rates then being offered for loans with similar terms to borrowers of similar credit quality. Federal Home Loan Bank stock: The fair value of Federal Home Loan Bank stock is based on the price which it may be resold to the Federal Home Loan Bank. Derivative instruments: The fair value of interest rate swaps reflects the estimated amounts that would have been received to terminate these contracts at the reporting date based upon pricing or valuation models applied to current market information. Interest rate caps are valued using the market standard methodology of discounting the future expected cash receipts that would occur if variable interest rates rose above the strike rate of the caps. The projected cash receipts on the caps are based on an expectation of future interest rates derived from observed market interest rate curves and volatilities. Interest receivable and Interest payable: The fair value of interest receivable and payable approximates carrying value. Deposits: The fair values of noninterest-bearing and interest-bearing demand accounts and savings deposits are equal to the amount payable on demand at the balance sheet date. The carrying amounts for variable rate, fixed-term certificates of deposit approximate their fair values at the balance sheet date. Fair values for fixed-rate certificates of deposit and other time deposits are estimated using a discounted cash flow calculation that applies interest rates currently being offered to a schedule of aggregated expected monthly maturities on such time deposits. Borrowings: The fair value of federal funds purchased approximates the carrying amount. The fair value of all other borrowings is estimated using a discounted cash flow calculation, based on current rates for similar debt.

Transfers Accounted for as Secu

Transfers Accounted for as Secured Borrowings	3 Months Ended
	Mar. 31, 2018
Banking and Thrift [Abstract]
Transfers Accounted for as Secured Borrowings	TRANSFERS ACCOUNTED FOR AS SECURED BORROWINGS The collateral pledged for all repurchase agreements that are accounted for as secured borrowings as of March 31, 2018 and December 31, 2017 were: March 31, 2018 Remaining Contractual Maturity of the Agreements Overnight and Continuous Up to 30 Days 30-90 Days Greater Than 90 Days Total U.S. Government-sponsored mortgage-backed securities $ 129,490 $ 300 $ 9,120 $ 138,910 December 31, 2017 Remaining Contractual Maturity of the Agreements Overnight and Continuous Up to 30 Days 30-90 Days Greater Than 90 Days Total U.S. Government-sponsored mortgage-backed securities $ 126,187 $ 1,340 $ 1,500 $ 7,596 $ 136,623

Accumulated Other Comprehensive

Accumulated Other Comprehensive Income (Loss)	3 Months Ended
	Mar. 31, 2018
Equity [Abstract]
Accumulated Other Comprehensive Income (Loss)	ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS) The following table summarizes the changes in the balances of each component of accumulated other comprehensive income (loss), net of tax, as of March 31, 2018 and 2017 : Accumulated Other Comprehensive Income (Loss) Unrealized Gains (Losses) on Securities Available for Sale Unrealized Gains (Losses) on Cash Flow Hedges Unrealized Gains (Losses) on Defined Benefit Plans Total Balance at December 31, 2017 $ 8,970 $ (1,125 ) $ (10,753 ) $ (2,908 ) Other comprehensive income before reclassifications (17,698 ) 644 (17,054 ) Amounts reclassified from accumulated other comprehensive income (1,271 ) 134 (1,137 ) Period change (18,969 ) 778 — (18,191 ) Reclassification adjustment under ASU 2018-02 1,932 (242 ) (2,316 ) (626 ) Balance at March 31, 2018 $ (8,067 ) $ (589 ) $ (13,069 ) $ (21,725 ) Balance at December 31, 2016 $ 1,035 $ (1,774 ) $ (12,842 ) $ (13,581 ) Other comprehensive income before reclassifications 10,110 23 10,133 Amounts reclassified from accumulated other comprehensive income (389 ) 174 (59 ) (274 ) Period change 9,721 197 (59 ) 9,859 Balance at March 31, 2017 $ 10,756 $ (1,577 ) $ (12,901 ) $ (3,722 ) The following tables present the reclassification adjustments out of accumulated other comprehensive income (loss) that were included in net income in the Consolidated Condensed Statements of Income for the three months ended March 31, 2018 and 2017 . Amount Reclassified from Accumulated Other Comprehensive Income (Loss) For the Three Months Ended March 31, Details about Accumulated Other Comprehensive Income (Loss)Components 2018 2017 Affected Line Item in the Statements of Income Unrealized gains (losses) on available for sale securities (1) Realized securities gains reclassified into income $ 1,609 $ 598 Other income - net realized gains on sales of available for sale securities Related income tax expense (338 ) (209 ) Income tax expense $ 1,271 $ 389 Unrealized gains (losses) on cash flow hedges (2) Interest rate contracts $ (170 ) $ (268 ) Interest expense - subordinated debentures and term loans Related income tax benefit 36 94 Income tax expense $ (134 ) $ (174 ) Unrealized gains (losses) on defined benefit plans Amortization of prior service costs $ 91 Other expenses - salaries and employee benefits Related income tax expense (32 ) Income tax expense $ — $ 59 Total reclassifications for the period, net of tax $ 1,137 $ 274 (1) For additional detail related to unrealized gains (losses) on available for sale securities and related amounts reclassified from accumulated other comprehensive income see NOTE 3. INVESTMENT SECURITIES of these Notes to Consolidated Condensed Financial Statements. (2) For additional detail related to unrealized gains (losses) on cash flow hedges and related amounts reclassified from accumulated other comprehensive income see NOTE 8. DERIVATIVE FINANCIAL INSTRUMENTS of these Notes to Consolidated Condensed Financial Statements.

Share-Based Compensation

Share-Based Compensation	3 Months Ended
	Mar. 31, 2018
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Share-Based Compensation	SHARE-BASED COMPENSATION Stock options and RSAs have been issued to directors, officers and other management employees under the Corporation's 1999 Long-term Equity Incentive Plan and the 2009 Long-term Equity Incentive Plan. The stock options, which have a ten year life, become 100 percent vested ranging from six months to two years and are fully exercisable when vested. Option exercise prices equal the Corporation's common stock closing price on NASDAQ on the date of grant. RSAs issued to employees and non-employee directors provide for the issuance of shares of the Corporation's common stock at no cost to the holder and generally vest after three years. The RSAs vest only if the employee is actively employed by the Corporation on the vesting date and, therefore, any unvested shares are forfeited. For non-employee directors, the RSAs vest only if the non-employee director remains as an active board member on the vesting date and, therefore, any unvested shares are forfeited. RSAs for employees and non-employee directors retired from the Corporation are either immediately vested at retirement or continue to vest after retirement, depending on the plan under which the shares were granted. Deferred Stock Units ("DSU") can be credited to non-employee directors who have elected to defer payment of compensation under the Corporation's 2008 Equity Compensation Plan for Non-employee Directors. DSUs credited are equal to the restricted shares that the non-employee director would have received under the plan. As of March 31, 2018 , there were no outstanding DSUs. The Corporation’s 2009 ESPP provides eligible employees of the Corporation and its subsidiaries an opportunity to purchase shares of common stock of the Corporation through quarterly offerings financed by payroll deductions. The price of the stock to be paid by the employees shall be equal to 85 percent of the average of the closing price of the Corporation’s common stock on each trading day during the offering period. However, in no event shall such purchase price be less than the lesser of an amount equal to 85 percent of the market price of the Corporation’s stock on the offering date or an amount equal to 85 percent of the market value on the date of purchase. Common stock purchases are made quarterly and are paid through advance payroll deductions up to a calendar year maximum of $25,000 . Compensation expense related to unvested share-based awards is recorded by recognizing the unamortized grant date fair value of these awards over the remaining service periods of those awards, with no change in historical reported fair values and earnings. Awards are valued at fair value in accordance with provisions of share-based compensation guidance and are recognized on a straight-line basis over the service periods of each award. To complete the exercise of vested stock options, RSA’s and ESPP options, the Corporation generally issues new shares from its authorized but unissued share pool. Share-based compensation for the three months ended March 31, 2018 was $875,000 compared to $573,000 for the three months ended March 31, 2017 . Share-based compensation has been recognized as a component of salaries and benefits expense in the accompanying Consolidated Condensed Statements of Income. Share-based compensation expense recognized in the Consolidated Condensed Statements of Income is based on awards ultimately expected to vest and is reduced for estimated forfeitures. Share-based compensation guidance requires forfeitures to be estimated at the time of grant and revised, if necessary, in subsequent periods, if actual forfeitures differ from those estimates. Pre-vesting forfeitures were estimated to be approximately 2.2 percent for the three months ended March 31, 2018 , based on historical experience. The following table summarizes the components of the Corporation's share-based compensation awards recorded as expense and the income tax benefit of such awards. Three Months Ended 2018 2017 Stock and ESPP Options Pre-tax compensation expense $ 24 $ 48 Income tax benefit (59 ) (246 ) Stock and ESPP option expense, net of income taxes $ (35 ) $ (198 ) Restricted Stock Awards Pre-tax compensation expense $ 851 $ 525 Income tax benefit (566 ) (710 ) Restricted stock awards expense, net of income taxes $ 285 $ (185 ) Total Share-Based Compensation Pre-tax compensation expense $ 875 $ 573 Income tax benefit (625 ) (956 ) Total share-based compensation expense, net of income taxes $ 250 $ (383 ) As of March 31, 2018 , unrecognized compensation expense related to RSAs was $5,436,000 and is expected to be recognized over a weighted-average period of 1.65 years. The Corporation did no t have any unrecognized compensation expense related to stock options as of March 31, 2018 . Stock option activity under the Corporation's stock option plans as of March 31, 2018 and changes during the three months ended March 31, 2018 , were as follows: Number of Weighted-Average Exercise Price Weighted Average Remaining Aggregate Outstanding at January 1, 2018 152,652 $ 16.71 Exercised (23,557 ) $ 22.71 Cancelled (200 ) $ 28.25 Outstanding March 31, 2018 128,895 $ 15.59 2.45 $ 3,365,525 Vested and Expected to Vest at March 31, 2018 128,895 $ 15.59 2.45 $ 3,365,525 Exercisable at March 31, 2018 128,895 $ 15.59 2.45 $ 3,365,525 The aggregate intrinsic value in the table above represents the total pre-tax intrinsic value (the difference between the Corporation's closing stock price on the last trading day of the first three months of 2018 and the exercise price, multiplied by the number of in-the-money options) that would have been received by the option holders had all option holders exercised their stock options on March 31, 2018 . The amount of aggregate intrinsic value will change based on the fair market value of the Corporation's common stock. The aggregate intrinsic value of stock options exercised during the three months ended March 31, 2018 and 2017 was $473,000 and $1,823,000 , respectively. Cash receipts of stock options exercised during this same period were $535,000 and $1,314,000 , respectively. The following table summarizes information on unvested RSAs outstanding as of March 31, 2018 : Number of Shares Weighted-Average Unvested RSAs at January 1, 2018 366,993 $ 29.79 Granted 4,687 $ 42.11 Vested (93,076 ) $ 22.91 Forfeited (140 ) $ 22.87 Unvested RSAs at March 31, 2018 278,464 $ 32.31 The grant date fair value of ESPP options was estimated at the beginning of the January 1, 2018 quarterly offering period of approximately $24,200 . The ESPP options vested during the three months ending March 31, 2018 , leaving no unrecognized compensation expense related to unvested ESPP options at March 31, 2018 .

Income Tax

Income Tax	3 Months Ended
	Mar. 31, 2018
Income Tax Disclosure [Abstract]
Income Tax	INCOME TAX The following table summarizes the major components creating differences between income taxes at the federal statutory and the effective tax rate recorded in the consolidated statements of income for the three months ended March 31, 2018 and 2017 : Three Months Ended 2018 2017 Reconciliation of Federal Statutory to Actual Tax Expense: Federal statutory income tax at 21% for 2018 and 35% for 2017 $ 9,091 $ 10,627 Tax-exempt interest income (2,015 ) (2,549 ) Share-based compensation (441 ) (755 ) Tax-exempt earnings and gains on life insurance (247 ) (314 ) Tax credits 39 (106 ) Other 184 265 Actual Tax Expense $ 6,611 $ 7,168 Effective Tax Rate 15.3 % 23.6 %

Net Income Per Share

Net Income Per Share	3 Months Ended
	Mar. 31, 2018
Earnings Per Share [Abstract]
Net Income Per Share	NET INCOME PER SHARE Basic net income per share is computed by dividing net income by the weighted-average shares outstanding during the reporting period. Diluted net income per share is computed by dividing net income by the combination of the weighted-average shares outstanding during the reporting period and all potentially dilutive common shares. Potentially dilutive common shares include stock options and RSAs issued under the Corporation's share-based compensation plans. Potentially dilutive common shares are excluded from the computation of diluted earnings per share in the periods where the effect would be antidilutive. The following table reconciles basic and diluted net income per share for the three months ended March 31, 2018 and 2017 . Three Months Ended March 31, 2018 2017 Net Income Weighted-Average Shares Per Share Net Income Weighted-Average Shares Per Share Net income available to common stockholders $ 36,679 49,192,647 $ 0.75 $ 23,193 40,984,481 $ 0.57 Effect of potentially dilutive stock options and restricted stock awards 235,325 236,105 Diluted net income per share $ 36,679 49,427,972 $ 0.74 $ 23,193 41,220,586 $ 0.56 For the three months ended March 31, 2018 and 2017 , there were no stock options with an option price greater than the average market price of the common shares.

Impact of Accounting Changes

Impact of Accounting Changes	3 Months Ended
	Mar. 31, 2018
Accounting Changes and Error Corrections [Abstract]
Impact of Accounting Changes	IMPACT OF ACCOUNTING CHANGES The Corporation continually monitors potential accounting changes and pronouncements. The following pronouncements have been deemed to have the most applicability to the Corporation's financial statements: FASB Accounting Standards Update No. 2017-12 - Derivatives and Hedging (Topic 815): Targeted Improvements to Accounting for Hedging Activities Summary - The FASB has issued an Accounting Standards Update (ASU) No. 2017-12, Derivatives and Hedging (Topic 815): Targeted Improvements to Accounting for Hedging Activities. The new standard is intended to improve and simplify accounting rules around hedge accounting. The ASU is effective for public companies in 2019 and private companies in 2020. Early adoption is permitted. The new standard refines and expands hedge accounting for both financial (e.g., interest rate) and commodity risks. Its provisions create more transparency around how economic results are presented, both on the face of the financial statements and in the footnotes, for investors and analysts. The new standard takes effect for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2018, for public companies and for fiscal years beginning after December 15, 2019 (and interim periods for fiscal years beginning after December 15, 2020), for private companies. Early adoption is permitted in any interim period or fiscal years before the effective date of the standard. The Corporation plans to adopt ASU 2017-12 in the first quarter of 2019. ASU 2017-12 requires a modified retrospective transition method in which the Corporation will recognize the cumulative effect of the change on the opening balance of each affected component of equity in the statement of financial position as of the date of adoption. While the Corporation continues to assess all potential impacts of the standard, adoption of the standard is not expected to have a significant effect on the Corporation’s consolidated financial statements. FASB Accounting Standards Update No. 2017-08 - Receivables - Nonrefundable Fees and Other Costs (Subtopic 310-20): Premium Amortization on Purchased Callable Debt Securities Summary - The FASB has issued Accounting Standards Update (ASU) No. 2017-08, Receivables-Nonrefundable Fees and Other Costs (Subtopic 310-20), Premium Amortization on Purchased Callable Debt Securities. The ASU shortens the amortization period for certain callable debt securities held at a premium to the earliest call date. Under current GAAP, entities normally amortize the premium as an adjustment of yield over the contractual life of the instrument. Stakeholders have expressed concerns with the current approach on the basis that current GAAP excludes certain callable debt securities from consideration of early repayment of principal even if the holder is certain that the call will be exercised. As a result, upon the exercise of a call on a callable debt security held at a premium, the unamortized premium is recorded as a loss in earnings. Further, there is diversity in practice (1) in the amortization period for premiums of callable debt securities, and (2) in how the potential for exercise of a call is factored into current impairment assessments. Another issue is that the practice in the United States is to quote, price, and trade callable debt securities assuming a model that incorporates consideration of calls (also referred to as “yield-to-worst” pricing). The ASU shortens the amortization period for certain callable debt securities held at a premium and requires the premium to be amortized to the earliest call date. However, the amendments do not require an accounting change for securities held at a discount; the discount continues to be amortized to maturity. The amendments are effective for public business entities for annual periods beginning after December 15, 2018, including interim periods within those annual periods. For other entities, the amendments are effective for annual periods beginning after December 15, 2019, and interim periods within annual periods beginning after December 15, 2020. Early adoption is permitted. Entities are required to apply the amendments on a modified retrospective basis through a cumulative-effect adjustment directly to retained earnings as of the beginning of the period of adoption. The entity is required to provide disclosures about a change in accounting principle in the period of adoption. The Corporation plans to adopt ASU 2017-08 in the first quarter of 2019. Adoption of this ASU is not expected to have a significant effect on the Corporation’s consolidated financial statements. FASB Accounting Standards Update No. 2016-13, Financial Instruments - Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments Summary - The FASB has issued Accounting Standards Update (ASU) No. 2016-13, Financial Instruments - Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments. This new guidance was issued to address concerns that current generally accepted accounting principles (GAAP) restricts the ability to record credit losses that are expected, but do not yet meet the “probable” threshold by replacing the current “incurred loss” model for recognizing credit losses with an “expected life of loan loss” model referred to as the Current Expected Credit Loss (CECL) model. Under the CECL model, certain financial assets carried at amortized cost, such as loans held for investment and held-to-maturity debt securities, are required to be presented at the net amount expected to be collected. The measurement of expected credit losses is to be based on information about past events, including historical experience, current conditions, and reasonable and supportable forecasts that affect the collectability of the reported amount. This measurement will take place at the time the financial asset is first added to the balance sheet and periodically thereafter. This differs significantly from the “incurred loss” model required under current GAAP, which delays recognition until it is probable a loss has been incurred. The change could materially affect how the allowance for loan losses is determined and cause a charge to earnings through the provision for loan losses. Such would adversely affect the financial condition of the Corporation. The ASU is effective for SEC filers for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2019 (i.e., January 1, 2020, for calendar year entities). Early application will be permitted for all organizations for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2018. The Corporation plans to adopt this ASU in the first quarter of 2020. The Corporation expects a one-time cumulative-effect adjustment to the allowance for loan losses will be recognized in retained earnings on the consolidated balance sheet as of the beginning of the first reporting period in which the new standard is effective, as is consistent with regulatory expectations set forth in interagency guidance issued at the end of 2016. The Corporation purchased vendor software and is currently in the implementation process. The implementation team meets on a regular basis to oversee activities and monitor progress. Methodologies are still being evaluated at this time so the magnitude of any such adjustment or the overall impact of the new standard on the financial condition or results of operations cannot yet be determined. FASB Accounting Standards Update No. 2016-02 - Leases (Topic 842) Summary - The FASB has issued its new lease accounting guidance in Accounting Standards Update (ASU) No. 2016-02, Leases (Topic 842). Under the new guidance, lessees will be required to recognize the following for all leases (with the exception of short-term leases) at the commencement date: • A lease liability, which is a lessee‘s obligation to make lease payments arising from a lease, measured on a discounted basis; and • A right-of-use asset, which is an asset that represents the lessee’s right to use, or control the use of, a specified asset for the lease term. Under the new guidance, lessor accounting is largely unchanged. Certain targeted improvements were made to align, where necessary, lessor accounting with the lessee accounting model and Topic 606, Revenue from Contracts with Customers. The new lease guidance simplified the accounting for sale and leaseback transactions primarily because lessees must recognize lease assets and lease liabilities. Lessees will no longer be provided with a source of off-balance sheet financing. Public business entities should apply the amendments in ASU 2016-02 for fiscal years beginning after December 15, 2018, including interim periods within those fiscal years (i.e., January 1, 2019, for a calendar year entity). Nonpublic business entities should apply the amendments for fiscal years beginning after December 15, 2019 (i.e., January 1, 2020, for a calendar year entity), and interim periods within fiscal years beginning after December 15, 2020. Early application is permitted for all public business entities and all nonpublic business entities upon issuance. Lessees (for capital and operating leases) and lessors (for sales-type, direct financing, and operating leases) must apply a modified retrospective transition approach for leases existing at, or entered into after, the beginning of the earliest comparative period presented in the financial statements. The modified retrospective approach would not require any transition accounting for leases that expired before the earliest comparative period presented. Lessees and lessors may not apply a full retrospective transition approach. The Corporation plans to adopt this ASU in the first quarter of 2019. The Corporation has an implementation team working through the provisions of ASU 2016-02, including a review of all leases (primarily operating leases related to banking centers and office space) to assess the impact on accounting, disclosures and the election of certain practical expedients. The Corporation has selected a third party software solution to assist with the accounting under the new standard. The Corporation expects a one-time adjustment to other assets and other liabilities on the consolidated balance sheet will occur during the first quarter of 2019. The magnitude of any such adjustment or the overall impact of the new standard on financial condition, results of operations and regulatory capital is being evaluated.

General Litigation and Regulato

General Litigation and Regulatory Examinations	3 Months Ended
	Mar. 31, 2018
Commitments and Contingencies Disclosure [Abstract]
General Litigation and Regulatory Examinations	GENERAL LITIGATION AND REGULATORY EXAMINATIONS The Corporation is subject to claims and lawsuits that arise primarily in the ordinary course of business. Additionally, the Corporation is subject to periodic examinations by various regulatory agencies. It is the opinion of management that the disposition or ultimate resolution of such claims, lawsuits, and examinations will not have a material adverse effect on the consolidated financial position, results of operations and cash flow of the Corporation.

Acquisitions (Tables)

Acquisitions (Tables)	3 Months Ended
	Mar. 31, 2018
Business Combinations [Abstract]
Schedule of preliminary valuations of the fair value of assets acquired and liabilities assumed	Fair Value Cash and cash equivalents $ 6,016 Interest-bearing time deposits 248,212 Investment securities 4,078 Loans held for sale 594 Loans 725,382 Premises and equipment 10,107 Federal Home Loan Bank stock 4,810 Interest receivable 3,445 Cash surrender value of life insurance 26,964 Other assets 11,780 Deposits (862,271 ) Securities sold under repurchase agreements (17,915 ) Federal Home Loan Bank Advances (47,575 ) Subordinated debentures (10,583 ) Interest payable (1,005 ) Other liabilities (14,472 ) Net tangible assets acquired 87,567 Other Intangible assets 17,403 Goodwill 153,636 Purchase price $ 258,606 Fair Value Cash and cash equivalents $ 48,532 Interest-bearing time deposits 292 Loans held for sale 7,626 Loans 224,680 Premises and equipment 1,986 Federal Home Loan Bank stock 1,091 Interest receivable 653 Other assets 1,620 Deposits (252,783 ) Interest payable (244 ) Other liabilities (3,106 ) Net tangible assets acquired 30,347 Core deposit intangible 4,526 Goodwill 47,719 Purchase price $ 82,592
Schedule of acquired loan data	Acquired loan data for IAB can be found in the table below: Fair Value of Acquired Loans at Acquisition Date Gross Contractual Amounts Receivable at Acquisition Date Best Estimate at Acquisition Date of Contractual Cash Flows Not Expected to be Collected Acquired receivables subject to ASC 310-30 $ 4,838 $ 14,131 $ 8,352 Acquired receivables not subject to ASC 310-30 $ 720,544 $ 864,613 $ 9,786 Acquired loan data for Arlington Bank can be found in the table below: Fair Value of Acquired Loans at Acquisition Date Gross Contractual Amounts Receivable at Acquisition Date Best Estimate at Acquisition Date of Contractual Cash Flows Not Expected to be Collected Acquired receivables subject to ASC 310-30 $ 2,625 $ 6,183 $ 2,891 Acquired receivables not subject to ASC 310-30 $ 222,055 $ 308,857 $ 2,741
Schedule of pro forma financial information	The results of operations of Arlington Bank and IAB have been included in the Corporation's consolidated financial statements since the acquisition dates. The following schedule includes pro forma results for the year ended December 31, 2017, as if the Arlington Bank and IAB acquisitions occurred as of the beginning of the period presented. 2017 Total revenue (net interest income plus other income) $ 380,324 Net income $ 95,009 Net income available to common shareholders Earnings per share: Basic $ 1.94 Diluted $ 1.93

Investment Securities (Tables)

Investment Securities (Tables)	3 Months Ended
	Mar. 31, 2018
Investments, Debt and Equity Securities [Abstract]
Schedule of amortized cost, gross unrealized gains, gross unrealized losses and approximate fair value of investment securities	The amortized cost, gross unrealized gains, gross unrealized losses and approximate market value of the Corporation's investment securities at the dates indicated were: Amortized Gross Gross Fair Available for sale at March 31, 2018 U.S. Government-sponsored agency securities $ 6,491 $ 8 $ 1 $ 6,498 State and municipal 510,884 6,588 7,238 510,234 U.S. Government-sponsored mortgage-backed securities 496,824 251 10,039 487,036 Corporate obligations 31 31 Total available for sale 1,014,230 6,847 17,278 1,003,799 Held to maturity at March 31, 2018 U.S. Government-sponsored agency securities 22,619 715 21,904 State and municipal 228,620 2,784 911 230,493 U.S. Government-sponsored mortgage-backed securities 287,782 988 3,762 285,008 Foreign Investments 1,000 6 994 Total held to maturity 540,021 3,772 5,394 538,399 Total Investment Securities $ 1,554,251 $ 10,619 $ 22,672 $ 1,542,198 Amortized Gross Gross Fair Available for sale at December 31, 2017 State and municipal $ 510,852 $ 16,932 $ 1,091 $ 526,693 U.S. Government-sponsored mortgage-backed securities 473,325 964 3,423 470,866 Corporate obligations 31 31 Equity securities 2,357 2,357 Total available for sale 986,565 17,896 4,514 999,947 Held to maturity at December 31, 2017 U.S. Government-sponsored agency securities 22,618 435 22,183 State and municipal 235,594 6,295 244 241,645 U.S. Government-sponsored mortgage-backed securities 301,443 3,341 1,404 303,380 Foreign Investment 1,000 1,000 Total held to maturity 560,655 9,636 2,083 568,208 Total Investment Securities $ 1,547,220 $ 27,532 $ 6,597 $ 1,568,155
Schedule of amortized cost and fair value of available for sale securities and held to maturity securities	The amortized cost and fair value of available for sale and held to maturity securities at March 31, 2018 and December 31, 2017 , by contractual maturity, are shown below. Expected maturities will differ from contractual maturities because issuers may have the right to call or prepay obligations with or without call or prepayment penalties. Available for Sale Held to Maturity Amortized Cost Fair Value Amortized Cost Fair Value Maturity Distribution at March 31, 2018: Due in one year or less $ 544 $ 549 $ 18,366 $ 18,675 Due after one through five years 4,982 5,064 68,198 67,756 Due after five through ten years 81,890 83,630 52,976 53,437 Due after ten years 429,990 427,520 112,699 113,523 517,406 516,763 252,239 253,391 U.S. Government-sponsored mortgage-backed securities 496,824 487,036 287,782 285,008 Total Investment Securities $ 1,014,230 $ 1,003,799 $ 540,021 $ 538,399 Available for Sale Held to Maturity Amortized Cost Fair Value Amortized Cost Fair Value Maturity Distribution at December 31, 2017 Due in one year or less $ 425 $ 425 $ 12,015 $ 12,158 Due after one through five years 5,040 5,204 76,146 76,334 Due after five through ten years 74,921 78,806 54,441 55,679 Due after ten years 430,497 442,289 116,610 120,657 510,883 526,724 259,212 264,828 U.S. Government-sponsored mortgage-backed securities 473,325 470,866 301,443 303,380 Equity securities 2,357 2,357 Total Investment Securities $ 986,565 $ 999,947 $ 560,655 $ 568,208
Schedule of gross gains on sales and redemptions of available for sale securities	Gross gains on the sales and redemptions of available for sale securities for the three months ended March 31, 2018 and 2017 are shown below. Three Months Ended 2018 2017 Sales and Redemptions of Available for Sale Securities: Gross gains $ 1,609 $ 598 Gross losses
Schedule of investment securities with unrealized losses, aggregated by investment category and length of time that individual securities have been in a continuous unrealized loss position	The following tables show the Corporation’s gross unrealized losses and fair value, aggregated by investment category and length of time the individual securities have been in a continuous unrealized loss position at March 31, 2018 , and December 31, 2017 : Less than 12 Months Total Fair Gross Fair Gross Fair Gross Temporarily Impaired Available for Sale Securities at March 31, 2018 U.S. Government-sponsored agency securities $ 371 $ 1 $ 371 $ 1 State and municipal 236,539 5,298 $ 28,126 $ 1,940 264,665 7,238 U.S. Government-sponsored mortgage-backed securities 385,626 6,956 65,490 3,083 451,116 10,039 Total Temporarily Impaired Available for Sale Securities 622,536 12,255 93,616 5,023 716,152 17,278 Temporarily Impaired Held to Maturity Securities at March 31, 2018 U.S. Government-sponsored agency securities 9,861 258 12,043 457 21,904 715 State and municipal 18,155 307 15,388 604 33,543 911 U.S. Government-sponsored mortgage-backed securities 177,080 2,154 40,866 1,608 217,946 3,762 Corporate Obligations 994 6 994 6 Total Temporarily Impaired Held to Maturity Securities 206,090 2,725 68,297 2,669 274,387 5,394 Total Temporarily Impaired Investment Securities $ 828,626 $ 14,980 $ 161,913 $ 7,692 $ 990,539 $ 22,672 Less than 12 Months Total Fair Gross Fair Gross Fair Gross Temporarily Impaired Available for Sale Securities at December 31, 2017 State and municipal $ 13,296 $ 198 $ 35,324 $ 893 $ 48,620 $ 1,091 U.S. Government-sponsored mortgage-backed securities 182,755 1,520 68,667 1,903 251,422 3,423 Total Temporarily Impaired Available for Sale Securities 196,051 1,718 103,991 2,796 300,042 4,514 Temporarily Impaired Held to Maturity Securities at December 31, 2017 U.S. Government-sponsored agency securities 9,988 131 12,196 304 22,184 435 State and municipal 2,430 36 15,805 208 18,235 244 U.S. Government-sponsored mortgage-backed securities 62,508 485 43,078 919 105,586 1,404 Total Temporarily Impaired Held to Maturity Securities 74,926 652 71,079 1,431 146,005 2,083 Total Temporarily Impaired Investment Securities $ 270,977 $ 2,370 $ 175,070 $ 4,227 $ 446,047 $ 6,597
Schedule of investments in debt and equity securities reported in the financial statements at an amount less than their historical cost	Certain investments in debt and equity securities are reported in the financial statements at an amount less than their historical cost as indicated in the table below. March 31, 2018 December 31, 2017 Investments reported at less than historical cost: Historical cost $ 1,013,210 $ 452,644 Fair value $ 990,539 $ 446,047 Percent of the Corporation's investment portfolio 64.2 % 28.6 %

Loans and Allowance (Tables)

Loans and Allowance (Tables)	3 Months Ended
	Mar. 31, 2018
Receivables [Abstract]
Composition of loan portfolio by loan class	The following table illustrates the composition of the Corporation’s loan portfolio by loan class for the periods indicated: March 31, 2018 December 31, 2017 Commercial and industrial loans $ 1,554,169 $ 1,493,493 Agricultural production financing and other loans to farmers 98,315 121,757 Real estate loans: Construction 590,093 612,219 Commercial and farmland 2,713,994 2,562,691 Residential 948,644 962,765 Home equity 510,545 514,021 Individuals' loans for household and other personal expenditures 88,235 86,935 Lease financing receivables, net of unearned income 2,193 2,527 Other commercial loans 395,508 394,791 Loans $ 6,901,696 $ 6,751,199 Allowance for loan losses (76,420 ) (75,032 ) Net Loans $ 6,825,276 $ 6,676,167
Changes in allowance for loan losses	The following tables summarize changes in the allowance for loan losses by loan segment for the three months ended March 31, 2018 and March 31, 2017 : Three Months Ended March 31, 2018 Commercial Commercial Consumer Residential Finance Total Allowance for loan losses: Balances, December 31, 2017 $ 30,418 $ 27,343 $ 3,732 $ 13,537 $ 2 $ 75,032 Provision for losses 840 84 274 1,302 2,500 Recoveries on loans 119 339 89 154 701 Loans charged off (609 ) (61 ) (199 ) (944 ) (1,813 ) Balances, March 31, 2018 $ 30,768 $ 27,705 $ 3,896 $ 14,049 $ 2 $ 76,420 Three Months Ended March 31, 2017 Commercial Commercial Consumer Residential Finance Total Allowance for loan losses: Balances, December 31, 2016 $ 27,696 $ 23,661 $ 2,923 $ 11,755 $ 2 $ 66,037 Provision for losses 1,197 247 249 692 2,385 Recoveries on loans 366 564 101 237 1,268 Loans charged off (735 ) (152 ) (153 ) (425 ) (1,465 ) Balances, March 31, 2017 $ 28,524 $ 24,320 $ 3,120 $ 12,259 $ 2 $ 68,225
Allowance for credit losses and loan portfolio by loan segment	The tables below show the Corporation’s allowance for loan losses and loan portfolio by loan segment as of the periods indicated. There was no related allowance for loan losses for loans acquired with deteriorated credit quality at March 31, 2018 or December 31, 2017. March 31, 2018 Commercial Commercial Consumer Residential Finance Total Allowance Balances: Individually evaluated for impairment $ 143 $ 758 $ 416 $ 1,317 Collectively evaluated for impairment 30,625 26,947 $ 3,896 13,633 $ 2 75,103 Total Allowance for Loan Losses $ 30,768 $ 27,705 $ 3,896 $ 14,049 $ 2 $ 76,420 Loan Balances: Individually evaluated for impairment $ 2,914 $ 16,501 $ 11 $ 2,738 $ 22,164 Collectively evaluated for impairment 2,042,193 3,268,036 88,224 1,454,894 $ 2,193 6,855,540 Loans acquired with deteriorated credit quality 2,885 19,550 1,557 23,992 Loans $ 2,047,992 $ 3,304,087 $ 88,235 $ 1,459,189 $ 2,193 $ 6,901,696 December 31, 2017 Commercial Commercial Consumer Residential Finance Total Allowance Balances: Individually evaluated for impairment $ 666 $ 567 $ 404 $ 1,637 Collectively evaluated for impairment 29,752 26,776 $ 3,732 13,133 $ 2 73,395 Total Allowance for Loan Losses $ 30,418 $ 27,343 $ 3,732 $ 13,537 $ 2 $ 75,032 Loan Balances: Individually evaluated for impairment $ 3,345 $ 17,432 $ 5 $ 2,429 $ 23,211 Collectively evaluated for impairment 2,005,275 3,135,481 86,930 1,472,821 $ 2,527 6,703,034 Loans acquired with deteriorated credit quality 1,421 21,997 1,536 24,954 Loans $ 2,010,041 $ 3,174,910 $ 86,935 $ 1,476,786 $ 2,527 $ 6,751,199
Summary of non-accrual loans by loan class	The following table summarizes the Corporation’s non-accrual loans by loan class as of the periods indicated: March 31, 2018 December 31, 2017 Commercial and industrial loans $ 3,238 $ 3,275 Agriculture production financing and other loans to farmers 638 1,027 Real estate loans: Construction 1,481 65 Commercial and farmland 13,944 12,951 Residential 6,765 9,444 Home equity 1,385 1,928 Individuals' loans for household and other personal expenditures 46 34 Total $ 27,497 $ 28,724
Composition of impaired loans by loan class	The following tables show the composition of the Corporation’s impaired loans, related allowance and interest income recognized while impaired by loan class as of the periods indicated: March 31, 2018 Unpaid Recorded Related Impaired loans with no related allowance: Commercial and industrial loans $ 7,863 $ 1,812 Agriculture production financing and other loans to farmers 660 640 Real estate Loans: Commercial and farmland 16,581 14,388 Residential 1,146 790 Home equity 40 8 Individuals' loans for household and other personal expenditures 11 11 Total $ 26,301 $ 17,649 Impaired loans with related allowance: Commercial and industrial loans $ 474 $ 462 $ 143 Real estate Loans: Construction 1,352 1,352 307 Commercial and farmland 823 761 451 Residential 1,697 1,636 341 Home equity 324 304 75 Total $ 4,670 $ 4,515 $ 1,317 Total Impaired Loans $ 30,971 $ 22,164 $ 1,317 December 31, 2017 Unpaid Recorded Related Impaired loans with no related allowance: Commercial and industrial loans $ 7,611 $ 1,536 Agriculture production financing and other loans to farmers 732 700 Real estate Loans: Commercial and farmland 16,758 15,162 Residential 833 519 Home equity 40 8 Individuals' loans for household and other personal expenditures 5 5 Total $ 25,979 $ 17,930 Impaired loans with related allowance: Commercial and industrial loans $ 812 $ 782 $ 552 Agriculture production financing and other loans to farmers 357 327 114 Real estate Loans: Commercial and farmland 2,989 2,270 567 Residential 1,616 1,572 327 Home equity 349 330 77 Total $ 6,123 $ 5,281 $ 1,637 Total Impaired Loans $ 32,102 $ 23,211 $ 1,637 Three Months Ended March 31, 2018 Three Months Ended March 31, 2017 Average Interest Average Interest Impaired loans with no related allowance: Commercial and industrial loans $ 1,845 $ 1,066 Agriculture production financing and other loans to farmers 640 Real estate Loans: Commercial and farmland 14,450 $ 48 14,963 $ 80 Residential 759 6 935 1 Home equity 8 26 Individuals' loans for household and other personal expenditures 12 7 Total $ 17,714 $ 54 $ 16,997 $ 81 Impaired loans with related allowance: Commercial and industrial loans $ 465 Agriculture production financing and other loans to farmers $ 657 Real estate Loans: Construction 1,352 Commercial and farmland 767 2,848 Residential 1,709 $ 12 1,062 $ 6 Home equity 305 2 260 2 Total $ 4,598 $ 14 $ 4,827 $ 8 Total Impaired Loans $ 22,312 $ 68 $ 21,824 $ 89
Credit quality of loan portfolio by loan class	The following tables summarize the credit quality of the Corporation’s loan portfolio, by loan class for the periods indicated. Consumer non-performing loans include accruing consumer loans 90 plus days delinquent and consumer non-accrual loans. The entire balance of a loan is considered delinquent if the minimum payment contractually required to be made is not received by the specified date. Loans that evidenced deterioration of credit quality since origination and it was probable, at acquisition, that all contractually required payments would not be collected are included in the applicable categories below. March 31, 2018 Commercial Commercial Commercial Substandard Commercial Commercial Loss Consumer Performing Consumer Total Commercial and industrial loans $ 1,465,692 $ 58,916 $ 29,561 $ 1,554,169 Agriculture production financing and other loans to farmers 57,888 16,599 23,828 98,315 Real estate Loans: Construction 553,131 1,363 11,918 $ 23,552 $ 129 590,093 Commercial and farmland 2,557,293 64,356 88,312 $ 1,117 2,914 2 2,713,994 Residential 179,135 5,198 5,340 31 753,126 5,814 948,644 Home equity 27,372 532 344 480,830 1,467 510,545 Individuals' loans for household and other personal expenditures 88,159 76 88,235 Lease financing receivables, net of unearned income 2,193 2,193 Other commercial loans 395,155 353 395,508 Loans $ 5,237,859 $ 146,964 $ 159,656 $ 1,148 $ 1,348,581 $ 7,488 $ 6,901,696 December 31, 2017 Commercial Commercial Commercial Substandard Commercial Commercial Loss Consumer Performing Consumer Total Commercial and industrial loans $ 1,418,401 $ 51,336 $ 23,386 $ 370 $ 1,493,493 Agriculture production financing and other loans to farmers 73,800 27,502 20,018 387 $ 50 121,757 Real estate Loans: Construction 587,906 828 981 $ 22,374 $ 130 612,219 Commercial and farmland 2,408,329 70,074 79,769 1,536 2,980 3 2,562,691 Residential 185,725 4,376 4,209 114 759,900 8,441 962,765 Home equity 28,554 457 286 482,661 2,063 514,021 Individuals' loans for household and other personal expenditures 86,875 60 86,935 Lease financing receivables, net of unearned income 2,527 2,527 Other commercial loans 394,222 569 394,791 Loans $ 5,099,464 $ 154,573 $ 129,218 $ 2,407 $ 50 $ 1,354,790 $ 10,697 $ 6,751,199
Past due aging of loan portfolio by loan class	The tables below show a past due aging of the Corporation’s loan portfolio, by loan class, as of March 31, 2018 , and December 31, 2017 : March 31, 2018 Current 30-59 Days 60-89 Days Loans > 90 Days Non-Accrual Total Past Due Total Commercial and industrial loans $ 1,549,330 $ 1,062 $ 49 $ 490 $ 3,238 $ 4,839 $ 1,554,169 Agriculture production financing and other loans to farmers 89,198 8,479 638 9,117 98,315 Real estate loans: Construction 588,424 188 1,481 1,669 590,093 Commercial and farmland 2,693,020 5,589 1,378 63 13,944 20,974 2,713,994 Residential 938,960 2,577 305 37 6,765 9,684 948,644 Home equity 506,922 1,638 481 119 1,385 3,623 510,545 Individuals' loans for household and other personal expenditures 87,933 170 57 29 46 302 88,235 Lease financing receivables, net of unearned income 2,193 2,193 Other commercial loans 395,508 395,508 Loans $ 6,851,488 $ 19,703 $ 2,270 $ 738 $ 27,497 $ 50,208 $ 6,901,696 December 31, 2017 Current 30-59 Days 60-89 Days Loans > 90 Days Non-Accrual Total Past Due Total Commercial and industrial loans $ 1,487,221 $ 2,967 $ 30 $ 3,275 $ 6,272 $ 1,493,493 Agriculture production financing and other loans to farmers 120,720 10 1,027 1,037 121,757 Real estate loans: Construction 610,896 1,193 $ 65 65 1,323 612,219 Commercial and farmland 2,542,048 6,923 166 603 12,951 20,643 2,562,691 Residential 948,947 4,010 308 56 9,444 13,818 962,765 Home equity 510,362 1,372 184 175 1,928 3,659 514,021 Individuals' loans for household and other personal expenditures 85,744 298 834 25 34 1,191 86,935 Lease financing receivables, net of unearned income 2,527 2,527 Other commercial loans 394,791 394,791 Loans $ 6,703,256 $ 16,773 $ 1,522 $ 924 $ 28,724 $ 47,943 $ 6,751,199
Schedules of troubled debt restructurings	The following tables summarize troubled debt restructures in the Corporation's loan portfolio that occurred during the periods indicated: Three Months Ended March 31, 2018 Pre-Modification Post-Modification Number Real estate loans: Residential $ 214 $ 222 5 Home equity 16 16 2 Individuals' loans for household and other personal expenditures 7 8 1 Total $ 237 $ 246 8 Three Months Ended March 31, 2017 Pre-Modification Post-Modification Number Real estate loans: Commercial and farmland $ 107 $ 241 3 Residential 121 122 2 Home equity 122 Total $ 350 $ 363 5 The following tables summarize the recorded investment of troubled debt restructures as of March 31, 2018 and 2017 , by modification type, that occurred during the periods indicated: Three Months Ended March 31, 2018 Term Rate Combination Total Real estate loans: Residential $ 38 $ 74 $ 106 $ 218 Home equity 16 10 26 Individuals' loans for household and other personal expenditures 7 7 Total $ 54 $ 91 $ 106 $ 251 Three Months Ended March 31, 2017 Term Rate Combination Total Real estate loans: Commercial and farmland $ 241 $ 241 Residential $ 122 122 Total $ 122 $ 241 $ 363
Troubled debt restructurings that subsequently defaulted	For purposes of this schedule, a loan is considered in default if it is 30 or more days past due. Three Months Ended March 31, 2018 Number of Loans Recorded Balance Real estate loans: Commercial and farmland 1 $ 324 Residential 3 108 Total 4 $ 432 Three Months Ended March 31, 2017 Number of Loans Recorded Balance Real estate loans: Commercial and farmland 1 $ 223 Total 1 $ 223

Purchased Credit Impaired Loa29

Purchased Credit Impaired Loans (Tables)	3 Months Ended
	Mar. 31, 2018
Receivables [Abstract]
Schedule of accretable yield, or income expected to be collected, and reclassifications from nonaccretable yield	The accretable yield, or income expected to be collected, and reclassifications from nonaccretable, are identified in the table below. Three Months Ended March 31, 2018 Three Months Ended March 31, 2017 Beginning balance $ 2,890 $ 3,950 Additions Accretion (510 ) (3,238 ) Reclassification from nonaccretable 295 2,370 Disposals Ending balance $ 2,675 $ 3,082

Goodwill (Tables)

Goodwill (Tables)	3 Months Ended
	Mar. 31, 2018
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of goodwill	2017 Balance, January 1 $ 244,000 Goodwill acquired 201,824 Measurement period adjustment (469 ) Balance, December 31 $ 445,355

Other Intangibles (Tables)

Other Intangibles (Tables)	3 Months Ended
	Mar. 31, 2018
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of core deposit	The carrying basis and accumulated amortization of recognized core deposit intangibles and other intangibles are noted below. March 31, 2018 December 31, 2017 Gross carrying amount $ 85,869 $ 63,940 Core deposit intangibles acquired 18,164 Other intangibles acquired 3,765 Accumulated amortization (56,447 ) (54,721 ) Total other intangibles $ 29,422 $ 31,148
Schedule of estimated future amortization expense	Estimated future amortization expense is summarized as follows: Amortization Expense 2018 $ 4,993 2019 5,169 2020 3,632 2021 3,427 2022 3,325 After 2022 8,876 $ 29,422

Derivative Financial Instrume32

Derivative Financial Instruments (Tables)	3 Months Ended
	Mar. 31, 2018
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Fair value of derivative financial instruments and their classification on Balance Sheet	The table below presents the fair value of the Corporation’s derivative financial instruments, as well as their classification on the Balance Sheet, as of March 31, 2018 , and December 31, 2017 . Asset Derivatives Liability Derivatives March 31, 2018 December 31, 2017 March 31, 2018 December 31, 2017 Balance Fair Balance Fair Balance Fair Balance Fair Derivatives designated as hedging instruments: Interest rate contracts Other Assets $ 258 Other Assets $ 18 Other Liabilities $ 689 Other Liabilities $ 1,383 Derivatives not designated as hedging instruments: Interest rate contracts Other Assets $ 11,376 Other Assets $ 7,305 Other Liabilities $ 11,376 Other Liabilities $ 7,305
Amount of gain (loss) recognized in other comprehensive income	The amount of gain (loss) recognized in other comprehensive income is included in the table below for the periods indicated. Derivatives in Cash Flow Hedging Relationships Amount of Gain (Loss) Recognized in Other Comprehensive Income on Derivative Three Months Ended March 31, 2018 March 31, 2017 Interest Rate Products $ 508 $ 34
Schedule of derivative instruments, gain (loss) in Income Statement	The amount of gain (loss) reclassified from other comprehensive income into income is included in the table below for the periods indicated. Derivatives Designated as Location of Gain (Loss) Amount of Gain (Loss) Reclassed from Other Comprehensive Income into Income (Effective Portion) Three Months Ended Three Months Ended Interest rate contracts Interest Expense $ (170 ) $ (268 )

Disclosures About Fair Value 33

Disclosures About Fair Value of Assets and Liabilities (Tables)	3 Months Ended
	Mar. 31, 2018
Fair Value Disclosures [Abstract]
Fair value measurements of assets and liabilities recognized in Consolidated Condensed Balance Sheets measured at fair value	The following table presents the fair value measurements of assets and liabilities recognized in the accompanying balance sheets measured at fair value on a recurring basis and the level within the ASC 820-10 fair value hierarchy in which the fair value measurements fall at March 31, 2018 , and December 31, 2017 . Fair Value Measurements Using: March 31, 2018 Fair Value Quoted Prices in Active Markets for Identical Assets Significant Other Significant Available for sale securities: U.S. Government-sponsored agency securities $ 6,498 $ 6,498 State and municipal 510,234 506,303 $ 3,931 U.S. Government-sponsored mortgage-backed securities 487,036 487,032 4 Corporate obligations 31 31 Interest rate swap asset 11,376 11,376 Interest rate cap 258 258 Interest rate swap liability 12,065 12,065 Fair Value Measurements Using: December 31, 2017 Fair Value Quoted Prices in Significant Other Observable Inputs Significant Available for sale securities: State and municipal $ 526,693 $ 522,750 $ 3,943 U.S. Government-sponsored mortgage-backed securities 470,866 470,866 Corporate obligations 31 31 Equity securities 2,357 2,353 4 Interest rate swap asset 7,305 7,305 Interest rate cap 18 18 Interest rate swap liability 8,688 8,688
Reconciliation of beginning and ending balances of recurring fair value measurements recognized in Consolidated Condensed Balance Sheets using significant unobservable Level 3 inputs	The following is a reconciliation of the beginning and ending balances of recurring fair value measurements recognized in the Consolidated Condensed Balance Sheets using significant unobservable (Level 3) inputs for the three months ended March 31, 2018 and 2017 . Available for Sale Securities Three Months Ended March 31, 2018 March 31, 2017 Balance at beginning of the period $ 3,978 $ 5,169 Included in other comprehensive income (25 ) 11 Principal payments 13 (1,901 ) Ending balance $ 3,966 $ 3,279
Description of valuation methodologies used for instruments measured at fair value on a non-recurring basis and recognized in Consolidated Condensed Balance Sheets	Following is a description of valuation methodologies used for instruments measured at fair value on a non-recurring basis and recognized in the accompanying balance sheets, as well as the general classification of such instruments pursuant to the valuation hierarchy for March 31, 2018 , and December 31, 2017 . Fair Value Measurements Using March 31, 2018 Fair Value Quoted Prices in Significant Other Significant Unobservable Impaired loans (collateral dependent) $ 7,833 $ 7,833 Other real estate owned 119 119 Fair Value Measurements Using December 31, 2017 Fair Value Quoted Prices in Significant Other Significant Unobservable Impaired loans (collateral dependent) $ 9,576 $ 9,576 Other real estate owned 859 859
Unobservable inputs used in recurring and nonrecurring Level 3 fair value measurements other than goodwill	The following table presents quantitative information about unobservable inputs used in recurring and nonrecurring Level 3 fair value measurements, other than goodwill, at March 31, 2018 and December 31, 2017 . March 31, 2018 Fair Value Valuation Technique Unobservable Inputs Range (Weighted-Average) State and municipal securities $ 3,931 Discounted cash flow Maturity/Call date 1 month to 20 yrs US Muni BQ curve A- to BBB- Discount rate 1% - 5% Corporate obligations and U.S. Government-sponsored mortgage backed securities $ 35 Discounted cash flow Risk free rate 3 month LIBOR plus premium for illiquidity plus 200bps Impaired loans (collateral dependent) $ 7,833 Collateral based measurements Discount to reflect current market conditions and ultimate collectability 0% - 10% (1%) Other real estate owned $ 119 Appraisals Discount to reflect current market conditions 0% - 24% (24%) December 31, 2017 Fair Value Valuation Technique Unobservable Inputs Range (Weighted-Average) State and municipal securities $ 3,943 Discounted cash flow Maturity/Call date 1 month to 20 yrs US Muni BQ curve A- to BBB- Discount rate .69% - 5% Corporate obligations and equity securities $ 35 Discounted cash flow Risk free rate 3 month LIBOR plus premium for illiquidity plus 200bps Impaired loans (collateral dependent) $ 9,576 Collateral based measurements Discount to reflect current market conditions and ultimate collectability 0% - 10% (1%) Other real estate owned $ 859 Appraisals Discount to reflect current market conditions 0% - 10% (2%)
Estimated fair values of financial instruments	The following table presents estimated fair values of the Corporation’s financial instruments and the level within the fair value hierarchy in which the fair value measurements fall at March 31, 2018 , and December 31, 2017 . March 31, 2018 Quoted Prices in Active Markets Significant Significant Unobservable Carrying Amount (Level 1) (Level 2) (Level 3) Assets: Cash and cash equivalents $ 128,828 $ 128,828 Interest-bearing time deposits 24,233 24,233 Investment securities available for sale 1,003,799 $ 999,833 $ 3,966 Investment securities held to maturity 540,021 527,253 11,146 Loans held for sale 4,469 4,469 Loans 6,825,276 6,649,237 Federal Home Loan Bank stock 24,588 24,588 Interest rate swap and cap asset 11,634 11,634 Interest receivable 35,223 35,223 Liabilities: Deposits $ 7,327,635 $ 5,849,466 $ 1,450,066 Borrowings: Federal funds purchased 50,000 50,000 Securities sold under repurchase agreements 138,910 138,770 Federal Home Loan Bank advances 449,419 443,804 Subordinated debentures and term loans 138,297 123,485 Interest rate swap liability 12,065 12,065 Interest payable 5,376 5,376 December 31, 2017 Quoted Prices in Active Markets Significant Significant Unobservable Carrying Amount (Level 1) (Level 2) (Level 3) Assets: Cash and cash equivalents $ 154,905 $ 154,905 Interest-bearing time deposits 35,027 35,027 Investment securities available for sale 999,947 $ 995,969 $ 3,978 Investment securities held to maturity 560,655 556,305 11,903 Loans held for sale 7,216 7,216 Loans 6,676,167 6,534,877 Federal Home Loan Bank stock 23,825 23,825 Interest rate swap and cap asset 7,323 7,323 Interest receivable 37,130 37,130 Liabilities: Deposits $ 7,172,530 $ 5,741,019 $ 1,406,526 Borrowings: Federal funds purchased 144,038 144,038 Securities sold under repurchase agreements 136,623 136,562 Federal Home Loan Bank advances 414,377 361,085 Subordinated debentures and term loans 139,349 120,085 Interest rate swap liability 8,688 8,688 Interest payable 4,390 4,390

Transfers Accounted for as Se34

Transfers Accounted for as Secured Borrowings (Tables)	3 Months Ended
	Mar. 31, 2018
Banking and Thrift [Abstract]
Schedule of collateral pledged for all repurchase agreements accounted for as secured borrowings	The collateral pledged for all repurchase agreements that are accounted for as secured borrowings as of March 31, 2018 and December 31, 2017 were: March 31, 2018 Remaining Contractual Maturity of the Agreements Overnight and Continuous Up to 30 Days 30-90 Days Greater Than 90 Days Total U.S. Government-sponsored mortgage-backed securities $ 129,490 $ 300 $ 9,120 $ 138,910 December 31, 2017 Remaining Contractual Maturity of the Agreements Overnight and Continuous Up to 30 Days 30-90 Days Greater Than 90 Days Total U.S. Government-sponsored mortgage-backed securities $ 126,187 $ 1,340 $ 1,500 $ 7,596 $ 136,623

Accumulated Other Comprehensi35

Accumulated Other Comprehensive Income (Loss) (Tables)	3 Months Ended
	Mar. 31, 2018
Equity [Abstract]
Schedule of accumulated other comprehensive income (loss)	The following table summarizes the changes in the balances of each component of accumulated other comprehensive income (loss), net of tax, as of March 31, 2018 and 2017 : Accumulated Other Comprehensive Income (Loss) Unrealized Gains (Losses) on Securities Available for Sale Unrealized Gains (Losses) on Cash Flow Hedges Unrealized Gains (Losses) on Defined Benefit Plans Total Balance at December 31, 2017 $ 8,970 $ (1,125 ) $ (10,753 ) $ (2,908 ) Other comprehensive income before reclassifications (17,698 ) 644 (17,054 ) Amounts reclassified from accumulated other comprehensive income (1,271 ) 134 (1,137 ) Period change (18,969 ) 778 — (18,191 ) Reclassification adjustment under ASU 2018-02 1,932 (242 ) (2,316 ) (626 ) Balance at March 31, 2018 $ (8,067 ) $ (589 ) $ (13,069 ) $ (21,725 ) Balance at December 31, 2016 $ 1,035 $ (1,774 ) $ (12,842 ) $ (13,581 ) Other comprehensive income before reclassifications 10,110 23 10,133 Amounts reclassified from accumulated other comprehensive income (389 ) 174 (59 ) (274 ) Period change 9,721 197 (59 ) 9,859 Balance at March 31, 2017 $ 10,756 $ (1,577 ) $ (12,901 ) $ (3,722 )
Reclassification out of accumulated other comprehensive income (loss)	The following tables present the reclassification adjustments out of accumulated other comprehensive income (loss) that were included in net income in the Consolidated Condensed Statements of Income for the three months ended March 31, 2018 and 2017 . Amount Reclassified from Accumulated Other Comprehensive Income (Loss) For the Three Months Ended March 31, Details about Accumulated Other Comprehensive Income (Loss)Components 2018 2017 Affected Line Item in the Statements of Income Unrealized gains (losses) on available for sale securities (1) Realized securities gains reclassified into income $ 1,609 $ 598 Other income - net realized gains on sales of available for sale securities Related income tax expense (338 ) (209 ) Income tax expense $ 1,271 $ 389 Unrealized gains (losses) on cash flow hedges (2) Interest rate contracts $ (170 ) $ (268 ) Interest expense - subordinated debentures and term loans Related income tax benefit 36 94 Income tax expense $ (134 ) $ (174 ) Unrealized gains (losses) on defined benefit plans Amortization of prior service costs $ 91 Other expenses - salaries and employee benefits Related income tax expense (32 ) Income tax expense $ — $ 59 Total reclassifications for the period, net of tax $ 1,137 $ 274 (1) For additional detail related to unrealized gains (losses) on available for sale securities and related amounts reclassified from accumulated other comprehensive income see NOTE 3. INVESTMENT SECURITIES of these Notes to Consolidated Condensed Financial Statements. (2) For additional detail related to unrealized gains (losses) on cash flow hedges and related amounts reclassified from accumulated other comprehensive income see NOTE 8. DERIVATIVE FINANCIAL INSTRUMENTS of these Notes to Consolidated Condensed Financial Statements.

Share-Based Compensation (Table

Share-Based Compensation (Tables)	3 Months Ended
	Mar. 31, 2018
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Components of share-based compensation awards	The following table summarizes the components of the Corporation's share-based compensation awards recorded as expense and the income tax benefit of such awards. Three Months Ended 2018 2017 Stock and ESPP Options Pre-tax compensation expense $ 24 $ 48 Income tax benefit (59 ) (246 ) Stock and ESPP option expense, net of income taxes $ (35 ) $ (198 ) Restricted Stock Awards Pre-tax compensation expense $ 851 $ 525 Income tax benefit (566 ) (710 ) Restricted stock awards expense, net of income taxes $ 285 $ (185 ) Total Share-Based Compensation Pre-tax compensation expense $ 875 $ 573 Income tax benefit (625 ) (956 ) Total share-based compensation expense, net of income taxes $ 250 $ (383 )
Stock option activity under stock option plans	Stock option activity under the Corporation's stock option plans as of March 31, 2018 and changes during the three months ended March 31, 2018 , were as follows: Number of Weighted-Average Exercise Price Weighted Average Remaining Aggregate Outstanding at January 1, 2018 152,652 $ 16.71 Exercised (23,557 ) $ 22.71 Cancelled (200 ) $ 28.25 Outstanding March 31, 2018 128,895 $ 15.59 2.45 $ 3,365,525 Vested and Expected to Vest at March 31, 2018 128,895 $ 15.59 2.45 $ 3,365,525 Exercisable at March 31, 2018 128,895 $ 15.59 2.45 $ 3,365,525
Unvested RSAs outstanding	The following table summarizes information on unvested RSAs outstanding as of March 31, 2018 : Number of Shares Weighted-Average Unvested RSAs at January 1, 2018 366,993 $ 29.79 Granted 4,687 $ 42.11 Vested (93,076 ) $ 22.91 Forfeited (140 ) $ 22.87 Unvested RSAs at March 31, 2018 278,464 $ 32.31

Income Tax (Tables)

Income Tax (Tables)	3 Months Ended
	Mar. 31, 2018
Income Tax Disclosure [Abstract]
Summary of differences between income taxes at federal statutory tax rate and effective tax rate	The following table summarizes the major components creating differences between income taxes at the federal statutory and the effective tax rate recorded in the consolidated statements of income for the three months ended March 31, 2018 and 2017 : Three Months Ended 2018 2017 Reconciliation of Federal Statutory to Actual Tax Expense: Federal statutory income tax at 21% for 2018 and 35% for 2017 $ 9,091 $ 10,627 Tax-exempt interest income (2,015 ) (2,549 ) Share-based compensation (441 ) (755 ) Tax-exempt earnings and gains on life insurance (247 ) (314 ) Tax credits 39 (106 ) Other 184 265 Actual Tax Expense $ 6,611 $ 7,168 Effective Tax Rate 15.3 % 23.6 %

Net Income Per Share (Tables)

Net Income Per Share (Tables)	3 Months Ended
	Mar. 31, 2018
Earnings Per Share [Abstract]
Basic and diluted net income per share	The following table reconciles basic and diluted net income per share for the three months ended March 31, 2018 and 2017 . Three Months Ended March 31, 2018 2017 Net Income Weighted-Average Shares Per Share Net Income Weighted-Average Shares Per Share Net income available to common stockholders $ 36,679 49,192,647 $ 0.75 $ 23,193 40,984,481 $ 0.57 Effect of potentially dilutive stock options and restricted stock awards 235,325 236,105 Diluted net income per share $ 36,679 49,427,972 $ 0.74 $ 23,193 41,220,586 $ 0.56

Acquisitions - Narrative (Detai

Acquisitions - Narrative (Details) $ / shares in Units, $ in Thousands	Jul. 14, 2017USD ($)bank_branchshares	May 19, 2017USD ($)bank_branchshares	Nov. 21, 2016USD ($)$ / sharesshares	Sep. 30, 2017USD ($)	Dec. 31, 2017USD ($)
IAB
Business Acquisition [Line Items]
Shares purchased (in shares) | shares			495,112
Percentage of interest acquired			12.10%	12.10%
Value of acquired shares			$ 19,800
Purchase price per share (usd per share) | $ / shares			$ 40
Number of banking centers acquired | bank_branch	16
Stock issued as a part of acquisition (in shares) | shares	6,000,000
Issuance of common stock related to acquisition	$ 238,800
Total purchase price	258,600
Fair value of equity interest after adjustment				$ 19,800
Remeasurement loss				$ 50
Other intangible assets	17,403
Operating revenue					$ 21,400
IAB | Core deposits
Business Acquisition [Line Items]
Other intangible assets	$ 13,638
Acquired intangible asset, expected useful life	10 years
IAB | Noncompete agreements
Business Acquisition [Line Items]
Other intangible assets	$ 3,765
Acquired intangible asset, expected useful life	2 years
IAB | Common Stock
Business Acquisition [Line Items]
Number of shares of common stock	1.653
Arlington Bank
Business Acquisition [Line Items]
Percentage of interest acquired		100.00%
Number of banking centers acquired | bank_branch		3
Stock issued as a part of acquisition (in shares) | shares		2,100,000
Issuance of common stock related to acquisition		$ 82,600
Other intangible assets		4,526
Operating revenue					9,000
Arlington Bank | Core deposits
Business Acquisition [Line Items]
Other intangible assets		$ 4,526
Acquired intangible asset, expected useful life		10 years
Arlington Bank | Common Stock
Business Acquisition [Line Items]
Number of shares of common stock		2.7245
Arlington Bank and IAB | Expenses directly attributable to acquisitions
Business Acquisition [Line Items]
Non-recurring expenses					$ 15,400

Acquisitions - Assets Acquired

Acquisitions - Assets Acquired and Liabilities Assumed (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017	Jul. 14, 2017	May 19, 2017	Dec. 31, 2016
Business Acquisition [Line Items]
Goodwill	$ 445,355	$ 445,355			$ 244,000
IAB
Business Acquisition [Line Items]
Cash and cash equivalents			$ 6,016
Interest-bearing time deposits			248,212
Investment securities			4,078
Loans held for sale			594
Loans			725,382
Premises and equipment			10,107
Federal Home Loan Bank stock			4,810
Interest receivable			3,445
Cash surrender value of life insurance			26,964
Other assets			11,780
Deposits			(862,271)
Securities sold under repurchase agreements			(17,915)
Federal Home Loan Bank Advances			(47,575)
Subordinated debentures			(10,583)
Interest payable			(1,005)
Other liabilities			(14,472)
Net tangible assets acquired			87,567
Core deposit intangible			17,403
Goodwill			153,636
Purchase price			$ 258,606
Arlington Bank
Business Acquisition [Line Items]
Cash and cash equivalents				$ 48,532
Interest-bearing time deposits				292
Loans held for sale				7,626
Loans				224,680
Premises and equipment				1,986
Federal Home Loan Bank stock				1,091
Interest receivable				653
Other assets				1,620
Deposits				(252,783)
Interest payable				(244)
Other liabilities				(3,106)
Net tangible assets acquired				30,347
Core deposit intangible				4,526
Goodwill				47,719
Purchase price				$ 82,592

Acquisitions - Schedule of Acqu

Acquisitions - Schedule of Acquired Loan Data (Details) - USD ($) $ in Thousands	Jul. 14, 2017	May 19, 2017
IAB
Business Acquisition [Line Items]
Fair Value of Acquired Loans at Acquisition Date, Acquired receivables subject to ASC 310-30	$ 4,838
Gross Contractual Amounts Receivable at Acquisition Date, Acquired receivables subject to ASC 310-30	14,131
Best Estimate at Acquisition Date of Contractual Cash Flows Not Expected to be Collected, Acquired receivables subject to ASC 310-30	8,352
Fair Value of Acquired Loans at Acquisition Date, Acquired receivables not subject to ASC 310-30	720,544
Gross Contractual Amounts Receivable at Acquisition Date, Acquired receivables not subject to ASC 310-30	864,613
Best Estimate at Acquisition Date of Contractual Cash Flows Not Expected to be Collected, Acquired receivables not subject to ASC 310-30	$ 9,786
Arlington Bank
Business Acquisition [Line Items]
Fair Value of Acquired Loans at Acquisition Date, Acquired receivables subject to ASC 310-30		$ 2,625
Gross Contractual Amounts Receivable at Acquisition Date, Acquired receivables subject to ASC 310-30		6,183
Best Estimate at Acquisition Date of Contractual Cash Flows Not Expected to be Collected, Acquired receivables subject to ASC 310-30		2,891
Fair Value of Acquired Loans at Acquisition Date, Acquired receivables not subject to ASC 310-30		222,055
Gross Contractual Amounts Receivable at Acquisition Date, Acquired receivables not subject to ASC 310-30		308,857
Best Estimate at Acquisition Date of Contractual Cash Flows Not Expected to be Collected, Acquired receivables not subject to ASC 310-30		$ 2,741

Acquisitions - Pro Forma Financ

Acquisitions - Pro Forma Financial Information (Details) - Arlington Bank and IAB $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2017USD ($)$ / shares
Business Acquisition [Line Items]
Total revenue (net interest income plus other income) | $	$ 380,324
Net income | $	$ 95,009
Basic (in dollars per share) | $ / shares	$ 1.94
Diluted (in dollars per share) | $ / shares	$ 1.93

Investment Securities - Amortiz

Investment Securities - Amortized Cost and Approximate Fair Value of Securities (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Available for sale securities
Total Investment Securities	$ 1,014,230	$ 986,565
Gross Unrealized Gains	6,847	17,896
Gross Unrealized Losses	17,278	4,514
Fair Value	1,003,799	999,947
Held to maturity securities
Total Investment Securities	540,021	560,655
Gross Unrealized Gains	3,772	9,636
Gross Unrealized Losses	5,394	2,083
Fair Value	538,399	568,208
Amortized Cost	1,554,251	1,547,220
Gross Unrealized Gains	10,619	27,532
Gross Unrealized Losses	22,672	6,597
Fair Value	1,542,198	1,568,155
U.S. Government-sponsored agency securities
Available for sale securities
Total Investment Securities	6,491
Gross Unrealized Gains	8
Gross Unrealized Losses	1
Fair Value	6,498
Held to maturity securities
Total Investment Securities	22,619	22,618
Gross Unrealized Gains
Gross Unrealized Losses	715	435
Fair Value	21,904	22,183
State and municipal
Available for sale securities
Total Investment Securities	510,884	510,852
Gross Unrealized Gains	6,588	16,932
Gross Unrealized Losses	7,238	1,091
Fair Value	510,234	526,693
Held to maturity securities
Total Investment Securities	228,620	235,594
Gross Unrealized Gains	2,784	6,295
Gross Unrealized Losses	911	244
Fair Value	230,493	241,645
U.S. Government-sponsored mortgage-backed securities
Available for sale securities
Total Investment Securities	496,824	473,325
Gross Unrealized Gains	251	964
Gross Unrealized Losses	10,039	3,423
Fair Value	487,036	470,866
Held to maturity securities
Total Investment Securities	287,782	301,443
Gross Unrealized Gains	988	3,341
Gross Unrealized Losses	3,762	1,404
Fair Value	285,008	303,380
Corporate obligations
Available for sale securities
Total Investment Securities	31	31
Gross Unrealized Gains
Gross Unrealized Losses
Fair Value	31	31
Equity securities
Available for sale securities
Total Investment Securities		2,357
Gross Unrealized Gains
Gross Unrealized Losses
Fair Value		2,357
Foreign Investments
Held to maturity securities
Total Investment Securities	1,000	1,000
Gross Unrealized Losses	6
Fair Value	$ 994	$ 1,000

Investment Securities - Amort44

Investment Securities - Amortized Cost and Fair Value of Available for Sale Securities and Held to Maturity Securities by Contractual Maturity (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Amortized Cost
Due in one year or less	$ 544	$ 425
Due after one through five years	4,982	5,040
Due after five through ten years	81,890	74,921
Due after ten years	429,990	430,497
Total debt securities with a single maturity date	517,406	510,883
Total Investment Securities	1,014,230	986,565
Fair Value
Due in one year or less	549	425
Due after one through five years	5,064	5,204
Due after five through ten years	83,630	78,806
Due after ten years	427,520	442,289
Total debt securities with a single maturity date	516,763	526,724
Total Investment Securities	1,003,799	999,947
Amortized Cost
Due in one year or less	18,366	12,015
Due after one through five years	68,198	76,146
Due after five through ten years	52,976	54,441
Due after ten years	112,699	116,610
Total debt securities with a single maturity date	252,239	259,212
Total Investment Securities	540,021	560,655
Fair Value
Due in one year or less	18,675	12,158
Due after one through five years	67,756	76,334
Due after five through ten years	53,437	55,679
Due after ten years	113,523	120,657
Total debt securities with a single maturity date	253,391	264,828
Investment securities held to maturity	538,399	568,208
U.S. Government-sponsored mortgage-backed securities
Amortized Cost
Without single maturity date	496,824	473,325
Fair Value
Without single maturity date	487,036	470,866
Amortized Cost
Without single maturity date	287,782	301,443
Fair Value
Without single maturity date	$ 285,008	303,380
Equity securities
Amortized Cost
Without single maturity date		2,357
Fair Value
Without single maturity date		2,357
Amortized Cost
Without single maturity date
Fair Value
Without single maturity date

Investment Securities - Narrati

Investment Securities - Narrative (Details) $ in Thousands	Mar. 31, 2018USD ($)security	Dec. 31, 2017USD ($)
Investments, Debt and Equity Securities [Abstract]
Carrying value of securities pledged as collateral	$ 552,899	$ 475,999
Book value of securities sold under agreements to repurchase	141,664	136,639
Schedule of Available for sale Securities and Held to maturity Securities [Line Items]
Held-to-maturity unrealized losses	5,394	$ 2,083
State and municipal
Schedule of Available for sale Securities and Held to maturity Securities [Line Items]
Available-for-sale unrealized losses	$ 7,238
Available-for-sale, number of securities in unrealized loss positions | security	208
Held-to-maturity unrealized losses	$ 911
Held-to-maturity, number of securities in unrealized loss positions | security	46
U.S. Government-sponsored agency securities
Schedule of Available for sale Securities and Held to maturity Securities [Line Items]
Available-for-sale unrealized losses	$ 1
Available-for-sale, number of securities in unrealized loss positions | security	1
Held-to-maturity unrealized losses	$ 715
Held-to-maturity, number of securities in unrealized loss positions | security	5
U.S. Government-sponsored mortgage-backed securities
Schedule of Available for sale Securities and Held to maturity Securities [Line Items]
Available-for-sale unrealized losses	$ 10,039
Available-for-sale, number of securities in unrealized loss positions | security	101
Held-to-maturity unrealized losses	$ 3,762
Held-to-maturity, number of securities in unrealized loss positions | security	76

Investment Securities - Gross G

Investment Securities - Gross Gains on Sales and Redemptions of Available for Sale Securities (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Sales and Redemptions of Available for Sale Securities:
Gross gains	$ 1,609	$ 598
Gross losses

Investment Securities - Investm

Investment Securities - Investments' Gross Unrealized Losses and Fair Value Aggregated by Investment Category and Length of Time in Continuous Unrealized Loss Position (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Fair Value
Less than 12 Months	$ 622,536	$ 196,051
12 Months or Longer	93,616	103,991
Total	716,152	300,042
Gross Unrealized Losses
Less than 12 Months	12,255	1,718
12 Months or Longer	5,023	2,796
Total	17,278	4,514
Fair Value
Less than 12 Months	206,090	74,926
12 Months or Longer	68,297	71,079
Total	274,387	146,005
Gross Unrealized Losses
Less than 12 Months	2,725	652
12 Months or Longer	2,669	1,431
Total	5,394	2,083
Available-for-sale Securities and Held-to-maturity Securities [Abstract]
Less than 12 Months, Fair Value	828,626	270,977
12 Months or Longer, Fair Value	161,913	175,070
Total, Fair Value	990,539	446,047
Less than 12 Months, Gross Unrealized Losses	14,980	2,370
12 Months or Longer, Gross Unrealized Losses	7,692	4,227
Total, Gross Unrealized Losses	22,672	6,597
U.S. Government-sponsored agency securities
Fair Value
Less than 12 Months	371
Total	371
Gross Unrealized Losses
Less than 12 Months	1
Total	1
State and municipal
Fair Value
Less than 12 Months	236,539	13,296
12 Months or Longer	28,126	35,324
Total	264,665	48,620
Gross Unrealized Losses
Less than 12 Months	5,298	198
12 Months or Longer	1,940	893
Total	7,238	1,091
U.S. Government-sponsored mortgage-backed securities
Fair Value
Less than 12 Months	385,626	182,755
12 Months or Longer	65,490	68,667
Total	451,116	251,422
Gross Unrealized Losses
Less than 12 Months	6,956	1,520
12 Months or Longer	3,083	1,903
Total	10,039	3,423
U.S. Government-sponsored agency securities
Fair Value
Less than 12 Months	9,861	9,988
12 Months or Longer	12,043	12,196
Total	21,904	22,184
Gross Unrealized Losses
Less than 12 Months	258	131
12 Months or Longer	457	304
Total	715	435
State and municipal
Fair Value
Less than 12 Months	18,155	2,430
12 Months or Longer	15,388	15,805
Total	33,543	18,235
Gross Unrealized Losses
Less than 12 Months	307	36
12 Months or Longer	604	208
Total	911	244
U.S. Government-sponsored mortgage-backed securities
Fair Value
Less than 12 Months	177,080	62,508
12 Months or Longer	40,866	43,078
Total	217,946	105,586
Gross Unrealized Losses
Less than 12 Months	2,154	485
12 Months or Longer	1,608	919
Total	3,762	$ 1,404
Corporate obligations
Fair Value
Less than 12 Months	994
Total	994
Gross Unrealized Losses
Less than 12 Months	6
Total	$ 6

Investment Securities - Inves48

Investment Securities - Investments in Debt and Equity Securities Reported Less than Historical Cost (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Schedule of Investments [Line Items]
Fair value	$ 990,539	$ 446,047
Investments reported at less than historical cost
Schedule of Investments [Line Items]
Historical cost	1,013,210	452,644
Fair value	$ 990,539	$ 446,047
Percent of the Corporation's investment portfolio	64.20%	28.60%

Loans and Allowance - Narrative

Loans and Allowance - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Dec. 31, 2017
Receivables [Abstract]
Loans held for sale	$ 4,469	$ 7,216
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	$ 6,901,696	6,751,199
Real estate loans - Residential
Accounts, Notes, Loans and Financing Receivable [Line Items]
Percentage of troubled debt restructured loans	91.00%
Mortgage loans with formal foreclosure proceedings	$ 1,465	2,302
Loans	1,459,189	1,476,786
Loans acquired with deteriorated credit quality
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	23,992	24,954
Loans acquired with deteriorated credit quality | Commercial and consumer loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	289	315
Loans acquired with deteriorated credit quality | Real estate loans - Residential
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	$ 1,557	$ 1,536

Loans and Allowance - Compositi

Loans and Allowance - Composition of Loan Portfolio by Loan Class (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017	Mar. 31, 2017	Dec. 31, 2016
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	$ 6,901,696	$ 6,751,199
Allowance for loan losses	(76,420)	(75,032)	$ (68,225)	$ (66,037)
Net Loans	6,825,276	6,676,167
Commercial and industrial loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	1,554,169	1,493,493
Agricultural production financing and other loans to farmers
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	98,315	121,757
Real estate loans - Construction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	590,093	612,219
Real estate loans - Commercial and farmland
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	2,713,994	2,562,691
Real estate loans - Residential
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	948,644	962,765
Allowance for loan losses	(14,049)	(13,537)	(12,259)	(11,755)
Real estate loans - Home equity
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	510,545	514,021
Individuals' loans for household and other personal expenditures
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	88,235	86,935
Allowance for loan losses	(3,896)	(3,732)	(3,120)	(2,923)
Lease financing receivables, net of unearned income
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	2,193	2,527
Allowance for loan losses	(2)	(2)	$ (2)	$ (2)
Other commercial loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	$ 395,508	$ 394,791

Loans and Allowance - Changes i

Loans and Allowance - Changes in Allowance for Loan Losses by Loan Segment (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Allowance for loan losses:
Beginning balance	$ 75,032	$ 66,037
Provision for losses	2,500	2,385
Recoveries on loans	701	1,268
Loans charged off	(1,813)	(1,465)
Ending balance	76,420	68,225
Commercial
Allowance for loan losses:
Beginning balance	30,418	27,696
Provision for losses	840	1,197
Recoveries on loans	119	366
Loans charged off	(609)	(735)
Ending balance	30,768	28,524
Commercial Real Estate
Allowance for loan losses:
Beginning balance	27,343	23,661
Provision for losses	84	247
Recoveries on loans	339	564
Loans charged off	(61)	(152)
Ending balance	27,705	24,320
Consumer
Allowance for loan losses:
Beginning balance	3,732	2,923
Provision for losses	274	249
Recoveries on loans	89	101
Loans charged off	(199)	(153)
Ending balance	3,896	3,120
Residential
Allowance for loan losses:
Beginning balance	13,537	11,755
Provision for losses	1,302	692
Recoveries on loans	154	237
Loans charged off	(944)	(425)
Ending balance	14,049	12,259
Lease financing receivables, net of unearned income
Allowance for loan losses:
Beginning balance	2	2
Provision for losses
Recoveries on loans
Loans charged off
Ending balance	$ 2	$ 2

Loans and Allowance - Allowance

Loans and Allowance - Allowance for Credit Losses and Loan Portfolio by Loan Segment (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017	Mar. 31, 2017	Dec. 31, 2016
Allowance Balances:
Individually evaluated for impairment	$ 1,317	$ 1,637
Collectively evaluated for impairment	75,103	73,395
Total Allowance for Loan Losses	76,420	75,032	$ 68,225	$ 66,037
Loan Balance [Abstract]
Individually evaluated for impairment	22,164	23,211
Collectively evaluated for impairment	6,855,540	6,703,034
Loans	6,901,696	6,751,199
Loans acquired with deteriorated credit quality
Loan Balance [Abstract]
Loans	23,992	24,954
Commercial
Allowance Balances:
Individually evaluated for impairment	143	666
Collectively evaluated for impairment	30,625	29,752
Total Allowance for Loan Losses	30,768	30,418	28,524	27,696
Loan Balance [Abstract]
Individually evaluated for impairment	2,914	3,345
Collectively evaluated for impairment	2,042,193	2,005,275
Loans	2,047,992	2,010,041
Commercial | Loans acquired with deteriorated credit quality
Loan Balance [Abstract]
Loans	2,885	1,421
Commercial Real Estate
Allowance Balances:
Individually evaluated for impairment	758	567
Collectively evaluated for impairment	26,947	26,776
Total Allowance for Loan Losses	27,705	27,343	24,320	23,661
Loan Balance [Abstract]
Individually evaluated for impairment	16,501	17,432
Collectively evaluated for impairment	3,268,036	3,135,481
Loans	3,304,087	3,174,910
Commercial Real Estate | Loans acquired with deteriorated credit quality
Loan Balance [Abstract]
Loans	19,550	21,997
Consumer
Allowance Balances:
Individually evaluated for impairment
Collectively evaluated for impairment	3,896	3,732
Total Allowance for Loan Losses	3,896	3,732	3,120	2,923
Loan Balance [Abstract]
Individually evaluated for impairment	11	5
Collectively evaluated for impairment	88,224	86,930
Loans	88,235	86,935
Consumer | Loans acquired with deteriorated credit quality
Loan Balance [Abstract]
Loans
Residential
Allowance Balances:
Individually evaluated for impairment	416	404
Collectively evaluated for impairment	13,633	13,133
Total Allowance for Loan Losses	14,049	13,537	12,259	11,755
Loan Balance [Abstract]
Individually evaluated for impairment	2,738	2,429
Collectively evaluated for impairment	1,454,894	1,472,821
Loans	1,459,189	1,476,786
Residential | Loans acquired with deteriorated credit quality
Loan Balance [Abstract]
Loans	1,557	1,536
Lease financing receivables, net of unearned income
Allowance Balances:
Individually evaluated for impairment
Collectively evaluated for impairment	2	2
Total Allowance for Loan Losses	2	2	$ 2	$ 2
Loan Balance [Abstract]
Individually evaluated for impairment
Collectively evaluated for impairment	2,193	2,527
Loans	2,193	2,527
Lease financing receivables, net of unearned income | Loans acquired with deteriorated credit quality
Loan Balance [Abstract]
Loans

Loans and Allowance - Summary o

Loans and Allowance - Summary of Non-Accrual Loans by Loan Class (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-accrual loans	$ 27,497	$ 28,724
Commercial and industrial loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-accrual loans	3,238	3,275
Agricultural production financing and other loans to farmers
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-accrual loans	638	1,027
Real estate loans - Construction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-accrual loans	1,481	65
Real estate loans - Commercial and farmland
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-accrual loans	13,944	12,951
Real estate loans - Residential
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-accrual loans	6,765	9,444
Real estate loans - Home Equity
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-accrual loans	1,385	1,928
Individuals' loans for household and other personal expenditures
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-accrual loans	$ 46	$ 34

Loans and Allowance - Composi54

Loans and Allowance - Composition of Impaired Loans by Loan Class (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Unpaid Principal Balance
Impaired loans with no related allowance	$ 26,301		$ 25,979
Impaired loans with related allowance	4,670		6,123
Total Impaired Loans	30,971		32,102
Recorded Investment
Impaired loans with no related allowance	17,649		17,930
Impaired loans with related allowance	4,515		5,281
Total Impaired Loans	22,164		23,211
Related Allowance	1,317		1,637
Average Recorded Investment
Impaired loans with no related allowance	17,714	$ 16,997
Impaired loans with related allowance	4,598	4,827
Total Impaired Loans	22,312	21,824
Interest Income Recognized
Impaired loans with no related allowance	54	81
Impaired loans with related allowance	14	8
Total Impaired Loans	68	89
Commercial and industrial loans
Unpaid Principal Balance
Impaired loans with no related allowance	7,863		7,611
Impaired loans with related allowance	474		812
Recorded Investment
Impaired loans with no related allowance	1,812		1,536
Impaired loans with related allowance	462		782
Related Allowance	143		552
Average Recorded Investment
Impaired loans with no related allowance	1,845	1,066
Impaired loans with related allowance	465
Interest Income Recognized
Impaired loans with no related allowance
Impaired loans with related allowance
Agricultural production financing and other loans to farmers
Unpaid Principal Balance
Impaired loans with no related allowance	660		732
Impaired loans with related allowance			357
Recorded Investment
Impaired loans with no related allowance	640		700
Impaired loans with related allowance			327
Related Allowance			114
Average Recorded Investment
Impaired loans with no related allowance	640
Impaired loans with related allowance		657
Interest Income Recognized
Impaired loans with no related allowance
Impaired loans with related allowance
Real estate loans - Construction
Unpaid Principal Balance
Impaired loans with related allowance	1,352
Recorded Investment
Impaired loans with related allowance	1,352
Related Allowance	307
Average Recorded Investment
Impaired loans with related allowance	1,352
Real estate loans - Commercial and farmland
Unpaid Principal Balance
Impaired loans with no related allowance	16,581		16,758
Impaired loans with related allowance	823		2,989
Recorded Investment
Impaired loans with no related allowance	14,388		15,162
Impaired loans with related allowance	761		2,270
Related Allowance	451		567
Average Recorded Investment
Impaired loans with no related allowance	14,450	14,963
Impaired loans with related allowance	767	2,848
Interest Income Recognized
Impaired loans with no related allowance	48	80
Impaired loans with related allowance
Real estate loans - Residential
Unpaid Principal Balance
Impaired loans with no related allowance	1,146		833
Impaired loans with related allowance	1,697		1,616
Recorded Investment
Impaired loans with no related allowance	790		519
Impaired loans with related allowance	1,636		1,572
Related Allowance	341		327
Average Recorded Investment
Impaired loans with no related allowance	759	935
Impaired loans with related allowance	1,709	1,062
Interest Income Recognized
Impaired loans with no related allowance	6	1
Impaired loans with related allowance	12	6
Real estate loans - Home equity
Unpaid Principal Balance
Impaired loans with no related allowance	40		40
Recorded Investment
Impaired loans with no related allowance	8		8
Average Recorded Investment
Impaired loans with no related allowance	8	26
Impaired loans with related allowance	305	260
Interest Income Recognized
Impaired loans with no related allowance
Impaired loans with related allowance	2	2
Individuals' loans for household and other personal expenditures
Unpaid Principal Balance
Impaired loans with no related allowance	11		5
Recorded Investment
Impaired loans with no related allowance	11		5
Average Recorded Investment
Impaired loans with no related allowance	12	7
Interest Income Recognized
Impaired loans with no related allowance
Home equity
Unpaid Principal Balance
Impaired loans with related allowance	324		349
Recorded Investment
Impaired loans with related allowance	304		330
Related Allowance	$ 75		$ 77

Loans and Allowance - Credit Qu

Loans and Allowance - Credit Quality of Loan Portfolio by Loan Class (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Financing Receivable, Recorded Investment [Line Items]
Loans	$ 6,901,696	$ 6,751,199
Commercial and industrial loans
Financing Receivable, Recorded Investment [Line Items]
Loans	1,554,169	1,493,493
Agricultural production financing and other loans to farmers
Financing Receivable, Recorded Investment [Line Items]
Loans	98,315	121,757
Real estate loans - Construction
Financing Receivable, Recorded Investment [Line Items]
Loans	590,093	612,219
Real estate loans - Commercial and farmland
Financing Receivable, Recorded Investment [Line Items]
Loans	2,713,994	2,562,691
Real estate loans - Residential
Financing Receivable, Recorded Investment [Line Items]
Loans	948,644	962,765
Real estate loans - Home equity
Financing Receivable, Recorded Investment [Line Items]
Loans	510,545	514,021
Individuals' loans for household and other personal expenditures
Financing Receivable, Recorded Investment [Line Items]
Loans	88,235	86,935
Lease financing receivables, net of unearned income
Financing Receivable, Recorded Investment [Line Items]
Loans	2,193	2,527
Other commercial loans
Financing Receivable, Recorded Investment [Line Items]
Loans	395,508	394,791
Commercial Pass
Financing Receivable, Recorded Investment [Line Items]
Loans	5,237,859	5,099,464
Commercial Pass | Commercial and industrial loans
Financing Receivable, Recorded Investment [Line Items]
Loans	1,465,692	1,418,401
Commercial Pass | Agricultural production financing and other loans to farmers
Financing Receivable, Recorded Investment [Line Items]
Loans	57,888	73,800
Commercial Pass | Real estate loans - Construction
Financing Receivable, Recorded Investment [Line Items]
Loans	553,131	587,906
Commercial Pass | Real estate loans - Commercial and farmland
Financing Receivable, Recorded Investment [Line Items]
Loans	2,557,293	2,408,329
Commercial Pass | Real estate loans - Residential
Financing Receivable, Recorded Investment [Line Items]
Loans	179,135	185,725
Commercial Pass | Real estate loans - Home equity
Financing Receivable, Recorded Investment [Line Items]
Loans	27,372	28,554
Commercial Pass | Lease financing receivables, net of unearned income
Financing Receivable, Recorded Investment [Line Items]
Loans	2,193	2,527
Commercial Pass | Other commercial loans
Financing Receivable, Recorded Investment [Line Items]
Loans	395,155	394,222
Commercial Special Mention
Financing Receivable, Recorded Investment [Line Items]
Loans	146,964	154,573
Commercial Special Mention | Commercial and industrial loans
Financing Receivable, Recorded Investment [Line Items]
Loans	58,916	51,336
Commercial Special Mention | Agricultural production financing and other loans to farmers
Financing Receivable, Recorded Investment [Line Items]
Loans	16,599	27,502
Commercial Special Mention | Real estate loans - Construction
Financing Receivable, Recorded Investment [Line Items]
Loans	1,363	828
Commercial Special Mention | Real estate loans - Commercial and farmland
Financing Receivable, Recorded Investment [Line Items]
Loans	64,356	70,074
Commercial Special Mention | Real estate loans - Residential
Financing Receivable, Recorded Investment [Line Items]
Loans	5,198	4,376
Commercial Special Mention | Real estate loans - Home equity
Financing Receivable, Recorded Investment [Line Items]
Loans	532	457
Commercial Special Mention | Lease financing receivables, net of unearned income
Financing Receivable, Recorded Investment [Line Items]
Loans
Commercial Substandard
Financing Receivable, Recorded Investment [Line Items]
Loans	159,656	129,218
Commercial Substandard | Commercial and industrial loans
Financing Receivable, Recorded Investment [Line Items]
Loans	29,561	23,386
Commercial Substandard | Agricultural production financing and other loans to farmers
Financing Receivable, Recorded Investment [Line Items]
Loans	23,828	20,018
Commercial Substandard | Real estate loans - Construction
Financing Receivable, Recorded Investment [Line Items]
Loans	11,918	981
Commercial Substandard | Real estate loans - Commercial and farmland
Financing Receivable, Recorded Investment [Line Items]
Loans	88,312	79,769
Commercial Substandard | Real estate loans - Residential
Financing Receivable, Recorded Investment [Line Items]
Loans	5,340	4,209
Commercial Substandard | Real estate loans - Home equity
Financing Receivable, Recorded Investment [Line Items]
Loans	344	286
Commercial Substandard | Lease financing receivables, net of unearned income
Financing Receivable, Recorded Investment [Line Items]
Loans
Commercial Substandard | Other commercial loans
Financing Receivable, Recorded Investment [Line Items]
Loans	353	569
Commercial Doubtful
Financing Receivable, Recorded Investment [Line Items]
Loans	1,148	2,407
Commercial Doubtful | Commercial and industrial loans
Financing Receivable, Recorded Investment [Line Items]
Loans		370
Commercial Doubtful | Agricultural production financing and other loans to farmers
Financing Receivable, Recorded Investment [Line Items]
Loans		387
Commercial Doubtful | Real estate loans - Commercial and farmland
Financing Receivable, Recorded Investment [Line Items]
Loans	1,117	1,536
Commercial Doubtful | Real estate loans - Residential
Financing Receivable, Recorded Investment [Line Items]
Loans	31	114
Commercial Doubtful | Real estate loans - Home equity
Financing Receivable, Recorded Investment [Line Items]
Loans
Commercial Loss
Financing Receivable, Recorded Investment [Line Items]
Loans		50
Commercial Loss | Agricultural production financing and other loans to farmers
Financing Receivable, Recorded Investment [Line Items]
Loans		50
Commercial Loss | Real estate loans - Commercial and farmland
Financing Receivable, Recorded Investment [Line Items]
Loans
Consumer Performing
Financing Receivable, Recorded Investment [Line Items]
Loans	1,348,581	1,354,790
Consumer Performing | Agricultural production financing and other loans to farmers
Financing Receivable, Recorded Investment [Line Items]
Loans
Consumer Performing | Real estate loans - Construction
Financing Receivable, Recorded Investment [Line Items]
Loans	23,552	22,374
Consumer Performing | Real estate loans - Commercial and farmland
Financing Receivable, Recorded Investment [Line Items]
Loans	2,914	2,980
Consumer Performing | Real estate loans - Residential
Financing Receivable, Recorded Investment [Line Items]
Loans	753,126	759,900
Consumer Performing | Real estate loans - Home equity
Financing Receivable, Recorded Investment [Line Items]
Loans	480,830	482,661
Consumer Performing | Individuals' loans for household and other personal expenditures
Financing Receivable, Recorded Investment [Line Items]
Loans	88,159	86,875
Consumer Non-Performing
Financing Receivable, Recorded Investment [Line Items]
Loans	7,488	10,697
Consumer Non-Performing | Real estate loans - Construction
Financing Receivable, Recorded Investment [Line Items]
Loans	129	130
Consumer Non-Performing | Real estate loans - Commercial and farmland
Financing Receivable, Recorded Investment [Line Items]
Loans	2	3
Consumer Non-Performing | Real estate loans - Residential
Financing Receivable, Recorded Investment [Line Items]
Loans	5,814	8,441
Consumer Non-Performing | Real estate loans - Home equity
Financing Receivable, Recorded Investment [Line Items]
Loans	1,467	2,063
Consumer Non-Performing | Individuals' loans for household and other personal expenditures
Financing Receivable, Recorded Investment [Line Items]
Loans	$ 76	$ 60

Loans and Allowance - Past Due

Loans and Allowance - Past Due Aging of Loan Portfolio by Loan Class (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	$ 6,851,488	$ 6,703,256
Non-Accrual	27,497	28,724
Total Past Due & Non-Accrual	50,208	47,943
Total	6,901,696	6,751,199
Commercial and industrial loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	1,549,330	1,487,221
Non-Accrual	3,238	3,275
Total Past Due & Non-Accrual	4,839	6,272
Total	1,554,169	1,493,493
Agricultural production financing and other loans to farmers
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	89,198	120,720
Non-Accrual	638	1,027
Total Past Due & Non-Accrual	9,117	1,037
Total	98,315	121,757
Real estate loans - Construction
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	588,424	610,896
Non-Accrual	1,481	65
Total Past Due & Non-Accrual	1,669	1,323
Total	590,093	612,219
Real estate loans - Commercial and farmland
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	2,693,020	2,542,048
Non-Accrual	13,944	12,951
Total Past Due & Non-Accrual	20,974	20,643
Total	2,713,994	2,562,691
Real estate loans - Residential
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	938,960	948,947
Non-Accrual	6,765	9,444
Total Past Due & Non-Accrual	9,684	13,818
Total	948,644	962,765
Real estate loans - Home equity
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	506,922	510,362
Non-Accrual	1,385	1,928
Total Past Due & Non-Accrual	3,623	3,659
Total	510,545	514,021
Individuals' loans for household and other personal expenditures
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	87,933	85,744
Non-Accrual	46	34
Total Past Due & Non-Accrual	302	1,191
Total	88,235	86,935
Lease financing receivables, net of unearned income
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	2,193	2,527
Total	2,193	2,527
Other commercial loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	395,508	394,791
Total Past Due & Non-Accrual
Total	395,508	394,791
30-59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	19,703	16,773
30-59 Days Past Due | Commercial and industrial loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	1,062	2,967
30-59 Days Past Due | Agricultural production financing and other loans to farmers
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	8,479
30-59 Days Past Due | Real estate loans - Construction
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	188	1,193
30-59 Days Past Due | Real estate loans - Commercial and farmland
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	5,589	6,923
30-59 Days Past Due | Real estate loans - Residential
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	2,577	4,010
30-59 Days Past Due | Real estate loans - Home equity
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	1,638	1,372
30-59 Days Past Due | Individuals' loans for household and other personal expenditures
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	170	298
60-89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	2,270	1,522
60-89 Days Past Due | Commercial and industrial loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	49	30
60-89 Days Past Due | Agricultural production financing and other loans to farmers
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due
60-89 Days Past Due | Real estate loans - Construction
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due
60-89 Days Past Due | Real estate loans - Commercial and farmland
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	1,378	166
60-89 Days Past Due | Real estate loans - Residential
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	305	308
60-89 Days Past Due | Real estate loans - Home equity
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	481	184
60-89 Days Past Due | Individuals' loans for household and other personal expenditures
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	57	834
60-89 Days Past Due | Other commercial loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due
Loans 90 Days And Accruing
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	738	924
Loans 90 Days And Accruing | Commercial and industrial loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	490
Loans 90 Days And Accruing | Agricultural production financing and other loans to farmers
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due
Loans 90 Days And Accruing | Real estate loans - Construction
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due		65
Loans 90 Days And Accruing | Real estate loans - Commercial and farmland
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	63	603
Loans 90 Days And Accruing | Real estate loans - Residential
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	37	56
Loans 90 Days And Accruing | Real estate loans - Home equity
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	119	175
Loans 90 Days And Accruing | Individuals' loans for household and other personal expenditures
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	$ 29	$ 25

Loans and Allowance - Summary57

Loans and Allowance - Summary of Troubled Debt Restructurings (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2018USD ($)loan	Mar. 31, 2017USD ($)loan
Financing Receivable, Modifications [Line Items]
Pre-Modification Recorded Balance	$ 237	$ 350
Post-Modification Recorded Balance	$ 246	$ 363
Number of Loans | loan	8	5
Real estate loans - Commercial and farmland
Financing Receivable, Modifications [Line Items]
Pre-Modification Recorded Balance		$ 107
Post-Modification Recorded Balance		$ 241
Number of Loans | loan		3
Real estate loans - Residential
Financing Receivable, Modifications [Line Items]
Pre-Modification Recorded Balance	$ 214	$ 121
Post-Modification Recorded Balance	$ 222	$ 122
Number of Loans | loan	5	2
Real estate loans - Home equity
Financing Receivable, Modifications [Line Items]
Pre-Modification Recorded Balance	$ 16	$ 122
Post-Modification Recorded Balance	$ 16
Number of Loans | loan	2
Individuals' loans for household and other personal expenditures
Financing Receivable, Modifications [Line Items]
Pre-Modification Recorded Balance	$ 7
Post-Modification Recorded Balance	$ 8
Number of Loans | loan	1

Loans and Allowance - Summary58

Loans and Allowance - Summary of Troubled Debt Restructurings by Modification Type (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Financing Receivable, Modifications [Line Items]
Modification	$ 251	$ 363
Term Modification
Financing Receivable, Modifications [Line Items]
Modification	54
Rate Modification
Financing Receivable, Modifications [Line Items]
Modification	91	122
Combination
Financing Receivable, Modifications [Line Items]
Modification	106	241
Real estate loans - Commercial and farmland
Financing Receivable, Modifications [Line Items]
Modification		241
Real estate loans - Commercial and farmland | Term Modification
Financing Receivable, Modifications [Line Items]
Modification
Real estate loans - Commercial and farmland | Rate Modification
Financing Receivable, Modifications [Line Items]
Modification
Real estate loans - Commercial and farmland | Combination
Financing Receivable, Modifications [Line Items]
Modification		241
Real estate loans - Residential
Financing Receivable, Modifications [Line Items]
Modification	218	122
Real estate loans - Residential | Term Modification
Financing Receivable, Modifications [Line Items]
Modification	38
Real estate loans - Residential | Rate Modification
Financing Receivable, Modifications [Line Items]
Modification	74	122
Real estate loans - Residential | Combination
Financing Receivable, Modifications [Line Items]
Modification	106
Real estate loans - Home equity
Financing Receivable, Modifications [Line Items]
Modification	26
Real estate loans - Home equity | Term Modification
Financing Receivable, Modifications [Line Items]
Modification	16
Real estate loans - Home equity | Rate Modification
Financing Receivable, Modifications [Line Items]
Modification	10
Real estate loans - Home equity | Combination
Financing Receivable, Modifications [Line Items]
Modification
Individuals' loans for household and other personal expenditures
Financing Receivable, Modifications [Line Items]
Modification	7
Individuals' loans for household and other personal expenditures | Rate Modification
Financing Receivable, Modifications [Line Items]
Modification	7
Individuals' loans for household and other personal expenditures | Combination
Financing Receivable, Modifications [Line Items]
Modification

Loans and Allowance - Subsequen

Loans and Allowance - Subsequent Default (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2018USD ($)loan	Mar. 31, 2017USD ($)loan
Financing Receivable, Modifications [Line Items]
Number of Loans | loan	4	1
Recorded Balance | $	$ 432	$ 223
Real estate loans - Commercial and farmland
Financing Receivable, Modifications [Line Items]
Number of Loans | loan	1	1
Recorded Balance | $	$ 324	$ 223
Real estate loans - Residential
Financing Receivable, Modifications [Line Items]
Number of Loans | loan	3
Recorded Balance | $	$ 108

Purchased Credit Impaired Loa60

Purchased Credit Impaired Loans - Accretable Yield or Income Expected to be Collected (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Accretable Yield Movement Schedule [Roll Forward]
Beginning balance	$ 2,890	$ 3,950
Additions
Accretion	(510)	(3,238)
Reclassification from nonaccretable	295	2,370
Disposals
Ending balance	2,675	$ 3,082
Loans acquired with deteriorated credit quality
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans acquired and accounted for under ASC 310-30, carrying amount	$ 24,300		$ 25,300

Goodwill - Narrative (Details)

Goodwill - Narrative (Details) - USD ($) $ in Thousands	May 19, 2017	Dec. 31, 2017	Mar. 31, 2018	Jul. 14, 2017	Dec. 31, 2016
Goodwill [Line Items]
Goodwill		$ 445,355	$ 445,355		$ 244,000
Goodwill, measurement period adjustment		$ (469)
IAB
Goodwill [Line Items]
Goodwill				$ 153,636
Arlington Bank
Goodwill [Line Items]
Goodwill	$ 47,719
Goodwill, measurement period adjustment	$ 469

Goodwill - Schedule of Goodwill

Goodwill - Schedule of Goodwill (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2017USD ($)
Goodwill [Roll Forward]
Goodwill, beginning balance	$ 244,000
Goodwill acquired	201,824
Measurement period adjustment	(469)
Goodwill, ending balance	$ 445,355

Other Intangibles - Narrative (

Other Intangibles - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Jul. 14, 2017	May 19, 2017
Minimum
Finite-Lived Intangible Assets [Line Items]
Useful life of core deposit intangibles and other intangibles	2 years
Maximum
Finite-Lived Intangible Assets [Line Items]
Useful life of core deposit intangibles and other intangibles	10 years
IAB
Finite-Lived Intangible Assets [Line Items]
Core deposit intangible		$ 17,403
IAB | Core deposits
Finite-Lived Intangible Assets [Line Items]
Core deposit intangible		13,638
IAB | Noncompete agreements
Finite-Lived Intangible Assets [Line Items]
Core deposit intangible		$ 3,765
Arlington Bank
Finite-Lived Intangible Assets [Line Items]
Core deposit intangible			$ 4,526
Arlington Bank | Core deposits
Finite-Lived Intangible Assets [Line Items]
Core deposit intangible			$ 4,526

Other Intangibles - Schedule of

Other Intangibles - Schedule of Core Deposit and Other Intangibles (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2018	Dec. 31, 2017
Acquired Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	$ 85,869	$ 63,940
Accumulated amortization	(56,447)	(54,721)
Total other intangibles	29,422	31,148
Core deposits
Acquired Finite-Lived Intangible Assets [Line Items]
Intangibles acquired		18,164
Other intangibles
Acquired Finite-Lived Intangible Assets [Line Items]
Intangibles acquired		$ 3,765

Other Intangibles - Estimated F

Other Intangibles - Estimated Future Amortization Expense (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Amortization Expense
2,018	$ 4,993
2,019	5,169
2,020	3,632
2,021	3,427
2,022	3,325
After 2,022	8,876
Total other intangibles	$ 29,422	$ 31,148

Derivative Financial Instrume66

Derivative Financial Instruments - Narrative (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2018USD ($)interest_rate_swapinterest_rate_capinstrument	Dec. 31, 2017USD ($)interest_rate_swapinterest_rate_cap
Derivative [Line Items]
Estimated amount to be transferred from accumulated other comprehensive income to earnings	$ 393
Termination value of derivatives in a net liability position	1,068
Derivative collateral posted	3,315
Not Designated as Hedging Instrument
Derivative [Line Items]
Notional amount of interest rate derivatives	$ 429,360
Federal Home Loan Bank Advances
Derivative [Line Items]
Number of debt instruments held | instrument	3
Cash Flow Hedging | Interest Rate Swap
Derivative [Line Items]
Number of interest rate derivatives held | interest_rate_swap	5	5
Notional amount of interest rate derivatives	$ 56,000	$ 56,000
Cash Flow Hedging | Interest Rate Swap | Trust Preferred Debt
Derivative [Line Items]
Notional amount of interest rate derivatives	26,000
Cash Flow Hedging | Interest Rate Swap | Federal Home Loan Bank Advances
Derivative [Line Items]
Notional amount of interest rate derivatives	$ 30,000
Cash Flow Hedging | Interest Rate Cap
Derivative [Line Items]
Number of interest rate derivatives held | interest_rate_cap	1	1
Notional amount of interest rate derivatives	$ 13,000	$ 13,000
Cash Flow Hedging | Interest Rate Cap | Trust Preferred Debt
Derivative [Line Items]
Notional amount of interest rate derivatives	$ 13,000

Derivative Financial Instrume67

Derivative Financial Instruments - Fair Value of Derivative Financial Instruments and Their Classification on Balance Sheet (Details) - Interest rate contracts - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Derivatives designated as hedging instruments | Other Assets
Derivatives, Fair Value [Line Items]
Asset Derivatives	$ 258	$ 18
Derivatives designated as hedging instruments | Other Liabilities
Derivatives, Fair Value [Line Items]
Liability Derivatives	689	1,383
Derivatives not designated as hedging instruments | Other Assets
Derivatives, Fair Value [Line Items]
Asset Derivatives	11,376	7,305
Derivatives not designated as hedging instruments | Other Liabilities
Derivatives, Fair Value [Line Items]
Liability Derivatives	$ 11,376	$ 7,305

Derivative Financial Instrume68

Derivative Financial Instruments - Effect of Derivative Financial Instruments on Other Comprehensive Income (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Designated as Hedging Instrument | Cash Flow Hedging | Interest Rate Products
Derivative [Line Items]
Amount of Gain (Loss) Recognized in Other Comprehensive Income on Derivative (Effective Portion)	$ 508	$ 34

Derivative Financial Instrume69

Derivative Financial Instruments - Effect of Derivative Financial Instruments on Income Statement (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Interest rate contracts | Derivatives designated as hedging instruments | Interest Expense
Derivative [Line Items]
Amount of Gain (Loss) Reclassified from Other Comprehensive Income into Income (Effective Portion)	$ (170)	$ (268)

Disclosures About Fair Value 70

Disclosures About Fair Value of Assets and Liabilities - Fair Value Measurements of Assets and Liabilities Measured at Fair Value on Recurring Basis (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale securities	$ 1,003,799	$ 999,947
Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale securities
Significant Other Observable Inputs (Level 2)
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale securities	999,833	995,969
Significant Unobservable Inputs (Level 3)
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale securities	3,966	3,978
Fair Value, Measurements, Recurring | Interest rate swap liability | Significant Other Observable Inputs (Level 2)
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Interest rate swap liability	12,065	8,688
Fair Value, Measurements, Recurring | U.S. Government-sponsored agency securities | Significant Other Observable Inputs (Level 2)
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale securities	6,498
Fair Value, Measurements, Recurring | State and municipal | Significant Other Observable Inputs (Level 2)
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale securities	506,303	522,750
Fair Value, Measurements, Recurring | State and municipal | Significant Unobservable Inputs (Level 3)
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale securities	3,931	3,943
Fair Value, Measurements, Recurring | U.S. Government-sponsored mortgage-backed securities | Significant Other Observable Inputs (Level 2)
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale securities	487,032	470,866
Fair Value, Measurements, Recurring | U.S. Government-sponsored mortgage-backed securities | Significant Unobservable Inputs (Level 3)
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale securities	4
Fair Value, Measurements, Recurring | Corporate obligations | Significant Unobservable Inputs (Level 3)
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale securities	31	31
Fair Value, Measurements, Recurring | Equity securities | Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale securities
Fair Value, Measurements, Recurring | Equity securities | Significant Other Observable Inputs (Level 2)
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale securities		2,353
Fair Value, Measurements, Recurring | Equity securities | Significant Unobservable Inputs (Level 3)
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale securities		4
Fair Value, Measurements, Recurring | Interest rate swap asset | Significant Other Observable Inputs (Level 2)
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Interest rate derivatives	11,376	7,305
Fair Value, Measurements, Recurring | Interest rate cap | Significant Other Observable Inputs (Level 2)
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Interest rate derivatives	258	18
Fair Value, Measurements, Recurring | Fair Value | Interest rate swap liability
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Interest rate swap liability	12,065	8,688
Fair Value, Measurements, Recurring | Fair Value | U.S. Government-sponsored agency securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale securities	6,498
Fair Value, Measurements, Recurring | Fair Value | State and municipal
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale securities	510,234	526,693
Fair Value, Measurements, Recurring | Fair Value | U.S. Government-sponsored mortgage-backed securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale securities	487,036	470,866
Fair Value, Measurements, Recurring | Fair Value | Corporate obligations
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale securities	31	31
Fair Value, Measurements, Recurring | Fair Value | Equity securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale securities		2,357
Fair Value, Measurements, Recurring | Fair Value | Interest rate swap asset
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Interest rate derivatives	11,376	7,305
Fair Value, Measurements, Recurring | Fair Value | Interest rate cap
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Interest rate derivatives	$ 258	$ 18

Disclosures About Fair Value 71

Disclosures About Fair Value of Assets and Liabilities - Reconciliation of Beginning and Ending Balances of Recurring Fair Value Measurements using Significant Unobservable Level 3 Inputs (Details) - Fair Value, Measurements, Recurring - Available for Sale Securities - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Available for Sale Securities
Balance at beginning of the period	$ 3,978	$ 5,169
Included in other comprehensive income	(25)	11
Principal payments	13	(1,901)
Ending balance	$ 3,966	$ 3,279

Disclosures About Fair Value 72

Disclosures About Fair Value of Assets and Liabilities - Transfers Between Levels (Details) - USD ($)	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Fair Value Disclosures [Abstract]
Transfers in or out of Level 3	$ 0	$ 0

Disclosures About Fair Value 73

Disclosures About Fair Value of Assets and Liabilities - Valuation Methodologies Used for Instruments Measured at Fair Value on Non-Recurring Basis (Details) - Fair Value, Measurements, Nonrecurring - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Impaired loans (collateral dependent)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	$ 7,833	$ 9,576
Impaired loans (collateral dependent) | Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	7,833	9,576
Other real estate owned
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	119	859
Other real estate owned | Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	$ 119	$ 859

Disclosures About Fair Value 74

Disclosures About Fair Value of Assets and Liabilities - Unobservable Inputs Used in Recurring and Nonrecurring Level 3 Fair Value Measurements Other Than Goodwill (Details) - Significant Unobservable Inputs (Level 3) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2018	Dec. 31, 2017
State and municipal securities | Discounted cash flow
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Fair Value	$ 3,931	$ 3,943
State and municipal securities | Discounted cash flow | Minimum
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Maturity/Call date	1 month	1 month
US Muni BQ curve	A-	A-
Discount rate	1.00%	0.69%
State and municipal securities | Discounted cash flow | Maximum
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Maturity/Call date	20 years	20 years
US Muni BQ curve	BBB-	BBB-
Discount rate	5.00%	5.00%
Corporate obligations and U.S. Government-sponsored mortgage backed securities | Discounted cash flow
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Fair Value	$ 35
Corporate obligations and equity securities | Discounted cash flow
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Fair Value		$ 35
Risk free rate	3 month LIBOR	3 month LIBOR
Discount to reflect current market conditions	2.00%	2.00%
Impaired loans (collateral dependent) | Collateral based measurements
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Fair Value	$ 7,833	$ 9,576
Impaired loans (collateral dependent) | Collateral based measurements | Minimum
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Discount to reflect current market conditions and ultimate collectability	0.00%	0.00%
Impaired loans (collateral dependent) | Collateral based measurements | Maximum
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Discount to reflect current market conditions and ultimate collectability	10.00%	10.00%
Impaired loans (collateral dependent) | Collateral based measurements | Weighted Average
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Discount to reflect current market conditions and ultimate collectability	1.00%	1.00%
Other real estate owned | Appraisals
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Fair Value	$ 119	$ 859
Other real estate owned | Appraisals | Minimum
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Discount to reflect current market conditions	0.00%	0.00%
Other real estate owned | Appraisals | Maximum
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Discount to reflect current market conditions	24.00%	10.00%
Other real estate owned | Appraisals | Weighted Average
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Discount to reflect current market conditions	24.00%	2.00%

Disclosures About Fair Value 75

Disclosures About Fair Value of Assets and Liabilities - Estimated Fair Values of Financial Instruments (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Assets:
Investment securities available for sale	$ 1,003,799	$ 999,947
Investment securities held to maturity	538,399	568,208
Loans held for sale	4,469	7,216
Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets:
Cash and cash equivalents	128,828	154,905
Interest-bearing time deposits	24,233	35,027
Investment securities available for sale
Liabilities:
Deposits	5,849,466	5,741,019
Significant Other Observable Inputs (Level 2)
Assets:
Investment securities available for sale	999,833	995,969
Investment securities held to maturity	527,253	556,305
Loans held for sale	4,469	7,216
Federal Home Loan Bank stock	24,588	23,825
Interest rate swap and cap asset	11,634	7,323
Interest receivable	35,223	37,130
Liabilities:
Deposits	1,450,066	1,406,526
Borrowings:
Federal funds purchased	50,000	144,038
Securities sold under repurchase agreements	138,770	136,562
Federal Home Loan Bank advances	443,804	361,085
Subordinated debentures and term loans	123,485	120,085
Interest rate swap liability	12,065	8,688
Interest payable	5,376	4,390
Significant Unobservable Inputs (Level 3)
Assets:
Investment securities available for sale	3,966	3,978
Investment securities held to maturity	11,146	11,903
Loans	6,649,237	6,534,877
Carrying Amount
Assets:
Cash and cash equivalents	128,828	154,905
Interest-bearing time deposits	24,233	35,027
Investment securities available for sale	1,003,799	999,947
Investment securities held to maturity	540,021	560,655
Loans held for sale	4,469	7,216
Loans	6,825,276	6,676,167
Federal Home Loan Bank stock	24,588	23,825
Interest rate swap and cap asset	11,634	7,323
Interest receivable	35,223	37,130
Liabilities:
Deposits	7,327,635	7,172,530
Borrowings:
Federal funds purchased	50,000	144,038
Securities sold under repurchase agreements	138,910	136,623
Federal Home Loan Bank advances	449,419	414,377
Subordinated debentures and term loans	138,297	139,349
Interest rate swap liability	12,065	8,688
Interest payable	$ 5,376	$ 4,390

Transfers Accounted for as Se76

Transfers Accounted for as Secured Borrowings (Details) - U.S. Government-sponsored mortgage-backed securities - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Assets Sold under Agreements to Repurchase [Line Items]
Collateral pledged for all repurchase agreements accounted for as secured borrowings	$ 138,910	$ 136,623
Overnight and Continuous
Assets Sold under Agreements to Repurchase [Line Items]
Collateral pledged for all repurchase agreements accounted for as secured borrowings	129,490	126,187
Up to 30 Days
Assets Sold under Agreements to Repurchase [Line Items]
Collateral pledged for all repurchase agreements accounted for as secured borrowings	300	1,340
30-90 Days
Assets Sold under Agreements to Repurchase [Line Items]
Collateral pledged for all repurchase agreements accounted for as secured borrowings		1,500
Greater Than 90 Days
Assets Sold under Agreements to Repurchase [Line Items]
Collateral pledged for all repurchase agreements accounted for as secured borrowings	$ 9,120	$ 7,596

Accumulated Other Comprehensi77

Accumulated Other Comprehensive Income (Loss) - Changes in Balances of Each Component (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Accumulated Other Comprehensive Income (Loss)
Beginning balance	$ 1,303,463
Other comprehensive income before reclassifications	(17,054)	$ 10,133
Amounts reclassified from accumulated other comprehensive income	(1,137)	(274)
Total other comprehensive income (loss), net of tax	(18,191)	9,859
Reclassification adjustment under ASU 2018-02	(626)
Ending balance	1,313,073
Total
Accumulated Other Comprehensive Income (Loss)
Beginning balance	(2,908)	(13,581)
Total other comprehensive income (loss), net of tax	(18,191)
Ending balance	(21,725)	(3,722)
Unrealized Gains (Losses) on Securities Available for Sale
Accumulated Other Comprehensive Income (Loss)
Beginning balance	8,970	1,035
Other comprehensive income before reclassifications	(17,698)	10,110
Amounts reclassified from accumulated other comprehensive income	(1,271)	(389)
Total other comprehensive income (loss), net of tax	(18,969)	9,721
Reclassification adjustment under ASU 2018-02	1,932
Ending balance	(8,067)	10,756
Unrealized Gains (Losses) on Cash Flow Hedges
Accumulated Other Comprehensive Income (Loss)
Beginning balance	(1,125)	(1,774)
Other comprehensive income before reclassifications	644	23
Amounts reclassified from accumulated other comprehensive income	134	174
Total other comprehensive income (loss), net of tax	778	197
Reclassification adjustment under ASU 2018-02	(242)
Ending balance	(589)	(1,577)
Unrealized Gains (Losses) on Defined Benefit Plans
Accumulated Other Comprehensive Income (Loss)
Beginning balance	(10,753)	(12,842)
Other comprehensive income before reclassifications
Amounts reclassified from accumulated other comprehensive income		(59)
Total other comprehensive income (loss), net of tax	0	(59)
Reclassification adjustment under ASU 2018-02	(2,316)
Ending balance	$ (13,069)	$ (12,901)

Accumulated Other Comprehensi78

Accumulated Other Comprehensive Income (Loss) - Reclassifications (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Reclassification Adjustments out of Accumulated Other Comprehensive Income [Line Items]
Other income - net realized gains on sales of available for sale securities	$ 1,609	$ 598
Interest expense - subordinated debentures and term loans	1,990	1,817
Amortization of prior service costs	32,226	25,732
Income tax expense	(6,611)	(7,168)
Total reclassifications for the period, net of tax	1,137	274
Unrealized gains (losses) on available for sale securities
Reclassification Adjustments out of Accumulated Other Comprehensive Income [Line Items]
Total reclassifications for the period, net of tax	1,271	389
Unrealized gains (losses) on cash flow hedges
Reclassification Adjustments out of Accumulated Other Comprehensive Income [Line Items]
Total reclassifications for the period, net of tax	(134)	(174)
Unrealized Gains (Losses) on Defined Benefit Plans
Reclassification Adjustments out of Accumulated Other Comprehensive Income [Line Items]
Total reclassifications for the period, net of tax		59
Amount Reclassified from Accumulated Other Comprehensive Income (Loss) for the Period | Unrealized gains (losses) on available for sale securities
Reclassification Adjustments out of Accumulated Other Comprehensive Income [Line Items]
Other income - net realized gains on sales of available for sale securities	1,609	598
Income tax expense	(338)	(209)
Amount Reclassified from Accumulated Other Comprehensive Income (Loss) for the Period | Unrealized gains (losses) on cash flow hedges
Reclassification Adjustments out of Accumulated Other Comprehensive Income [Line Items]
Income tax expense	36	94
Amount Reclassified from Accumulated Other Comprehensive Income (Loss) for the Period | Unrealized gains (losses) on cash flow hedges | Interest rate contracts
Reclassification Adjustments out of Accumulated Other Comprehensive Income [Line Items]
Interest expense - subordinated debentures and term loans	(170)	(268)
Amount Reclassified from Accumulated Other Comprehensive Income (Loss) for the Period | Unrealized Gains (Losses) on Defined Benefit Plans
Reclassification Adjustments out of Accumulated Other Comprehensive Income [Line Items]
Amortization of prior service costs		91
Income tax expense		(32)
Total reclassifications for the period, net of tax	$ 0	$ 59

Share-Based Compensation - Narr

Share-Based Compensation - Narrative (Details) - USD ($)	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of average closing price to be paid by employees	85.00%
Maximum common stock purchases through advance payroll deductions in a calendar year	$ 25,000
Share-based compensation	$ 875,000	$ 573,000
Forfeiture rate	2.20%
Unrecognized compensation expense related to stock options	$ 0
Aggregate intrinsic value of stock options exercised	473,000	1,823,000
Cash receipts of stock options exercised	$ 535,000	$ 1,314,000
Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock option term	10 years
Stock options vesting percentage	100.00%
Stock Options | Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vested period	6 months
Stock Options | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vested period	2 years
RSAs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vested period	3 years
Outstanding DSUs (in shares)	278,464		366,993
Unrecognized compensation expense related to RSAs	$ 5,436,000
Unrecognized compensation expense expected recognition period	1 year 7 months 23 days
DSUs | Non-employee Director
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Outstanding DSUs (in shares)	0
ESPP
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation expense related to stock options	$ 0
Grant date fair value of ESPP options	$ 24,000

Share-Based Compensation - Comp

Share-Based Compensation - Components of Share-Based Compensation Awards (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Pre-tax compensation expense	$ 875	$ 573
Income tax benefit	(625)	(956)
Total share-based compensation expense, net of income taxes	250	(383)
Stock and ESPP Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Pre-tax compensation expense	24	48
Income tax benefit	(59)	(246)
Total share-based compensation expense, net of income taxes	(35)	(198)
Restricted Stock Awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Pre-tax compensation expense	851	525
Income tax benefit	(566)	(710)
Total share-based compensation expense, net of income taxes	$ 285	$ (185)

Share-Based Compensation - Stoc

Share-Based Compensation - Stock Option Activity under Stock Option Plans (Details)	3 Months Ended
	Mar. 31, 2018USD ($)$ / sharesshares
Number of Shares
Beginning balance (in shares) | shares	152,652
Exercised (in shares) | shares	(23,557)
Cancelled (in shares) | shares	(200)
Ending balance (in shares) | shares	128,895
Vested and Expected to Vest (in shares) | shares	128,895
Exercisable (in shares) | shares	128,895
Weighted-Average Exercise Price
Beginning balance (in dollars per share) | $ / shares	$ 16.71
Exercised (in dollars per share) | $ / shares	22.71
Cancelled (in dollars per share) | $ / shares	28.25
Ending balance (in dollars per share) | $ / shares	15.59
Vested and Expected to Vest (in dollars per share) | $ / shares	15.59
Exercisable (in dollars per share) | $ / shares	$ 15.59
Weighted Average Remaining Contractual Term (in Years)
Outstanding (term)	2 years 5 months 12 days
Vested and Expected to Vest (term)	2 years 5 months 12 days
Exercisable (term)	2 years 5 months 12 days
Aggregate Intrinsic Value
Outstanding | $	$ 3,365,525
Vested and Expected to Vest | $	3,365,525
Exercisable | $	$ 3,365,525

Share-Based Compensation - Unve

Share-Based Compensation - Unvested RSAs Outstanding (Details) - RSAs	3 Months Ended
	Mar. 31, 2018$ / sharesshares
Number of Shares
Unvested RSAs, Beginning Balance (in shares) | shares	366,993
Granted (in shares) | shares	4,687
Vested (in shares) | shares	(93,076)
Forfeited (in shares) | shares	(140)
Unvested RSAs, Ending Balance (in shares) | shares	278,464
Weighted-Average Grant Date Fair Value
Unvested RSAs, Beginning Balance (in dollars per share) | $ / shares	$ 29.79
Granted (in dollars per share) | $ / shares	42.11
Vested (in dollars per share) | $ / shares	22.91
Forfeited (in dollars per share) | $ / shares	22.87
Unvested RSAs, Ending Balance (in dollars per share) | $ / shares	$ 32.31

Income Tax (Details)

Income Tax (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Reconciliation of Federal Statutory to Actual Tax Expense:
Federal statutory income tax at 21% for 2018 and 35% for 2017	$ 9,091	$ 10,627
Tax-exempt interest income	(2,015)	(2,549)
Share-based compensation	(441)	(755)
Tax-exempt earnings and gains on life insurance	(247)	(314)
Tax credits	39	(106)
Other	184	265
Actual Tax Expense	$ 6,611	$ 7,168
Federal statutory income tax rate	21.00%	35.00%
Effective Tax Rate	15.30%	23.60%

Net Income Per Share - Reconcil

Net Income Per Share - Reconciliation of Basic and Diluted Net Income Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Net Income
Net income available to common stockholders	$ 36,679	$ 23,193
Diluted net income per share	$ 36,679	$ 23,193
Weighted-Average Shares
Net income available to common stockholders (in shares)	49,192,647	40,984,481
Effect of potentially dilutive stock options and restricted stock awards (in shares)	235,325	236,105
Diluted net income per share (in shares)	49,427,972	41,220,586
Per Share Amount
Net income available to common stockholders (in dollars per share)	$ 0.75	$ 0.57
Diluted net income per share (in dollars per share)	$ 0.74	$ 0.56

Net Income Per Share - Narrativ

Net Income Per Share - Narrative (Details)	3 Months Ended
	Mar. 31, 2018shares
Stock Options
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Stock options not included in the earnings per share calculation (in shares)	0