First Merchants (FRME) 10-Q 7 Aug 19 2019 Q2 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	6 Months Ended
	Jun. 30, 2019	Jul. 31, 2019
Cover page.
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Jun. 30, 2019
Document Transition Report	false
Entity File Number	0-17071
Entity Registrant Name	FIRST MERCHANTS CORP
Entity Incorporation, State or Country Code	IN
Entity Tax Identification Number	35-1544218
Entity Address, Address Line One	200 East Jackson Street
Entity Address, City or Town	Muncie
Entity Address, State or Province	IN
Entity Address, Postal Zip Code	47305-2814
City Area Code	765
Local Phone Number	747-1500
Title of 12(b) Security	Common Stock, $0.125 state value per share
Trading Symbol	FRME
Security Exchange Name	NASDAQ
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		49,696,573
Amendment Flag	false
Entity Central Index Key	0000712534
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	Q2
Current Fiscal Year End Date	--12-31

CONSOLIDATED CONDENSED BALANCE

CONSOLIDATED CONDENSED BALANCE SHEETS - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
ASSETS
Cash and cash equivalents	$ 128,185	$ 139,247
Interest-bearing time deposits	129,614	36,963
Investment securities available for sale	1,399,959	1,142,195
Investment securities held to maturity (fair value of $708,915 and $489,217)	692,965	490,387
Loans held for sale	5,854	4,778
Loans, net of allowance for loan losses of $81,274 and $80,552	7,430,096	7,143,915
Premises and equipment	91,767	93,420
Federal Home Loan Bank stock	24,588	24,588
Interest receivable	45,150	40,881
Goodwill	445,355	445,355
Other intangibles	21,381	24,429
Cash surrender value of life insurance	226,241	224,939
Other real estate owned	1,131	2,179
Tax asset, deferred and receivable	12,340	23,668
Other assets	83,231	47,772
TOTAL ASSETS	10,737,857	9,884,716
Deposits:
Noninterest-bearing	1,353,165	1,447,907
Interest-bearing	6,966,163	6,306,686
Total Deposits	8,319,328	7,754,593
Borrowings:
Federal funds purchased	75,000	104,000
Securities sold under repurchase agreements	119,674	113,512
Federal Home Loan Bank advances	460,042	314,986
Subordinated debentures and term loans	138,574	138,463
Total Borrowings	793,290	670,961
Interest payable	6,740	5,607
Other liabilities	116,863	45,295
Total Liabilities	9,236,221	8,476,456
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 - 49,280,188 and 49,158,238 shares	6,182	6,169
Additional paid-in capital	841,365	840,052
Retained earnings	639,362	583,336
Accumulated other comprehensive income (loss)	14,602	(21,422)
Total Stockholders' Equity	1,501,636	1,408,260
TOTAL LIABILITIES AND STOCKHOLDERS' EQUITY	$ 10,737,857	$ 9,884,716

CONSOLIDATED CONDENSED BALANC_2

CONSOLIDATED CONDENSED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Statement of Financial Position [Abstract]
Investment securities held to maturity - fair value	$ 708,915	$ 489,217
Loans - allowance for loan losses	$ 81,274	$ 80,552
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)	49,456,594	49,349,800
Common Stock, outstanding (in shares)	49,456,594	49,349,800

CONSOLIDATED CONDENSED STATEMEN

CONSOLIDATED CONDENSED STATEMENTS OF INCOME (Unaudited) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Loans receivable:
Taxable	$ 92,824	$ 84,663	$ 183,305	$ 162,930
Tax exempt	4,244	3,632	8,397	7,228
Investment securities:
Taxable	6,998	5,434	13,093	10,530
Tax exempt	7,454	6,246	14,325	12,372
Deposits with financial institutions	784	633	1,659	764
Federal Home Loan Bank stock	335	263	673	667
Total Interest Income	112,639	100,871	221,452	194,491
INTEREST EXPENSE
Deposits	23,087	12,165	42,681	21,167
Federal funds purchased	117	61	210	441
Securities sold under repurchase agreements	342	172	672	345
Federal Home Loan Bank advances	1,692	1,845	3,506	4,004
Subordinated debentures and term loans	2,123	2,057	4,239	4,047
Total Interest Expense	27,361	16,300	51,308	30,004
NET INTEREST INCOME	85,278	84,571	170,144	164,487
Provision for loan losses	500	1,663	1,700	4,163
NET INTEREST INCOME AFTER PROVISION FOR LOAN LOSSES	84,778	82,908	168,444	160,324
OTHER INCOME
Increase in cash surrender value of life insurance	927	907	1,916	1,985
Gains on life insurance benefits	19	100	19	198
Net gains and fees on sales of loans	1,736	1,600	3,031	3,421
Net realized gains on sales of available for sale securities	1,843	1,122	2,983	2,731
Other income	1,064	681	1,394	1,185
Total Other Income	21,614	18,191	40,327	37,752
OTHER EXPENSES
Salaries and employee benefits	32,709	32,192	65,737	64,418
Net occupancy	4,469	4,348	9,496	9,018
Equipment	4,117	3,556	7,759	7,224
Marketing	2,752	1,474	3,826	2,358
Outside data processing fees	3,929	3,462	7,613	6,426
Printing and office supplies	334	324	649	658
Intangible asset amortization	1,520	1,718	3,048	3,444
FDIC assessments	678	711	1,385	1,430
Other real estate owned and foreclosure expenses	903	362	2,068	764
Professional and other outside services	2,376	1,789	4,260	3,330
Other expenses	3,800	3,568	8,367	8,121
Total Other Expenses	57,587	53,504	114,208	107,191
INCOME BEFORE INCOME TAX	48,805	47,595	94,563	90,885
Income tax expense	7,749	7,961	14,690	14,572
NET INCOME AVAILABLE TO COMMON STOCKHOLDERS	$ 41,056	$ 39,634	$ 79,873	$ 76,313
Per Share Data:
Basic Net Income Available to Common Stockholders (in dollars per share)	$ 0.83	$ 0.80	$ 1.62	$ 1.55
Diluted Net Income Available to Common Stockholders (in dollars per share)	0.83	0.80	1.61	1.54
Cash Dividends Paid (in dollars per share)	$ 0.26	$ 0.22	$ 0.48	$ 0.40
Average Diluted Shares Outstanding (in shares)	49,549,887	49,451,406	49,545,152	49,440,045
Service charges on deposit accounts
OTHER INCOME
Other income	$ 5,437	$ 5,038	$ 10,532	$ 9,815
Fiduciary and wealth management fees
OTHER INCOME
Other income	3,931	3,595	7,749	7,391
Card payment fees
OTHER INCOME
Other income	4,829	4,462	9,655	9,056
Other customer fees
OTHER INCOME
Other income	341	455	780	897
Derivative hedge fees
OTHER INCOME
Other income	$ 1,487	$ 231	$ 2,268	$ 1,073

CONSOLIDATED CONDENSED STATEM_2

CONSOLIDATED CONDENSED STATEMENTS OF COMPREHENSIVE INCOME (Unaudited) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Statement of Comprehensive Income [Abstract]
Net income	$ 41,056	$ 39,634	$ 79,873	$ 76,313
Other comprehensive income (loss), net of tax:
Unrealized holding gain (loss) on securities available for sale arising during the period, net of tax of $4,822, $683, $10,402, and $4,874	18,140	(2,570)	39,130	(20,268)
Unrealized gain (loss) on cash flow hedges arising during the period, net of tax of $148, $61, $230 and $167	(553)		(862)
Unrealized gain (loss) on cash flow hedges arising during the period, net of tax of $148, $61, $230 and $167		230		874
Reclassification adjustment for net gains included in net income, net of tax of $369, $214, $596 and $516	(1,390)	(803)	(2,244)	(1,940)
Total other comprehensive income (loss), net of tax	16,197	(3,143)	36,024	(21,334)
Comprehensive income	$ 57,253	$ 36,491	$ 115,897	$ 54,979

CONSOLIDATED CONDENSED STATEM_3

CONSOLIDATED CONDENSED STATEMENTS OF COMPREHENSIVE INCOME (Unaudited) (Parenthetical) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Statement of Comprehensive Income [Abstract]
Unrealized holding gain (loss) on securities available for sale arising during the period, tax	$ 4,822	$ (683)	$ 10,402	$ (4,874)
Unrealized gain (loss) on cash flow hedges arising during the period, tax		61		167
Unrealized gain (loss) on cash flow hedges arising during the period, tax	(148)		(230)
Reclassification adjustment for net losses (gains) included in net income, tax	$ 369	$ 214	$ 596	$ 516

CONSOLIDATED CONDENSED STATEM_4

CONSOLIDATED CONDENSED STATEMENTS OF STOCKHOLDERS' EQUITY (Unaudited) - USD ($) $ in Thousands	Total	Preferred	Common Stock	Additional Paid in Capital	Retained Earnings	Accumulated Other Comprehensive Income
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	76,313				76,313
Other comprehensive income (loss), net of tax	(21,334)					(21,334)
Cash dividends on common stock	(19,808)				(19,808)
Reclassification adjustment under ASU 2018-02	0				626	(626)
Share-based compensation (in shares)			98,021
Share-based compensation	1,653		$ 12	1,641
Stock issued under employee benefit plans (in shares)			9,205
Stock issued under employee benefit plans	344		$ 1	343
Stock issued under dividend reinvestment and stock purchase plan (in shares)			12,111
Stock issued under dividend reinvestment and stock purchase plan	555		$ 2	553
Stock options exercised (in shares)			44,932
Stock options exercised	953		$ 6	947
Stock redeemed (in shares)			(42,319)
Stock redeemed	(1,811)		$ (6)	(1,805)
Ending balance (in shares) at Jun. 30, 2018		125	49,280,188
Ending balance at Jun. 30, 2018	1,340,328	$ 125	$ 6,160	836,549	522,362	(24,868)
Beginning balance (in shares) at Mar. 31, 2018		125	49,243,096
Beginning balance at Mar. 31, 2018	1,313,073	$ 125	$ 6,155	834,894	493,624	(21,725)
Comprehensive income:
Net income	39,634				39,634
Other comprehensive income (loss), net of tax	(3,143)					(3,143)
Cash dividends on common stock	(10,896)				(10,896)
Share-based compensation (in shares)			4,945
Share-based compensation	776		$ 0	776
Stock issued under employee benefit plans (in shares)			4,842
Stock issued under employee benefit plans	187		$ 0	187
Stock issued under dividend reinvestment and stock purchase plan (in shares)			6,497
Stock issued under dividend reinvestment and stock purchase plan	305		$ 1	304
Stock options exercised (in shares)			21,375
Stock options exercised	418		$ 3	415
Stock redeemed (in shares)			(567)
Stock redeemed	(26)		$ 1	(27)
Ending balance (in shares) at Jun. 30, 2018		125	49,280,188
Ending balance at Jun. 30, 2018	1,340,328	$ 125	$ 6,160	836,549	522,362	(24,868)
Beginning balance (in shares) at Dec. 31, 2018		125	49,349,800
Beginning balance at Dec. 31, 2018	1,408,260	$ 125	$ 6,169	840,052	583,336	(21,422)
Comprehensive income:
Net income	79,873				79,873
Other comprehensive income (loss), net of tax	36,024					36,024
Cash dividends on common stock	(23,847)				(23,847)
Reclassification adjustment under ASU 2018-02						(626)
Share-based compensation (in shares)			108,638
Share-based compensation	1,825		$ 14	1,811
Stock issued under employee benefit plans (in shares)			11,247
Stock issued under employee benefit plans	362		$ 1	361
Stock issued under dividend reinvestment and stock purchase plan (in shares)			18,686
Stock issued under dividend reinvestment and stock purchase plan	$ 709		$ 2	707
Stock options exercised (in shares)	11,200		11,200
Stock options exercised	$ 105		$ 1	104
Stock redeemed (in shares)			(42,977)
Stock redeemed	(1,675)		$ (5)	(1,670)
Ending balance (in shares) at Jun. 30, 2019		125	49,456,594
Ending balance at Jun. 30, 2019	1,501,636	$ 125	$ 6,182	841,365	639,362	14,602
Beginning balance (in shares) at Mar. 31, 2019		125	49,428,468
Beginning balance at Mar. 31, 2019	1,455,848	$ 125	$ 6,179	839,919	611,220	(1,595)
Comprehensive income:
Net income	41,056				41,056
Other comprehensive income (loss), net of tax	16,197					16,197
Cash dividends on common stock	(12,914)				(12,914)
Share-based compensation (in shares)			4,978
Share-based compensation	844		$ 1	843
Stock issued under employee benefit plans (in shares)			5,908
Stock issued under employee benefit plans	188		$ 0	188
Stock issued under dividend reinvestment and stock purchase plan (in shares)			10,178
Stock issued under dividend reinvestment and stock purchase plan	369		$ 1	368
Stock options exercised (in shares)			7,500
Stock options exercised	65		$ 1	64
Stock redeemed (in shares)			(438)
Stock redeemed	(17)		$ 0	(17)
Ending balance (in shares) at Jun. 30, 2019		125	49,456,594
Ending balance at Jun. 30, 2019	$ 1,501,636	$ 125	$ 6,182	$ 841,365	$ 639,362	$ 14,602

CONSOLIDATED CONDENSED STATEM_5

CONSOLIDATED CONDENSED STATEMENT OF STOCKHOLDERS' EQUITY (Unaudited) (Parenthetical) - $ / shares	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Statement of Stockholders' Equity [Abstract]
Cash dividends on common stock (in dollars per share)	$ 0.26	$ 0.22	$ 0.48	$ 0.40

CONSOLIDATED CONDENSED STATEM_6

CONSOLIDATED CONDENSED STATEMENTS OF CASH FLOWS (Unaudited) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018
Cash Flow From Operating Activities:
Net income	$ 79,873	$ 76,313
Adjustments to reconcile net income to net cash provided by operating activities:
Provision for loan losses	1,700	4,163
Depreciation and amortization	4,379	4,409
Change in deferred taxes	(398)	3,043
Share-based compensation	1,825	1,653
Loans originated for sale	(183,498)	(178,913)
Proceeds from sales of loans held for sale	184,667	186,556
Gains on sales of loans held for sale	(2,245)	(2,473)
Gains on sales of securities available for sale	(2,983)	(2,731)
Increase in cash surrender of life insurance	(1,916)	(1,985)
Gains on life insurance benefits	(19)	(198)
Change in interest receivable	(4,269)	(1,400)
Change in interest payable	1,133	417
Other adjustments	4,759	(7,132)
Net cash provided by operating activities	83,008	81,722
Cash Flows from Investing Activities:
Net change in interest-bearing deposits	(92,651)	(1,572)
Purchases of:
Securities available for sale	(306,291)	(260,786)
Securities held to maturity	(238,559)	0
Proceeds from sales of securities available for sale	82,052	100,293
Proceeds from maturities of:
Securities available for sale	53,910	36,124
Securities held to maturity	35,185	36,750
Change in Federal Home Loan Bank stock	0	(763)
Net change in loans	(288,195)	(337,800)
Proceeds from the sale of other real estate owned	827	1,746
Proceeds from life insurance benefits	633	2,835
Other adjustments	(3,691)	3,082
Net cash used in investing activities	(756,780)	(420,091)
Net change in :
Demand and savings deposits	400,314	291,984
Certificates of deposit and other time deposits	164,421	39,301
Borrowings	533,010	901,407
Repayment of borrowings	(410,689)	(895,568)
Cash dividends on common stock	(23,847)	(19,808)
Stock issued under employee benefit plans	362	344
Stock issued under dividend reinvestment and stock purchase plans	709	555
Stock options exercised	105	953
Stock redeemed	(1,675)	(1,811)
Net cash provided by financing activities	662,710	317,357
Net Change in Cash and Cash Equivalents	(11,062)	(21,012)
Cash and Cash Equivalents, January 1	139,247	154,905
Cash and Cash Equivalents, June 30	128,185	133,893
Additional cash flow information:
Interest paid	50,175	29,587
Income tax paid (refunded)	11,499	8,019
Loans transferred to other real estate owned	314	252
Fixed assets transferred to other real estate owned	965	0
Non-cash investing activities using trade date accounting	40,618	$ 210
ROU assets obtained in exchange for new operating lease liabilities	$ 23,384

General

General	6 Months Ended
	Jun. 30, 2019
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, 2018 , 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, 2018 filed with the Securities and Exchange Commission. The results of operations for the three and six months ended June 30, 2019 , 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 Adopted in 2019 FASB Accounting Standards Updates No. 2018-11 - Leases (Topic 842): Targeted Improvements - The FASB issued Accounting Standards Update (ASU) No. 2018-11, Leases (Topic 842): Targeted Improvements. This ASU was intended to reduce costs and ease implementation of the leases standard for financial statement preparers. ASU 2018-11 provided a new transition method and a practical expedient for separating components of a contract. ASU 2018-11 provided entities with an additional (and optional) transition method to adopt the new leases standard. Under this new transition method, an entity initially applied the new leases standard at the adoption date and recognized a cumulative-effect adjustment to the opening balance of retained earnings in the period of adoption. Consequently, the Corporation's reporting for the comparative periods presented in the financial statements in the period of adoption is in accordance with GAAP in Topic 840, Leases. The Corporation must provide the required Topic 840 disclosures for all periods that continue to be in accordance with Topic 840. The amendments did not change the existing disclosure requirements in Topic 840 (for example, they did not create interim disclosure requirements that the Corporation previously was not required to provide). The Corporation adopted this new transition method on January 1, 2019, but did not recognize a cumulative-effect adjustment to the opening balance of retained earnings at adoption. Lease disclosures are included in NOTE 7. LEASES, in the Notes to Consolidated Condensed Financial Statements of this Quarterly Report on Form 10-Q. The amendments in ASU 2018-11 provided lessors with a practical expedient, by class of underlying asset, to not separate non-lease components from the associated lease component and, instead, to account for those components as a single component if the non-lease components otherwise would be accounted for under the new revenue guidance (Topic 606) and both of the following are met: * The timing and pattern of transfer of the non-lease component(s) and associated lease component are the same. * The lease component, if accounted for separately, would be classified as an operating lease. An entity electing this practical expedient (including an entity that accounts for the combined component entirely in Topic 606) is required to disclose certain information, by class of underlying asset, as specified in the ASU. The Corporation elected the practical expedient to not separate non-lease components from the associated lease component at adoption, which was January 1, 2019. FASB Accounting Standards Update No. 2018-07 - Compensation - Stock Compensation (Topic 718): Improvements to Nonemployee Share-Based Payment Accounting - The FASB issued an Accounting Standards Update (ASU) intended to reduce cost and complexity and to improve financial reporting for non-employee share-based payments. The ASU expanded the scope of Topic 718, Compensation-Stock Compensation (which currently only includes share-based payments to employees) to include share-based payments issued to non-employees for goods or services. Consequently, the accounting for share-based payments to non-employees and employees is substantially aligned. The ASU supersedes Subtopic 505-50, Equity-Equity-Based Payments to Non-Employees. The Corporation adopted the standard in the first quarter of 2019 and adoption of the standard did not 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 - The FASB 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 shortened the amortization period for certain callable debt securities held at a premium to the earliest call date. Under previous GAAP, entities normally amortized the premium as an adjustment of yield over the contractual life of the instrument. Stakeholders expressed concerns with the approach on the basis that GAAP excluded certain callable debt securities from consideration of early repayment of principal even if the holder was certain the call would be exercised. As a result, upon the exercise of a call on a callable debt security held at a premium, the unamortized premium was recorded as a loss in earnings. Further, there was 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 was factored into current impairment assessments. Another issue was that the practice in the United States was to quote, price, and trade callable debt securities using a model that incorporated consideration of calls (also referred to as “yield-to-worst” pricing). The ASU shortened the amortization period for certain callable debt securities held at a premium and required the premium to be amortized to the earliest call date. However, the amendments did not require an accounting change for securities held at a discount; the discount continues to be amortized to maturity. The Corporation was required to apply the amendments on a modified retrospective basis through a cumulative-effect adjustment directly to retained earnings at adoption. The Corporation adopted ASU 2017-08 on January 1, 2019 and adoption of the standard did not have a significant effect on the Corporation’s consolidated financial statements. FASB Accounting Standards Update No. 2016-02 - Leases (Topic 842) - The FASB issued new lease accounting guidance in Accounting Standards Update (ASU) No. 2016-02, Leases (Topic 842). Under the new guidance, lessees 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 ("ROU") 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 are no longer provided with a source of off-balance sheet financing. The Corporation elected the package of practical expedients permitted under the transition guidance within the new standard, which among other things, allowed the Corporation to carry forward the historical lease classification. The Corporation elected to not apply ASC 842 to short-term leases (leases with a term of 12 months or less). Leases with an initial term of 12 months or less are not recorded on the balance sheet as the Corporation expenses the lease on a straight-line basis over the lease term. The Corporation also elected the practical expedient to not separate nonlease components from lease components. Variable payments are not included as part of the consideration of a lease contract and all of the Corporation's nonlease components contain variable payments; therefore, this election will not have any impact on the ROU asset or lease liability. The Corporation adopted this ASU on January 1, 2019 and recorded a ROU asset of $23.3 million and a lease liability of $23.8 million at adoption. Lease disclosures are included in NOTE 7. LEASES, in the Notes to Consolidated Condensed Financial Statements of this Quarterly Report on Form 10-Q. Revenue Recognition Revenue recognition guidance 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 revenue recognition guidance, 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 the guidance, 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. New Accounting Pronouncements Not Yet Adopted 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 Updates No. 2018-15 - Intangibles - Goodwill and Other - Internal-Use Software (Subtopic 350-40): Customer's Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement That Is a Service Contract Summary - The FASB has issued Accounting Standards Update (ASU) No. 2018-15, Intangibles-Goodwill and Other-Internal-Use Software (Subtopic 350-40): Customer’s Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement That Is a Service Contract, which reduces complexity for the accounting for costs of implementing a cloud computing service arrangement. This standard aligns the accounting for implementation costs of hosting arrangements, regardless of whether they convey a license to the hosted software. The ASU aligns the following requirements for capitalizing implementation costs: * Those incurred in a hosting arrangement that is a service contract, and * Those incurred to develop or obtain internal-use software (and hosting arrangements that include an internal-use software license). For calendar-year public companies, the changes will be effective for fiscal years ending after December 15, 2019. For all other calendar-year companies and organizations, the changes will be effective for fiscal years ending after December 15, 2020. The Corporation plans to adopt the standard in the first quarter of 2020, but adoption of the standard is not expected to have a significant impact on the Corporation’s consolidated financial statements. FASB Accounting Standards Updates No. 2018-14 - Compensation - Retirement Benefits - Defined Benefit Plans - General (Subtopic 715-20): Disclosure Framework - Changes to the Disclosure Requirements for Defined Benefit Plans Summary - The FASB has issued ASU No. 2018-14, Compensation - Retirement Benefits - Defined Benefit Plans - General (Subtopic 715-20): Disclosure Framework - Changes to the Disclosure Requirements for Defined Benefit Plans, that applies to all employers that sponsor defined benefit pension or other postretirement plans. The amendments modify the disclosure requirements for employers that sponsor defined benefit pension or other postretirement plans. Disclosure Requirements Deleted * The amounts in accumulated other comprehensive income expected to be recognized as components of net periodic benefit cost over the next fiscal year. * The amount and timing of plan assets expected to be returned to the employer. * Related party disclosures about the amount of future annual benefits covered by insurance and annuity contracts and significant transactions between the employer or related parties and the plan. * For public entities, the effects of a one-percentage-point change in assumed health care cost trend rates on the (a) aggregate of the service and interest cost components of net periodic benefit costs and (b) benefit obligation for postretirement health care benefits. Disclosure Requirements Added * An explanation of the reasons for significant gains and losses related to changes in the benefit obligation for the period. The amendments also clarify the disclosure requirements in paragraph 715-20-50-3, which state that the following information for defined benefit pension plans should be disclosed: * The projected benefit obligation (PBO) and fair value of plan assets for plans with PBOs in excess of plan assets. * The accumulated benefit obligation (ABO) and fair value of plan assets for plans with ABOs in excess of plan assets. ASU No. 2018-14 is effective for fiscal years ending after December 15, 2020, for public business entities and for fiscal years ending after December 15, 2021, for all other entities. Early adoption is permitted for all entities. The Corporation plans to adopt the standard in the first quarter of 2020, but adoption of the standard is not expected to have a significant impact on the Corporation’s disclosures. FASB Accounting Standards Updates No. 2018-13 - Fair Value Measurement (Topic 820): Disclosure Framework - Changes to the Disclosure Requirements for Fair Value Measurement Summary - The FASB has issued ASU No. 2018-13, Fair Value Measurement (Topic 820): Disclosure Framework - Changes to the Disclosure Requirements for Fair Value Measurement. ASU No. 2018-13 modifies the disclosure requirements on fair value measurements in Topic 820. Certain disclosure requirements related to transfers between Level 1 and Level 2 of the fair value hierarchy and Level 3 valuation process were removed from Topic 820. Disclosures were also added to Topic 820 for changes in unrealized gains and losses for the period included in other comprehensive income for recurring Level 3 fair value measurements held at the end of the reporting period and the range and weighted average of significant unobservable inputs used to develop Level 3 fair value measurements. In addition, the amendments eliminate at a minimum from the phrase “an entity shall disclose at a minimum” to promote the appropriate exercise of discretion by entities when considering fair value measurement disclosures and to clarify that materiality is an appropriate consideration of entities and their auditors when evaluating disclosure requirements. The amendments in ASU No. 2018-13 are effective for all entities for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2019. The amendments on changes in unrealized gains and losses, the range and weighted average of significant unobservable inputs used to develop Level 3 fair value measurements, and the narrative description of measurement uncertainty should be applied prospectively for only the most recent interim or annual period presented in the initial fiscal year of adoption. All other amendments should be applied retrospectively to all periods presented upon their effective date. Early adoption is permitted. An entity is permitted to early adopt any removed or modified disclosures upon issuance of ASU No. 2018-13 and delay adoption of the additional disclosures until their effective date. The Corporation plans to adopt the standard in the first quarter of 2020, but adoption of the standard is not expected to have a significant impact on the Corporation’s disclosures. 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 established an implementation team that meets on a regular basis to oversee activities and monitor progress. Third party software has been implemented and initial models have been developed. The implementation team is testing the models by conducting limited parallel runs and testing the sensitivity of assumptions. Forecasting methodologies continue to be refined and outputs from those models challenged. 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.

Pending Merger

Pending Merger	6 Months Ended
	Jun. 30, 2019
Business Combinations [Abstract]
Pending Merger	PENDING MERGER MBT Financial Corp. On October 9, 2018, the Corporation and MBT Financial Corp., a Michigan corporation ("MBT"), entered into an Agreement and Plan of Reorganization and Merger (the "Merger Agreement"), pursuant to which MBT will, subject to the terms and conditions of the Merger Agreement, merge with and into the Corporation (the "Holding Company Merger"), whereupon the separate corporate existence of MBT will cease and the Corporation will survive. Immediately following the Holding Company Merger, MBT's wholly-owned subsidiary, Monroe Bank & Trust, will be merged with and into the Bank (the "Bank Merger" and, together with the Holding Company Merger, the "Mergers"), with the Bank continuing as the surviving bank. Based on the closing price of the Corporation's common stock on October 9, 2018 of $45.71 per share, the transaction value is estimated at approximately $290.9 million . The transaction is expected to be a tax-free exchange for MBT's shareholders who will be receiving the Corporation's common stock pursuant to the Holding Company Merger. MBT's total assets as of June 30, 2019 were $1.3 billion . At a special meeting held on February 14, 2019, the shareholders of MBT approved the Merger Agreement and the transactions contemplated by the Merger Agreement. In addition, on January 3, 2019, the FDIC issued its order approving the Bank Merger, subject to certain customary conditions. On June 27, 2019, the FDIC reconfirmed its approval and extended the time for consummation until September 30, 2019. On February 18, 2019, the Indiana DFI approved the Bank Merger. On June 20, 2019, the DFI reconfirmed its approval. On June 13, 2019, the Corporation filed an application with the Federal Reserve Bank of Chicago seeking its approval of the merger. Consummation of the Mergers remain subject to satisfaction of other customary closing conditions contained in the Merger Agreement. The Mergers are expected to close during the third quarter of 2019.

Investment Securities

Investment Securities	6 Months Ended
	Jun. 30, 2019
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 June 30, 2019 U.S. Government-sponsored agency securities $ 33,494 $ 453 $ — $ 33,947 State and municipal 685,123 30,835 200 715,758 U.S. Government-sponsored mortgage-backed securities 642,298 8,532 607 650,223 Corporate obligations 31 — — 31 Total available for sale 1,360,946 39,820 807 1,399,959 Held to maturity at June 30, 2019 U.S. Government-sponsored agency securities 33,865 20 66 33,819 State and municipal 310,076 10,987 22 321,041 U.S. Government-sponsored mortgage-backed securities 347,524 5,257 226 352,555 Foreign investment 1,500 — — 1,500 Total held to maturity 692,965 16,264 314 708,915 Total Investment Securities $ 2,053,911 $ 56,084 $ 1,121 $ 2,108,874 Amortized Gross Gross Fair Available for sale at December 31, 2018 U.S. Government-sponsored agency securities $ 13,493 $ 92 $ 3 $ 13,582 State and municipal 605,994 5,995 5,854 606,135 U.S. Government-sponsored mortgage-backed securities 530,209 634 8,396 522,447 Corporate obligations 31 — — 31 Total available for sale 1,149,727 6,721 14,253 1,142,195 Held to maturity at December 31, 2018 U.S. Government-sponsored agency securities 22,618 — 545 22,073 State and municipal 197,909 2,858 872 199,895 U.S. Government-sponsored mortgage-backed securities 268,860 713 3,323 266,250 Foreign investment 1,000 — 1 999 Total held to maturity 490,387 3,571 4,741 489,217 Total Investment Securities $ 1,640,114 $ 10,292 $ 18,994 $ 1,631,412 The change in unrealized gains/losses from December 31, 2018 to June 30, 2019 is primarily due to the changes in interest rates. The longer term points on the yield curve have declined since year-end which increases the fair value of securities held in the portfolio. The amortized cost and fair value of available for sale and held to maturity securities at June 30, 2019 and December 31, 2018 , 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 June 30, 2019: Due in one year or less $ 1,131 $ 1,138 $ 3,784 $ 3,782 Due after one through five years 3,752 3,851 46,941 46,914 Due after five through ten years 74,311 76,604 78,716 81,769 Due after ten years 639,454 668,143 216,000 223,895 718,648 749,736 345,441 356,360 U.S. Government-sponsored mortgage-backed securities 642,298 650,223 347,524 352,555 Total Investment Securities $ 1,360,946 $ 1,399,959 $ 692,965 $ 708,915 Available for Sale Held to Maturity Amortized Cost Fair Value Amortized Cost Fair Value Maturity Distribution at December 31, 2018 Due in one year or less $ 13,092 $ 13,144 $ 4,732 $ 4,730 Due after one through five years 5,311 5,378 49,054 48,473 Due after five through ten years 73,280 74,411 62,873 64,163 Due after ten years 527,835 526,815 104,868 105,601 619,518 619,748 221,527 222,967 U.S. Government-sponsored mortgage-backed securities 530,209 522,447 268,860 266,250 Total Investment Securities $ 1,149,727 $ 1,142,195 $ 490,387 $ 489,217 The carrying value of securities pledged as collateral, to secure borrowings and for other purposes, was $483,230,000 at June 30, 2019 , and $416,155,000 at December 31, 2018 . The book value of securities sold under agreements to repurchase amounted to $119,266,000 at June 30, 2019 , and $116,691,000 at December 31, 2018 . Gross gains on the sales and redemptions of available for sale securities for the three and six months ended June 30, 2019 and 2018 are shown below. Three Months Ended Six Months Ended 2019 2018 2019 2018 Sales and Redemptions of Available for Sale Securities: Gross gains $ 1,843 $ 1,122 $ 2,983 $ 2,731 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 June 30, 2019 , and December 31, 2018 : Less than 12 Months Total Fair Gross Fair Gross Fair Gross Temporarily Impaired Available for Sale Securities at June 30, 2019 State and municipal $ 7,699 $ 16 $ 7,080 $ 184 $ 14,779 $ 200 U.S. Government-sponsored mortgage-backed securities 7,791 15 75,152 592 82,943 607 Total Temporarily Impaired Available for Sale Securities 15,490 31 82,232 776 97,722 807 Temporarily Impaired Held to Maturity Securities at June 30, 2019 U.S. Government-sponsored agency securities — — 15,454 66 15,454 66 State and municipal 6,421 22 — — 6,421 22 U.S. Government-sponsored mortgage-backed securities 74 — 36,614 226 36,688 226 Total Temporarily Impaired Held to Maturity Securities 6,495 22 52,068 292 58,563 314 Total Temporarily Impaired Investment Securities $ 21,985 $ 53 $ 134,300 $ 1,068 $ 156,285 $ 1,121 Less than 12 Months Total Fair Gross Fair Gross Fair Gross Temporarily Impaired Available for Sale Securities at December 31, 2018 U.S. Government-sponsored agency securities $ 1,490 $ 3 $ — $ — $ 1,490 $ 3 State and municipal 234,431 3,958 38,028 1,896 272,459 5,854 U.S. Government-sponsored mortgage-backed securities 196,601 2,400 217,121 5,996 413,722 8,396 Total Temporarily Impaired Available for Sale Securities 432,522 6,361 255,149 7,892 687,671 14,253 Temporarily Impaired Held to Maturity Securities at December 31, 2018 U.S. Government-sponsored agency securities — — 22,073 545 22,073 545 State and municipal 14,952 369 16,786 503 31,738 872 U.S. Government-sponsored mortgage-backed securities 102,828 876 87,268 2,447 190,096 3,323 Foreign investment — — 999 1 999 1 Total Temporarily Impaired Held to Maturity Securities 117,780 1,245 127,126 3,496 244,906 4,741 Total Temporarily Impaired Investment Securities $ 550,302 $ 7,606 $ 382,275 $ 11,388 $ 932,577 $ 18,994 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. June 30, 2019 December 31, 2018 Investments reported at less than historical cost: Historical cost $ 157,406 $ 951,571 Fair value 156,285 932,577 Gross unrealized losses $ 1,121 $ 18,994 Percent of the Corporation's investment portfolio 7.5 % 57.1 % The Corporation's 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 other-than-temporary-impairment ("OTTI") is identified. The Corporation’s management has evaluated all securities with unrealized losses for OTTI and concluded no OTTI existed at June 30, 2019 . 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 June 30, 2019 . The state and municipal securities portfolio contains unrealized losses of $200,000 on seven securities and $22,000 on two securities in the available for sale and held to maturity portfolios, respectively. The U.S. Government-Sponsored Agency securities portfolio contains no unrealized losses in the available for sale portfolio and $66,000 on three securities in the held to maturity portfolio. 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 June 30, 2019 . The mortgage-backed securities portfolio contains unrealized losses of $607,000 on twenty-nine securities and $226,000 on fourteen 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	6 Months Ended
	Jun. 30, 2019
Receivables [Abstract]
Loans and Allowance	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 June 30, 2019 , and December 31, 2018 , were $5,854,000 and $4,778,000 , respectively. The following table illustrates the composition of the Corporation’s loan portfolio by loan class for the periods indicated: June 30, 2019 December 31, 2018 Commercial and industrial loans $ 1,877,042 $ 1,726,664 Agricultural production financing and other loans to farmers 83,452 92,404 Real estate loans: Construction 624,548 545,729 Commercial and farmland 2,821,689 2,832,102 Residential 993,802 966,421 Home equity 548,006 528,157 Individuals' loans for household and other personal expenditures 98,384 99,788 Public finance and other commercial loans 464,447 433,202 Loans $ 7,511,370 $ 7,224,467 Allowance for loan losses (81,274 ) (80,552 ) Net Loans $ 7,430,096 $ 7,143,915 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 June 30, 2019 . 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 but not impaired 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 and six months ended June 30, 2019 and June 30, 2018 : Three Months Ended June 30, 2019 Commercial Commercial Consumer Residential Total Allowance for loan losses: Balances, March 31, 2019 $ 33,069 $ 29,434 $ 4,026 $ 14,373 $ 80,902 Provision for losses 100 320 36 44 500 Recoveries on loans 344 778 100 212 1,434 Loans charged off (311 ) (1,001 ) (92 ) (158 ) (1,562 ) Balances, June 30, 2019 $ 33,202 $ 29,531 $ 4,070 $ 14,471 $ 81,274 Six Months Ended June 30, 2019 Commercial Commercial Consumer Residential Total Allowance for loan losses: Balances, December 31, 2018 $ 32,657 $ 29,609 $ 3,964 $ 14,322 $ 80,552 Provision for losses 336 1,089 141 134 1,700 Recoveries on loans 886 1,023 218 312 2,439 Loans charged off (677 ) (2,190 ) (253 ) (297 ) (3,417 ) Balances, June 30, 2019 $ 33,202 $ 29,531 $ 4,070 $ 14,471 $ 81,274 Three Months Ended June 30, 2018 Commercial Commercial Consumer Residential Total Allowance for loan losses: Balances, March 31, 2018 $ 30,770 $ 27,705 $ 3,896 $ 14,049 $ 76,420 Provision for losses 471 954 60 178 1,663 Recoveries on loans 1,283 1,213 98 596 3,190 Loans charged off (1,057 ) (2,141 ) (133 ) (399 ) (3,730 ) Balances, June 30, 2018 $ 31,467 $ 27,731 $ 3,921 $ 14,424 $ 77,543 Six Months Ended June 30, 2018 Commercial Commercial Consumer Residential Total Allowance for loan losses: Balances, December 31, 2017 $ 30,420 $ 27,343 $ 3,732 $ 13,537 $ 75,032 Provision for losses 1,311 1,038 334 1,480 4,163 Recoveries on loans 1,402 1,552 187 750 3,891 Loans charged off (1,666 ) (2,202 ) (332 ) (1,343 ) (5,543 ) Balances, June 30, 2018 $ 31,467 $ 27,731 $ 3,921 $ 14,424 $ 77,543 The tables below show the Corporation’s allowance for loan losses and loan portfolio by loan segment as of the periods indicated. June 30, 2019 Commercial Commercial Consumer Residential Total Allowance Balances: Individually evaluated for impairment $ 1,849 $ 14 $ 1 $ 432 $ 2,296 Collectively evaluated for impairment 31,353 29,517 4,069 14,039 78,978 Total Allowance for Loan Losses $ 33,202 $ 29,531 $ 4,070 $ 14,471 $ 81,274 Loan Balances: Individually evaluated for impairment $ 5,090 $ 14,419 $ 14 $ 2,450 $ 21,973 Collectively evaluated for impairment 2,418,481 3,419,930 98,370 1,538,533 7,475,314 Loans acquired with deteriorated credit quality 1,370 11,888 — 825 14,083 Loans $ 2,424,941 $ 3,446,237 $ 98,384 $ 1,541,808 $ 7,511,370 December 31, 2018 Commercial Commercial Consumer Residential Total Allowance Balances: Individually evaluated for impairment $ — $ 1,435 $ 1 $ 436 $ 1,872 Collectively evaluated for impairment 32,657 28,174 3,963 13,886 78,680 Total Allowance for Loan Losses $ 32,657 $ 29,609 $ 3,964 $ 14,322 $ 80,552 Loan Balances: Individually evaluated for impairment $ 1,838 $ 17,756 $ 18 $ 2,413 $ 22,025 Collectively evaluated for impairment 2,248,330 3,347,686 99,770 1,490,872 7,186,658 Loans acquired with deteriorated credit quality 2,102 12,389 — 1,293 15,784 Loans $ 2,252,270 $ 3,377,831 $ 99,788 $ 1,494,578 $ 7,224,467 Loans individually evaluated for impairment are comprised of commercial and consumer loans deemed impaired in accordance with ASC 310-10. This includes loans acquired with deteriorated credit quality totaling $1,824,000 with $329,000 of related allowance for loan losses at June 30, 2019 and $1,541,000 with no related allowance for loan losses at December 31, 2018. 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: June 30, 2019 December 31, 2018 Commercial and industrial loans $ 2,770 $ 1,803 Agriculture production financing and other loans to farmers 2,785 679 Real estate loans: Construction 6,918 8,667 Commercial and farmland 6,340 8,156 Residential 4,579 4,966 Home equity 1,826 1,481 Individuals' loans for household and other personal expenditures 64 42 Public finance and other commercial loans 353 354 Total $ 25,635 $ 26,148 Impaired loans include loans deemed impaired according to the guidance set forth in ASC 310-10. Commercial loans under $500,000 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: June 30, 2019 Unpaid Recorded Related Impaired loans with no related allowance: Commercial and industrial loans $ 1,048 $ 1,012 $ — Agriculture production financing and other loans to farmers 679 668 — Real estate Loans: Construction 7,978 6,909 — Commercial and farmland 10,160 7,381 — Residential 117 99 — Home equity 49 49 — Public finance and other commercial loans 353 353 — Total $ 20,384 $ 16,471 $ — Impaired loans with related allowance: Commercial and industrial loans $ 1,185 $ 940 $ 455 Agriculture production financing and other loans to farmers $ 2,167 $ 2,117 $ 1,394 Real estate Loans: Commercial and farmland 134 129 14 Residential 1,976 1,953 362 Home equity 366 349 70 Individuals' loans for household and other personal expenditures 14 14 1 Total $ 5,842 $ 5,502 $ 2,296 Total Impaired Loans $ 26,226 $ 21,973 $ 2,296 December 31, 2018 Unpaid Recorded Related Impaired loans with no related allowance: Commercial and industrial loans $ 828 $ 806 $ — Agriculture production financing and other loans to farmers 679 679 — Real estate Loans: Construction 1,352 614 — Commercial and farmland 11,176 8,994 — Residential 118 100 — Home equity 49 48 — Public finance and other commercial loans 353 353 — Total $ 14,555 $ 11,594 $ — Impaired loans with related allowance: Real estate Loans: Construction $ 7,978 $ 7,977 $ 1,429 Commercial and farmland 171 171 6 Residential 1,958 1,907 362 Home equity 376 358 74 Individuals' loans for household and other personal expenditures 18 18 1 Total $ 10,501 $ 10,431 $ 1,872 Total Impaired Loans $ 25,056 $ 22,025 $ 1,872 Three Months Ended June 30, 2019 Six Months Ended June 30, 2019 Average Interest Average Interest Impaired loans with no related allowance: Commercial and industrial loans $ 1,013 $ — $ 1,021 $ — Agriculture production financing and other loans to farmers 668 — 672 — Real estate Loans: Construction 7,314 — 7,792 — Commercial and farmland 7,998 39 8,187 78 Residential 38 1 38 2 Home equity 49 — 49 — Public finance and other commercial loans 353 — 353 — Total $ 17,433 $ 40 $ 18,112 $ 80 Impaired loans with related allowance: Commercial and industrial loans $ 940 $ — $ 940 $ — Agriculture production financing and other loans to farmers 2,117 — 2,134 — Real estate Loans: Commercial and farmland 157 — 164 — Residential 2,021 16 2,029 32 Home equity 351 3 352 6 Individuals' loans for household and other personal expenditures 14 — 15 — Total $ 5,600 $ 19 $ 5,634 $ 38 Total Impaired Loans $ 23,033 $ 59 $ 23,746 $ 118 Three Months Ended June 30, 2018 Six Months Ended June 30, 2018 Average Interest Average Interest Impaired loans with no related allowance: Commercial and industrial loans $ 1,004 $ — $ 1,006 $ — Agriculture production financing and other loans to farmers 640 — 640 — Real estate Loans: Construction 1,106 — 1,167 — Commercial and farmland 9,935 40 10,241 87 Residential 63 1 63 2 Individuals' loans for household and other personal expenditures 10 — 11 — Public finance and other commercial loans — — — — Total $ 12,758 $ 41 $ 13,128 $ 89 Impaired loans with related allowance: Commercial and industrial loans $ 108 $ — $ 108 $ — Real estate Loans: Residential 1,714 12 1,726 24 Home equity 302 2 303 5 Total $ 2,124 $ 14 $ 2,137 $ 29 Total Impaired Loans $ 14,882 $ 55 $ 15,265 $ 118 Impaired loans in the above tables 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-days or more 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. June 30, 2019 Commercial Commercial Commercial Substandard Commercial Commercial Loss Consumer Performing Consumer Total Commercial and industrial loans $ 1,781,040 $ 53,407 $ 42,266 $ 329 $ — $ — $ — $ 1,877,042 Agriculture production financing and other loans to farmers 67,837 5,478 10,137 — — — — 83,452 Real estate Loans: Construction 591,962 1,444 7,712 — — 23,430 624,548 Commercial and farmland 2,645,338 79,586 94,179 450 — 2,136 — 2,821,689 Residential 156,622 5,833 3,425 — — 823,309 4,613 993,802 Home equity 27,324 585 758 — — 517,620 1,719 548,006 Individuals' loans for household and other personal expenditures — — — — — 98,320 64 98,384 Public finance and other commercial loans 464,094 — 353 — — — — 464,447 Loans $ 5,734,217 $ 146,333 $ 158,830 $ 779 $ — $ 1,464,815 $ 6,396 $ 7,511,370 December 31, 2018 Commercial Commercial Commercial Substandard Commercial Commercial Loss Consumer Performing Consumer Total Commercial and industrial loans $ 1,660,879 $ 23,246 $ 42,539 $ — $ — $ — $ — $ 1,726,664 Agriculture production financing and other loans to farmers 78,446 5,966 7,992 — — — — 92,404 Real estate Loans: Construction 492,358 2,185 24,224 — — 25,419 1,543 545,729 Commercial and farmland 2,669,491 76,037 84,288 — — 2,285 1 2,832,102 Residential 170,075 7,373 2,076 — — 782,080 4,817 966,421 Home equity 24,653 535 457 — — 500,996 1,516 528,157 Individuals' loans for household and other personal expenditures — — — — — 99,741 47 99,788 Public finance and other commercial loans 432,849 — 353 — — — — 433,202 Loans $ 5,528,751 $ 115,342 $ 161,929 $ — $ — $ 1,410,521 $ 7,924 $ 7,224,467 The tables below show a past due aging of the Corporation’s loan portfolio, by loan class, as of June 30, 2019 , and December 31, 2018 : June 30, 2019 Current 30-59 Days 60-89 Days Loans 90 Days or More Past Due And Accruing Non-Accrual Total Past Due Total Commercial and industrial loans $ 1,874,004 $ 248 $ 20 $ — $ 2,770 $ 3,038 $ 1,877,042 Agriculture production financing and other loans to farmers 80,634 33 — — 2,785 2,818 83,452 Real estate loans: Construction 617,519 111 — — 6,918 7,029 624,548 Commercial and farmland 2,808,422 6,751 176 — 6,340 13,267 2,821,689 Residential 984,086 4,540 422 175 4,579 9,716 993,802 Home equity 544,338 1,308 500 34 1,826 3,668 548,006 Individuals' loans for household and other personal expenditures 97,826 407 87 — 64 558 98,384 Public finance and other commercial loans 464,094 — — — 353 353 464,447 Loans $ 7,470,923 $ 13,398 $ 1,205 $ 209 $ 25,635 $ 40,447 $ 7,511,370 December 31, 2018 Current 30-59 Days 60-89 Days Loans 90 Days or More Past Due And Accruing Non-Accrual Total Past Due Total Commercial and industrial loans $ 1,723,337 $ 1,093 $ 182 $ 249 $ 1,803 $ 3,327 $ 1,726,664 Agriculture production financing and other loans to farmers 89,440 2,285 — — 679 2,964 92,404 Real estate loans: Construction 535,520 64 — 1,478 8,667 10,209 545,729 Commercial and farmland 2,822,515 1,253 178 — 8,156 9,587 2,832,102 Residential 959,252 1,756 430 17 4,966 7,169 966,421 Home equity 524,198 2,164 207 107 1,481 3,959 528,157 Individuals' loans for household and other personal expenditures 99,499 179 64 4 42 289 99,788 Public finance and other commercial loans 432,848 — — — 354 354 433,202 Loans $ 7,186,609 $ 8,794 $ 1,061 $ 1,855 $ 26,148 $ 37,858 $ 7,224,467 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 June 30, 2019 Six Months Ended June 30, 2019 Pre-Modification Post-Modification Number Pre-Modification Post-Modification Number Real estate loans: Residential $ 171 $ 164 4 $ 261 $ 254 5 Total $ 171 $ 164 4 $ 261 $ 254 5 Three Months Ended June 30, 2018 Six Months Ended June 30, 2018 Pre-Modification Post-Modification Number Pre-Modification Post-Modification Number Real estate loans: Residential $ 122 $ 125 2 $ 336 $ 347 7 Home equity — — — 16 16 2 Individuals' loans for household and other personal expenditures — — — 7 8 1 Total $ 122 $ 125 2 $ 359 $ 371 10 The following tables summarize the recorded investment of troubled debt restructures as of June 30, 2019 and 2018 , by modification type, that occurred during the periods indicated: Three Months Ended June 30, 2019 Term Rate Combination Total Real estate loans: Residential $ — $ — $ 164 $ 164 Total $ — $ — $ 164 $ 164 Six Months Ended June 30, 2019 Term Rate Combination Total Real estate loans: Residential $ — $ 89 $ 164 $ 253 Total $ — $ 89 $ 164 $ 253 Three Months Ended June 30, 2018 Term Rate Combination Total Real estate loans: Residential $ — $ 91 $ 34 $ 125 Total $ — $ 91 $ 34 $ 125 Six Months Ended June 30, 2018 Term Rate Combination Total Real estate loans: Residential $ 37 $ 163 $ 139 $ 339 Home equity 60 10 — 70 Individuals' loans for household and other personal expenditures — 7 — 7 Total $ 97 $ 180 $ 139 $ 416 Loans secured by residential real estate made up 100 percent of the post-modification balance of troubled debt restructured loans made in the three and six months ended June 30, 2019 . The same loan classification made up 100 percent of the post-modification balance of troubled debt restructured loans made in the three months ended June 30, 2018. The following tables summarize troubled debt restructures that occurred during the twelve months ended June 30, 2019 and 2018, that subsequently defaulted during the period indicated and remained in default at period end. A loan is considered in default if it is 30-days or more past due. Three Months Ended June 30, 2019 Six Months Ended June 30, 2019 Number of Loans Recorded Balance Number of Loans Recorded Balance Real estate loans: Residential 1 $ 62 1 $ 62 Total 1 $ 62 1 $ 62 Three Months Ended June 30, 2018 Six Months Ended June 30, 2018 Number of Loans Recorded Balance Number of Loans Recorded Balance Real estate loans: Commercial and farmland — — 1 $ 272 Residential 2 $ 132 3 190 Total 2 $ 132 4 $ 462 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 $777,000 and $800,000 at June 30, 2019 and December 31, 2018, 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-days or more delinquent, are included in the ASC 450 loss estimate.

Purchased Credit Impaired Loans

Purchased Credit Impaired Loans	6 Months Ended
	Jun. 30, 2019
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 June 30, 2019 and December 31, 2018 was $15.9 million and $17.3 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 June 30, 2019 Six Months Ended June 30, 2019 Accretable yield beginning balance $ 2,064 $ 2,143 Additions — — Accretion (638 ) (1,218 ) Reclassification from nonaccretable 488 989 Disposals — — Accretable yield ending balance $ 1,914 $ 1,914 Three Months Ended June 30, 2018 Six Months Ended June 30, 2018 Accretable yield beginning balance $ 2,675 $ 2,890 Additions — — Accretion (927 ) (1,437 ) Reclassification from nonaccretable 675 970 Disposals — — Accretable yield ending balance $ 2,423 $ 2,423 There were no loans acquired during the six months ended June 30, 2019 and 2018, for which it was probable that all contractually required payments would not be collected.

Other Intangibles

Other Intangibles	6 Months Ended
	Jun. 30, 2019
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. The carrying basis and accumulated amortization of recognized core deposit intangibles and other intangibles are noted below. June 30, 2019 December 31, 2018 Gross carrying amount $ 85,869 $ 85,869 Accumulated amortization (64,488 ) (61,440 ) Total other intangibles $ 21,381 $ 24,429 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 2019 $ 2,121 2020 3,632 2021 3,427 2022 3,325 2023 3,175 After 2023 5,701 $ 21,381

Leases

Leases	6 Months Ended
	Jun. 30, 2019
Leases [Abstract]
Leases	LEASES The Corporation adopted ASU No. 2016-02 - Leases (Topic 842) , as amended, as of January 1, 2019 for certain retail branches, office space, land and equipment. The Corporation elected the package of practical expedients permitted under the transition guidance within the new standard, which among other things, allowed the Corporation to carry forward the historical lease classification. Operating leases are included in the operating lease right-of use ("ROU") asset, which is included in other assets and the lease liability is included in other liabilities in our condensed balance sheets. The Corporation does not have any finance leases. ROU assets represent the Corporation's right to use an underlying asset for the lease term and lease liabilities represent the Corporation's obligation to make lease payments arising from the lease. Operating lease ROU assets and liabilities are recognized at commencement date based on the present value of lease payments over the lease term. As most of the Corporation's leases do not provide an implicit rate, the Corporation typically uses its incremental borrowing rate based on information available at commencement date in determining the present value of lease payments. Lease terms may include options to extend or terminate the lease. The exercise of such lease renewal options is at the Corporation's sole discretion and is not included in the present value of lease obligations unless it is reasonably certain that the option will be exercised. The depreciable life of assets and leasehold improvements are limited by the expected lease term, unless there is a transfer of title or purchase option reasonably certain of exercise. Certain of the Corporation's lease agreements include rental payments adjusted periodically for inflation. The Corporation's lease agreements do not contain any material residual value guarantees or material restrictive covenants. Supplemental balance sheet information related to leases is presented in the table below as of June 30, 2019 . June 30, 2019 Operating lease assets $ 21,968 Total lease assets $ 21,968 Operating lease liabilities $ 22,603 Total Lease liabilities $ 22,603 Weighted average remaining lease term (years) Operating leases 9.5 Weighted average discount rate Operating leases 3.40 % The table below presents the components of lease expense for the periods indicated. Three Months Ended Six Months Ended Lease Cost: Operating lease cost $ 911 $ 1,806 Short-term lease cost 30 73 Variable lease cost 253 511 Total lease cost $ 1,194 $ 2,390 Supplemental cash flow information related to leases is presented in the tables below. Maturity of lease liabilities Operating Leases Remaining 2019 $ 1,774 2020 3,388 2021 3,114 2022 2,999 2023 2,628 2024 and after 12,771 Total lease payments $ 26,674 Less: Present value discount 4,071 Present value of lease liabilities $ 22,603 Other Information Six Months Ended Cash paid for amounts included in the measurement of lease liabilities Operating cash flows from operating leases $ 1,634 ROU assets obtained in exchange for new operating lease liabilities $ 23,384

Derivative Financial Instrument

Derivative Financial Instruments	6 Months Ended
	Jun. 30, 2019
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 June 30, 2019 , the Corporation had four interest rate swaps with a notional amount of $46.0 million and one interest rate cap with a notional amount of $13.0 million that were designated as cash flow hedges. As of December 31, 2018 , the Corporation had four interest rate swaps with a notional amount of $46.0 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 2019 , $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 $20.0 million of interest rate swaps were used to hedge the variable cash outflows (LIBOR-based) associated with two Federal Home Loan Bank advances. During the six months ended June 30, 2019 and 2018 , 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 $438,000 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 June 30, 2019 , the notional amount of customer-facing swaps was approximately $548,951,000 . 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 June 30, 2019 , and December 31, 2018 . Asset Derivatives Liability Derivatives June 30, 2019 December 31, 2018 June 30, 2019 December 31, 2018 Balance Fair Balance Fair Balance Fair Balance Fair Derivatives designated as hedging instruments: Interest rate contracts Other Assets $ — Other Assets $ 135 Other Liabilities $ 1,609 Other Liabilities $ 688 Derivatives not designated as hedging instruments: Interest rate contracts Other Assets $ 25,059 Other Assets $ 11,948 Other Liabilities $ 25,059 Other Liabilities $ 11,948 The Corporation's derivative hedge asset and derivative hedge liability increased $13.1 million and $14.0 million , respectively from December 31, 2018. The increases are primarily due to a $71.2 million increase in outstanding notional balance. Additionally, yield curve rates used for valuation purposes were lower at each term point as of June 30, 2019 compared to December 31, 2018. 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 Six Months Ended June 30, 2019 June 30, 2018 June 30, 2019 June 30, 2018 Interest Rate Products $ (701 ) $ 291 $ (1,092 ) $ 799 Effect of Derivative Instruments on the Income Statement The Corporation did not recognize any gains or losses from derivative financial instruments in the Consolidated Condensed Statements of Income for the three and six months ended June 30, 2019 and 2018 . 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 $ (84 ) $ (105 ) Derivatives Designated as Location of Gain (Loss) Amount of Gain (Loss) Reclassed from Other Comprehensive Income into Income (Effective Portion) Six Months Ended Six Months Ended Interest rate contracts Interest Expense $ (143 ) $ (275 ) 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 June 30, 2019 , the termination value of derivatives in a net liability position related to these agreements was $26,045,000 . As of June 30, 2019 , the Corporation has minimum collateral posting thresholds with certain of its derivative counterparties and has posted collateral of $28,405,000 . The Corporation did not breach any of these provisions as of June 30, 2019 , but if the Corporation had breached these provisions, 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	6 Months Ended
	Jun. 30, 2019
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 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 agency and 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 June 30, 2019 , and December 31, 2018 . Fair Value Measurements Using: June 30, 2019 Fair Value Quoted Prices in Active Markets for Identical Assets Significant Other Significant Available for sale securities: U.S. Government-sponsored agency securities $ 33,947 $ — $ 33,947 $ — State and municipal 715,758 — 712,818 2,940 U.S. Government-sponsored mortgage-backed securities 650,223 — 650,219 4 Corporate obligations 31 — — 31 Interest rate swap asset 25,059 — 25,059 — Interest rate swap liability 26,668 — 26,668 — Fair Value Measurements Using: December 31, 2018 Fair Value Quoted Prices in Significant Other Observable Inputs Significant Available for sale securities: U.S. Government-sponsored agency securities $ 13,582 $ — $ 13,582 $ — State and municipal 606,135 — 602,842 3,293 U.S. Government-sponsored mortgage-backed securities 522,447 — 522,443 4 Corporate obligations 31 — — 31 Interest rate swap and cap asset 12,083 — 12,083 — Interest rate swap liability 12,636 — 12,636 — There were no gains or losses included in earnings that were attributable to the changes in unrealized gains or losses related to assets or liabilities held at June 30, 2019 or December 31, 2018 . Level 3 Reconciliation The following is a reconciliation of the beginning and ending balances of recurring fair value measurements recognized in the accompanying balance sheets using significant unobservable Level 3 inputs for the three and six months ended June 30, 2019 and 2018 . Available for Sale Securities Three Months Ended Six Months Ended June 30, 2019 June 30, 2018 June 30, 2019 June 30, 2018 Balance at beginning of the period $ 2,936 $ 3,966 $ 3,328 $ 3,978 Included in other comprehensive income 37 1 80 (24 ) Principal payments 2 3 (433 ) 16 Ending balance $ 2,975 $ 3,970 $ 2,975 $ 3,970 Transfers Between Levels There were no transfers in or out of Level 3 for the three and six months ended June 30, 2019 and 2018 . 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 June 30, 2019 , and December 31, 2018 . Fair Value Measurements Using June 30, 2019 Fair Value Quoted Prices in Significant Other Significant Unobservable Impaired loans (collateral dependent) $ 12,966 $ — $ — $ 12,966 Other real estate owned 174 — — 174 Fair Value Measurements Using December 31, 2018 Fair Value Quoted Prices in Significant Other Significant Unobservable Impaired loans (collateral dependent) $ 11,866 $ — $ — $ 11,866 Other real estate owned 657 — — 657 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 2018 and 2019 , 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 June 30, 2019 and December 31, 2018 . June 30, 2019 Fair Value Valuation Technique Unobservable Inputs Range (Weighted-Average) State and municipal securities $ 2,940 Discounted cash flow Maturity/Call date 1 month to 15 yrs US Muni BQ curve A- to BBB- Discount rate 2% - 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) $ 12,966 Collateral based measurements Discount to reflect current market conditions and ultimate collectability 0% - 10% (4%) Other real estate owned $ 174 Appraisals Discount to reflect current market conditions 0% - 51% (30%) December 31, 2018 Fair Value Valuation Technique Unobservable Inputs Range (Weighted-Average) State and municipal securities $ 3,293 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) $ 11,866 Collateral based measurements Discount to reflect current market conditions and ultimate collectability 0% - 10% (6%) Other real estate owned $ 657 Appraisals Discount to reflect current market conditions 0% - 10% (4%) 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 and U.S. Government-sponsored Mortgage Backed 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 June 30, 2019 , and December 31, 2018 . June 30, 2019 Quoted Prices in Active Markets Significant Significant Unobservable Carrying Amount (Level 1) (Level 2) (Level 3) Assets: Cash and cash equivalents $ 128,185 $ 128,185 $ — $ — Interest-bearing time deposits 129,614 129,614 — — Investment securities available for sale 1,399,959 — 1,396,984 2,975 Investment securities held to maturity 692,965 — 701,905 7,010 Loans held for sale 5,854 — 5,854 — Loans 7,430,096 — — 7,408,511 Federal Home Loan Bank stock 24,588 — 24,588 — Interest rate swap asset 25,059 — 25,059 — Interest receivable 45,150 — 45,150 — Liabilities: Deposits $ 8,319,328 $ 6,688,194 $ 1,627,381 $ — Borrowings: Federal funds purchased 75,000 — 75,000 — Securities sold under repurchase agreements 119,674 — 119,488 — Federal Home Loan Bank advances 460,042 — 461,582 — Subordinated debentures and term loans 138,574 — 127,594 — Interest rate swap liability 26,668 — 26,668 — Interest payable 6,740 — 6,740 — December 31, 2018 Quoted Prices in Active Markets Significant Significant Unobservable Carrying Amount (Level 1) (Level 2) (Level 3) Assets: Cash and cash equivalents $ 139,247 $ 139,247 $ — $ — Interest-bearing time deposits 36,963 36,963 — — Investment securities available for sale 1,142,195 — 1,138,867 3,328 Investment securities held to maturity 490,387 — 481,377 7,840 Loans held for sale 4,778 — 4,778 — Loans 7,143,915 — — 7,004,193 Federal Home Loan Bank stock 24,588 — 24,588 — Interest rate swap and cap asset 12,083 — 12,083 — Interest receivable 40,881 — 40,881 — Liabilities: Deposits $ 7,754,593 $ 6,267,879 $ 1,464,129 $ — Borrowings: Federal funds purchased 104,000 — 104,000 — Securities sold under repurchase agreements 113,512 — 113,437 — Federal Home Loan Bank advances 314,986 — 318,728 — Subordinated debentures and term loans 138,463 — 127,298 — Interest rate swap liability 12,636 — 12,636 — Interest payable 5,607 — 5,607 —

Transfers Accounted for as Secu

Transfers Accounted for as Secured Borrowings	6 Months Ended
	Jun. 30, 2019
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 June 30, 2019 and December 31, 2018 were: June 30, 2019 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 $ 110,233 $ — $ — $ 9,441 $ 119,674 December 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 $ 104,883 $ 1,014 $ 7,615 $ — $ 113,512

Accumulated Other Comprehensive

Accumulated Other Comprehensive Income (Loss)	6 Months Ended
	Jun. 30, 2019
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 June 30, 2019 and 2018 : 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, 2018 $ (6,343 ) $ (559 ) $ (14,520 ) $ (21,422 ) Other comprehensive income before reclassifications 39,130 (862 ) — 38,268 Amounts reclassified from accumulated other comprehensive income (2,357 ) 113 — (2,244 ) Period change 36,773 (749 ) — 36,024 Balance at June 30, 2019 $ 30,430 $ (1,308 ) $ (14,520 ) $ 14,602 Balance at December 31, 2017 $ 8,970 $ (1,125 ) $ (10,753 ) $ (2,908 ) Other comprehensive income before reclassifications (20,268 ) 874 — (19,394 ) Amounts reclassified from accumulated other comprehensive income (2,157 ) 217 — (1,940 ) Period change (22,425 ) 1,091 — (21,334 ) Reclassification adjustment under ASU 2018-02 1,932 (242 ) (2,316 ) (626 ) Balance at June 30, 2018 $ (11,523 ) $ (276 ) $ (13,069 ) $ (24,868 ) 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 and six months ended June 30, 2019 and 2018 . Amount Reclassified from Accumulated Other Comprehensive Income (Loss) For the Three Months Ended June 30, Details about Accumulated Other Comprehensive Income (Loss) Components 2019 2018 Affected Line Item in the Statements of Income Unrealized gains (losses) on available for sale securities (1) Realized securities gains reclassified into income $ 1,843 $ 1,122 Other income - net realized gains on sales of available for sale securities Related income tax expense (387 ) (236 ) Income tax expense $ 1,456 $ 886 Unrealized gains (losses) on cash flow hedges (2) Interest rate contracts $ (84 ) $ (105 ) Interest expense - subordinated debentures and term loans Related income tax benefit 18 22 Income tax expense $ (66 ) $ (83 ) Total reclassifications for the period, net of tax $ 1,390 $ 803 Amount Reclassified from Accumulated Other Comprehensive Income (Loss) For the Six Months Ended June 30, Details about Accumulated Other Comprehensive Income (Loss) Components 2019 2018 Affected Line Item in the Statements of Income Unrealized gains (losses) on available for sale securities (1) Realized securities gains reclassified into income $ 2,983 $ 2,731 Other income - net realized gains on sales of available for sale securities Related income tax expense (626 ) (574 ) Income tax expense $ 2,357 $ 2,157 Unrealized gains (losses) on cash flow hedges (2) Interest rate contracts $ (143 ) $ (275 ) Interest expense - subordinated debentures and term loans Related income tax benefit 30 58 Income tax expense $ (113 ) $ (217 ) Total reclassifications for the period, net of tax $ 2,244 $ 1,940 (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	6 Months Ended
	Jun. 30, 2019
Share-based Payment Arrangement [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 2009 Long-term Equity Incentive Plan, the 2019 Long-term Equity Incentive Plan, and the Equity Compensation Plan for Non-Employee Directors. The stock options, which have a ten year life, become 100 percent vested based on time ranging from one year 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. The 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 3 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. The RSAs for employees and non-employee directors are either immediately vested at retirement, disability or death, or, continue to vest after retirement, disability or death, depending on the plan under which the shares were granted. The Corporation’s 2009 ESPP and 2019 ESPP provide 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 . The 2009 ESPP expired on June 30, 2019. 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 and six months ended June 30, 2019 was $844,000 and $1,825,000 , respectively, compared to $776,000 and $1,653,000 , respectively, for the three and six months ended June 30, 2018 . 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 1.7 percent for the six months ended June 30, 2019 , based on historical experience. The following table summarizes the components of the Corporation's share-based compensation awards recorded as an expense and the income tax benefit of such awards. Three Months Ended Six Months Ended 2019 2018 2019 2018 Stock and ESPP Options Pre-tax compensation expense $ 25 $ 24 $ 36 $ 49 Income tax benefit (41 ) (80 ) (57 ) (138 ) Stock and ESPP option expense, net of income taxes $ (16 ) $ (56 ) $ (21 ) $ (89 ) Restricted Stock Awards Pre-tax compensation expense $ 819 $ 752 $ 1,789 $ 1,604 Income tax benefit (186 ) (181 ) (726 ) (747 ) Restricted stock awards expense, net of income taxes $ 633 $ 571 $ 1,063 $ 857 Total Share-Based Compensation Pre-tax compensation expense $ 844 $ 776 $ 1,825 $ 1,653 Income tax benefit (227 ) (261 ) (783 ) (885 ) Total share-based compensation expense, net of income taxes $ 617 $ 515 $ 1,042 $ 768 As of June 30, 2019 , unrecognized compensation expense related to RSAs was $5,431,000 and is expected to be recognized over a weighted-average period of 1.54 years. The Corporation did no t have any unrecognized compensation expense related to stock options as of June 30, 2019 . Stock option activity under the Corporation's stock option plans as of June 30, 2019 and changes during the six months ended June 30, 2019 , were as follows: Number of Weighted-Average Exercise Price Weighted Average Remaining Aggregate Outstanding at January 1, 2019 76,300 $ 12.40 Exercised (11,200 ) $ 9.34 Cancelled — $ — Outstanding June 30, 2019 65,100 $ 12.92 2.77 $ 1,625,958 Vested and Expected to Vest at June 30, 2019 65,100 $ 12.92 2.77 $ 1,625,958 Exercisable at June 30, 2019 65,100 $ 12.92 2.77 $ 1,625,958 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 six months of 2019 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 June 30, 2019 . 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 six months ended June 30, 2019 and 2018 was $308,000 and $1,038,000 , respectively. Cash receipts of stock options exercised during this same period were $105,000 and $953,000 , respectively. The following table summarizes information on unvested RSAs outstanding as of June 30, 2019 : Number of Shares Weighted-Average Unvested RSAs at January 1, 2019 344,362 $ 36.80 Granted 7,034 $ 37.78 Vested (108,638 ) $ 23.48 Forfeited (1,900 ) $ 40.54 Unvested RSAs at June 30, 2019 240,858 $ 42.81 The grant date fair value of ESPP options was estimated to be $25,000 at the beginning of the April 1, 2019 quarterly offering period. The ESPP options vested during the three months ending June 30, 2019 , leaving no unrecognized compensation expense related to unvested ESPP options at June 30, 2019 .

Income Tax

Income Tax	6 Months Ended
	Jun. 30, 2019
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 and six months ended June 30, 2019 and 2018 : Three Months Ended Six Months Ended 2019 2018 2019 2018 Reconciliation of Federal Statutory to Actual Tax Expense: Federal statutory income tax at 21% $ 10,249 $ 9,995 $ 19,858 $ 19,086 Tax-exempt interest income (2,403 ) (2,045 ) (4,670 ) (4,060 ) Share-based compensation (41 ) (91 ) (391 ) (532 ) Tax-exempt earnings and gains on life insurance (199 ) (211 ) (406 ) (458 ) Tax credits (63 ) (62 ) (141 ) (23 ) Other 206 375 440 559 Actual Tax Expense $ 7,749 $ 7,961 $ 14,690 $ 14,572 Effective Tax Rate 15.9 % 16.7 % 15.5 % 16.0 %

Net Income Per Share

Net Income Per Share	6 Months Ended
	Jun. 30, 2019
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 and six months ended June 30, 2019 and 2018 . Three Months Ended June 30, 2019 2018 Net Income Weighted-Average Shares Per Share Net Income Weighted-Average Shares Per Share Net income available to common stockholders $ 41,056 49,432,167 $ 0.83 $ 39,634 49,252,580 $ 0.80 Effect of potentially dilutive stock options and restricted stock awards 117,720 198,826 Diluted net income per share $ 41,056 49,549,887 $ 0.83 $ 39,634 49,451,406 $ 0.80 Six Months Ended June 30, 2019 2018 Net Income Weighted-Average Shares Per Share Net Income Weighted-Average Shares Per Share Net income available to common stockholders $ 79,873 49,400,770 $ 1.62 $ 76,313 49,222,779 $ 1.55 Effect of potentially dilutive stock options and restricted stock awards 144,382 217,266 Diluted net income per share $ 79,873 49,545,152 $ 1.61 $ 76,313 49,440,045 $ 1.54 For the three and six months ended June 30, 2019 and 2018 , there were no

General Litigation and Regulato

General Litigation and Regulatory Examinations	6 Months Ended
	Jun. 30, 2019
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 general 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. A discussion of the Bank’s Settlement Agreement and Agreed Order with the United States Department of Justice is contained in the "REGULATORY DEVELOPMENTS" section of Part I, Item 2. Management’s Discussion & Analysis of this Quarterly Report on Form 10-Q.

General (Policies)

General (Policies)	6 Months Ended
	Jun. 30, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
New Accounting Pronouncements Not Yet Adopted	New Accounting Pronouncements Not Yet Adopted 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 Updates No. 2018-15 - Intangibles - Goodwill and Other - Internal-Use Software (Subtopic 350-40): Customer's Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement That Is a Service Contract Summary - The FASB has issued Accounting Standards Update (ASU) No. 2018-15, Intangibles-Goodwill and Other-Internal-Use Software (Subtopic 350-40): Customer’s Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement That Is a Service Contract, which reduces complexity for the accounting for costs of implementing a cloud computing service arrangement. This standard aligns the accounting for implementation costs of hosting arrangements, regardless of whether they convey a license to the hosted software. The ASU aligns the following requirements for capitalizing implementation costs: * Those incurred in a hosting arrangement that is a service contract, and * Those incurred to develop or obtain internal-use software (and hosting arrangements that include an internal-use software license). For calendar-year public companies, the changes will be effective for fiscal years ending after December 15, 2019. For all other calendar-year companies and organizations, the changes will be effective for fiscal years ending after December 15, 2020. The Corporation plans to adopt the standard in the first quarter of 2020, but adoption of the standard is not expected to have a significant impact on the Corporation’s consolidated financial statements. FASB Accounting Standards Updates No. 2018-14 - Compensation - Retirement Benefits - Defined Benefit Plans - General (Subtopic 715-20): Disclosure Framework - Changes to the Disclosure Requirements for Defined Benefit Plans Summary - The FASB has issued ASU No. 2018-14, Compensation - Retirement Benefits - Defined Benefit Plans - General (Subtopic 715-20): Disclosure Framework - Changes to the Disclosure Requirements for Defined Benefit Plans, that applies to all employers that sponsor defined benefit pension or other postretirement plans. The amendments modify the disclosure requirements for employers that sponsor defined benefit pension or other postretirement plans. Disclosure Requirements Deleted * The amounts in accumulated other comprehensive income expected to be recognized as components of net periodic benefit cost over the next fiscal year. * The amount and timing of plan assets expected to be returned to the employer. * Related party disclosures about the amount of future annual benefits covered by insurance and annuity contracts and significant transactions between the employer or related parties and the plan. * For public entities, the effects of a one-percentage-point change in assumed health care cost trend rates on the (a) aggregate of the service and interest cost components of net periodic benefit costs and (b) benefit obligation for postretirement health care benefits. Disclosure Requirements Added * An explanation of the reasons for significant gains and losses related to changes in the benefit obligation for the period. The amendments also clarify the disclosure requirements in paragraph 715-20-50-3, which state that the following information for defined benefit pension plans should be disclosed: * The projected benefit obligation (PBO) and fair value of plan assets for plans with PBOs in excess of plan assets. * The accumulated benefit obligation (ABO) and fair value of plan assets for plans with ABOs in excess of plan assets. ASU No. 2018-14 is effective for fiscal years ending after December 15, 2020, for public business entities and for fiscal years ending after December 15, 2021, for all other entities. Early adoption is permitted for all entities. The Corporation plans to adopt the standard in the first quarter of 2020, but adoption of the standard is not expected to have a significant impact on the Corporation’s disclosures. FASB Accounting Standards Updates No. 2018-13 - Fair Value Measurement (Topic 820): Disclosure Framework - Changes to the Disclosure Requirements for Fair Value Measurement Summary - The FASB has issued ASU No. 2018-13, Fair Value Measurement (Topic 820): Disclosure Framework - Changes to the Disclosure Requirements for Fair Value Measurement. ASU No. 2018-13 modifies the disclosure requirements on fair value measurements in Topic 820. Certain disclosure requirements related to transfers between Level 1 and Level 2 of the fair value hierarchy and Level 3 valuation process were removed from Topic 820. Disclosures were also added to Topic 820 for changes in unrealized gains and losses for the period included in other comprehensive income for recurring Level 3 fair value measurements held at the end of the reporting period and the range and weighted average of significant unobservable inputs used to develop Level 3 fair value measurements. In addition, the amendments eliminate at a minimum from the phrase “an entity shall disclose at a minimum” to promote the appropriate exercise of discretion by entities when considering fair value measurement disclosures and to clarify that materiality is an appropriate consideration of entities and their auditors when evaluating disclosure requirements. The amendments in ASU No. 2018-13 are effective for all entities for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2019. The amendments on changes in unrealized gains and losses, the range and weighted average of significant unobservable inputs used to develop Level 3 fair value measurements, and the narrative description of measurement uncertainty should be applied prospectively for only the most recent interim or annual period presented in the initial fiscal year of adoption. All other amendments should be applied retrospectively to all periods presented upon their effective date. Early adoption is permitted. An entity is permitted to early adopt any removed or modified disclosures upon issuance of ASU No. 2018-13 and delay adoption of the additional disclosures until their effective date. The Corporation plans to adopt the standard in the first quarter of 2020, but adoption of the standard is not expected to have a significant impact on the Corporation’s disclosures. 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 established an implementation team that meets on a regular basis to oversee activities and monitor progress. Third party software has been implemented and initial models have been developed. The implementation team is testing the models by conducting limited parallel runs and testing the sensitivity of assumptions. Forecasting methodologies continue to be refined and outputs from those models challenged. 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.

Investment Securities (Tables)

Investment Securities (Tables)	6 Months Ended
	Jun. 30, 2019
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 June 30, 2019 U.S. Government-sponsored agency securities $ 33,494 $ 453 $ — $ 33,947 State and municipal 685,123 30,835 200 715,758 U.S. Government-sponsored mortgage-backed securities 642,298 8,532 607 650,223 Corporate obligations 31 — — 31 Total available for sale 1,360,946 39,820 807 1,399,959 Held to maturity at June 30, 2019 U.S. Government-sponsored agency securities 33,865 20 66 33,819 State and municipal 310,076 10,987 22 321,041 U.S. Government-sponsored mortgage-backed securities 347,524 5,257 226 352,555 Foreign investment 1,500 — — 1,500 Total held to maturity 692,965 16,264 314 708,915 Total Investment Securities $ 2,053,911 $ 56,084 $ 1,121 $ 2,108,874 Amortized Gross Gross Fair Available for sale at December 31, 2018 U.S. Government-sponsored agency securities $ 13,493 $ 92 $ 3 $ 13,582 State and municipal 605,994 5,995 5,854 606,135 U.S. Government-sponsored mortgage-backed securities 530,209 634 8,396 522,447 Corporate obligations 31 — — 31 Total available for sale 1,149,727 6,721 14,253 1,142,195 Held to maturity at December 31, 2018 U.S. Government-sponsored agency securities 22,618 — 545 22,073 State and municipal 197,909 2,858 872 199,895 U.S. Government-sponsored mortgage-backed securities 268,860 713 3,323 266,250 Foreign investment 1,000 — 1 999 Total held to maturity 490,387 3,571 4,741 489,217 Total Investment Securities $ 1,640,114 $ 10,292 $ 18,994 $ 1,631,412
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 June 30, 2019 and December 31, 2018 , 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 June 30, 2019: Due in one year or less $ 1,131 $ 1,138 $ 3,784 $ 3,782 Due after one through five years 3,752 3,851 46,941 46,914 Due after five through ten years 74,311 76,604 78,716 81,769 Due after ten years 639,454 668,143 216,000 223,895 718,648 749,736 345,441 356,360 U.S. Government-sponsored mortgage-backed securities 642,298 650,223 347,524 352,555 Total Investment Securities $ 1,360,946 $ 1,399,959 $ 692,965 $ 708,915 Available for Sale Held to Maturity Amortized Cost Fair Value Amortized Cost Fair Value Maturity Distribution at December 31, 2018 Due in one year or less $ 13,092 $ 13,144 $ 4,732 $ 4,730 Due after one through five years 5,311 5,378 49,054 48,473 Due after five through ten years 73,280 74,411 62,873 64,163 Due after ten years 527,835 526,815 104,868 105,601 619,518 619,748 221,527 222,967 U.S. Government-sponsored mortgage-backed securities 530,209 522,447 268,860 266,250 Total Investment Securities $ 1,149,727 $ 1,142,195 $ 490,387 $ 489,217
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 and six months ended June 30, 2019 and 2018 are shown below. Three Months Ended Six Months Ended 2019 2018 2019 2018 Sales and Redemptions of Available for Sale Securities: Gross gains $ 1,843 $ 1,122 $ 2,983 $ 2,731 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 June 30, 2019 , and December 31, 2018 : Less than 12 Months Total Fair Gross Fair Gross Fair Gross Temporarily Impaired Available for Sale Securities at June 30, 2019 State and municipal $ 7,699 $ 16 $ 7,080 $ 184 $ 14,779 $ 200 U.S. Government-sponsored mortgage-backed securities 7,791 15 75,152 592 82,943 607 Total Temporarily Impaired Available for Sale Securities 15,490 31 82,232 776 97,722 807 Temporarily Impaired Held to Maturity Securities at June 30, 2019 U.S. Government-sponsored agency securities — — 15,454 66 15,454 66 State and municipal 6,421 22 — — 6,421 22 U.S. Government-sponsored mortgage-backed securities 74 — 36,614 226 36,688 226 Total Temporarily Impaired Held to Maturity Securities 6,495 22 52,068 292 58,563 314 Total Temporarily Impaired Investment Securities $ 21,985 $ 53 $ 134,300 $ 1,068 $ 156,285 $ 1,121 Less than 12 Months Total Fair Gross Fair Gross Fair Gross Temporarily Impaired Available for Sale Securities at December 31, 2018 U.S. Government-sponsored agency securities $ 1,490 $ 3 $ — $ — $ 1,490 $ 3 State and municipal 234,431 3,958 38,028 1,896 272,459 5,854 U.S. Government-sponsored mortgage-backed securities 196,601 2,400 217,121 5,996 413,722 8,396 Total Temporarily Impaired Available for Sale Securities 432,522 6,361 255,149 7,892 687,671 14,253 Temporarily Impaired Held to Maturity Securities at December 31, 2018 U.S. Government-sponsored agency securities — — 22,073 545 22,073 545 State and municipal 14,952 369 16,786 503 31,738 872 U.S. Government-sponsored mortgage-backed securities 102,828 876 87,268 2,447 190,096 3,323 Foreign investment — — 999 1 999 1 Total Temporarily Impaired Held to Maturity Securities 117,780 1,245 127,126 3,496 244,906 4,741 Total Temporarily Impaired Investment Securities $ 550,302 $ 7,606 $ 382,275 $ 11,388 $ 932,577 $ 18,994
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. June 30, 2019 December 31, 2018 Investments reported at less than historical cost: Historical cost $ 157,406 $ 951,571 Fair value 156,285 932,577 Gross unrealized losses $ 1,121 $ 18,994 Percent of the Corporation's investment portfolio 7.5 % 57.1 %

Loans and Allowance (Tables)

Loans and Allowance (Tables)	6 Months Ended
	Jun. 30, 2019
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: June 30, 2019 December 31, 2018 Commercial and industrial loans $ 1,877,042 $ 1,726,664 Agricultural production financing and other loans to farmers 83,452 92,404 Real estate loans: Construction 624,548 545,729 Commercial and farmland 2,821,689 2,832,102 Residential 993,802 966,421 Home equity 548,006 528,157 Individuals' loans for household and other personal expenditures 98,384 99,788 Public finance and other commercial loans 464,447 433,202 Loans $ 7,511,370 $ 7,224,467 Allowance for loan losses (81,274 ) (80,552 ) Net Loans $ 7,430,096 $ 7,143,915
Changes in allowance for loan losses	The following tables summarize changes in the allowance for loan losses by loan segment for the three and six months ended June 30, 2019 and June 30, 2018 : Three Months Ended June 30, 2019 Commercial Commercial Consumer Residential Total Allowance for loan losses: Balances, March 31, 2019 $ 33,069 $ 29,434 $ 4,026 $ 14,373 $ 80,902 Provision for losses 100 320 36 44 500 Recoveries on loans 344 778 100 212 1,434 Loans charged off (311 ) (1,001 ) (92 ) (158 ) (1,562 ) Balances, June 30, 2019 $ 33,202 $ 29,531 $ 4,070 $ 14,471 $ 81,274 Six Months Ended June 30, 2019 Commercial Commercial Consumer Residential Total Allowance for loan losses: Balances, December 31, 2018 $ 32,657 $ 29,609 $ 3,964 $ 14,322 $ 80,552 Provision for losses 336 1,089 141 134 1,700 Recoveries on loans 886 1,023 218 312 2,439 Loans charged off (677 ) (2,190 ) (253 ) (297 ) (3,417 ) Balances, June 30, 2019 $ 33,202 $ 29,531 $ 4,070 $ 14,471 $ 81,274 Three Months Ended June 30, 2018 Commercial Commercial Consumer Residential Total Allowance for loan losses: Balances, March 31, 2018 $ 30,770 $ 27,705 $ 3,896 $ 14,049 $ 76,420 Provision for losses 471 954 60 178 1,663 Recoveries on loans 1,283 1,213 98 596 3,190 Loans charged off (1,057 ) (2,141 ) (133 ) (399 ) (3,730 ) Balances, June 30, 2018 $ 31,467 $ 27,731 $ 3,921 $ 14,424 $ 77,543 Six Months Ended June 30, 2018 Commercial Commercial Consumer Residential Total Allowance for loan losses: Balances, December 31, 2017 $ 30,420 $ 27,343 $ 3,732 $ 13,537 $ 75,032 Provision for losses 1,311 1,038 334 1,480 4,163 Recoveries on loans 1,402 1,552 187 750 3,891 Loans charged off (1,666 ) (2,202 ) (332 ) (1,343 ) (5,543 ) Balances, June 30, 2018 $ 31,467 $ 27,731 $ 3,921 $ 14,424 $ 77,543
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. June 30, 2019 Commercial Commercial Consumer Residential Total Allowance Balances: Individually evaluated for impairment $ 1,849 $ 14 $ 1 $ 432 $ 2,296 Collectively evaluated for impairment 31,353 29,517 4,069 14,039 78,978 Total Allowance for Loan Losses $ 33,202 $ 29,531 $ 4,070 $ 14,471 $ 81,274 Loan Balances: Individually evaluated for impairment $ 5,090 $ 14,419 $ 14 $ 2,450 $ 21,973 Collectively evaluated for impairment 2,418,481 3,419,930 98,370 1,538,533 7,475,314 Loans acquired with deteriorated credit quality 1,370 11,888 — 825 14,083 Loans $ 2,424,941 $ 3,446,237 $ 98,384 $ 1,541,808 $ 7,511,370 December 31, 2018 Commercial Commercial Consumer Residential Total Allowance Balances: Individually evaluated for impairment $ — $ 1,435 $ 1 $ 436 $ 1,872 Collectively evaluated for impairment 32,657 28,174 3,963 13,886 78,680 Total Allowance for Loan Losses $ 32,657 $ 29,609 $ 3,964 $ 14,322 $ 80,552 Loan Balances: Individually evaluated for impairment $ 1,838 $ 17,756 $ 18 $ 2,413 $ 22,025 Collectively evaluated for impairment 2,248,330 3,347,686 99,770 1,490,872 7,186,658 Loans acquired with deteriorated credit quality 2,102 12,389 — 1,293 15,784 Loans $ 2,252,270 $ 3,377,831 $ 99,788 $ 1,494,578 $ 7,224,467
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: June 30, 2019 December 31, 2018 Commercial and industrial loans $ 2,770 $ 1,803 Agriculture production financing and other loans to farmers 2,785 679 Real estate loans: Construction 6,918 8,667 Commercial and farmland 6,340 8,156 Residential 4,579 4,966 Home equity 1,826 1,481 Individuals' loans for household and other personal expenditures 64 42 Public finance and other commercial loans 353 354 Total $ 25,635 $ 26,148
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: June 30, 2019 Unpaid Recorded Related Impaired loans with no related allowance: Commercial and industrial loans $ 1,048 $ 1,012 $ — Agriculture production financing and other loans to farmers 679 668 — Real estate Loans: Construction 7,978 6,909 — Commercial and farmland 10,160 7,381 — Residential 117 99 — Home equity 49 49 — Public finance and other commercial loans 353 353 — Total $ 20,384 $ 16,471 $ — Impaired loans with related allowance: Commercial and industrial loans $ 1,185 $ 940 $ 455 Agriculture production financing and other loans to farmers $ 2,167 $ 2,117 $ 1,394 Real estate Loans: Commercial and farmland 134 129 14 Residential 1,976 1,953 362 Home equity 366 349 70 Individuals' loans for household and other personal expenditures 14 14 1 Total $ 5,842 $ 5,502 $ 2,296 Total Impaired Loans $ 26,226 $ 21,973 $ 2,296 December 31, 2018 Unpaid Recorded Related Impaired loans with no related allowance: Commercial and industrial loans $ 828 $ 806 $ — Agriculture production financing and other loans to farmers 679 679 — Real estate Loans: Construction 1,352 614 — Commercial and farmland 11,176 8,994 — Residential 118 100 — Home equity 49 48 — Public finance and other commercial loans 353 353 — Total $ 14,555 $ 11,594 $ — Impaired loans with related allowance: Real estate Loans: Construction $ 7,978 $ 7,977 $ 1,429 Commercial and farmland 171 171 6 Residential 1,958 1,907 362 Home equity 376 358 74 Individuals' loans for household and other personal expenditures 18 18 1 Total $ 10,501 $ 10,431 $ 1,872 Total Impaired Loans $ 25,056 $ 22,025 $ 1,872 Three Months Ended June 30, 2019 Six Months Ended June 30, 2019 Average Interest Average Interest Impaired loans with no related allowance: Commercial and industrial loans $ 1,013 $ — $ 1,021 $ — Agriculture production financing and other loans to farmers 668 — 672 — Real estate Loans: Construction 7,314 — 7,792 — Commercial and farmland 7,998 39 8,187 78 Residential 38 1 38 2 Home equity 49 — 49 — Public finance and other commercial loans 353 — 353 — Total $ 17,433 $ 40 $ 18,112 $ 80 Impaired loans with related allowance: Commercial and industrial loans $ 940 $ — $ 940 $ — Agriculture production financing and other loans to farmers 2,117 — 2,134 — Real estate Loans: Commercial and farmland 157 — 164 — Residential 2,021 16 2,029 32 Home equity 351 3 352 6 Individuals' loans for household and other personal expenditures 14 — 15 — Total $ 5,600 $ 19 $ 5,634 $ 38 Total Impaired Loans $ 23,033 $ 59 $ 23,746 $ 118 Three Months Ended June 30, 2018 Six Months Ended June 30, 2018 Average Interest Average Interest Impaired loans with no related allowance: Commercial and industrial loans $ 1,004 $ — $ 1,006 $ — Agriculture production financing and other loans to farmers 640 — 640 — Real estate Loans: Construction 1,106 — 1,167 — Commercial and farmland 9,935 40 10,241 87 Residential 63 1 63 2 Individuals' loans for household and other personal expenditures 10 — 11 — Public finance and other commercial loans — — — — Total $ 12,758 $ 41 $ 13,128 $ 89 Impaired loans with related allowance: Commercial and industrial loans $ 108 $ — $ 108 $ — Real estate Loans: Residential 1,714 12 1,726 24 Home equity 302 2 303 5 Total $ 2,124 $ 14 $ 2,137 $ 29 Total Impaired Loans $ 14,882 $ 55 $ 15,265 $ 118
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-days or more 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. June 30, 2019 Commercial Commercial Commercial Substandard Commercial Commercial Loss Consumer Performing Consumer Total Commercial and industrial loans $ 1,781,040 $ 53,407 $ 42,266 $ 329 $ — $ — $ — $ 1,877,042 Agriculture production financing and other loans to farmers 67,837 5,478 10,137 — — — — 83,452 Real estate Loans: Construction 591,962 1,444 7,712 — — 23,430 624,548 Commercial and farmland 2,645,338 79,586 94,179 450 — 2,136 — 2,821,689 Residential 156,622 5,833 3,425 — — 823,309 4,613 993,802 Home equity 27,324 585 758 — — 517,620 1,719 548,006 Individuals' loans for household and other personal expenditures — — — — — 98,320 64 98,384 Public finance and other commercial loans 464,094 — 353 — — — — 464,447 Loans $ 5,734,217 $ 146,333 $ 158,830 $ 779 $ — $ 1,464,815 $ 6,396 $ 7,511,370 December 31, 2018 Commercial Commercial Commercial Substandard Commercial Commercial Loss Consumer Performing Consumer Total Commercial and industrial loans $ 1,660,879 $ 23,246 $ 42,539 $ — $ — $ — $ — $ 1,726,664 Agriculture production financing and other loans to farmers 78,446 5,966 7,992 — — — — 92,404 Real estate Loans: Construction 492,358 2,185 24,224 — — 25,419 1,543 545,729 Commercial and farmland 2,669,491 76,037 84,288 — — 2,285 1 2,832,102 Residential 170,075 7,373 2,076 — — 782,080 4,817 966,421 Home equity 24,653 535 457 — — 500,996 1,516 528,157 Individuals' loans for household and other personal expenditures — — — — — 99,741 47 99,788 Public finance and other commercial loans 432,849 — 353 — — — — 433,202 Loans $ 5,528,751 $ 115,342 $ 161,929 $ — $ — $ 1,410,521 $ 7,924 $ 7,224,467
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 June 30, 2019 , and December 31, 2018 : June 30, 2019 Current 30-59 Days 60-89 Days Loans 90 Days or More Past Due And Accruing Non-Accrual Total Past Due Total Commercial and industrial loans $ 1,874,004 $ 248 $ 20 $ — $ 2,770 $ 3,038 $ 1,877,042 Agriculture production financing and other loans to farmers 80,634 33 — — 2,785 2,818 83,452 Real estate loans: Construction 617,519 111 — — 6,918 7,029 624,548 Commercial and farmland 2,808,422 6,751 176 — 6,340 13,267 2,821,689 Residential 984,086 4,540 422 175 4,579 9,716 993,802 Home equity 544,338 1,308 500 34 1,826 3,668 548,006 Individuals' loans for household and other personal expenditures 97,826 407 87 — 64 558 98,384 Public finance and other commercial loans 464,094 — — — 353 353 464,447 Loans $ 7,470,923 $ 13,398 $ 1,205 $ 209 $ 25,635 $ 40,447 $ 7,511,370 December 31, 2018 Current 30-59 Days 60-89 Days Loans 90 Days or More Past Due And Accruing Non-Accrual Total Past Due Total Commercial and industrial loans $ 1,723,337 $ 1,093 $ 182 $ 249 $ 1,803 $ 3,327 $ 1,726,664 Agriculture production financing and other loans to farmers 89,440 2,285 — — 679 2,964 92,404 Real estate loans: Construction 535,520 64 — 1,478 8,667 10,209 545,729 Commercial and farmland 2,822,515 1,253 178 — 8,156 9,587 2,832,102 Residential 959,252 1,756 430 17 4,966 7,169 966,421 Home equity 524,198 2,164 207 107 1,481 3,959 528,157 Individuals' loans for household and other personal expenditures 99,499 179 64 4 42 289 99,788 Public finance and other commercial loans 432,848 — — — 354 354 433,202 Loans $ 7,186,609 $ 8,794 $ 1,061 $ 1,855 $ 26,148 $ 37,858 $ 7,224,467
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 June 30, 2019 Six Months Ended June 30, 2019 Pre-Modification Post-Modification Number Pre-Modification Post-Modification Number Real estate loans: Residential $ 171 $ 164 4 $ 261 $ 254 5 Total $ 171 $ 164 4 $ 261 $ 254 5 Three Months Ended June 30, 2018 Six Months Ended June 30, 2018 Pre-Modification Post-Modification Number Pre-Modification Post-Modification Number Real estate loans: Residential $ 122 $ 125 2 $ 336 $ 347 7 Home equity — — — 16 16 2 Individuals' loans for household and other personal expenditures — — — 7 8 1 Total $ 122 $ 125 2 $ 359 $ 371 10 The following tables summarize the recorded investment of troubled debt restructures as of June 30, 2019 and 2018 , by modification type, that occurred during the periods indicated: Three Months Ended June 30, 2019 Term Rate Combination Total Real estate loans: Residential $ — $ — $ 164 $ 164 Total $ — $ — $ 164 $ 164 Six Months Ended June 30, 2019 Term Rate Combination Total Real estate loans: Residential $ — $ 89 $ 164 $ 253 Total $ — $ 89 $ 164 $ 253 Three Months Ended June 30, 2018 Term Rate Combination Total Real estate loans: Residential $ — $ 91 $ 34 $ 125 Total $ — $ 91 $ 34 $ 125 Six Months Ended June 30, 2018 Term Rate Combination Total Real estate loans: Residential $ 37 $ 163 $ 139 $ 339 Home equity 60 10 — 70 Individuals' loans for household and other personal expenditures — 7 — 7 Total $ 97 $ 180 $ 139 $ 416
Troubled debt restructurings that subsequently defaulted	A loan is considered in default if it is 30-days or more past due. Three Months Ended June 30, 2019 Six Months Ended June 30, 2019 Number of Loans Recorded Balance Number of Loans Recorded Balance Real estate loans: Residential 1 $ 62 1 $ 62 Total 1 $ 62 1 $ 62 Three Months Ended June 30, 2018 Six Months Ended June 30, 2018 Number of Loans Recorded Balance Number of Loans Recorded Balance Real estate loans: Commercial and farmland — — 1 $ 272 Residential 2 $ 132 3 190 Total 2 $ 132 4 $ 462

Purchased Credit Impaired Loa_2

Purchased Credit Impaired Loans (Tables)	6 Months Ended
	Jun. 30, 2019
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 June 30, 2019 Six Months Ended June 30, 2019 Accretable yield beginning balance $ 2,064 $ 2,143 Additions — — Accretion (638 ) (1,218 ) Reclassification from nonaccretable 488 989 Disposals — — Accretable yield ending balance $ 1,914 $ 1,914 Three Months Ended June 30, 2018 Six Months Ended June 30, 2018 Accretable yield beginning balance $ 2,675 $ 2,890 Additions — — Accretion (927 ) (1,437 ) Reclassification from nonaccretable 675 970 Disposals — — Accretable yield ending balance $ 2,423 $ 2,423

Other Intangibles (Tables)

Other Intangibles (Tables)	6 Months Ended
	Jun. 30, 2019
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. June 30, 2019 December 31, 2018 Gross carrying amount $ 85,869 $ 85,869 Accumulated amortization (64,488 ) (61,440 ) Total other intangibles $ 21,381 $ 24,429
Schedule of estimated future amortization expense	Estimated future amortization expense is summarized as follows: Amortization Expense 2019 $ 2,121 2020 3,632 2021 3,427 2022 3,325 2023 3,175 After 2023 5,701 $ 21,381

Leases (Tables)

Leases (Tables)	6 Months Ended
	Jun. 30, 2019
Leases [Abstract]
Supplemental balance sheet information	Supplemental balance sheet information related to leases is presented in the table below as of June 30, 2019 . June 30, 2019 Operating lease assets $ 21,968 Total lease assets $ 21,968 Operating lease liabilities $ 22,603 Total Lease liabilities $ 22,603 Weighted average remaining lease term (years) Operating leases 9.5 Weighted average discount rate Operating leases 3.40 %
Components of lease expense	The table below presents the components of lease expense for the periods indicated. Three Months Ended Six Months Ended Lease Cost: Operating lease cost $ 911 $ 1,806 Short-term lease cost 30 73 Variable lease cost 253 511 Total lease cost $ 1,194 $ 2,390
Supplemental cash flow information	Supplemental cash flow information related to leases is presented in the tables below. Maturity of lease liabilities Operating Leases Remaining 2019 $ 1,774 2020 3,388 2021 3,114 2022 2,999 2023 2,628 2024 and after 12,771 Total lease payments $ 26,674 Less: Present value discount 4,071 Present value of lease liabilities $ 22,603 Other Information Six Months Ended Cash paid for amounts included in the measurement of lease liabilities Operating cash flows from operating leases $ 1,634 ROU assets obtained in exchange for new operating lease liabilities $ 23,384

Derivative Financial Instrume_2

Derivative Financial Instruments (Tables)	6 Months Ended
	Jun. 30, 2019
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 June 30, 2019 , and December 31, 2018 . Asset Derivatives Liability Derivatives June 30, 2019 December 31, 2018 June 30, 2019 December 31, 2018 Balance Fair Balance Fair Balance Fair Balance Fair Derivatives designated as hedging instruments: Interest rate contracts Other Assets $ — Other Assets $ 135 Other Liabilities $ 1,609 Other Liabilities $ 688 Derivatives not designated as hedging instruments: Interest rate contracts Other Assets $ 25,059 Other Assets $ 11,948 Other Liabilities $ 25,059 Other Liabilities $ 11,948
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 Six Months Ended June 30, 2019 June 30, 2018 June 30, 2019 June 30, 2018 Interest Rate Products $ (701 ) $ 291 $ (1,092 ) $ 799
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 $ (84 ) $ (105 ) Derivatives Designated as Location of Gain (Loss) Amount of Gain (Loss) Reclassed from Other Comprehensive Income into Income (Effective Portion) Six Months Ended Six Months Ended Interest rate contracts Interest Expense $ (143 ) $ (275 )

Disclosures About Fair Value _2

Disclosures About Fair Value of Assets and Liabilities (Tables)	6 Months Ended
	Jun. 30, 2019
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 June 30, 2019 , and December 31, 2018 . Fair Value Measurements Using: June 30, 2019 Fair Value Quoted Prices in Active Markets for Identical Assets Significant Other Significant Available for sale securities: U.S. Government-sponsored agency securities $ 33,947 $ — $ 33,947 $ — State and municipal 715,758 — 712,818 2,940 U.S. Government-sponsored mortgage-backed securities 650,223 — 650,219 4 Corporate obligations 31 — — 31 Interest rate swap asset 25,059 — 25,059 — Interest rate swap liability 26,668 — 26,668 — Fair Value Measurements Using: December 31, 2018 Fair Value Quoted Prices in Significant Other Observable Inputs Significant Available for sale securities: U.S. Government-sponsored agency securities $ 13,582 $ — $ 13,582 $ — State and municipal 606,135 — 602,842 3,293 U.S. Government-sponsored mortgage-backed securities 522,447 — 522,443 4 Corporate obligations 31 — — 31 Interest rate swap and cap asset 12,083 — 12,083 — Interest rate swap liability 12,636 — 12,636 —
Reconciliation of beginning and ending balances of recurring fair value measurements recognized in Consolidated Condensed Balance Sheets using significant unobservable Level 3 inputs	the three and six months ended June 30, 2019 and 2018 . Available for Sale Securities Three Months Ended Six Months Ended June 30, 2019 June 30, 2018 June 30, 2019 June 30, 2018 Balance at beginning of the period $ 2,936 $ 3,966 $ 3,328 $ 3,978 Included in other comprehensive income 37 1 80 (24 ) Principal payments 2 3 (433 ) 16 Ending balance $ 2,975 $ 3,970 $ 2,975 $ 3,970
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 June 30, 2019 , and December 31, 2018 . Fair Value Measurements Using June 30, 2019 Fair Value Quoted Prices in Significant Other Significant Unobservable Impaired loans (collateral dependent) $ 12,966 $ — $ — $ 12,966 Other real estate owned 174 — — 174 Fair Value Measurements Using December 31, 2018 Fair Value Quoted Prices in Significant Other Significant Unobservable Impaired loans (collateral dependent) $ 11,866 $ — $ — $ 11,866 Other real estate owned 657 — — 657
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 June 30, 2019 and December 31, 2018 . June 30, 2019 Fair Value Valuation Technique Unobservable Inputs Range (Weighted-Average) State and municipal securities $ 2,940 Discounted cash flow Maturity/Call date 1 month to 15 yrs US Muni BQ curve A- to BBB- Discount rate 2% - 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) $ 12,966 Collateral based measurements Discount to reflect current market conditions and ultimate collectability 0% - 10% (4%) Other real estate owned $ 174 Appraisals Discount to reflect current market conditions 0% - 51% (30%) December 31, 2018 Fair Value Valuation Technique Unobservable Inputs Range (Weighted-Average) State and municipal securities $ 3,293 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) $ 11,866 Collateral based measurements Discount to reflect current market conditions and ultimate collectability 0% - 10% (6%) Other real estate owned $ 657 Appraisals Discount to reflect current market conditions 0% - 10% (4%)
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 June 30, 2019 , and December 31, 2018 . June 30, 2019 Quoted Prices in Active Markets Significant Significant Unobservable Carrying Amount (Level 1) (Level 2) (Level 3) Assets: Cash and cash equivalents $ 128,185 $ 128,185 $ — $ — Interest-bearing time deposits 129,614 129,614 — — Investment securities available for sale 1,399,959 — 1,396,984 2,975 Investment securities held to maturity 692,965 — 701,905 7,010 Loans held for sale 5,854 — 5,854 — Loans 7,430,096 — — 7,408,511 Federal Home Loan Bank stock 24,588 — 24,588 — Interest rate swap asset 25,059 — 25,059 — Interest receivable 45,150 — 45,150 — Liabilities: Deposits $ 8,319,328 $ 6,688,194 $ 1,627,381 $ — Borrowings: Federal funds purchased 75,000 — 75,000 — Securities sold under repurchase agreements 119,674 — 119,488 — Federal Home Loan Bank advances 460,042 — 461,582 — Subordinated debentures and term loans 138,574 — 127,594 — Interest rate swap liability 26,668 — 26,668 — Interest payable 6,740 — 6,740 — December 31, 2018 Quoted Prices in Active Markets Significant Significant Unobservable Carrying Amount (Level 1) (Level 2) (Level 3) Assets: Cash and cash equivalents $ 139,247 $ 139,247 $ — $ — Interest-bearing time deposits 36,963 36,963 — — Investment securities available for sale 1,142,195 — 1,138,867 3,328 Investment securities held to maturity 490,387 — 481,377 7,840 Loans held for sale 4,778 — 4,778 — Loans 7,143,915 — — 7,004,193 Federal Home Loan Bank stock 24,588 — 24,588 — Interest rate swap and cap asset 12,083 — 12,083 — Interest receivable 40,881 — 40,881 — Liabilities: Deposits $ 7,754,593 $ 6,267,879 $ 1,464,129 $ — Borrowings: Federal funds purchased 104,000 — 104,000 — Securities sold under repurchase agreements 113,512 — 113,437 — Federal Home Loan Bank advances 314,986 — 318,728 — Subordinated debentures and term loans 138,463 — 127,298 — Interest rate swap liability 12,636 — 12,636 — Interest payable 5,607 — 5,607 —

Transfers Accounted for as Se_2

Transfers Accounted for as Secured Borrowings (Tables)	6 Months Ended
	Jun. 30, 2019
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 June 30, 2019 and December 31, 2018 were: June 30, 2019 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 $ 110,233 $ — $ — $ 9,441 $ 119,674 December 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 $ 104,883 $ 1,014 $ 7,615 $ — $ 113,512

Accumulated Other Comprehensi_2

Accumulated Other Comprehensive Income (Loss) (Tables)	6 Months Ended
	Jun. 30, 2019
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 June 30, 2019 and 2018 : 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, 2018 $ (6,343 ) $ (559 ) $ (14,520 ) $ (21,422 ) Other comprehensive income before reclassifications 39,130 (862 ) — 38,268 Amounts reclassified from accumulated other comprehensive income (2,357 ) 113 — (2,244 ) Period change 36,773 (749 ) — 36,024 Balance at June 30, 2019 $ 30,430 $ (1,308 ) $ (14,520 ) $ 14,602 Balance at December 31, 2017 $ 8,970 $ (1,125 ) $ (10,753 ) $ (2,908 ) Other comprehensive income before reclassifications (20,268 ) 874 — (19,394 ) Amounts reclassified from accumulated other comprehensive income (2,157 ) 217 — (1,940 ) Period change (22,425 ) 1,091 — (21,334 ) Reclassification adjustment under ASU 2018-02 1,932 (242 ) (2,316 ) (626 ) Balance at June 30, 2018 $ (11,523 ) $ (276 ) $ (13,069 ) $ (24,868 )
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 and six months ended June 30, 2019 and 2018 . Amount Reclassified from Accumulated Other Comprehensive Income (Loss) For the Three Months Ended June 30, Details about Accumulated Other Comprehensive Income (Loss) Components 2019 2018 Affected Line Item in the Statements of Income Unrealized gains (losses) on available for sale securities (1) Realized securities gains reclassified into income $ 1,843 $ 1,122 Other income - net realized gains on sales of available for sale securities Related income tax expense (387 ) (236 ) Income tax expense $ 1,456 $ 886 Unrealized gains (losses) on cash flow hedges (2) Interest rate contracts $ (84 ) $ (105 ) Interest expense - subordinated debentures and term loans Related income tax benefit 18 22 Income tax expense $ (66 ) $ (83 ) Total reclassifications for the period, net of tax $ 1,390 $ 803 Amount Reclassified from Accumulated Other Comprehensive Income (Loss) For the Six Months Ended June 30, Details about Accumulated Other Comprehensive Income (Loss) Components 2019 2018 Affected Line Item in the Statements of Income Unrealized gains (losses) on available for sale securities (1) Realized securities gains reclassified into income $ 2,983 $ 2,731 Other income - net realized gains on sales of available for sale securities Related income tax expense (626 ) (574 ) Income tax expense $ 2,357 $ 2,157 Unrealized gains (losses) on cash flow hedges (2) Interest rate contracts $ (143 ) $ (275 ) Interest expense - subordinated debentures and term loans Related income tax benefit 30 58 Income tax expense $ (113 ) $ (217 ) Total reclassifications for the period, net of tax $ 2,244 $ 1,940 (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)	6 Months Ended
	Jun. 30, 2019
Share-based Payment Arrangement [Abstract]
Components of share-based compensation awards	The following table summarizes the components of the Corporation's share-based compensation awards recorded as an expense and the income tax benefit of such awards. Three Months Ended Six Months Ended 2019 2018 2019 2018 Stock and ESPP Options Pre-tax compensation expense $ 25 $ 24 $ 36 $ 49 Income tax benefit (41 ) (80 ) (57 ) (138 ) Stock and ESPP option expense, net of income taxes $ (16 ) $ (56 ) $ (21 ) $ (89 ) Restricted Stock Awards Pre-tax compensation expense $ 819 $ 752 $ 1,789 $ 1,604 Income tax benefit (186 ) (181 ) (726 ) (747 ) Restricted stock awards expense, net of income taxes $ 633 $ 571 $ 1,063 $ 857 Total Share-Based Compensation Pre-tax compensation expense $ 844 $ 776 $ 1,825 $ 1,653 Income tax benefit (227 ) (261 ) (783 ) (885 ) Total share-based compensation expense, net of income taxes $ 617 $ 515 $ 1,042 $ 768
Stock option activity under stock option plans	Stock option activity under the Corporation's stock option plans as of June 30, 2019 and changes during the six months ended June 30, 2019 , were as follows: Number of Weighted-Average Exercise Price Weighted Average Remaining Aggregate Outstanding at January 1, 2019 76,300 $ 12.40 Exercised (11,200 ) $ 9.34 Cancelled — $ — Outstanding June 30, 2019 65,100 $ 12.92 2.77 $ 1,625,958 Vested and Expected to Vest at June 30, 2019 65,100 $ 12.92 2.77 $ 1,625,958 Exercisable at June 30, 2019 65,100 $ 12.92 2.77 $ 1,625,958
Unvested RSAs outstanding	The following table summarizes information on unvested RSAs outstanding as of June 30, 2019 : Number of Shares Weighted-Average Unvested RSAs at January 1, 2019 344,362 $ 36.80 Granted 7,034 $ 37.78 Vested (108,638 ) $ 23.48 Forfeited (1,900 ) $ 40.54 Unvested RSAs at June 30, 2019 240,858 $ 42.81

Income Tax (Tables)

Income Tax (Tables)	6 Months Ended
	Jun. 30, 2019
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 and six months ended June 30, 2019 and 2018 : Three Months Ended Six Months Ended 2019 2018 2019 2018 Reconciliation of Federal Statutory to Actual Tax Expense: Federal statutory income tax at 21% $ 10,249 $ 9,995 $ 19,858 $ 19,086 Tax-exempt interest income (2,403 ) (2,045 ) (4,670 ) (4,060 ) Share-based compensation (41 ) (91 ) (391 ) (532 ) Tax-exempt earnings and gains on life insurance (199 ) (211 ) (406 ) (458 ) Tax credits (63 ) (62 ) (141 ) (23 ) Other 206 375 440 559 Actual Tax Expense $ 7,749 $ 7,961 $ 14,690 $ 14,572 Effective Tax Rate 15.9 % 16.7 % 15.5 % 16.0 %

Net Income Per Share (Tables)

Net Income Per Share (Tables)	6 Months Ended
	Jun. 30, 2019
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 and six months ended June 30, 2019 and 2018 . Three Months Ended June 30, 2019 2018 Net Income Weighted-Average Shares Per Share Net Income Weighted-Average Shares Per Share Net income available to common stockholders $ 41,056 49,432,167 $ 0.83 $ 39,634 49,252,580 $ 0.80 Effect of potentially dilutive stock options and restricted stock awards 117,720 198,826 Diluted net income per share $ 41,056 49,549,887 $ 0.83 $ 39,634 49,451,406 $ 0.80 Six Months Ended June 30, 2019 2018 Net Income Weighted-Average Shares Per Share Net Income Weighted-Average Shares Per Share Net income available to common stockholders $ 79,873 49,400,770 $ 1.62 $ 76,313 49,222,779 $ 1.55 Effect of potentially dilutive stock options and restricted stock awards 144,382 217,266 Diluted net income per share $ 79,873 49,545,152 $ 1.61 $ 76,313 49,440,045 $ 1.54

General (Details)

General (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Jan. 01, 2019
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Operating lease assets	$ 21,968
Operating lease liabilities	$ 22,603
ASU 2016-02
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Operating lease assets		$ 23,300
Operating lease liabilities		$ 23,800

Pending Merger (Details)

Pending Merger (Details) - USD ($) $ / shares in Units, $ in Thousands	Oct. 09, 2018	Jun. 30, 2019	Dec. 31, 2018
Business Acquisition [Line Items]
Share price (in dollars per share)	$ 45.71
Assets		$ 10,737,857	$ 9,884,716
MBT
Business Acquisition [Line Items]
Total purchase price	$ 290,900
Assets		$ 1,300,000

Investment Securities - Amortiz

Investment Securities - Amortized Cost and Approximate Fair Value of Securities (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Available for sale securities
Total Investment Securities	$ 1,360,946	$ 1,149,727
Gross Unrealized Gains	39,820	6,721
Gross Unrealized Losses	807	14,253
Investment securities available for sale	1,399,959	1,142,195
Held to maturity securities
Total Investment Securities	692,965	490,387
Gross Unrealized Gains	16,264	3,571
Gross Unrealized Losses	314	4,741
Fair Value	708,915	489,217
Amortized Cost	2,053,911	1,640,114
Gross Unrealized Gains	56,084	10,292
Gross Unrealized Losses	1,121	18,994
Fair Value	2,108,874	1,631,412
U.S. Government-sponsored agency securities
Available for sale securities
Total Investment Securities	33,494	13,493
Gross Unrealized Gains	453	92
Gross Unrealized Losses	0	3
Investment securities available for sale	33,947	13,582
Held to maturity securities
Total Investment Securities	33,865	22,618
Gross Unrealized Gains	20	0
Gross Unrealized Losses	66	545
Fair Value	33,819	22,073
State and municipal
Available for sale securities
Total Investment Securities	685,123	605,994
Gross Unrealized Gains	30,835	5,995
Gross Unrealized Losses	200	5,854
Investment securities available for sale	715,758	606,135
Held to maturity securities
Total Investment Securities	310,076	197,909
Gross Unrealized Gains	10,987	2,858
Gross Unrealized Losses	22	872
Fair Value	321,041	199,895
U.S. Government-sponsored mortgage-backed securities
Available for sale securities
Total Investment Securities	642,298	530,209
Gross Unrealized Gains	8,532	634
Gross Unrealized Losses	607	8,396
Investment securities available for sale	650,223	522,447
Held to maturity securities
Total Investment Securities	347,524	268,860
Gross Unrealized Gains	5,257	713
Gross Unrealized Losses	226	3,323
Fair Value	352,555	266,250
Corporate obligations
Available for sale securities
Total Investment Securities	31	31
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Investment securities available for sale	31	31
Foreign investment
Held to maturity securities
Total Investment Securities	1,500	1,000
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	1
Fair Value	$ 1,500	$ 999

Investment Securities - Amort_2

Investment Securities - Amortized Cost and Fair Value of Available for Sale Securities and Held to Maturity Securities by Contractual Maturity (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Amortized Cost
Due in one year or less	$ 1,131	$ 13,092
Due after one through five years	3,752	5,311
Due after five through ten years	74,311	73,280
Due after ten years	639,454	527,835
Total debt securities with a single maturity date	718,648	619,518
Total Investment Securities	1,360,946	1,149,727
Fair Value
Due in one year or less	1,138	13,144
Due after one through five years	3,851	5,378
Due after five through ten years	76,604	74,411
Due after ten years	668,143	526,815
Total debt securities with a single maturity date	749,736	619,748
Total Investment Securities	1,399,959	1,142,195
Amortized Cost
Due in one year or less	3,784	4,732
Due after one through five years	46,941	49,054
Due after five through ten years	78,716	62,873
Due after ten years	216,000	104,868
Total debt securities with a single maturity date	345,441	221,527
Total Investment Securities	692,965	490,387
Fair Value
Due in one year or less	3,782	4,730
Due after one through five years	46,914	48,473
Due after five through ten years	81,769	64,163
Due after ten years	223,895	105,601
Total debt securities with a single maturity date	356,360	222,967
Investment securities held to maturity	708,915	489,217
U.S. Government-sponsored mortgage-backed securities
Amortized Cost
Without single maturity date	642,298	530,209
Fair Value
Without single maturity date	650,223	522,447
Amortized Cost
Without single maturity date	347,524	268,860
Fair Value
Without single maturity date	$ 352,555	$ 266,250

Investment Securities - Narrati

Investment Securities - Narrative (Details) $ in Thousands	Jun. 30, 2019USD ($)security	Dec. 31, 2018USD ($)
Investments, Debt and Equity Securities [Abstract]
Carrying value of securities pledged as collateral	$ 483,230	$ 416,155
Book value of securities sold under agreements to repurchase	119,266	116,691
Schedule of Available for sale Securities and Held to maturity Securities [Line Items]
Gross Unrealized Losses	807	14,253
Held-to-maturity unrealized losses	314	$ 4,741
State and municipal
Schedule of Available for sale Securities and Held to maturity Securities [Line Items]
Gross Unrealized Losses	$ 200
Number of securities in unrealized loss positions | security	7
Held-to-maturity unrealized losses	$ 22
Held-to-maturity, number of securities in unrealized loss positions | security	2
U.S. Government-sponsored agency securities
Schedule of Available for sale Securities and Held to maturity Securities [Line Items]
Held-to-maturity unrealized losses	$ 66
Held-to-maturity, number of securities in unrealized loss positions | security	3
U.S. Government-sponsored mortgage-backed securities
Schedule of Available for sale Securities and Held to maturity Securities [Line Items]
Gross Unrealized Losses	$ 607
Number of securities in unrealized loss positions | security	29
Held-to-maturity unrealized losses	$ 226
Held-to-maturity, number of securities in unrealized loss positions | security	14

Investment Securities - Gross G

Investment Securities - Gross Gains on Sales and Redemptions of Available for Sale Securities (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Sales and Redemptions of Available for Sale Securities:
Gross gains	$ 1,843	$ 1,122	$ 2,983	$ 2,731
Gross losses	$ 0	$ 0	$ 0	$ 0

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	Jun. 30, 2019	Dec. 31, 2018
Fair Value
Less than 12 Months	$ 15,490	$ 432,522
12 Months or Longer	82,232	255,149
Total	97,722	687,671
Gross Unrealized Losses
Less than 12 Months	31	6,361
12 Months or Longer	776	7,892
Total	807	14,253
Fair Value
Less than 12 Months	6,495	117,780
12 Months or Longer	52,068	127,126
Total	58,563	244,906
Gross Unrealized Losses
Less than 12 Months	22	1,245
12 Months or Longer	292	3,496
Total	314	4,741
Less than 12 Months, Fair Value	21,985	550,302
12 Months or Longer, Fair Value	134,300	382,275
Total, Fair Value	156,285	932,577
Less than 12 Months, Gross Unrealized Losses	53	7,606
12 Months or Longer, Gross Unrealized Losses	1,068	11,388
Total, Gross Unrealized Losses	1,121	18,994
U.S. Government-sponsored agency securities
Fair Value
Less than 12 Months		1,490
12 Months or Longer		0
Total		1,490
Gross Unrealized Losses
Less than 12 Months		3
12 Months or Longer		0
Total		3
Fair Value
Less than 12 Months	0	0
12 Months or Longer	15,454	22,073
Total	15,454	22,073
Gross Unrealized Losses
Less than 12 Months	0	0
12 Months or Longer	66	545
Total	66	545
State and municipal
Fair Value
Less than 12 Months	7,699	234,431
12 Months or Longer	7,080	38,028
Total	14,779	272,459
Gross Unrealized Losses
Less than 12 Months	16	3,958
12 Months or Longer	184	1,896
Total	200	5,854
Fair Value
Less than 12 Months	6,421	14,952
12 Months or Longer	0	16,786
Total	6,421	31,738
Gross Unrealized Losses
Less than 12 Months	22	369
12 Months or Longer	0	503
Total	22	872
U.S. Government-sponsored mortgage-backed securities
Fair Value
Less than 12 Months	7,791	196,601
12 Months or Longer	75,152	217,121
Total	82,943	413,722
Gross Unrealized Losses
Less than 12 Months	15	2,400
12 Months or Longer	592	5,996
Total	607	8,396
Fair Value
Less than 12 Months	74	102,828
12 Months or Longer	36,614	87,268
Total	36,688	190,096
Gross Unrealized Losses
Less than 12 Months	0	876
12 Months or Longer	226	2,447
Total	$ 226	3,323
Foreign investment
Fair Value
Less than 12 Months		0
12 Months or Longer		999
Total		999
Gross Unrealized Losses
Less than 12 Months		0
12 Months or Longer		1
Total		$ 1

Investment Securities - Inves_2

Investment Securities - Investments in Debt and Equity Securities Reported Less than Historical Cost (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Schedule of Investments [Line Items]
Fair value	$ 156,285	$ 932,577
Investments reported at less than historical cost
Schedule of Investments [Line Items]
Historical cost	157,406	951,571
Fair value	156,285	932,577
Gross unrealized losses	$ 1,121	$ 18,994
Percent of the Corporation's investment portfolio	7.50%	57.10%

Loans and Allowance - Narrative

Loans and Allowance - Narrative (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Mar. 31, 2018	Dec. 31, 2017
Receivables [Abstract]
Loans held for sale	$ 5,854,000		$ 5,854,000		$ 4,778,000
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	7,511,370,000		7,511,370,000		7,224,467,000
Loans - allowance for loan losses	81,274,000	$ 77,543,000	81,274,000	$ 80,902,000	80,552,000	$ 76,420,000	$ 75,032,000
Residential
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	1,541,808,000		1,541,808,000		1,494,578,000
Loans - allowance for loan losses	$ 14,471,000	$ 14,424,000	$ 14,471,000	$ 14,373,000	14,322,000	$ 14,049,000	$ 13,537,000
Percentage of troubled debt restructured loans	100.00%	100.00%	100.00%
Mortgage loans with formal foreclosure proceedings	$ 777,000		$ 777,000		800,000
Loans acquired with deteriorated credit quality
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	14,083,000		14,083,000		15,784,000
Loans acquired with deteriorated credit quality | Commercial and consumer loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	1,824,000		1,824,000		1,541,000
Loans - allowance for loan losses	329,000		329,000		0
Loans acquired with deteriorated credit quality | Residential
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	$ 825,000		$ 825,000		$ 1,293,000

Loans and Allowance - Compositi

Loans and Allowance - Composition of Loan Portfolio by Loan Class (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	$ 7,511,370		$ 7,224,467
Allowance for loan losses	(81,274)	$ (80,902)	(80,552)	$ (77,543)	$ (76,420)	$ (75,032)
Net Loans	7,430,096		7,143,915
Commercial and industrial loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	1,877,042		1,726,664
Agricultural production financing and other loans to farmers
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	83,452		92,404
Construction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	624,548		545,729
Commercial and farmland
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	2,821,689		2,832,102
Residential
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	993,802		966,421
Allowance for loan losses	(14,471)	(14,373)	(14,322)	(14,424)	(14,049)	(13,537)
Home equity
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	548,006		528,157
Individuals' loans for household and other personal expenditures
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	98,384		99,788
Allowance for loan losses	(4,070)	$ (4,026)	(3,964)	$ (3,921)	$ (3,896)	$ (3,732)
Public finance and other commercial loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	$ 464,447		$ 433,202

Loans and Allowance - Changes i

Loans and Allowance - Changes in Allowance for Loan Losses by Loan Segment (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Allowance for loan losses:
Beginning balance	$ 80,902	$ 76,420	$ 80,552	$ 75,032
Provision for losses	500	1,663	1,700	4,163
Recoveries on loans	1,434	3,190	2,439	3,891
Loans charged off	(1,562)	(3,730)	(3,417)	(5,543)
Ending balance	81,274	77,543	81,274	77,543
Commercial
Allowance for loan losses:
Beginning balance	33,069	30,770	32,657	30,420
Provision for losses	100	471	336	1,311
Recoveries on loans	344	1,283	886	1,402
Loans charged off	(311)	(1,057)	(677)	(1,666)
Ending balance	33,202	31,467	33,202	31,467
Commercial Real Estate
Allowance for loan losses:
Beginning balance	29,434	27,705	29,609	27,343
Provision for losses	320	954	1,089	1,038
Recoveries on loans	778	1,213	1,023	1,552
Loans charged off	(1,001)	(2,141)	(2,190)	(2,202)
Ending balance	29,531	27,731	29,531	27,731
Consumer
Allowance for loan losses:
Beginning balance	4,026	3,896	3,964	3,732
Provision for losses	36	60	141	334
Recoveries on loans	100	98	218	187
Loans charged off	(92)	(133)	(253)	(332)
Ending balance	4,070	3,921	4,070	3,921
Residential
Allowance for loan losses:
Beginning balance	14,373	14,049	14,322	13,537
Provision for losses	44	178	134	1,480
Recoveries on loans	212	596	312	750
Loans charged off	(158)	(399)	(297)	(1,343)
Ending balance	$ 14,471	$ 14,424	$ 14,471	$ 14,424

Loans and Allowance - Allowance

Loans and Allowance - Allowance for Credit Losses and Loan Portfolio by Loan Segment (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017
Allowance Balances:
Individually evaluated for impairment	$ 2,296		$ 1,872
Collectively evaluated for impairment	78,978		78,680
Total Allowance for Loan Losses	81,274	$ 80,902	80,552	$ 77,543	$ 76,420	$ 75,032
Loan Balance [Abstract]
Individually evaluated for impairment	21,973		22,025
Collectively evaluated for impairment	7,475,314		7,186,658
Loans	7,511,370		7,224,467
Loans acquired with deteriorated credit quality
Loan Balance [Abstract]
Loans	14,083		15,784
Commercial
Allowance Balances:
Individually evaluated for impairment	1,849		0
Collectively evaluated for impairment	31,353		32,657
Total Allowance for Loan Losses	33,202	33,069	32,657	31,467	30,770	30,420
Loan Balance [Abstract]
Individually evaluated for impairment	5,090		1,838
Collectively evaluated for impairment	2,418,481		2,248,330
Loans	2,424,941		2,252,270
Commercial | Loans acquired with deteriorated credit quality
Loan Balance [Abstract]
Loans	1,370		2,102
Commercial Real Estate
Allowance Balances:
Individually evaluated for impairment	14		1,435
Collectively evaluated for impairment	29,517		28,174
Total Allowance for Loan Losses	29,531	29,434	29,609	27,731	27,705	27,343
Loan Balance [Abstract]
Individually evaluated for impairment	14,419		17,756
Collectively evaluated for impairment	3,419,930		3,347,686
Loans	3,446,237		3,377,831
Commercial Real Estate | Loans acquired with deteriorated credit quality
Loan Balance [Abstract]
Loans	11,888		12,389
Consumer
Allowance Balances:
Individually evaluated for impairment	1		1
Collectively evaluated for impairment	4,069		3,963
Total Allowance for Loan Losses	4,070	4,026	3,964	3,921	3,896	3,732
Loan Balance [Abstract]
Individually evaluated for impairment	14		18
Collectively evaluated for impairment	98,370		99,770
Loans	98,384		99,788
Residential
Allowance Balances:
Individually evaluated for impairment	432		436
Collectively evaluated for impairment	14,039		13,886
Total Allowance for Loan Losses	14,471	$ 14,373	14,322	$ 14,424	$ 14,049	$ 13,537
Loan Balance [Abstract]
Individually evaluated for impairment	2,450		2,413
Collectively evaluated for impairment	1,538,533		1,490,872
Loans	1,541,808		1,494,578
Residential | Loans acquired with deteriorated credit quality
Loan Balance [Abstract]
Loans	$ 825		$ 1,293

Loans and Allowance - Summary o

Loans and Allowance - Summary of Non-Accrual Loans by Loan Class (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-accrual loans	$ 25,635	$ 26,148
Commercial and industrial loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-accrual loans	2,770	1,803
Agricultural production financing and other loans to farmers
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-accrual loans	2,785	679
Construction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-accrual loans	6,918	8,667
Commercial and farmland
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-accrual loans	6,340	8,156
Residential
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-accrual loans	4,579	4,966
Home equity
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-accrual loans	1,826	1,481
Individuals' loans for household and other personal expenditures
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-accrual loans	64	42
Public finance and other commercial loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-accrual loans	$ 353	$ 354

Loans and Allowance - Composi_2

Loans and Allowance - Composition of Impaired Loans by Loan Class (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018	Dec. 31, 2018
Unpaid Principal Balance
Impaired loans with no related allowance	$ 20,384		$ 20,384		$ 14,555
Impaired loans with related allowance	5,842		5,842		10,501
Total Impaired Loans	26,226		26,226		25,056
Recorded Investment
Impaired loans with no related allowance	16,471		16,471		11,594
Impaired loans with related allowance	5,502		5,502		10,431
Total Impaired Loans	21,973		21,973		22,025
Related Allowance	2,296		2,296		1,872
Average Recorded Investment
Impaired loans with no related allowance	17,433	$ 12,758	18,112	$ 13,128
Impaired loans with related allowance	5,600	2,124	5,634	2,137
Total Impaired Loans	23,033	14,882	23,746	15,265
Interest Income Recognized
Impaired loans with no related allowance	40	41	80	89
Impaired loans with related allowance	19	14	38	29
Total Impaired Loans	59	55	118	118
Commercial and industrial loans
Unpaid Principal Balance
Impaired loans with no related allowance	1,048		1,048		828
Impaired loans with related allowance	1,185		1,185
Recorded Investment
Impaired loans with no related allowance	1,012		1,012		806
Impaired loans with related allowance	940		940
Related Allowance	455		455
Average Recorded Investment
Impaired loans with no related allowance	1,013	1,004	1,021	1,006
Impaired loans with related allowance	940	108	940	108
Interest Income Recognized
Impaired loans with no related allowance	0	0	0	0
Impaired loans with related allowance	0		0	0
Agricultural production financing and other loans to farmers
Unpaid Principal Balance
Impaired loans with no related allowance	679		679		679
Impaired loans with related allowance	2,167		2,167
Recorded Investment
Impaired loans with no related allowance	668		668		679
Impaired loans with related allowance	2,117		2,117
Related Allowance	1,394		1,394
Average Recorded Investment
Impaired loans with no related allowance	668	640	672	640
Impaired loans with related allowance	2,117		2,134
Interest Income Recognized
Impaired loans with no related allowance	0	0	0	0
Impaired loans with related allowance	0		0
Construction
Unpaid Principal Balance
Impaired loans with no related allowance	7,978		7,978		1,352
Impaired loans with related allowance					7,978
Recorded Investment
Impaired loans with no related allowance	6,909		6,909		614
Impaired loans with related allowance					7,977
Related Allowance					1,429
Average Recorded Investment
Impaired loans with no related allowance	7,314	1,106	7,792	1,167
Interest Income Recognized
Impaired loans with no related allowance	0	0	0	0
Commercial and farmland
Unpaid Principal Balance
Impaired loans with no related allowance	10,160		10,160		11,176
Impaired loans with related allowance	134		134		171
Recorded Investment
Impaired loans with no related allowance	7,381		7,381		8,994
Impaired loans with related allowance	129		129		171
Related Allowance	14		14		6
Average Recorded Investment
Impaired loans with no related allowance	7,998	9,935	8,187	10,241
Impaired loans with related allowance	157		164
Interest Income Recognized
Impaired loans with no related allowance	39	40	78	87
Residential
Unpaid Principal Balance
Impaired loans with no related allowance	117		117		118
Impaired loans with related allowance	1,976		1,976		1,958
Recorded Investment
Impaired loans with no related allowance	99		99		100
Impaired loans with related allowance	1,953		1,953		1,907
Related Allowance	362		362		362
Average Recorded Investment
Impaired loans with no related allowance	38	63	38	63
Impaired loans with related allowance	2,021	1,714	2,029	1,726
Interest Income Recognized
Impaired loans with no related allowance	1	1	2	2
Impaired loans with related allowance	16	12	32	24
Home equity
Unpaid Principal Balance
Impaired loans with no related allowance	49		49		49
Impaired loans with related allowance	366		366		376
Recorded Investment
Impaired loans with no related allowance	49		49		48
Impaired loans with related allowance	349		349		358
Related Allowance	70		70		74
Average Recorded Investment
Impaired loans with no related allowance	49		49
Impaired loans with related allowance	351	302	352	303
Interest Income Recognized
Impaired loans with no related allowance			0
Impaired loans with related allowance	3	2	6	5
Individuals' loans for household and other personal expenditures
Unpaid Principal Balance
Impaired loans with related allowance	14		14		18
Recorded Investment
Impaired loans with related allowance	14		14		18
Related Allowance	1		1		1
Average Recorded Investment
Impaired loans with no related allowance		10		11
Impaired loans with related allowance	14		15
Interest Income Recognized
Impaired loans with no related allowance		0		0
Impaired loans with related allowance			0
Public finance and other commercial loans
Unpaid Principal Balance
Impaired loans with no related allowance	353		353		353
Recorded Investment
Impaired loans with no related allowance	353		353		$ 353
Average Recorded Investment
Impaired loans with no related allowance	$ 353	0	353	0
Interest Income Recognized
Impaired loans with no related allowance		$ 0	$ 0	$ 0

Loans and Allowance - Credit Qu

Loans and Allowance - Credit Quality of Loan Portfolio by Loan Class (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	$ 7,511,370	$ 7,224,467
Commercial and industrial loans
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	1,877,042	1,726,664
Agricultural production financing and other loans to farmers
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	83,452	92,404
Construction
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	624,548	545,729
Commercial and farmland
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	2,821,689	2,832,102
Residential
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	993,802	966,421
Home equity
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	548,006	528,157
Individuals' loans for household and other personal expenditures
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	98,384	99,788
Public finance and other commercial loans
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	464,447	433,202
Commercial Pass
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	5,734,217	5,528,751
Commercial Pass | Commercial and industrial loans
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	1,781,040	1,660,879
Commercial Pass | Agricultural production financing and other loans to farmers
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	67,837	78,446
Commercial Pass | Construction
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	591,962	492,358
Commercial Pass | Commercial and farmland
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	2,645,338	2,669,491
Commercial Pass | Residential
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	156,622	170,075
Commercial Pass | Home equity
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	27,324	24,653
Commercial Pass | Individuals' loans for household and other personal expenditures
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	0	0
Commercial Pass | Public finance and other commercial loans
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	464,094	432,849
Commercial Special Mention
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	146,333	115,342
Commercial Special Mention | Commercial and industrial loans
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	53,407	23,246
Commercial Special Mention | Agricultural production financing and other loans to farmers
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	5,478	5,966
Commercial Special Mention | Construction
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	1,444	2,185
Commercial Special Mention | Commercial and farmland
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	79,586	76,037
Commercial Special Mention | Residential
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	5,833	7,373
Commercial Special Mention | Home equity
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	585	535
Commercial Special Mention | Individuals' loans for household and other personal expenditures
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	0	0
Commercial Special Mention | Public finance and other commercial loans
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	0	0
Commercial Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	158,830	161,929
Commercial Substandard | Commercial and industrial loans
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	42,266	42,539
Commercial Substandard | Agricultural production financing and other loans to farmers
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	10,137	7,992
Commercial Substandard | Construction
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	7,712	24,224
Commercial Substandard | Commercial and farmland
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	94,179	84,288
Commercial Substandard | Residential
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	3,425	2,076
Commercial Substandard | Home equity
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	758	457
Commercial Substandard | Individuals' loans for household and other personal expenditures
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	0	0
Commercial Substandard | Public finance and other commercial loans
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	353	353
Commercial Doubtful
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	779	0
Commercial Doubtful | Commercial and industrial loans
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	329	0
Commercial Doubtful | Agricultural production financing and other loans to farmers
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	0	0
Commercial Doubtful | Construction
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	0	0
Commercial Doubtful | Commercial and farmland
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	450	0
Commercial Doubtful | Residential
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	0	0
Commercial Doubtful | Home equity
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	0	0
Commercial Doubtful | Individuals' loans for household and other personal expenditures
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	0	0
Commercial Doubtful | Public finance and other commercial loans
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	0	0
Commercial Loss
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	0	0
Commercial Loss | Commercial and industrial loans
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	0	0
Commercial Loss | Agricultural production financing and other loans to farmers
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	0	0
Commercial Loss | Construction
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	0	0
Commercial Loss | Commercial and farmland
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	0	0
Commercial Loss | Residential
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	0	0
Commercial Loss | Home equity
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	0	0
Commercial Loss | Individuals' loans for household and other personal expenditures
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	0	0
Commercial Loss | Public finance and other commercial loans
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	0	0
Consumer Performing
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	1,464,815	1,410,521
Consumer Performing | Commercial and industrial loans
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	0	0
Consumer Performing | Agricultural production financing and other loans to farmers
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	0	0
Consumer Performing | Construction
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	23,430	25,419
Consumer Performing | Commercial and farmland
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	2,136	2,285
Consumer Performing | Residential
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	823,309	782,080
Consumer Performing | Home equity
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	517,620	500,996
Consumer Performing | Individuals' loans for household and other personal expenditures
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	98,320	99,741
Consumer Performing | Public finance and other commercial loans
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	0	0
Consumer Non-Performing
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	6,396	7,924
Consumer Non-Performing | Commercial and industrial loans
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	0	0
Consumer Non-Performing | Agricultural production financing and other loans to farmers
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	0	0
Consumer Non-Performing | Construction
Financing Receivable, Credit Quality Indicator [Line Items]
Loans		1,543
Consumer Non-Performing | Commercial and farmland
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	0	1
Consumer Non-Performing | Residential
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	4,613	4,817
Consumer Non-Performing | Home equity
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	1,719	1,516
Consumer Non-Performing | Individuals' loans for household and other personal expenditures
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	64	47
Consumer Non-Performing | Public finance and other commercial loans
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	$ 0	$ 0

Loans and Allowance - Past Due

Loans and Allowance - Past Due Aging of Loan Portfolio by Loan Class (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Financing Receivable, Past Due [Line Items]
Current	$ 7,470,923	$ 7,186,609
Non-Accrual	25,635	26,148
Total Past Due & Non-Accrual	40,447	37,858
Total	7,511,370	7,224,467
Commercial and industrial loans
Financing Receivable, Past Due [Line Items]
Current	1,874,004	1,723,337
Non-Accrual	2,770	1,803
Total Past Due & Non-Accrual	3,038	3,327
Total	1,877,042	1,726,664
Agricultural production financing and other loans to farmers
Financing Receivable, Past Due [Line Items]
Current	80,634	89,440
Non-Accrual	2,785	679
Total Past Due & Non-Accrual	2,818	2,964
Total	83,452	92,404
Construction
Financing Receivable, Past Due [Line Items]
Current	617,519	535,520
Non-Accrual	6,918	8,667
Total Past Due & Non-Accrual	7,029	10,209
Total	624,548	545,729
Commercial and farmland
Financing Receivable, Past Due [Line Items]
Current	2,808,422	2,822,515
Non-Accrual	6,340	8,156
Total Past Due & Non-Accrual	13,267	9,587
Total	2,821,689	2,832,102
Residential
Financing Receivable, Past Due [Line Items]
Current	984,086	959,252
Non-Accrual	4,579	4,966
Total Past Due & Non-Accrual	9,716	7,169
Total	993,802	966,421
Home equity
Financing Receivable, Past Due [Line Items]
Current	544,338	524,198
Non-Accrual	1,826	1,481
Total Past Due & Non-Accrual	3,668	3,959
Total	548,006	528,157
Individuals' loans for household and other personal expenditures
Financing Receivable, Past Due [Line Items]
Current	97,826	99,499
Non-Accrual	64	42
Total Past Due & Non-Accrual	558	289
Total	98,384	99,788
Public finance and other commercial loans
Financing Receivable, Past Due [Line Items]
Current	464,094	432,848
Non-Accrual	353	354
Total Past Due & Non-Accrual	353	354
Total	464,447	433,202
30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Past Due	13,398	8,794
30-59 Days Past Due | Commercial and industrial loans
Financing Receivable, Past Due [Line Items]
Past Due	248	1,093
30-59 Days Past Due | Agricultural production financing and other loans to farmers
Financing Receivable, Past Due [Line Items]
Past Due	33	2,285
30-59 Days Past Due | Construction
Financing Receivable, Past Due [Line Items]
Past Due	111	64
30-59 Days Past Due | Commercial and farmland
Financing Receivable, Past Due [Line Items]
Past Due	6,751	1,253
30-59 Days Past Due | Residential
Financing Receivable, Past Due [Line Items]
Past Due	4,540	1,756
30-59 Days Past Due | Home equity
Financing Receivable, Past Due [Line Items]
Past Due	1,308	2,164
30-59 Days Past Due | Individuals' loans for household and other personal expenditures
Financing Receivable, Past Due [Line Items]
Past Due	407	179
30-59 Days Past Due | Public finance and other commercial loans
Financing Receivable, Past Due [Line Items]
Past Due	0	0
60-89 Days Past Due
Financing Receivable, Past Due [Line Items]
Past Due	1,205	1,061
60-89 Days Past Due | Commercial and industrial loans
Financing Receivable, Past Due [Line Items]
Past Due	20	182
60-89 Days Past Due | Agricultural production financing and other loans to farmers
Financing Receivable, Past Due [Line Items]
Past Due	0	0
60-89 Days Past Due | Construction
Financing Receivable, Past Due [Line Items]
Past Due	0	0
60-89 Days Past Due | Commercial and farmland
Financing Receivable, Past Due [Line Items]
Past Due	176	178
60-89 Days Past Due | Residential
Financing Receivable, Past Due [Line Items]
Past Due	422	430
60-89 Days Past Due | Home equity
Financing Receivable, Past Due [Line Items]
Past Due	500	207
60-89 Days Past Due | Individuals' loans for household and other personal expenditures
Financing Receivable, Past Due [Line Items]
Past Due	87	64
60-89 Days Past Due | Public finance and other commercial loans
Financing Receivable, Past Due [Line Items]
Past Due	0	0
Loans 90 Days or More Past Due And Accruing
Financing Receivable, Past Due [Line Items]
Past Due	209	1,855
Loans 90 Days or More Past Due And Accruing | Commercial and industrial loans
Financing Receivable, Past Due [Line Items]
Past Due	0	249
Loans 90 Days or More Past Due And Accruing | Agricultural production financing and other loans to farmers
Financing Receivable, Past Due [Line Items]
Past Due	0	0
Loans 90 Days or More Past Due And Accruing | Construction
Financing Receivable, Past Due [Line Items]
Past Due	0	1,478
Loans 90 Days or More Past Due And Accruing | Commercial and farmland
Financing Receivable, Past Due [Line Items]
Past Due	0	0
Loans 90 Days or More Past Due And Accruing | Residential
Financing Receivable, Past Due [Line Items]
Past Due	175	17
Loans 90 Days or More Past Due And Accruing | Home equity
Financing Receivable, Past Due [Line Items]
Past Due	34	107
Loans 90 Days or More Past Due And Accruing | Individuals' loans for household and other personal expenditures
Financing Receivable, Past Due [Line Items]
Past Due	0	4
Loans 90 Days or More Past Due And Accruing | Public finance and other commercial loans
Financing Receivable, Past Due [Line Items]
Past Due	$ 0	$ 0

Loans and Allowance - Summary_2

Loans and Allowance - Summary of Troubled Debt Restructurings (Details) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019USD ($)loan	Jun. 30, 2018USD ($)loan	Jun. 30, 2019USD ($)loan	Jun. 30, 2018USD ($)loan
Financing Receivable, Troubled Debt Restructuring [Line Items]
Pre-Modification Recorded Balance	$ 171	$ 122	$ 261	$ 359
Post-Modification Recorded Balance	$ 164	$ 125	$ 254	$ 371
Number of Loans | loan	4	2	5	10
Residential
Financing Receivable, Troubled Debt Restructuring [Line Items]
Pre-Modification Recorded Balance	$ 171	$ 122	$ 261	$ 336
Post-Modification Recorded Balance	$ 164	$ 125	$ 254	$ 347
Number of Loans | loan	4	2	5	7
Home equity
Financing Receivable, Troubled Debt Restructuring [Line Items]
Pre-Modification Recorded Balance		$ 0		$ 16
Post-Modification Recorded Balance		$ 0		$ 16
Number of Loans | loan		0		2
Individuals' loans for household and other personal expenditures
Financing Receivable, Troubled Debt Restructuring [Line Items]
Pre-Modification Recorded Balance				$ 7
Post-Modification Recorded Balance				$ 8
Number of Loans | loan				1

Loans and Allowance - Summary_3

Loans and Allowance - Summary of Troubled Debt Restructurings by Modification Type (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Financing Receivable, Troubled Debt Restructuring [Line Items]
Modification	$ 164	$ 125	$ 253	$ 416
Term Modification
Financing Receivable, Troubled Debt Restructuring [Line Items]
Modification	0		0	97
Rate Modification
Financing Receivable, Troubled Debt Restructuring [Line Items]
Modification	0	91	89	180
Combination
Financing Receivable, Troubled Debt Restructuring [Line Items]
Modification	164	34	164	139
Residential
Financing Receivable, Troubled Debt Restructuring [Line Items]
Modification	164	125	253	339
Residential | Term Modification
Financing Receivable, Troubled Debt Restructuring [Line Items]
Modification			0	37
Residential | Rate Modification
Financing Receivable, Troubled Debt Restructuring [Line Items]
Modification	0	91	89	163
Residential | Combination
Financing Receivable, Troubled Debt Restructuring [Line Items]
Modification	$ 164	$ 34	$ 164	139
Home equity
Financing Receivable, Troubled Debt Restructuring [Line Items]
Modification				70
Home equity | Term Modification
Financing Receivable, Troubled Debt Restructuring [Line Items]
Modification				60
Home equity | Rate Modification
Financing Receivable, Troubled Debt Restructuring [Line Items]
Modification				10
Home equity | Combination
Financing Receivable, Troubled Debt Restructuring [Line Items]
Modification				0
Individuals' loans for household and other personal expenditures
Financing Receivable, Troubled Debt Restructuring [Line Items]
Modification				7
Individuals' loans for household and other personal expenditures | Term Modification
Financing Receivable, Troubled Debt Restructuring [Line Items]
Modification				0
Individuals' loans for household and other personal expenditures | Rate Modification
Financing Receivable, Troubled Debt Restructuring [Line Items]
Modification				7
Individuals' loans for household and other personal expenditures | Combination
Financing Receivable, Troubled Debt Restructuring [Line Items]
Modification				$ 0

Loans and Allowance - Subsequen

Loans and Allowance - Subsequent Default (Details) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019USD ($)loan	Jun. 30, 2018USD ($)loan	Jun. 30, 2019USD ($)loan	Jun. 30, 2018USD ($)loan
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Loans | loan	1	2	1	4
Recorded Balance | $	$ 62	$ 132	$ 62	$ 462
Commercial and farmland
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Loans | loan		0		1
Recorded Balance | $		$ 0		$ 272
Residential
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Loans | loan	1	2	1	3
Recorded Balance | $	$ 62	$ 132	$ 62	$ 190

Purchased Credit Impaired Loa_3

Purchased Credit Impaired Loans - Accretable Yield or Income Expected to be Collected (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018	Dec. 31, 2018
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Accretable Yield Movement Schedule [Roll Forward]
Accretable yield beginning balance	$ 2,064	$ 2,675	$ 2,143	$ 2,890
Additions	0	0	0	0
Accretion	(638)	(927)	(1,218)	(1,437)
Reclassification from nonaccretable	488	675	989	970
Disposals	0	0	0	0
Accretable yield ending balance	1,914	$ 2,423	1,914	$ 2,423
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	$ 15,900		$ 15,900		$ 17,300

Other Intangibles - Narrative (

Other Intangibles - Narrative (Details)	6 Months Ended
	Jun. 30, 2019
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

Other Intangibles - Schedule of

Other Intangibles - Schedule of Core Deposit and Other Intangibles (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Goodwill and Intangible Assets Disclosure [Abstract]
Gross carrying amount	$ 85,869	$ 85,869
Accumulated amortization	(64,488)	(61,440)
Total other intangibles	$ 21,381	$ 24,429

Other Intangibles - Estimated F

Other Intangibles - Estimated Future Amortization Expense (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Amortization Expense
2019	$ 2,121
2020	3,632
2021	3,427
2022	3,325
2023	3,175
After 2023	5,701
Total other intangibles	$ 21,381	$ 24,429

Leases - Supplemental Balance S

Leases - Supplemental Balance Sheet Information (Details) $ in Thousands	Jun. 30, 2019USD ($)
Leases [Abstract]
Operating lease assets	$ 21,968
Operating lease liabilities	$ 22,603
Weighted average remaining lease term (years)	9 years 6 months
Weighted average discount rate	3.40%

Leases - Components of Lease Ex

Leases - Components of Lease Expense (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2019
Lease Cost:
Operating lease cost	$ 911	$ 1,806
Short-term lease cost	30	73
Variable lease cost	253	511
Total lease cost	$ 1,194	$ 2,390

Leases - Supplemental Cash Flow

Leases - Supplemental Cash Flow Information (Details) $ in Thousands	6 Months Ended
	Jun. 30, 2019USD ($)
Maturity of lease liabilities
Remaining 2019	$ 1,774
2020	3,388
2021	3,114
2022	2,999
2023	2,628
2024 and after	12,771
Total lease payments	26,674
Less: Present value discount	4,071
Present value of lease liabilities	22,603
Other Information
Operating cash flows from operating leases	1,634
ROU assets obtained in exchange for new operating lease liabilities	$ 23,384

Derivative Financial Instrume_3

Derivative Financial Instruments - Narrative (Details) $ in Thousands	6 Months Ended
	Jun. 30, 2019USD ($)interest_rate_swapinterest_rate_capinstrument	Dec. 31, 2018USD ($)interest_rate_swapinterest_rate_cap
Derivative [Line Items]
Estimated amount to be transferred from accumulated other comprehensive income to earnings	$ 438
Termination value of derivatives in a net liability position	26,045
Derivative collateral posted	28,405
Not Designated as Hedging Instrument
Derivative [Line Items]
Notional amount of interest rate derivatives	$ 548,951
Federal Home Loan Bank Advances
Derivative [Line Items]
Number of debt instruments held | instrument	2
Interest rate contracts | Not Designated as Hedging Instrument
Derivative [Line Items]
Increase in derivative assets	$ 13,100
Increase in derivative liabilities	14,000
Increase in outstanding notional balance	$ 71,200
Cash Flow Hedging | Interest Rate Swap
Derivative [Line Items]
Number of interest rate derivatives held | interest_rate_swap	4	4
Notional amount of interest rate derivatives	$ 46,000	$ 46,000
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	$ 20,000
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 Instrume_4

Derivative Financial Instruments - Fair Value of Derivative Financial Instruments and Their Classification on Balance Sheet (Details) - Interest rate contracts - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Derivatives designated as hedging instruments | Other Assets
Derivatives, Fair Value [Line Items]
Asset Derivatives	$ 0	$ 135
Derivatives designated as hedging instruments | Other Liabilities
Derivatives, Fair Value [Line Items]
Liability Derivatives	1,609	688
Derivatives not designated as hedging instruments | Other Assets
Derivatives, Fair Value [Line Items]
Asset Derivatives	25,059	11,948
Derivatives not designated as hedging instruments | Other Liabilities
Derivatives, Fair Value [Line Items]
Liability Derivatives	$ 25,059	$ 11,948

Derivative Financial Instrume_5

Derivative Financial Instruments - Effect of Derivative Financial Instruments on Other Comprehensive Income (Details) - Designated as Hedging Instrument - Cash Flow Hedging - Interest Rate Products - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Derivative [Line Items]
Amount of Gain (Loss) Recognized in Other Comprehensive Income on Derivative (Effective Portion)	$ (701)		$ (1,092)
Amount of Gain (Loss) Recognized in Other Comprehensive Income on Derivative (Effective Portion)		$ 291		$ 799

Derivative Financial Instrume_6

Derivative Financial Instruments - Effect of Derivative Financial Instruments on Income Statement (Details) - Interest rate contracts - Derivatives designated as hedging instruments - Interest Expense - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Derivative [Line Items]
Amount of Gain (Loss) Reclassified from Other Comprehensive Income into Income (Effective Portion)	$ (84)		$ (143)
Amount of Gain (Loss) Reclassed from Other Comprehensive Income into Income (Effective Portion)		$ (105)		$ (275)

Disclosures About Fair Value _3

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	Jun. 30, 2019	Dec. 31, 2018
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investment securities available for sale	$ 1,399,959	$ 1,142,195
Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investment securities available for sale	0	0
Significant Other Observable Inputs (Level 2)
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investment securities available for sale	1,396,984	1,138,867
Significant Unobservable Inputs (Level 3)
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investment securities available for sale	2,975	3,328
Fair Value, Measurements, Recurring | Interest rate swap liability | Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Interest rate swap liability	0	0
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	26,668	12,636
Fair Value, Measurements, Recurring | Interest rate swap liability | Significant Unobservable Inputs (Level 3)
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Interest rate swap liability	0	0
Fair Value, Measurements, Recurring | Fair Value | Interest rate swap liability
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Interest rate swap liability	26,668	12,636
U.S. Government-sponsored agency securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investment securities available for sale	33,947	13,582
U.S. Government-sponsored agency securities | Fair Value, Measurements, Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investment securities available for sale	0	0
U.S. Government-sponsored agency securities | Fair Value, Measurements, Recurring | Significant Other Observable Inputs (Level 2)
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investment securities available for sale	33,947	13,582
U.S. Government-sponsored agency securities | Fair Value, Measurements, Recurring | Significant Unobservable Inputs (Level 3)
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investment securities available for sale	0	0
U.S. Government-sponsored agency securities | Fair Value, Measurements, Recurring | Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investment securities available for sale	33,947	13,582
State and municipal
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investment securities available for sale	715,758	606,135
State and municipal | Fair Value, Measurements, Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investment securities available for sale	0	0
State and municipal | Fair Value, Measurements, Recurring | Significant Other Observable Inputs (Level 2)
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investment securities available for sale	712,818	602,842
State and municipal | Fair Value, Measurements, Recurring | Significant Unobservable Inputs (Level 3)
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investment securities available for sale	2,940	3,293
State and municipal | Fair Value, Measurements, Recurring | Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investment securities available for sale	715,758	606,135
U.S. Government-sponsored mortgage-backed securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investment securities available for sale	650,223	522,447
U.S. Government-sponsored mortgage-backed securities | Fair Value, Measurements, Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investment securities available for sale	0	0
U.S. Government-sponsored mortgage-backed securities | Fair Value, Measurements, Recurring | Significant Other Observable Inputs (Level 2)
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investment securities available for sale	650,219	522,443
U.S. Government-sponsored mortgage-backed securities | Fair Value, Measurements, Recurring | Significant Unobservable Inputs (Level 3)
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investment securities available for sale	4	4
U.S. Government-sponsored mortgage-backed securities | Fair Value, Measurements, Recurring | Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investment securities available for sale	650,223	522,447
Corporate obligations
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investment securities available for sale	31	31
Corporate obligations | Fair Value, Measurements, Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investment securities available for sale	0	0
Corporate obligations | Fair Value, Measurements, Recurring | Significant Other Observable Inputs (Level 2)
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investment securities available for sale	0	0
Corporate obligations | Fair Value, Measurements, Recurring | Significant Unobservable Inputs (Level 3)
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investment securities available for sale	31	31
Corporate obligations | Fair Value, Measurements, Recurring | Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investment securities available for sale	31	31
Interest rate swap asset | Fair Value, Measurements, Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Interest rate derivatives	0	0
Interest rate swap asset | Fair Value, Measurements, Recurring | Significant Other Observable Inputs (Level 2)
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Interest rate derivatives	25,059	12,083
Interest rate swap asset | Fair Value, Measurements, Recurring | Significant Unobservable Inputs (Level 3)
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Interest rate derivatives	0	0
Interest rate swap asset | Fair Value, Measurements, Recurring | Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Interest rate derivatives	$ 25,059	$ 12,083

Disclosures About Fair Value _4

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		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Available for Sale Securities
Balance at beginning of the period	$ 2,936	$ 3,966	$ 3,328	$ 3,978
Included in other comprehensive income	37	1	80	(24)
Principal payments	2	3	(433)	16
Ending balance	$ 2,975	$ 3,970	$ 2,975	$ 3,970

Disclosures About Fair Value _5

Disclosures About Fair Value of Assets and Liabilities - Transfers Between Levels (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Fair Value Disclosures [Abstract]
Transfers in or out of Level 3	$ 0	$ 0	$ 0	$ 0

Disclosures About Fair Value _6

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	Jun. 30, 2019	Dec. 31, 2018
Impaired loans (collateral dependent)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	$ 12,966	$ 11,866
Impaired loans (collateral dependent) | Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	0	0
Impaired loans (collateral dependent) | Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	0	0
Impaired loans (collateral dependent) | Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	12,966	11,866
Other real estate owned
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	174	657
Other real estate owned | Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	0	0
Other real estate owned | Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	0	0
Other real estate owned | Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	$ 174	$ 657

Disclosures About Fair Value _7

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) $ in Thousands	6 Months Ended	12 Months Ended
	Jun. 30, 2019USD ($)	Dec. 31, 2018USD ($)
State and municipal securities | Discounted cash flow
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Fair Value	$ 2,940	$ 3,293
State and municipal securities | Discounted cash flow | Minimum
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Maturity/Call date	1 month	1 month
US Muni BQ curve	A-	A-
State and municipal securities | Discounted cash flow | Maximum
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Maturity/Call date	15 years	20 years
US Muni BQ curve	BBB-	BBB-
Corporate obligations and U.S. Government-sponsored mortgage backed securities | Discounted cash flow
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Fair Value	$ 35
Corporate obligations and equity securities | Discounted cash flow
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Fair Value		$ 35
Impaired loans (collateral dependent) | Collateral based measurements
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Fair Value	12,966	11,866
Other real estate owned | Appraisals
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Fair Value	$ 174	$ 657
Discount rate | State and municipal securities | Discounted cash flow | Minimum
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Discount rate	0.02	0.0069
Discount rate | State and municipal securities | Discounted cash flow | Maximum
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Discount rate	0.05	0.05
Risk free rate | Corporate obligations and U.S. Government-sponsored mortgage backed securities | Discounted cash flow
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Risk free rate	3 month LIBOR
Risk free rate | Corporate obligations and equity securities | Discounted cash flow
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Risk free rate		3 month LIBOR
Discount to reflect current market conditions | Corporate obligations and U.S. Government-sponsored mortgage backed securities | Discounted cash flow
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Discount rate	0.0200
Discount to reflect current market conditions | Corporate obligations and equity securities | Discounted cash flow
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Discount rate		0.0200
Discount to reflect current market conditions and ultimate collectability | Impaired loans (collateral dependent) | Collateral based measurements | Minimum
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Discount to reflect current market conditions and ultimate collectability	0	0
Discount to reflect current market conditions and ultimate collectability | Impaired loans (collateral dependent) | Collateral based measurements | Maximum
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Discount to reflect current market conditions and ultimate collectability	0.10	0.10
Discount to reflect current market conditions and ultimate collectability | Impaired loans (collateral dependent) | Collateral based measurements | Weighted Average
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Discount to reflect current market conditions and ultimate collectability	0.04	0.06
Discount to reflect current market conditions | Other real estate owned | Appraisals | Minimum
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Other real estate owned	0	0
Discount to reflect current market conditions | Other real estate owned | Appraisals | Maximum
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Other real estate owned	0.51	0.10
Discount to reflect current market conditions | Other real estate owned | Appraisals | Weighted Average
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Other real estate owned	0.30	0.04

Disclosures About Fair Value _8

Disclosures About Fair Value of Assets and Liabilities - Estimated Fair Values of Financial Instruments (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Assets:
Investment securities available for sale	$ 1,399,959	$ 1,142,195
Investment securities held to maturity	708,915	489,217
Loans held for sale	5,854	4,778
Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets:
Cash and cash equivalents	128,185	139,247
Interest-bearing time deposits	129,614	36,963
Investment securities available for sale	0	0
Investment securities held to maturity	0	0
Loans held for sale	0	0
Loans	0	0
Federal Home Loan Bank stock	0	0
Interest rate swap and cap asset	0	0
Interest receivable	0	0
Liabilities:
Deposits	6,688,194	6,267,879
Borrowings:
Federal funds purchased	0	0
Securities sold under repurchase agreements	0	0
Federal Home Loan Bank advances	0	0
Subordinated debentures and term loans	0	0
Interest rate swap liability	0	0
Interest payable	0	0
Significant Other Observable Inputs (Level 2)
Assets:
Cash and cash equivalents	0	0
Interest-bearing time deposits	0	0
Investment securities available for sale	1,396,984	1,138,867
Investment securities held to maturity	701,905	481,377
Loans held for sale	5,854	4,778
Loans	0	0
Federal Home Loan Bank stock	24,588	24,588
Interest rate swap and cap asset	25,059	12,083
Interest receivable	45,150	40,881
Liabilities:
Deposits	1,627,381	1,464,129
Borrowings:
Federal funds purchased	75,000	104,000
Securities sold under repurchase agreements	119,488	113,437
Federal Home Loan Bank advances	461,582	318,728
Subordinated debentures and term loans	127,594	127,298
Interest rate swap liability	26,668	12,636
Interest payable	6,740	5,607
Significant Unobservable Inputs (Level 3)
Assets:
Cash and cash equivalents	0	0
Interest-bearing time deposits	0	0
Investment securities available for sale	2,975	3,328
Investment securities held to maturity	7,010	7,840
Loans held for sale	0	0
Loans	7,408,511	7,004,193
Federal Home Loan Bank stock	0	0
Interest rate swap and cap asset	0	0
Interest receivable	0	0
Liabilities:
Deposits	0	0
Borrowings:
Federal funds purchased	0	0
Securities sold under repurchase agreements	0	0
Federal Home Loan Bank advances	0	0
Subordinated debentures and term loans	0	0
Interest rate swap liability	0	0
Interest payable	0	0
Carrying Amount
Assets:
Cash and cash equivalents	128,185	139,247
Interest-bearing time deposits	129,614	36,963
Investment securities available for sale	1,399,959	1,142,195
Investment securities held to maturity	692,965	490,387
Loans held for sale	5,854	4,778
Loans	7,430,096	7,143,915
Federal Home Loan Bank stock	24,588	24,588
Interest rate swap and cap asset	25,059	12,083
Interest receivable	45,150	40,881
Liabilities:
Deposits	8,319,328	7,754,593
Borrowings:
Federal funds purchased	75,000	104,000
Securities sold under repurchase agreements	119,674	113,512
Federal Home Loan Bank advances	460,042	314,986
Subordinated debentures and term loans	138,574	138,463
Interest rate swap liability	26,668	12,636
Interest payable	$ 6,740	$ 5,607

Transfers Accounted for as Se_3

Transfers Accounted for as Secured Borrowings (Details) - U.S. Government-sponsored mortgage-backed securities - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Assets Sold under Agreements to Repurchase [Line Items]
Collateral pledged for all repurchase agreements accounted for as secured borrowings	$ 119,674	$ 113,512
Overnight and Continuous
Assets Sold under Agreements to Repurchase [Line Items]
Collateral pledged for all repurchase agreements accounted for as secured borrowings	110,233	104,883
Up to 30 Days
Assets Sold under Agreements to Repurchase [Line Items]
Collateral pledged for all repurchase agreements accounted for as secured borrowings	0	1,014
30-90 Days
Assets Sold under Agreements to Repurchase [Line Items]
Collateral pledged for all repurchase agreements accounted for as secured borrowings	0	7,615
Greater Than 90 Days
Assets Sold under Agreements to Repurchase [Line Items]
Collateral pledged for all repurchase agreements accounted for as secured borrowings	$ 9,441	$ 0

Accumulated Other Comprehensi_3

Accumulated Other Comprehensive Income (Loss) - Changes in Balances of Each Component (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Accumulated Other Comprehensive Income (Loss)
Beginning balance	$ 1,455,848	$ 1,313,073	$ 1,408,260	$ 1,303,463
Other comprehensive income before reclassifications			38,268	(19,394)
Amounts reclassified from accumulated other comprehensive income	(1,390)	(803)	(2,244)	(1,940)
Total other comprehensive income (loss), net of tax	16,197	(3,143)	36,024	(21,334)
Reclassification adjustment under ASU 2018-02				0
Ending balance	1,501,636	1,340,328	1,501,636	1,340,328
Total
Accumulated Other Comprehensive Income (Loss)
Beginning balance	(1,595)	(21,725)	(21,422)	(2,908)
Total other comprehensive income (loss), net of tax	16,197	(3,143)	36,024	(21,334)
Reclassification adjustment under ASU 2018-02			(626)	(626)
Ending balance	14,602	(24,868)	14,602	(24,868)
Unrealized Gains (Losses) on Securities Available for Sale
Accumulated Other Comprehensive Income (Loss)
Beginning balance			(6,343)	8,970
Other comprehensive income before reclassifications			39,130	(20,268)
Amounts reclassified from accumulated other comprehensive income	(1,456)	(886)	(2,357)	(2,157)
Total other comprehensive income (loss), net of tax			36,773	(22,425)
Reclassification adjustment under ASU 2018-02			1,932
Ending balance	30,430	(11,523)	30,430	(11,523)
Unrealized Gains (Losses) on Cash Flow Hedges
Accumulated Other Comprehensive Income (Loss)
Beginning balance			(559)
Other comprehensive income before reclassifications			(862)
Amounts reclassified from accumulated other comprehensive income	66		113
Total other comprehensive income (loss), net of tax			(749)
Ending balance	(1,308)		(1,308)
Unrealized Gains (Losses) on Cash Flow Hedges
Accumulated Other Comprehensive Income (Loss)
Beginning balance				(1,125)
Other comprehensive income before reclassifications				874
Amounts reclassified from accumulated other comprehensive income		83		217
Total other comprehensive income (loss), net of tax				1,091
Reclassification adjustment under ASU 2018-02			(242)
Ending balance		(276)		(276)
Unrealized Gains (Losses) on Defined Benefit Plans
Accumulated Other Comprehensive Income (Loss)
Beginning balance			(14,520)	(10,753)
Other comprehensive income before reclassifications			0	0
Amounts reclassified from accumulated other comprehensive income			0	0
Total other comprehensive income (loss), net of tax			0	0
Reclassification adjustment under ASU 2018-02			(2,316)
Ending balance	$ (14,520)	$ (13,069)	$ (14,520)	$ (13,069)

Accumulated Other Comprehensi_4

Accumulated Other Comprehensive Income (Loss) - Reclassifications (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Reclassification Adjustments out of Accumulated Other Comprehensive Income [Line Items]
Net realized gains on sales of available for sale securities	$ 1,843	$ 1,122	$ 2,983	$ 2,731
Interest expense - subordinated debentures and term loans	2,123	2,057	4,239	4,047
Income tax expense	(7,749)	(7,961)	(14,690)	(14,572)
Total reclassifications for the period, net of tax	1,390	803	2,244	1,940
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	1,456	886	2,357	2,157
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	(66)		(113)
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		(83)		(217)
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]
Net realized gains on sales of available for sale securities	1,843	1,122	2,983	2,731
Income tax expense	(387)	(236)	(626)	(574)
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	18		30
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	$ (84)		$ (143)
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		22		58
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		$ (105)		$ (275)

Share-Based Compensation - Narr

Share-Based Compensation - Narrative (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
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	$ 844,000	$ 776,000	$ 1,825,000	$ 1,653,000
Forfeiture rate			1.70%
Unrecognized compensation expense related to stock options	0		$ 0
Aggregate intrinsic value of stock options exercised			308,000	1,038,000
Cash receipts of stock options exercised			$ 105,000	$ 953,000
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			1 year
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
Unrecognized compensation expense related to RSAs	5,431,000		$ 5,431,000
Unrecognized compensation expense expected recognition period			1 year 6 months 14 days
ESPP
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation expense related to stock options	0		$ 0
Grant date fair value of ESPP options	$ 25,000

Share-Based Compensation - Comp

Share-Based Compensation - Components of Share-Based Compensation Awards (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Pre-tax compensation expense	$ 844	$ 776	$ 1,825	$ 1,653
Income tax benefit	(227)	(261)	(783)	(885)
Total share-based compensation expense, net of income taxes	617	515	1,042	768
Stock and ESPP Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Pre-tax compensation expense	25	24	36	49
Income tax benefit	(41)	(80)	(57)	(138)
Total share-based compensation expense, net of income taxes	(16)	(56)	(21)	(89)
Restricted Stock Awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Pre-tax compensation expense	819	752	1,789	1,604
Income tax benefit	(186)	(181)	(726)	(747)
Total share-based compensation expense, net of income taxes	$ 633	$ 571	$ 1,063	$ 857

Share-Based Compensation - Stoc

Share-Based Compensation - Stock Option Activity under Stock Option Plans (Details) - USD ($)	6 Months Ended
	Jun. 30, 2019
Number of Shares
Beginning balance (in shares)	76,300
Exercised (in shares)	(11,200)
Cancelled (in shares)	0
Ending balance (in shares)	65,100
Vested and Expected to Vest (in shares)	65,100
Exercisable (in shares)	65,100
Weighted-Average Exercise Price
Beginning balance (in dollars per share)	$ 12.40
Exercised (in dollars per share)	9.34
Cancelled (in dollars per share)	0
Ending balance (in dollars per share)	12.92
Vested and Expected to Vest (in dollars per share)	12.92
Exercisable (in dollars per share)	$ 12.92
Weighted Average Remaining Contractual Term (in Years)
Outstanding (term)	2 years 9 months 7 days
Vested and Expected to Vest (term)	2 years 9 months 7 days
Exercisable (term)	2 years 9 months 7 days
Aggregate Intrinsic Value
Outstanding	$ 1,625,958
Vested and Expected to Vest	1,625,958
Exercisable	$ 1,625,958

Share-Based Compensation - Unve

Share-Based Compensation - Unvested RSAs Outstanding (Details) - RSAs	6 Months Ended
	Jun. 30, 2019$ / sharesshares
Number of Shares
Unvested RSAs, Beginning Balance (in shares) | shares	344,362
Granted (in shares) | shares	7,034
Vested (in shares) | shares	(108,638)
Forfeited (in shares) | shares	(1,900)
Unvested RSAs, Ending Balance (in shares) | shares	240,858
Weighted-Average Grant Date Fair Value
Unvested RSAs, Beginning Balance (in dollars per share) | $ / shares	$ 36.80
Granted (in dollars per share) | $ / shares	37.78
Vested (in dollars per share) | $ / shares	23.48
Forfeited (in dollars per share) | $ / shares	40.54
Unvested RSAs, Ending Balance (in dollars per share) | $ / shares	$ 42.81

Income Tax (Details)

Income Tax (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Reconciliation of Federal Statutory to Actual Tax Expense:
Federal statutory income tax at 21%	$ 10,249	$ 9,995	$ 19,858	$ 19,086
Tax-exempt interest income	(2,403)	(2,045)	(4,670)	(4,060)
Share-based compensation	(41)	(91)	(391)	(532)
Tax-exempt earnings and gains on life insurance	(199)	(211)	(406)	(458)
Tax credits	(63)	(62)	(141)	(23)
Other	206	375	440	559
Actual Tax Expense	$ 7,749	$ 7,961	$ 14,690	$ 14,572
Federal statutory income tax rate	21.00%	21.00%
Effective Tax Rate	15.90%	16.70%	15.50%	16.00%

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		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Net Income
Net income available to common stockholders	$ 41,056	$ 39,634	$ 79,873	$ 76,313
Diluted net income per share	$ 41,056	$ 39,634	$ 79,873	$ 76,313
Weighted-Average Shares
Net income available to common stockholders (in shares)	49,432,167	49,252,580	49,400,770	49,222,779
Effect of potentially dilutive stock options and restricted stock awards (in shares)	117,720	198,826	144,382	217,266
Diluted net income per share (in shares)	49,549,887	49,451,406	49,545,152	49,440,045
Per Share Amount
Net income available to common stockholders (in dollars per share)	$ 0.83	$ 0.80	$ 1.62	$ 1.55
Diluted net income per share (in dollars per share)	$ 0.83	$ 0.80	$ 1.61	$ 1.54

Net Income Per Share - Narrativ

Net Income Per Share - Narrative (Details) - shares	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
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	0	0	0