First Financial Bancorp. (FFBC) 10-Q 7 May 18 2018 Q1 Quarterly report Financial data

Document and Entity Information

Document and Entity Information Document - shares	3 Months Ended
	Mar. 31, 2018	May 04, 2018
Document Information [Line Items]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Mar. 31, 2018
Document Fiscal Year Focus	2,018
Document Fiscal Period Focus	Q1
Trading Symbol	FFBC
Entity Registrant Name	FIRST FINANCIAL BANCORP /OH/
Entity Central Index Key	708,955
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		97,810,841

CONSOLIDATED BALANCE SHEETS

CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
ASSETS
Cash and due from banks	$ 116,581	$ 150,650
Interest-bearing deposits with other banks	10,200	33,974
Investment securities available-for-sale, at fair value (amortized cost $1,370,844 at March 31, 2018 and $1,348,227 at December 31, 2017)	1,359,381	1,349,408
Investment securities held-to-maturity (fair value $623,967 at March 31, 2018 and $653,101 at December 31, 2017)	633,722	654,008
Other investments	53,070	53,140
Loans held for sale	8,048	11,502
Loans
Commercial	1,943,741	1,912,743
Lease financing	81,617	89,347
Real estate - construction	494,665	467,730
Real estate-commercial	2,544,051	2,490,091
Real estate-residential	468,584	471,391
Home equity	483,643	493,604
Installment	39,248	41,586
Credit card	46,472	46,691
Total loans and leases	6,102,021	6,013,183
Allowance for loan and lease losses	54,380	54,021
Net loans and leases	6,047,641	5,959,162
Premises and equipment	127,046	125,036
Goodwill and other intangibles	209,053	209,379
Accrued interest and other assets	333,687	350,664
Total assets	8,898,429	8,896,923
Deposits
Interest-bearing	1,442,399	1,453,463
Savings	2,450,196	2,462,420
Time	1,545,273	1,317,105
Total interest-bearing deposits	5,437,868	5,232,988
Noninterest-bearing	1,572,636	1,662,058
Total deposits	7,010,504	6,895,046
Federal funds purchased and securities sold under agreements to repurchase	56,732	72,265
Federal Home Loan Bank short-term borrowings	601,600	742,300
Total short-term borrowings	658,332	814,565
Long-term debt	169,695	119,654
Total borrowed funds	828,027	934,219
Accrued interest and other liabilities	119,913	136,994
Total liabilities	7,958,444	7,966,259
SHAREHOLDERS' EQUITY
Common stock - no par value Authorized - 160,000,000 shares Issued - 68,730,731 shares in 2017 and 2016	571,457	573,109
Retained earnings	515,498	491,847
Accumulated other comprehensive loss	(34,683)	(20,390)
Treasury stock, at cost, 6,516,908 shares in 2018 and 6,661,644 shares in 2017	(112,287)	(113,902)
Total shareholders' equity	939,985	930,664
Total liabilities and shareholders' equity	$ 8,898,429	$ 8,896,923

CONSOLIDATED BALANCE SHEETS CON

CONSOLIDATED BALANCE SHEETS CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Statement of Financial Position [Abstract]
Available-for-sale Securities, Amortized Cost Basis	$ 1,370,844	$ 1,348,227
Held-to-maturity Securities, Fair Value	$ 623,967	$ 653,101
Common Stock, No Par Value	$ 0	$ 0
Common Stock, Shares Authorized	160,000,000	160,000,000
Common Stock, Shares, Issued	68,730,731	68,730,731
Treasury Stock, Shares	6,516,908	6,661,644

CONSOLIDATED STATEMENTS OF INCO

CONSOLIDATED STATEMENTS OF INCOME - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Interest income
Loans, including fees	$ 74,920	$ 66,868
Investment securities
Taxable	13,670	11,608
Tax-exempt	1,657	1,353
Total interest on investment securities	15,327	12,961
Other earning assets	107	(1,001)
Total interest income	90,354	78,828
Interest expense
Deposits	10,298	6,925
Short-term borrowings	2,663	1,432
Long-term borrowings	1,581	1,539
Total interest expense	14,542	9,896
Net interest income	75,812	68,932
Provision for loan and lease losses	2,303	367
Net interest income after provision for loan and lease losses	73,509	68,565
Noninterest income
Service charges on deposit accounts	5,039	4,644
Trust and wealth management fees	3,954	3,747
Bankcard income	3,394	3,135
Client derivative fees	1,757	1,103
Net gains from sales of loans	588	1,216
Net gains (losses) on sales of investment securities	0	516
Other	2,206	3,003
Total noninterest income	16,938	17,364
Noninterest expenses
Salaries and employee benefits	31,102	31,750
Net occupancy	4,497	4,515
Furniture and equipment	2,040	2,177
Data processing	3,672	3,298
Marketing	801	510
Communication	459	447
Professional services	2,198	1,758
State intangible tax	765	721
FDIC assessments	894	932
Loss (gain) - other real estate owned	77	24
Other	5,783	4,913
Total noninterest expenses	52,288	51,045
Income before income taxes	38,159	34,884
Income tax expense	7,653	10,470
Net income	$ 30,506	$ 24,414
Earnings per common share
Basic	$ 0.49	$ 0.40
Diluted	0.49	0.39
Cash dividends declared per share	$ 0.19	$ 0.17
Average common shares outstanding - basic	61,654,686	61,398,414
Average common shares outstanding - diluted	62,180,744	62,140,384

CONSOLIDATED STATEMENTS OF COMP

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Statement of Comprehensive Income [Abstract]
Net income	$ 30,506	$ 24,414
Other comprehensive (loss) income, net of tax
Unrealized gains (losses) on investment securities arising during the period	(9,830)	1,487
Change in retirement obligation	323	189
Unrealized gain (loss) on derivatives	156	128
Other comprehensive income (loss)	(9,351)	1,804
Comprehensive income	$ 21,155	$ 26,218

CONSOLIDATED STATEMENTS OF CHAN

CONSOLIDATED STATEMENTS OF CHANGES IN SHAREHOLDERS' EQUITY - USD ($) $ in Thousands	Total	Common Stock	Retained earnings	Accumulated other comprehensive income (loss)	Treasury stock
Beginning Balances (in shares) at Dec. 31, 2016		68,730,731			(6,751,179)
Beginning Balances at Dec. 31, 2016	$ 865,224	$ 570,382	$ 437,188	$ (28,443)	$ (113,903)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	24,414		24,414
Other comprehensive income (loss)	1,804			1,804
Cash dividends declared :
Common stock at $0.19 per share in 2018 and $0.17 per share in 2017	(10,529)		(10,529)
Stock Issued During Period, Shares, Other					1,484
Adjustments to Additional Paid in Capital, Other	0	(25)			$ 25
Exercise of stock options, net of shares purchased (in shares)					34,037
Exercise of stock options, net of shares purchased	197	(377)			$ 574
Restricted stock awards, net of forfeitures (in shares)					119,212
Restricted stock awards, net of forfeitures	(2,532)	(3,556)			$ 1,024
Share-based compensation expense	1,487	$ 1,487
Ending Balances (in shares) at Mar. 31, 2017		68,730,731			(6,596,446)
Ending Balances at Mar. 31, 2017	880,065	$ 567,911	451,073	(26,639)	$ (112,280)
Beginning Balances (in shares) at Dec. 31, 2017		68,730,731			(6,661,644)
Beginning Balances at Dec. 31, 2017	930,664	$ 573,109	491,847	(20,390)	$ (113,902)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	30,506		30,506
Reclassification from AOCI, Current Period, Tax	0		4,942	(4,942)
Other comprehensive income (loss)	(9,351)			(9,351)
Cash dividends declared :
Common stock at $0.19 per share in 2018 and $0.17 per share in 2017	(11,797)		(11,797)
Stock Issued During Period, Shares, Other					1,428
Adjustments to Additional Paid in Capital, Other	0	(24)			$ 24
Exercise of stock options, net of shares purchased (in shares)					11,800
Exercise of stock options, net of shares purchased	137	(65)			$ 202
Restricted stock awards, net of forfeitures (in shares)					131,508
Restricted stock awards, net of forfeitures	(2,128)	(3,517)			$ 1,389
Share-based compensation expense	1,954	$ 1,954
Ending Balances (in shares) at Mar. 31, 2018		68,730,731			(6,516,908)
Ending Balances at Mar. 31, 2018	$ 939,985	$ 571,457	$ 515,498	$ (34,683)	$ (112,287)

CONSOLIDATED STATEMENTS OF CHA7

CONSOLIDATED STATEMENTS OF CHANGES IN SHAREHOLDERS' EQUITY CONSOLIDATED STATEMENTS OF CHANGES IN SHAREHOLDERS EQUITY (Parenthetical) - $ / shares	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Common Stock, Dividends, Per Share, Declared	$ 0.19	$ 0.17

CONSOLIDATED STATEMENTS OF CASH

CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Operating activities
Net income	$ 30,506	$ 24,414
Adjustments to reconcile net income to net cash provided by operating activities:
Provision for loan and lease losses	2,303	367
Depreciation and amortization	3,076	3,260
Stock-based compensation expense	1,954	1,487
Pension expense (income)	(156)	(319)
Net amortization (accretion) on investment securities	2,801	2,176
Net (gains) losses on sales of investment securities	0	(516)
Originations of loans held for sale	(22,383)	(32,085)
Net gains from sales of loans held for sale	(588)	(1,216)
Proceeds from sales of loans held for sale	24,542	38,633
Deferred income taxes	(1,736)	75
Decrease (increase) cash surrender value of life insurance	(786)	448
Decrease (increase) in interest receivable	(1,687)	(1,735)
Decrease (increase) in indemnification asset	(1,900)	(1,244)
(Decrease) increase in interest payable	(1,013)	(1,424)
Decrease (increase) in other assets	15,414	957
(Decrease) increase in other liabilities	(3,391)	(3,082)
Net cash provided by (used in) operating activities	52,328	31,788
Investing activities
Proceeds from sales of securities available-for-sale	0	22,239
Proceeds from calls, paydowns and maturities of securities available-for-sale	52,252	49,418
Purchases of securities available-for-sale	(77,037)	(219,761)
Proceeds from calls, paydowns and maturities of securities held-to-maturity	19,718	38,497
Payments to Acquire Held-to-maturity Securities	0	14,441
Net decrease (increase) in interest-bearing deposits with other banks	23,774	43,392
Net decrease (increase) in loans and leases	(89,526)	1,257
Proceeds from disposal of other real estate owned	2,222	1,162
Purchases of premises and equipment	(4,979)	(3,066)
Net cash provided by (used in) investing activities	(73,576)	(81,303)
Financing activities
Net (decrease) increase in total deposits	115,458	4,088
Net (decrease) increase in short-term borrowings	(156,233)	51,272
Proceeds from FHLB borrowings	50,000	0
Cash dividends paid on common stock	(22,183)	(9,811)
Proceeds from exercise of stock options	137	282
Net cash provided by (used in) financing activities	(12,821)	45,831
Cash and due from banks:
Change in cash and due from banks	(34,069)	(3,684)
Cash and due from banks at beginning of period	150,650	121,598
Cash and due from banks at end of period	$ 116,581	$ 117,914

BASIS OF PRESENTATION

BASIS OF PRESENTATION	3 Months Ended
	Mar. 31, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
BASIS OF PRESENTATION	BASIS OF PRESENTATION The Consolidated Financial Statements of First Financial Bancorp., a financial holding company principally serving Ohio, Indiana and Kentucky, include the accounts and operations of First Financial and its wholly-owned subsidiary, First Financial Bank. All significant intercompany transactions and accounts have been eliminated in consolidation. Certain reclassifications of prior periods' amounts have been made to conform to current year presentation. Such reclassifications had no effect on net earnings. The preparation of financial statements in conformity with GAAP requires management to make estimates, assumptions and judgments that affect the amounts reported in the Consolidated Financial Statements and accompanying Notes. These estimates, assumptions and judgments are inherently subjective and may be susceptible to significant change. Actual realized amounts could differ materially from these estimates. These interim financial statements have been prepared in accordance with the instructions to Form 10-Q and Article 10 of Regulation S-X, and serve to update the Form 10-K for the year ended December 31, 2017 . These interim financial statements may not include all information and notes necessary to constitute a complete set of financial statements under GAAP applicable to annual periods and it is suggested that these interim statements be read in conjunction with the Form 10-K. Management believes these unaudited consolidated financial statements reflect all adjustments of a normal recurring nature which are necessary for a fair presentation of the results for the interim periods presented. The results of operations for the interim periods are not necessarily indicative of the results that may be expected for the full year or any other interim period. The Consolidated Balance Sheet as of December 31, 2017 has been derived from the audited financial statements in the Company’s 2017

RECENTLY ADOPTED AND ISSUED ACC

RECENTLY ADOPTED AND ISSUED ACCOUNTING STANDARDS	3 Months Ended
	Mar. 31, 2018
Recently Adopted and Issued Accounting Standards [Abstract]
Recently Adopted and Issued Accounting Standards Disclosure [Text Block]	RECENTLY ADOPTED AND ISSUED ACCOUNTING STANDARDS In May 2014, the FASB issued an update (ASU 2014-09, Revenue from Contracts with Customers) which outlines a single comprehensive model for entities to use in accounting for revenue arising from contracts with customers and supersedes most current revenue recognition guidance, including industry-specific guidance. Under the revised standard, an entity recognizes revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. The ASU applies to all contracts with customers except those that are within the scope of other topics in the FASB Accounting Standards Codification. Certain of the ASU’s provisions also apply to transfers of nonfinancial assets, including in-substance nonfinancial assets that are not an output of an entity’s ordinary activities, such as sales of property, plant, and equipment; real estate; or intangible assets. The ASU also requires significantly expanded disclosures about revenue recognition. For further detail, see Note 13 – Revenue Recognition. In January 2016, the FASB issued an update (ASU 2016-01, Financial Instruments-Overall: Recognition and Measurement of Financial Assets and Financial Liabilities) which requires entities to measure many equity investments at fair value and recognize changes in fair value in net income. This update does not apply to equity investments that result in consolidation, those accounted for under the equity method and certain others, and will eliminate use of the available for sale classification for equity securities while providing a new measurement alternative for equity investments that do not have readily determinable fair values and do not qualify for the net asset value practical expedient. This update also requires public business entities to use the exit price notion when measuring the fair value of financial instruments for disclosure purposes. The guidance in this ASU became effective in the first quarter of 2018 and did not have a material impact on the Consolidated Financial Statements. In accordance with the guidance, the Company measured the fair value of its financial instruments as of March 31, 2018 using an exit price notion. For further detail, see Note 15 – Fair Value Disclosures. In February 2016, the FASB issued an update (ASU 2016-02, Leases) which requires lessees to record most leases on their balance sheet and recognize leasing expenses in the income statement. Operating leases, except for short-term leases that are subject to an accounting policy election, will be recorded on the balance sheet for lessees by establishing a lease liability and corresponding right-of-use asset. The guidance in this ASU will become effective for interim and annual reporting periods beginning after December 15, 2018, with early adoption permitted. Given operating leases outstanding as of March 31, 2018, First Financial does not expect this ASU to have a material impact on the income statement, but does anticipate an increase in the Company's assets and liabilities. Decisions to repurchase, modify or renew leases prior to the implementation date will impact this level of materiality. In June 2016, the FASB issued an update (ASU 2016-13, Financial Instruments-Credit Losses: Measurement of Credit Losses on Financial Instruments) which significantly changes how entities are required to measure credit losses for most financial assets and certain other instruments that are not measured at fair value through net income. This update will replace the current incurred loss approach for estimating credit losses with an expected loss model for instruments measured at amortized cost, including loans and leases. Expected credit losses are required to be based on amortized cost and reflect losses expected over the remaining contractual life of the asset. Management is expected to consider any available information relevant to assessing the collectibility of contractual cash flows, such as information about past events, current conditions, voluntary prepayments and reasonable and supportable forecasts, when developing expected credit loss estimates. In addition to the new framework for calculating the ALLL, this update requires allowances for available-for-sale debt securities rather than a reduction of the security's carrying amount under the current other-than-temporary impairment model. This update also simplifies the accounting model for purchased credit-impaired debt securities and loans and will require new and updated footnote disclosures. The guidance in this ASU will become effective for interim and annual reporting periods beginning after December 15, 2019. Early adoption is permitted for all entities for interim and annual reporting periods beginning after December 15, 2018. First Financial has formed an internal committee that is currently evaluating the impact of this update on its Consolidated Financial Statements. In August 2016, the FASB issued an update (ASU 2016-15 Statement of Cash Flows: Classification of Certain Cash Receipts and Cash Payments) which may change how an entity classifies certain cash receipts and cash payments on its statement of cash flows to reduce diversity in practice. The update also provides guidance on when an entity should separate cash flows and classify them into more than one class and when an entity should classify the aggregate of those cash flows into a single class based on the predominance principle. The guidance in this ASU became effective in the first quarter of 2018 and did not have a material impact on the Consolidated Financial Statements. In January 2017, the FASB issued an update (ASU 2017-04, Intangibles - Goodwill and Other (Topic 350), Simplifying the Test for Goodwill Impairment) which simplifies the subsequent measurement of goodwill by eliminating Step 2 from goodwill impairment testing. This update requires an entity to perform its annual, or interim, goodwill impairment test by comparing the fair value of a reporting unit with its carrying amount, and recognize an impairment charge for the amount by which the carrying amount exceeds the reporting unit’s fair value, with any loss recognized not to exceed the total amount of goodwill allocated to that reporting unit. Additionally, the update requires consideration of the income tax effects from any tax deductible goodwill on the carrying amount of the reporting unit when measuring the goodwill impairment loss, if applicable, and eliminates the requirements for any reporting unit with a zero or negative carrying amount to perform a qualitative assessment. First Financial early adopted the provisions set forth in this update in 2017. Adoption of this update did not have a material impact on First Financial's Consolidated Financial Statements. In March 2017, the FASB issued an update (ASU 2017-07, Compensation - Retirement Benefits (Topic 715), Improving the Presentation of the Net Periodic Pension Cost and Net Periodic Postretirement Benefit Cost) which requires disaggregation of the service cost component from the other components of net benefit cost. This update also provides explicit guidance on how to present the service cost component and the other components of net benefit cost in the income statement and allows only the service cost component of net benefit cost to be eligible for capitalization. The guidance in this ASU became effective in the first quarter of 2018 and did not have a material impact on the Consolidated Financial Statements. In March 2017, the FASB issued an update (ASU 2017-08, Receivables - Nonrefundable Fees and Other Costs (Subtopic 310-20), Premium Amortization on Purchased Callable Debt Securities) which amends the amortization period for certain purchased callable debt securities held at a premium and shortens the amortization period for the premium to the earliest call date rather than as an adjustment of yield over the contractual life of the instrument. This update more closely aligns the amortization period of premiums and discounts to expectations incorporated in market pricing on the underlying securities, as in most cases, market participants price securities to the call date that produces the worst yield when the coupon is above current market rates (that is, the security is trading at a premium) and price securities to maturity when the coupon is below market rates (that is, the security is trading at a discount) in anticipation that the borrower will act in its economic best interest in an attempt to more closely align interest income recorded on bonds held at a premium or a discount with the economics of the underlying instrument. The guidance in this ASU will become effective for reporting periods, beginning after December 15, 2018, with early adoption permitted. First Financial is currently evaluating the impact of this update on its Consolidated Financial Statements. In May 2017, the FASB issued an update (ASU 2017-09, Compensation - Stock Compensation (Topic 718), Scope of Modification Accounting), which provides clarity and reduces the diversity in practice, cost and complexity when accounting for a change to the terms or conditions of a share-based payment award. The amendments in this update provide guidance about which changes to the terms or conditions of a share-based payment award require an entity to apply modification accounting in Topic 718 clarifying that an entity will not apply modification accounting to a share-based payment award if the award's fair value (or calculated value or intrinsic value), vesting conditions and classification as an equity or liability instrument are the same immediately before and after the change. The guidance in this ASU became effective in the first quarter of 2018 and did not have a material impact on the Consolidated Financial Statements. In August 2017, the FASB issued an update (ASU 2017-12, Derivatives and Hedging: Targeted Improvements to Accounting for Hedging Activities) to better align financial reporting for hedging activities with the economic objectives of those activities. This update aligns certain aspects of hedge documentation, effectiveness assessments, accounting and disclosures, and expands permissible hedge strategies as of the date of adoption. The guidance in this ASU will become effective for reporting periods beginning after December 15, 2018, with early adoption permitted, and will require a modified retrospective transition method with recognition of the cumulative effect of the change on the opening balance of each affected component of equity. Amended disclosures will be required prospectively. First Financial is currently evaluating the impact of this update on its Consolidated Financial Statements. In February 2018, the FASB issued an update (ASU 2018-02, Income statement-Reporting Comprehensive Income: Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income), which allows a reclassification from accumulated other comprehensive income to retained earnings for stranded tax effects resulting from the Tax Cuts and Jobs Act. Consequently, the amendments eliminated the stranded tax effects resulting from the Tax Cuts and Jobs Act and will improve the usefulness of information reported to financial statement users. The amendments only relate to the reclassification of the income tax effects of the Tax Cuts and Jobs Act, and the underlying guidance that requires that the effect of a change in tax laws or rates be included in income from continuing operations is not effected. The amendments in this update also require certain disclosures about stranded tax effects. The guidance in this ASU will become effective for reporting periods beginning after December 15, 2018, with early adoption permitted, and will be applied either in the period of adoption or retrospectively to each period in which the effect of the change in the U.S. federal corporate income tax rate in the Tax Cuts and Jobs Act is recognized. First Financial early adopted the provisions set forth in this update in the first quarter of 2018, and as a result, reclassified $4.9 million

INVESTMENTS

INVESTMENTS	3 Months Ended
	Mar. 31, 2018
Investments, Debt and Equity Securities [Abstract]
INVESTMENTS	INVESTMENTS For the three months ended March 31, 2018 , there were no sales of available-for-sale securities. For the three months ended March 31, 2017 , proceeds on the sale of $22.2 million of available-for-sale securities resulted in gains of $0.5 million . The following is a summary of held-to-maturity and available-for-sale investment securities as of March 31, 2018 : Held-to-maturity Available-for-sale (Dollars in thousands) Amortized Unrecognized gain Unrecognized loss Fair Amortized cost Unrealized gain Unrealized loss Fair U.S. Treasuries $ 0 $ 0 $ 0 $ 0 $ 98 $ 0 $ (2 ) $ 96 Securities of U.S. government agencies and corporations 10,627 0 (188 ) 10,439 25,689 244 (193 ) 25,740 Mortgage-backed securities - residential 155,208 1,225 (2,817 ) 153,616 288,757 375 (6,689 ) 282,443 Mortgage-backed securities - commercial 251,253 228 (5,348 ) 246,133 153,770 47 (2,875 ) 150,942 Collateralized mortgage obligations 135,143 86 (2,798 ) 132,431 305,496 558 (4,791 ) 301,263 Obligations of state and other political subdivisions 81,491 829 (972 ) 81,348 121,813 1,307 (1,696 ) 121,424 Asset-backed securities 0 0 0 0 391,943 1,351 (782 ) 392,512 Other securities 0 0 0 0 83,278 2,027 (344 ) 84,961 Total $ 633,722 $ 2,368 $ (12,123 ) $ 623,967 $ 1,370,844 $ 5,909 $ (17,372 ) $ 1,359,381 The following is a summary of held-to-maturity and available-for-sale investment securities as of December 31, 2017 : Held-to-maturity Available-for-sale (Dollars in thousands) Amortized Unrecognized gain Unrecognized Fair Amortized Unrealized Unrealized Fair U.S. Treasuries $ 0 $ 0 $ 0 $ 0 $ 98 $ 0 $ (1 ) $ 97 Securities of U.S. government agencies and corporations 11,168 0 (76 ) 11,092 15,695 220 0 15,915 Mortgage-backed securities - residential 162,093 2,042 (1,535 ) 162,600 290,793 849 (2,599 ) 289,043 Mortgage-backed securities - commercial 255,027 1,372 (3,000 ) 253,399 150,356 164 (1,417 ) 149,103 Collateralized mortgage obligations 143,545 354 (1,602 ) 142,297 306,095 1,158 (1,861 ) 305,392 Obligations of state and other political subdivisions 82,175 1,804 (266 ) 83,713 124,269 2,162 (676 ) 125,755 Asset-backed securities 0 0 0 0 377,655 1,628 (306 ) 378,977 Other securities 0 0 0 0 83,266 2,147 (287 ) 85,126 Total $ 654,008 $ 5,572 $ (6,479 ) $ 653,101 $ 1,348,227 $ 8,328 $ (7,147 ) $ 1,349,408 The following table provides a summary of investment securities by contractual maturity as of March 31, 2018 , except for residential and commercial mortgage-backed securities, collateralized mortgage obligations and asset-backed securities, which are shown as single totals due to the unpredictability of the timing in principal repayments. Held-to-maturity Available-for-sale (Dollars in thousands) Amortized cost Fair value Amortized cost Fair value By Contractual Maturity: Due in one year or less $ 165 $ 165 $ 2,296 $ 2,292 Due after one year through five years 4,277 4,279 37,023 36,960 Due after five years through ten years 2,499 2,632 82,431 83,521 Due after ten years 85,177 84,711 109,128 109,448 Mortgage-backed securities - residential 155,208 153,616 288,757 282,443 Mortgage-backed securities - commercial 251,253 246,133 153,770 150,942 Collateralized mortgage obligations 135,143 132,431 305,496 301,263 Asset-backed securities 0 0 391,943 392,512 Total $ 633,722 $ 623,967 $ 1,370,844 $ 1,359,381 Gains and losses on debt securities are generally due to fluctuations in current market yields relative to the yields of the debt securities at their amortized cost. All securities with unrealized losses are reviewed quarterly to determine if any impairment is considered other than temporary, requiring a write-down to fair value. First Financial considers the percentage loss on a security, duration of the loss, average life or duration of the security, credit rating of the security and payment performance, as well as the Company's intent and ability to hold the security to maturity, when determining whether any impairment is other than temporary. At this time First Financial does not intend to sell, and it is not more likely than not that the Company will be required to sell, debt securities temporarily impaired prior to maturity or recovery of the recorded value. First Financial had no other than temporary impairment related to its investment securities portfolio as of March 31, 2018 or December 31, 2017 . As of March 31, 2018 , the Company's investment securities portfolio consisted of 774 securities, of which 359 were in an unrealized loss position. As of December 31, 2017, the Company's investment securities portfolio consisted of 775 securities, of which 237 were in an unrealized loss position. The following tables provide the fair value and gross unrealized losses on investment securities in an unrealized loss position, aggregated by investment category and the length of time the individual securities have been in a continuous loss position: March 31, 2018 Less than 12 months 12 months or more Total (Dollars in thousands) Fair value Unrealized loss Fair Unrealized Fair Unrealized U.S. Treasuries $ 96 $ (2 ) $ 0 $ 0 $ 96 $ (2 ) Securities of U.S. Government agencies and corporations 26,347 (381 ) 0 0 26,347 (381 ) Mortgage-backed securities - residential 252,396 (3,712 ) 123,671 (5,794 ) 376,067 (9,506 ) Mortgage-backed securities - commercial 233,201 (4,185 ) 75,822 (4,038 ) 309,023 (8,223 ) Collateralized mortgage obligations 274,159 (3,915 ) 96,641 (3,674 ) 370,800 (7,589 ) Obligations of state and other political subdivisions 98,207 (1,879 ) 21,420 (789 ) 119,627 (2,668 ) Asset-backed securities 89,530 (613 ) 23,113 (169 ) 112,643 (782 ) Other securities 4,616 (29 ) 7,100 (315 ) 11,716 (344 ) Total $ 978,552 $ (14,716 ) $ 347,767 $ (14,779 ) $ 1,326,319 $ (29,495 ) December 31, 2017 Less than 12 months 12 months or more Total Fair Unrealized Fair Unrealized Fair Unrealized (Dollars in thousands) value loss value loss value loss U.S. Treasuries $ 97 $ (1 ) $ 0 $ 0 $ 97 $ (1 ) Securities of U.S. Government agencies and corporations 11,092 (76 ) 0 0 11,092 (76 ) Mortgage-backed securities - residential 175,183 (1,109 ) 108,782 (3,025 ) 283,965 (4,134 ) Mortgage-backed securities - commercial 132,818 (1,713 ) 72,139 (2,704 ) 204,957 (4,417 ) Collateralized mortgage obligations 164,909 (1,138 ) 101,436 (2,325 ) 266,345 (3,463 ) Obligations of state and other political subdivisions 38,450 (507 ) 21,639 (435 ) 60,089 (942 ) Asset-backed securities 44,941 (200 ) 24,396 (106 ) 69,337 (306 ) Other securities 2,605 (1 ) 7,124 (286 ) 9,729 (287 ) Total $ 570,095 $ (4,745 ) $ 335,516 $ (8,881 ) $ 905,611 $ (13,626 )

LOANS AND LEASES

LOANS AND LEASES	3 Months Ended
	Mar. 31, 2018
Receivables [Abstract]
LOANS AND LEASES	LOANS AND LEASES First Financial offers clients a variety of commercial and consumer loan and lease products with distinct interest rates and payment terms. Commercial loan categories include commercial and industrial, commercial real estate, construction real estate and lease financing. Consumer loan categories include residential real estate, home equity, installment and credit card. Lending activities are primarily concentrated in states where the Bank operates banking centers (Ohio, Indiana and Kentucky). First Financial also offers two nationwide lending platforms, one that provides equipment and leasehold improvement financing for franchisees in the quick service and casual dining restaurant sector and another that provides loans accounts primarily to insurance agents and brokers that are secured by commissions and cash collateral. Credit Quality. To facilitate the monitoring of credit quality for commercial loans, and for purposes of determining an appropriate ALLL, First Financial utilizes the following categories of credit grades: Pass - Higher quality loans that do not fit any of the other categories described below. Special Mention - First Financial assigns a special mention rating to loans and leases with potential weaknesses that deserve management's close attention. If left uncorrected, these potential weaknesses may result in deterioration of the repayment prospects for the loan or lease or in First Financial's credit position at some future date. Substandard - First Financial assigns a substandard rating to loans or leases that are inadequately protected by the current sound financial worth and paying capacity of the borrower or of the collateral pledged, if any. Substandard loans and leases have well-defined weaknesses that jeopardize repayment of the debt. Substandard loans and leases are characterized by the distinct possibility that the Company will sustain some loss if the deficiencies are not addressed. Doubtful - First Financial assigns a doubtful rating to loans and leases with all the attributes of a substandard rating with the added characteristic that the weaknesses make collection or liquidation in full highly questionable and improbable, on the basis of currently existing facts, conditions and values. The possibility of loss is extremely high, but because of certain important and reasonably specific pending factors that may work to the advantage and strengthening of the credit quality of the loan or lease, its classification as an estimated loss is deferred until its more exact status may be determined. Pending factors include proposed merger, acquisition or liquidation procedures, capital injection, perfecting liens on additional collateral and refinancing plans. The credit grades previously described are derived from standard regulatory rating definitions and are assigned upon initial approval of credit to borrowers and updated periodically thereafter. First Financial considers repayment performance to be the best indicator of credit quality for consumer loans. Consumer loans that have principal and interest payments that are past due by 90 days or more are generally classified as nonperforming. Additionally, consumer loans that have been modified in a TDR are classified as nonperforming. Purchased impaired loans are not classified as nonperforming assets as the loans are considered to be performing under FASB ASC Topic 310-30. Commercial and consumer credit exposure by risk attribute was as follows: As of March 31, 2018 Commercial Real Estate Lease (Dollars in thousands) & industrial Construction Commercial financing Total Pass $ 1,911,912 $ 482,679 $ 2,502,882 $ 80,489 $ 4,977,962 Special Mention 5,228 11,947 6,422 0 23,597 Substandard 26,601 39 34,747 1,128 62,515 Doubtful 0 0 0 0 0 Total $ 1,943,741 $ 494,665 $ 2,544,051 $ 81,617 $ 5,064,074 (Dollars in thousands) Residential real estate Home equity Installment Credit card Total Performing $ 461,409 $ 479,470 $ 38,942 $ 46,472 $ 1,026,293 Nonperforming 7,175 4,173 306 0 11,654 Total $ 468,584 $ 483,643 $ 39,248 $ 46,472 $ 1,037,947 As of December 31, 2017 Commercial Real Estate Lease (Dollars in thousands) & industrial Construction Commercial financing Total Pass $ 1,882,464 $ 467,687 $ 2,446,999 $ 88,078 $ 4,885,228 Special Mention 6,226 0 4,436 0 10,662 Substandard 24,053 43 38,656 1,269 64,021 Doubtful 0 0 0 0 0 Total $ 1,912,743 $ 467,730 $ 2,490,091 $ 89,347 $ 4,959,911 (Dollars in thousands) Residential real estate Home equity Installment Credit card Total Performing $ 463,459 $ 489,148 $ 41,331 $ 46,691 $ 1,040,629 Nonperforming 7,932 4,456 255 0 12,643 Total $ 471,391 $ 493,604 $ 41,586 $ 46,691 $ 1,053,272 Delinquency. Loans are considered past due or delinquent when the contractual principal or interest due in accordance with the terms of the loan agreement or any portion thereof remains unpaid after the date of the scheduled payment. Loan delinquency, including loans classified as nonaccrual, was as follows: As of March 31, 2018 (Dollars in thousands) 30 – 59 60 – 89 > 90 days Total Current Subtotal Purchased impaired Total > 90 days Loans Commercial & industrial $ 1,399 $ 4,857 $ 1,323 $ 7,579 $ 1,933,461 $ 1,941,040 $ 2,701 $ 1,943,741 $ 0 Lease financing 943 0 0 943 80,674 81,617 0 81,617 0 Construction real estate 0 0 0 0 494,389 494,389 276 494,665 0 Commercial real estate 236 3,317 12,255 15,808 2,475,106 2,490,914 53,137 2,544,051 0 Residential real estate 497 341 1,359 2,197 427,689 429,886 38,698 468,584 0 Home equity 1,395 508 2,000 3,903 476,446 480,349 3,294 483,643 0 Installment 284 74 271 629 38,018 38,647 601 39,248 0 Credit card 459 228 529 1,216 45,256 46,472 0 46,472 529 Total $ 5,213 $ 9,325 $ 17,737 $ 32,275 $ 5,971,039 $ 6,003,314 $ 98,707 $ 6,102,021 $ 529 As of December 31, 2017 (Dollars in thousands) 30 – 59 60 – 89 > 90 days Total Current Subtotal Purchased impaired Total > 90 days Loans Commercial & industrial $ 755 $ 1,657 $ 5,078 $ 7,490 $ 1,901,821 $ 1,909,311 $ 3,432 $ 1,912,743 $ 0 Lease financing 485 0 0 485 88,862 89,347 0 89,347 0 Construction real estate 234 0 0 234 467,216 467,450 280 467,730 0 Commercial real estate 1,716 201 8,777 10,694 2,419,969 2,430,663 59,428 2,490,091 0 Residential real estate 526 811 1,992 3,329 430,500 433,829 37,562 471,391 0 Home equity 2,716 394 1,753 4,863 485,127 489,990 3,614 493,604 0 Installment 179 29 205 413 40,529 40,942 644 41,586 0 Credit card 285 87 62 434 46,257 46,691 0 46,691 62 Total $ 6,896 $ 3,179 $ 17,867 $ 27,942 $ 5,880,281 $ 5,908,223 $ 104,960 $ 6,013,183 $ 62 Nonaccrual. Loans are classified as nonaccrual when, in the opinion of management, collection of principal or interest is doubtful or when principal or interest payments are 90 days or more past due. Generally, loans are classified as nonaccrual due to the continued failure to adhere to contractual payment terms by the borrower, coupled with other pertinent factors. When a loan is classified as nonaccrual, the accrual of interest income is discontinued and previously accrued but unpaid interest is reversed. Any payments received while a loan is on nonaccrual status are applied as a reduction to the carrying value of the loan. A loan classified as nonaccrual may return to accrual status if collection of future principal and interest payments is no longer doubtful. Purchased impaired loans are classified as performing, even though they may be contractually past due, as any nonpayment of contractual principal or interest is considered in the periodic re-estimation of expected cash flows and is included in the resulting recognition of current period provision for loan and lease losses or prospective yield adjustments. Troubled Debt Restructurings. A loan modification is considered a TDR when the borrower is experiencing financial difficulty and concessions are made by the Company that would not otherwise be considered for a borrower with similar credit characteristics. The most common types of modifications include interest rate reductions, maturity extensions and modifications to principal amortization, including interest-only structures. Modified terms are dependent upon the financial position and needs of the individual borrower. If the modification agreement is violated, the loan is managed by the Company’s credit administration group for resolution, which may result in foreclosure in the case of real estate. TDRs are generally classified as nonaccrual for a minimum period of six months and may qualify for return to accrual status once they have demonstrated performance with the restructured terms of the loan agreement. First Financial had 204 TDRs totaling $21.0 million at March 31, 2018 , including $14.9 million on accrual status and $6.0 million classified as nonaccrual. First Financial had an insignificant amount of commitments outstanding to lend additional funds to borrowers whose loan terms have been modified through TDRs, and the ALLL included reserves of $2.0 million related to TDRs at March 31, 2018 . For the three months ended March 31, 2018 , First Financial charged off $0.1 million for the portion of TDRs determined to be uncollectible. Additionally, as of March 31, 2018 , approximately $13.3 million of accruing TDRs have been performing in accordance with the restructured terms for more than one year. First Financial had 214 TDRs totaling $23.9 million at December 31, 2017 , including $17.5 million of loans on accrual status and $6.4 million classified as nonaccrual. First Financial had an insignificant amount of commitments outstanding to lend additional funds to borrowers whose loan terms had been modified through TDRs. At December 31, 2017 , the ALLL included reserves of $1.3 million related to TDRs, and $17.2 million of the accruing TDRs had been performing in accordance with the restructured terms for more than one year. The following tables provide information on loan modifications classified as TDRs during the three months ended March 31, 2018 and 2017 : Three months ended March 31, 2018 March 31, 2017 (Dollars in thousands) Number of loans Pre-modification loan balance Period end balance Number of loans Pre-modification loan balance Period end balance Commercial & industrial 4 $ 928 $ 913 2 $ 3,502 $ 3,441 Construction real estate 0 0 0 0 0 0 Commercial real estate 2 72 72 0 0 0 Residential real estate 2 93 93 0 0 0 Home equity 0 0 0 0 0 0 Installment 0 0 0 0 0 0 Total 8 $ 1,093 $ 1,078 2 $ 3,502 $ 3,441 The following table provides information on how TDRs were modified during the three months ended March 31, 2018 and 2017 : Three months ended March 31, (Dollars in thousands) 2018 2017 Extended maturities $ 888 $ 674 Adjusted interest rates 52 2,767 Combination of rate and maturity changes 0 0 Forbearance 0 0 Other (1) 138 0 Total $ 1,078 $ 3,441 (1) Includes covenant modifications and other concessions, or combination of concessions, that do not consist of interest rate adjustments, forbearance and maturity extensions First Financial considers repayment performance as an indication of the effectiveness of the Company's loan modifications. Borrowers that are 90 days or more past due on any principal or interest payments, or who prematurely terminate a restructured loan agreement without paying off the contractual principal balance (for example, in a deed-in-lieu arrangement), are considered to be in payment default of the terms of the TDR agreement. There were no TDRs for which there was a payment default during the period that occurred within twelve months of the loan modification for the three months ended March 31, 2018 or March 31, 2017 . Impaired Loans. Loans classified as nonaccrual and loans modified as TDRs are considered impaired. The following table provides information on impaired loans, excluding purchased impaired loans: (Dollars in thousands) March 31, 2018 December 31, 2017 Impaired loans Nonaccrual loans (1) Commercial & industrial $ 6,275 $ 5,229 Lease financing 0 82 Construction real estate 26 29 Commercial real estate 16,878 10,616 Residential real estate 3,324 4,140 Home equity 3,484 3,743 Installment 296 243 Nonaccrual loans 30,283 24,082 Accruing troubled debt restructurings 14,943 17,545 Total impaired loans $ 45,226 $ 41,627 (1) Nonaccrual loans include nonaccrual TDRs of $6.0 million and $6.4 million as of March 31, 2018 and December 31, 2017 , respectively. Three months ended March 31, (Dollars in thousands) 2018 2017 Interest income effect on impaired loans Gross amount of interest that would have been recorded under original terms $ 802 $ 816 Interest included in income Nonaccrual loans 80 142 Troubled debt restructurings 124 226 Total interest included in income 204 368 Net impact on interest income $ 598 $ 448 First Financial individually reviews all impaired commercial loan relationships, as well as consumer loan TDRs, greater than $250,000 , to determine if a specific allowance is necessary based on the borrower’s overall financial condition, payment record, support from guarantors and the realizable value of any collateral. Specific allowances are based on discounted cash flows using the loan's initial effective interest rate or the fair value of the collateral for certain collateral dependent loans. First Financial's investment in impaired loans was as follows: As of March 31, 2018 As of December 31, 2017 (Dollars in thousands) Current balance Contractual principal balance Related allowance Current balance Contractual Related Loans with no related allowance recorded Commercial & industrial $ 8,571 $ 8,777 $ 0 $ 7,162 $ 8,460 $ 0 Lease financing 0 0 0 82 82 0 Construction real estate 26 58 0 29 60 0 Commercial real estate 24,377 28,871 0 18,423 20,837 0 Residential real estate 6,130 7,282 0 6,876 8,145 0 Home equity 4,072 4,884 0 4,356 5,399 0 Installment 306 469 0 255 422 0 Total 43,482 50,341 0 37,183 43,405 0 Loans with an allowance recorded Commercial & industrial 239 317 100 169 169 169 Lease financing 0 0 0 0 0 0 Construction real estate 0 0 0 0 0 0 Commercial real estate 359 359 26 3,119 3,120 448 Residential real estate 1,045 1,045 160 1,056 1,063 160 Home equity 101 101 2 100 100 2 Installment 0 0 0 0 0 0 Total 1,744 1,822 288 4,444 4,452 779 Total Commercial & industrial 8,810 9,094 100 7,331 8,629 169 Lease financing 0 0 0 82 82 0 Construction real estate 26 58 0 29 60 0 Commercial real estate 24,736 29,230 26 21,542 23,957 448 Residential real estate 7,175 8,327 160 7,932 9,208 160 Home equity 4,173 4,985 2 4,456 5,499 2 Installment 306 469 0 255 422 0 Total $ 45,226 $ 52,163 $ 288 $ 41,627 $ 47,857 $ 779 First Financial's average impaired loans by class and interest income recognized by class was as follows: Three months ended March 31, 2018 March 31, 2017 (Dollars in thousands) Average Interest Average Interest Loans with no related allowance recorded Commercial & industrial $ 7,867 $ 26 $ 15,607 $ 109 Lease financing 41 0 149 1 Construction real estate 28 1 538 0 Commercial real estate 21,400 99 19,939 160 Residential real estate 6,503 47 8,033 46 Home equity 4,214 20 4,111 24 Installment 281 0 413 2 Total 40,334 193 48,790 342 Loans with an allowance recorded Commercial & industrial 204 0 1,094 13 Lease financing 0 0 0 0 Construction real estate 0 0 0 0 Commercial real estate 1,739 3 4,374 5 Residential real estate 1,051 7 1,185 7 Home equity 101 1 101 1 Installment 0 0 0 0 Total 3,095 11 6,754 26 Total Commercial & industrial 8,071 26 16,701 122 Lease financing 41 0 149 1 Construction real estate 28 1 538 0 Commercial real estate 23,139 102 24,313 165 Residential real estate 7,554 54 9,218 53 Home equity 4,315 21 4,212 25 Installment 281 0 413 2 Total $ 43,429 $ 204 $ 55,544 $ 368 OREO. OREO consists of properties acquired by the Company primarily through the loan foreclosure or repossession process, or other resolution activity that results in partial or total satisfaction of problem loans. Changes in OREO were as follows: Three months ended March 31, (Dollars in thousands) 2018 2017 Balance at beginning of period $ 2,781 $ 6,284 Additions Commercial & industrial 170 122 Residential real estate 459 165 Total additions 629 287 Disposals Commercial & industrial (2,104 ) (925 ) Residential real estate (118 ) (237 ) Total disposals (2,222 ) (1,162 ) Valuation adjustment Commercial & industrial (97 ) (46 ) Residential real estate (26 ) (63 ) Total valuation adjustment (123 ) (109 ) Balance at end of period $ 1,065 $ 5,300 FDIC indemnification asset. The FDIC indemnification asset results from the loss sharing agreements entered into in conjunction with First Financial's FDIC-assisted transactions, and represents expected reimbursements from the FDIC for losses on covered assets. In the first quarter of 2018, First Financial received a settlement payment from the FDIC finalizing the termination of its loss sharing agreements. Therefore, First Financial had no FDIC indemnification asset balance as of March 31, 2018 . All future recoveries, gains, losses and expenses related to assets previously covered under loss sharing agreements will be fully recognized by First Financial. As of December 31, 2017 , the FDIC indemnification asset balance was $1.9 million

ALLOWANCE FOR LOAN AND LEASE LO

ALLOWANCE FOR LOAN AND LEASE LOSSES	3 Months Ended
	Mar. 31, 2018
Receivables [Abstract]
ALLOWANCE FOR LOAN AND LEASE LOSSES	ALLOWANCE FOR LOAN AND LEASE LOSSES Loans and leases. Management maintains the ALLL at a level that it considers sufficient to absorb probable incurred loan and lease losses inherent in the portfolio. Management determines the adequacy of the ALLL based on historical loss experience as well as other significant factors such as composition of the portfolio, economic conditions, geographic footprint, the results of periodic internal and external evaluations of delinquent, nonaccrual and classified loans and any other adverse situations that may affect a specific borrower's ability to repay, including the timing of future payments. The ALLL is increased by provision expense and decreased by charge-offs, net of recoveries of amounts previously charged-off. First Financial's policy is to charge-off all or a portion of a loan when, in management's opinion, it is unlikely to collect the principal amount owed in full either through payments from the borrower or from the liquidation of collateral. Changes in the allowance for loan and lease losses by loan category were as follows: Three months ended March 31, 2018 Real Estate (Dollars in thousands) Commercial & industrial Lease financing Construction Commercial Residential Home equity Installment Credit card Total Allowance for loan and lease losses: Balance at beginning of period $ 17,598 $ 675 $ 3,577 $ 20,930 $ 4,683 $ 4,935 $ 307 $ 1,316 $ 54,021 Provision for loan and lease losses 889 (49 ) 690 815 114 (294 ) (49 ) 187 2,303 Loans charged off (885 ) 0 0 (2,176 ) (96 ) (242 ) (16 ) (254 ) (3,669 ) Recoveries 436 0 0 752 26 429 48 34 1,725 Total net charge-offs (449 ) 0 0 (1,424 ) (70 ) 187 32 (220 ) (1,944 ) Ending allowance for loan and lease losses $ 18,038 $ 626 $ 4,267 $ 20,321 $ 4,727 $ 4,828 $ 290 $ 1,283 $ 54,380 As of March 31, 2018 Real Estate (Dollars in thousands) Commercial & industrial Lease financing Construction Commercial Residential Home equity Installment Credit card Total Ending allowance balance attributable to loans Individually evaluated for impairment $ 100 $ 0 $ 0 $ 26 $ 160 $ 2 $ 0 $ 0 $ 288 Collectively evaluated for impairment 17,938 626 4,267 20,295 4,567 4,826 290 1,283 54,092 Ending allowance for loan and lease losses $ 18,038 $ 626 $ 4,267 $ 20,321 $ 4,727 $ 4,828 $ 290 $ 1,283 $ 54,380 Loans Individually evaluated for impairment $ 8,810 $ 0 $ 26 $ 24,736 $ 7,175 $ 4,173 $ 306 $ 0 $ 45,226 Collectively evaluated for impairment 1,934,931 81,617 494,639 2,519,315 461,409 479,470 38,942 46,472 6,056,795 Total loans $ 1,943,741 $ 81,617 $ 494,665 $ 2,544,051 $ 468,584 $ 483,643 $ 39,248 $ 46,472 $ 6,102,021 Three months ended March 31, 2017 Real Estate (Dollars in thousands) Commercial & industrial Lease financing Construction Commercial Residential Home equity Installment Credit card Total Allowance for loan and lease losses: Balance at beginning of period $ 19,225 $ 716 $ 3,282 $ 26,540 $ 3,208 $ 3,043 $ 388 $ 1,559 $ 57,961 Provision for loan and lease losses (596 ) (100 ) 325 (2,566 ) 2,329 805 9 161 367 Loans charged off (1,743 ) 0 0 (485 ) (61 ) (180 ) (49 ) (232 ) (2,750 ) Recoveries 262 0 0 256 9 106 71 44 748 Total net charge-offs (1,481 ) 0 0 (229 ) (52 ) (74 ) 22 (188 ) (2,002 ) Ending allowance for loan and lease losses $ 17,148 $ 616 $ 3,607 $ 23,745 $ 5,485 $ 3,774 $ 419 $ 1,532 $ 56,326 As of December 31, 2017 Real Estate (Dollars in thousands) Commercial & industrial Lease financing Construction Commercial Residential Home equity Installment Credit card Total Ending allowance balance attributable to loans Individually evaluated for impairment $ 169 $ 0 $ 0 $ 448 $ 160 $ 2 $ 0 $ 0 $ 779 Collectively evaluated for impairment 17,429 675 3,577 20,482 4,523 4,933 307 1,316 53,242 Ending allowance for loan and lease losses $ 17,598 $ 675 $ 3,577 $ 20,930 $ 4,683 $ 4,935 $ 307 $ 1,316 $ 54,021 Loans Individually evaluated for impairment $ 7,331 $ 82 $ 29 $ 21,542 $ 7,932 $ 4,456 $ 255 $ 0 $ 41,627 Collectively evaluated for impairment 1,905,412 89,265 467,701 2,468,549 463,459 489,148 41,331 46,691 5,971,556 Total loans $ 1,912,743 $ 89,347 $ 467,730 $ 2,490,091 $ 471,391 $ 493,604 $ 41,586 $ 46,691 $ 6,013,183

GOODWILL AND OTHER INTANGIBLE A

GOODWILL AND OTHER INTANGIBLE ASSETS	3 Months Ended
	Mar. 31, 2018
Goodwill and Intangible Assets Disclosure [Abstract]
GOODWILL AND OTHER INTANGIBLE ASSETS	GOODWILL AND OTHER INTANGIBLE ASSETS Goodwill. Assets and liabilities acquired in a business combination are recorded at their estimated fair values as of the acquisition date. The excess cost of the acquisition over the fair value of net assets acquired is recorded as goodwill. First Financial had goodwill of $204.1 million as of March 31, 2018 and December 31, 2017 , respectively, and recorded no additional goodwill during 2018 or 2017. Goodwill is evaluated for impairment on an annual basis as of October 1 of each year, or whenever events or changes in circumstances indicate that the fair value of a reporting unit may be below its carrying value. First Financial performed its most recent annual impairment test as of October 1, 2017 and no impairment was indicated. As of March 31, 2018 , no events or changes in circumstances indicated that the fair value of a reporting unit was below its carrying value. Other intangible assets. As of March 31, 2018 and December 31, 2017 , First Financial had $5.0 million and $5.3 million , respectively, of other intangible assets, which primarily consist of core deposit intangibles and are included in Goodwill and other intangibles in the Consolidated Balance Sheets. Core deposit intangibles represent the estimated fair value of acquired customer deposit relationships. Core deposit intangibles are recorded at fair value on the date of acquisition and are then amortized on an accelerated basis over their estimated useful lives. Core deposit intangibles were $3.1 million and $3.3 million as of March 31, 2018 and December 31, 2017 , respectively. First Financial's core deposit intangibles have an estimated weighted average remaining life of 3.6 years . Amortization expense recognized on intangible assets for the three months ended March 31, 2018 and 2017 was $0.3 million

BORROWINGS

BORROWINGS	3 Months Ended
	Mar. 31, 2018
Debt Disclosure [Abstract]
BORROWINGS	BORROWINGS Short-term borrowings on the Consolidated Balance Sheets include repurchase agreements utilized for corporate sweep accounts with cash management account agreements in place, overnight advances from the FHLB and a short-term line of credit. All repurchase agreements are subject to terms and conditions of repurchase/security agreements between the Bank and the client. To secure its liability to the client, the Bank is authorized to sell or repurchase U.S. Treasury, government agency and mortgage-backed securities. First Financial had $601.6 million in short-term borrowings with the FHLB at March 31, 2018 and $742.3 million as of December 31, 2017 . These short-term borrowings are used to manage normal liquidity needs and support the Company's asset and liability management strategies. First Financial has a $15.0 million short-term credit facility with an unaffiliated bank that matures on May 29, 2018. This facility can have a variable or fixed interest rate and provides First Financial additional liquidity, if needed, for various corporate activities including the repurchase of First Financial common stock and the payment of dividends to shareholders. As of March 31, 2018 and December 31, 2017 , there was no outstanding balance. The credit agreement requires First Financial to comply with certain covenants including those related to asset quality and capital levels, and First Financial was in compliance with all covenants associated with this facility as of March 31, 2018 and December 31, 2017 . In 2015, First Financial issued $120.0 million of subordinated notes, which have a fixed interest rate of 5.125% payable semiannually and mature on August 25, 2025. These notes are not redeemable by the Company, or callable by the holders of the notes prior to maturity. The subordinated notes are treated as Tier 2 capital for regulatory capital purposes and are included in Long-term debt on the Consolidated Balance Sheets. Long-term debt also includes $50.2 million and $0.2 million of FHLB long-term advances as of March 31, 2018 and December 31, 2017 , respectively. The $50.0 million of additional FHLB long-term advance matures in 2020 with a fixed rate of 2.63% . These instruments are primarily utilized to reduce overnight liquidity risk and to mitigate interest rate sensitivity on the Consolidated Balance Sheets. The following is a summary of First Financial's long-term debt: March 31, 2018 December 31, 2017 (Dollars in thousands) Amount Average rate Amount Average rate Subordinated notes $ 120,000 5.13 % $ 120,000 5.13 % Unamortized debt issuance costs (1,318 ) N/A (1,362 ) N/A FHLB borrowings 50,238 2.63 % 241 1.09 % Capital loan with municipality 775 0.00 % 775 0.00 % Total long-term debt $ 169,695 4.40 % $ 119,654 5.14 %

ACCUMULATED OTHER COMPREHENSIVE

ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS)	3 Months Ended
	Mar. 31, 2018
Equity [Abstract]
ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS)	ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS) Shareholders’ equity is affected by transactions and valuations of asset and liability positions that require adjustments to accumulated other comprehensive income (loss). The related tax effects allocated to other comprehensive income and reclassifications out of accumulated other comprehensive income (loss) are as follows: Three months ended March 31, 2018 Total other comprehensive income (loss) Total accumulated other comprehensive income (loss) (Dollars in thousands) Prior to Reclass Reclass from Pre-tax Tax-effect Net of tax Beginning Balance Net Activity Reclass of Stranded Tax Effects Ending Balance Unrealized gain (loss) on investment securities $ (12,536 ) $ 0 $ (12,536 ) $ 2,706 $ (9,830 ) $ (182 ) $ (9,830 ) $ (39 ) $ (10,051 ) Unrealized gain (loss) on derivatives 202 0 202 (46 ) 156 (577 ) 156 (124 ) (545 ) Retirement obligation 0 (419 ) 419 (96 ) 323 (19,631 ) 323 (4,779 ) (24,087 ) Total $ (12,334 ) $ (419 ) $ (11,915 ) $ 2,564 $ (9,351 ) $ (20,390 ) $ (9,351 ) $ (4,942 ) $ (34,683 ) Three months ended March 31, 2017 Total other comprehensive income (loss) Total accumulated other comprehensive income (loss) (Dollars in thousands) Prior to Reclass Reclass from Pre-tax Tax-effect Net of tax Beginning Balance Net Activity Ending Balance Unrealized gain (loss) on investment securities $ 2,832 $ 516 $ 2,316 $ (829 ) $ 1,487 $ (4,549 ) $ 1,487 $ (3,062 ) Unrealized gain (loss) on derivatives 203 0 203 (75 ) 128 (1,091 ) 128 (963 ) Retirement obligation 0 (335 ) 335 (146 ) 189 (22,803 ) 189 (22,614 ) Total $ 3,035 $ 181 $ 2,854 $ (1,050 ) $ 1,804 $ (28,443 ) $ 1,804 $ (26,639 ) The following table presents the activity reclassified from accumulated other comprehensive income into income during the three month periods ended March 31, 2018 and 2017, respectively: Amount reclassified from accumulated other comprehensive income (1) Three months ended March 31, (Dollars in thousands) 2018 2017 Affected Line Item in the Consolidated Statements of Income Realized gains and losses on securities available-for-sale $ 0 $ 516 Net gains on sales of investments securities Defined benefit pension plan Amortization of prior service cost (2) 103 103 Salaries and employee benefits Recognized net actuarial loss (2) (522 ) (438 ) Salaries and employee benefits Defined benefit pension plan total (419 ) (335 ) Total reclassifications for the period, before tax $ (419 ) $ 181 (1) Negative amounts are reductions to net income. (2)

DERIVATIVES

DERIVATIVES	3 Months Ended
	Mar. 31, 2018
Derivative Instruments and Hedging Activities Disclosure [Abstract]
DERIVATIVES	DERIVATIVES First Financial uses certain derivative instruments, including interest rate caps, floors and swaps, to meet the needs of its clients while managing the interest rate risk associated with certain transactions. First Financial does not use derivatives for speculative purposes. First Financial primarily utilizes interest rate swaps as a means to offer borrowers credit-based products that meet their needs. First Financial may also utilize interest rate swaps to manage the interest rate risk profile of the Company. Interest rate payments are exchanged with counterparties based on the notional amount established in the interest rate agreement. As only interest rate payments are exchanged, the cash requirements and credit risk associated with interest rate swaps are significantly less than the notional amount and the Company’s credit risk exposure is limited to the market value of the instruments. First Financial manages market value credit risk through counterparty credit policies, which require the Company to maintain a total derivative notional position of less than 35% of assets, total credit exposure of less than 3% of capital and no single counterparty credit risk exposure greater than $20.0 million . The Company is currently below all single counterparty and portfolio limits. At March 31, 2018 , the Company had a total counterparty notional amount outstanding of $908.6 million , spread among fourteen counterparties, with an outstanding asset from these contracts of $10.4 million . At December 31, 2017 , the Company had a total counterparty notional amount outstanding of $837.5 million , spread among thirteen counterparties, with an outstanding liability from these contracts of $1.3 million . First Financial monitors its derivative credit exposure to borrowers by monitoring the creditworthiness of the related loan customers through the normal credit review processes the Company performs on all borrowers. Additionally, the Company monitors derivative credit risk exposure related to problem loans through the Company's ALLL committee. First Financial considers the market value of a derivative instrument to be part of the carrying value of the related loan for these purposes as the borrower is contractually obligated to pay First Financial this amount in the event the derivative contract is terminated. Client Derivatives. First Financial utilizes interest rate swaps as a means to offer commercial borrowers fixed rate funding while providing the Company with floating rate assets. The following table details the classification and amounts recognized in the Consolidated Balance Sheets for client derivatives: March 31, 2018 December 31, 2017 Estimated fair value Estimated fair value (Dollars in thousands) Balance sheet classification Notional amount Gain Loss Notional amount Gain Loss Client derivatives - instruments associated with loans Matched interest rate swaps with borrower Accrued interest and other assets $ 908,216 $ 3,100 $ (13,225 ) $ 837,040 $ 7,153 $ (5,529 ) Matched interest rate swaps with counterparty Accrued interest and other liabilities 908,216 13,225 (3,102 ) 837,040 5,529 (7,158 ) Total $ 1,816,432 $ 16,325 $ (16,327 ) $ 1,674,080 $ 12,682 $ (12,687 ) In connection with its use of derivative instruments, First Financial and its counterparties are required to post cash collateral to offset the market position of the derivative instruments under certain conditions. First Financial maintains the right to offset these derivative positions with the collateral posted against them by or with the relevant counterparties. First Financial classifies the derivative cash collateral outstanding with its counterparties as an adjustment to the fair value of the derivative contracts within Accrued interest and other assets or Accrued interest and other liabilities in the Consolidated Balance Sheets. The following table discloses the gross and net amounts of client derivative liabilities recognized in the Consolidated Balance Sheets: March 31, 2018 December 31, 2017 (Dollars in thousands) Gross amounts of recognized liabilities Gross amounts offset in the Consolidated Balance Sheets Net amounts of assets presented in the Consolidated Balance Sheets Gross amounts of recognized liabilities Gross amounts offset in the Consolidated Balance Sheets Net amounts of assets presented in the Consolidated Balance Sheets Client derivatives Matched interest rate swaps with counterparty $ 16,327 $ 24,475 $ 40,802 $ 12,687 $ 2,279 $ 14,966 The following table details the derivative financial instruments, the average remaining maturities and the weighted-average interest rates being paid and received by First Financial at March 31, 2018 : Weighted-average rate (Dollars in thousands) Notional amount Average maturity (years) Fair value Receive Pay Client derivatives Receive fixed, matched interest rate swaps with borrower $ 908,216 5.8 $ (10,125 ) 4.47 % 3.80 % Pay fixed, matched interest rate swaps with counterparty 908,216 5.8 10,123 3.80 % 4.47 % Total client derivatives $ 1,816,432 5.8 $ (2 ) 4.13 % 4.13 % Credit Derivatives. In conjunction with participating interests in commercial loans, First Financial periodically enters into risk participation agreements with counterparties whereby First Financial assumes a portion of the credit exposure associated with an interest rate swap on the participated loan in exchange for a fee. Under these agreements, First Financial will make payments to the counterparty if the loan customer defaults on its obligation to perform under the interest rate swap contract with the counterparty. The total notional value of these agreements totaled $95.6 million as of March 31, 2018 and $95.9 million as of December 31, 2017 . The fair value of these agreements is recorded in Accrued interest and other liabilities on the Consolidated Balance Sheets. Mortgage Derivatives. First Financial enters into IRLCs and forward commitments for the future delivery of mortgage loans to third party investors, which are considered derivatives. When borrowers secure an IRLC with First Financial and the loan is intended to be sold, First Financial will enter into forward commitments for the future delivery of the loans to third party investors in order to hedge against the effect of changes in interest rates impacting IRLCs and loans held for sale. At March 31, 2018 , the notional amount of the IRLCs was $13.0 million and the notional amount of forward commitments was $10.1 million . As of December 31, 2017 , the notional amount of IRLCs was $12.3 million and the notional amount of forward commitments was $15.4 million . The fair value of these agreements was recorded on the Consolidated Balance Sheets in Accrued interest and other assets and was $0.1 million at both March 31, 2018 and December 31, 2017

COMMITMENTS AND CONTINGENCIES

COMMITMENTS AND CONTINGENCIES	3 Months Ended
	Mar. 31, 2018
Commitments and Contingencies Disclosure [Abstract]
COMMITMENTS AND CONTINGENCIES	COMMITMENTS AND CONTINGENCIES First Financial offers a variety of financial instruments including standby letters of credit and outstanding commitments to extend credit to assist clients in meeting their requirement for liquidity and credit enhancement. GAAP does not require these financial instruments to be recorded in the Consolidated Financial Statements. First Financial utilizes the same credit policies in issuing commitments and conditional obligations as it does for credit instruments recorded on the Consolidated Balance Sheets. First Financial’s exposure to credit loss in the event of nonperformance by the counterparty is represented by the contractual amounts of those instruments. First Financial utilizes the ALLL methodology to maintain a reserve that it considers sufficient to absorb probable incurred losses inherent in letters of credit and outstanding loan commitments and records the reserve within Accrued interest and other liabilities on the Consolidated Balance Sheets. Loan commitments. Loan commitments are agreements to extend credit to a client, absent any violation of conditions established in the commitment agreement. Commitments generally have fixed expiration dates or other termination clauses and may require payment of a fee. Since many of the commitments are expected to expire without being drawn upon, the total commitment amounts do not necessarily represent future cash requirements. The amount of collateral obtained, if deemed necessary by First Financial upon extension of credit, is based on management’s credit evaluation of the client. The collateral held varies, but may include securities, real estate, inventory, plant or equipment. First Financial had commitments outstanding to extend credit totaling $2.0 billion and $2.1 billion at March 31, 2018 and December 31, 2017 , respectively. As of March 31, 2018 , loan commitments with a fixed interest rate totaled $75.6 million while commitments with variable interest rates totaled $2.0 billion . At December 31, 2017 , loan commitments with a fixed interest rate totaled $44.3 million while commitments with variable interest rates totaled $2.0 billion . The fixed rate loan commitments have interest rates ranging from 0.00% to 21.00% and maturities ranging from less than 1 year to 30 years . Letters of credit. Letters of credit are conditional commitments issued by First Financial to guarantee the performance of a client to a third party. First Financial’s portfolio of letters of credit consists primarily of performance assurances made on behalf of clients who have a contractual commitment to produce or deliver goods or services. The risk to First Financial arises from its obligation to make payment in the event of the client's contractual default to produce the contracted good or service to a third party. First Financial issued letters of credit aggregating $25.0 million and $25.3 million at March 31, 2018 and December 31, 2017 , respectively. Management conducts regular reviews of these instruments on an individual client basis. Investments in affordable housing tax credits. First Financial has made investments in certain qualified affordable housing tax credits. These credits are an indirect federal subsidy that provide tax incentives to encourage investment in the development, acquisition and rehabilitation of affordable rental housing, and allow investors to claim tax credits and other tax benefits (such as deductions from taxable income for operating losses) on their federal income tax returns. The principal risk associated with qualified affordable housing investments is the potential for noncompliance with the tax code requirements, such as failure to rent property to qualified tenants, resulting in the unavailability or recapture of the tax credits and other tax benefits. Investments in affordable housing projects are accounted for under the proportional amortization method and are included in Accrued interest and other assets in the Consolidated Balance Sheets. First Financial's affordable housing commitments totaled $33.2 million and $35.9 million as of March 31, 2018 and December 31, 2017 , respectively. The Company recognized tax credits of $1.1 million and $0.8 million for the three months ended March 31, 2018 and 2017 , respectively. The Company recognized amortization expense which was included in income tax expense of $1.3 million and $1.0 million for the three months ended March 31, 2018 and 2017 , respectively. First Financial had no affordable housing contingent commitments as of March 31, 2018 or December 31, 2017 . Investments in historic tax credits. First Financial has noncontrolling financial investments in private investment funds and partnerships which are not consolidated. These investments may generate a return through the realization of federal and state income tax credits, as well as other tax benefits, such as tax deductions from net operating losses of the investments over a period of time. Investments in historic tax credits are accounted for under the equity method of accounting and are carried in Accrued interest and other assets on the Consolidated Balance Sheets. The Company’s recorded investment in these entities was approximately $2.9 million at March 31, 2018 and $3.0 million at December 31, 2017 . The maximum exposure to loss related to these investments was $2.9 million at March 31, 2018 and $3.0 million at December 31, 2017 , representing the Company’s investment balance and its unfunded commitments to invest additional amounts. Investments in historic tax credits resulted in $0.1 million of tax credits for each of the three months ended March 31, 2018 and 2017 , respectively. Contingencies/Litigation. First Financial and its subsidiaries are engaged in various matters of litigation, other assertions of improper or fraudulent loan practices or lending violations and other matters from time to time, and have a number of unresolved claims pending. Additionally, as part of the ordinary course of business, First Financial and its subsidiaries are parties to litigation involving claims to the ownership of funds in particular accounts, the collection of delinquent accounts, challenges to security interests in collateral and foreclosure interests that are incidental to our regular business activities. While the ultimate liability with respect to these other litigation matters and claims cannot be determined at this time, First Financial believes that damages, if any, and other amounts relating to pending matters are not probable or cannot be reasonably estimated as of March 31, 2018 . Reserves are established for these various matters of litigation, when appropriate, under FASB ASC Topic 450, Contingencies, based in part upon the advice of legal counsel. First Financial had no reserves related to litigation matters as of March 31, 2018 or December 31, 2017

INCOME TAXES

INCOME TAXES	3 Months Ended
	Mar. 31, 2018
Income Tax Disclosure [Abstract]
INCOME TAXES	INCOME TAXES For the first quarter 2018 , income tax expense was $7.7 million , resulting in an effective tax rate of 20.1% compared with income tax expense of $10.5 million and an effective tax rate of 30.0% for the comparable period in 2017. ASU 2016-09, Compensation-Stock Compensation Improvements to Employee Share-Based Payment Accounting, requires the recognition of the income tax effects of share-based awards through the income statement as a component of income tax expense. First Financial recorded a $0.4 million and $1.1 million tax benefit as a result of share awards vesting and exercised during the first quarters of 2018 and 2017, respectively. On December 22, 2017, the Tax Cuts and Jobs Act was signed into law. As a result, First Financial valued its deferred tax assets and liabilities as well as its investments in affordable housing projects utilizing a 21% federal rate during the first quarter of 2018 compared to a 35% rate in the first quarter of 2017. At both March 31, 2018 and December 31, 2017 , First Financial had $2.9 million of unrecognized tax benefits, as determined in FASB ASC Topic 740-10, Income Taxes that, if recognized, would favorably affect the effective income tax rate in future periods. The unrecognized tax benefits relate to state income tax exposures from taking tax positions where the Company believes it is likely that, upon examination, a state may take a position contrary to the position taken by the Company. The Company believes that resolution regarding our uncertain tax positions is reasonably possible within the next twelve months and could result in full, partial or no recognition of the benefit. First Financial recognizes interest accrued related to unrecognized tax benefits and penalties as income tax expense. At March 31, 2018 and December 31, 2017 , the Company had no interest or penalties recorded. First Financial and its subsidiaries are subject to U.S. federal income tax as well as state and local income tax in several jurisdictions. Tax years prior to 2014 have been closed and are no longer subject to U.S. federal income tax examinations. Tax years 2014 through 2017 remain open to examination by the federal taxing authority.

EMPLOYEE BENEFIT PLANS

EMPLOYEE BENEFIT PLANS	3 Months Ended
	Mar. 31, 2018
Retirement Benefits [Abstract]
EMPLOYEE BENEFIT PLANS	EMPLOYEE BENEFIT PLANS First Financial sponsors a non-contributory defined benefit pension plan covering substantially all employees and uses a December 31 measurement date for the plan. Plan assets were primarily invested in fixed income and publicly traded equity mutual funds. The pension plan does not directly own any shares of First Financial common stock or any other First Financial security or product. First Financial made no cash contributions to fund the pension plan during the three months ended March 31, 2018 , or the year ended December 31, 2017, and does not expect to make cash contributions to the plan through the remainder of 2018. As a result of the plan’s actuarial projections, First Financial recorded income of 0.2 million and 0.3 million for the three months ended March 31, 2018 and 2017, respectively. The following table sets forth information concerning amounts recognized in First Financial’s Consolidated Statements of Income related to the Company's pension plan: Three months ended March 31, (Dollars in thousands) 2018 2017 Service cost $ 1,295 $ 1,238 Interest cost 590 589 Expected return on assets (2,460 ) (2,481 ) Amortization of prior service cost (103 ) (103 ) Net actuarial loss 522 438 Net periodic benefit (income) cost $ (156 ) $ (319 )

EARNINGS PER COMMON SHARE

EARNINGS PER COMMON SHARE	3 Months Ended
	Mar. 31, 2018
Earnings Per Share [Abstract]
EARNINGS PER COMMON SHARE	EARNINGS PER COMMON SHARE The following table sets forth the computation of basic and diluted earnings per share: Three months ended March 31, (Dollars in thousands, except per share data) 2018 2017 Numerator Net income available to common shareholders $ 30,506 $ 24,414 Denominator Basic earnings per common share - weighted average shares 61,654,686 61,398,414 Effect of dilutive securities Employee stock awards 464,254 674,589 Warrants 61,804 67,381 Diluted earnings per common share - adjusted weighted average shares 62,180,744 62,140,384 Earnings per share available to common shareholders Basic $ 0.49 $ 0.40 Diluted $ 0.49 $ 0.39 Warrants to purchase 101,808 and 112,233 shares of the Company's common stock were outstanding as of March 31, 2018 and 2017 , respectively. These warrants, each representing the right to purchase one share of common stock, no par value per share, have an exercise price of $12.11 and expire on December 23, 2018. Stock options and warrants with exercise prices greater than the average market price of the common shares were not included in the computation of net income per diluted share, as they would have been antidilutive. Using the end of period price of the Company's common shares, there were no antidilutive options at March 31, 2018 and March 31, 2017

REVENUE RECOGNITION REVENUE REC

REVENUE RECOGNITION REVENUE RECOGNITION	3 Months Ended
	Mar. 31, 2018
Revenue Recognition [Abstract]
REVENUE RECOGNITION	REVENUE RECOGNITION On January 1, 2018, the Company adopted ASU No. 2014-09, Revenue from Contracts with Customers using the modified retrospective method applied to all contracts not completed as of January 1, 2018. Results for reporting periods beginning after January 1, 2018 are presented under the guidance set forth in this update while prior period amounts continue to be reported in accordance with legacy GAAP. Adoption of this update did not result in a change to the accounting for any of the in-scope revenue streams. As such, no cumulative effect adjustment to retained earnings was recorded. The majority of the Company's revenues come from interest income and other sources, including loans, leases, securities and derivatives, that are outside the scope of this guidance. The Company's services that fall within the scope of this ASU are presented within Noninterest income and are recognized as revenue as the Company satisfies its obligation to the customer. Services within the scope of this guidance include service charges on deposits, wealth management fees, bankcard income, investment brokerage fees and the sale of OREO. Service charges on deposit accounts. The Company 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 as that is the point in time the Company fulfills the customer's request. Account maintenance fees, which relate primarily to monthly maintenance, are earned over the course of a month, representing the period over which the Company satisfies the performance obligation. Similarly, overdraft fees are recognized at the point in time that the overdraft occurs as this corresponds with the Company's performance obligation. Service charges on deposit accounts are withdrawn from the customer's account balance. Trust and wealth management fees. Trust and wealth management fees are primarily asset-based, but can also include flat fees based upon a specific service rendered, such as tax preparation services. The Company’s performance obligation is generally satisfied over time and the resulting fees are recognized monthly, based upon the month-end market value of the assets under management and the applicable fees. The Company does not earn performance-based incentives. Optional services such as real estate sales and tax return preparation services are also available to existing trust and wealth management customers. The Company’s performance obligation for these transactional-based services is generally satisfied, and related revenue recognized as incurred. Bankcard income. The Company earns interchange fees from cardholder transactions conducted through the Visa payment network. 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. Interchange income is presented on the Consolidated Statements of Income net of expenses. Gross interchange income for the first quarter of 2018 was $5.4 million , which was partially offset by $2.0 million of expenses within Noninterest income. Gains/losses on sale of OREO. The Company 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 the executed deed. When the Company finances the sale of OREO to the buyer, the Company assesses whether the buyer is committed to perform their obligations under the contract and whether collectibility 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 Company adjusts the transaction price and related gain (loss) on sale if a significant component is present. Other. Other noninterest income consists of other recurring revenue streams such as transaction fees, safe deposit rental income, insurance commissions, merchant referral income and brokerage revenue. Transaction fees primarily include check printing sales commissions, collection fees, and wire transfer fees which arise from in-branch transactions. Safe deposit rental income arises from services charged to the customer on an annual basis and recognized upon receipt of payment. Insurance commissions are agent commissions earned by the Company and earned upon the effective date of the bound coverage. Merchant referral income is associated with a program whereby the Company receives a share of processing revenue that is generated from clients that were referred by First Financial to the service provider. Revenue is recognized at the point in time when the transaction occurs. Brokerage revenue represents fees from investment brokerage services provided to customers by a third party provider. The Company receives commissions from the third-party service provider on a monthly basis based upon customer activity for the month. The fees are recognized monthly and a receivable is recorded until commissions are paid the following month. Because the Company (i) acts as an agent in arranging the relationship between the customer and the third-party service provider and (ii) does not control the services rendered to the customers, investment brokerage fees are presented net of related costs.

FAIR VALUE DISCLOSURES

FAIR VALUE DISCLOSURES	3 Months Ended
	Mar. 31, 2018
Fair Value Disclosures [Abstract]
FAIR VALUE DISCLOSURES	FAIR VALUE DISCLOSURES Fair Value Measurement The fair value framework as disclosed in the Fair Value Topic includes a hierarchy which focuses on prioritizing the inputs used in valuation techniques. The fair value hierarchy gives the highest priority to quoted prices in active markets for identical assets or liabilities (Level 1), a lower priority to observable inputs other than quoted prices in active markets for identical assets and liabilities (Level 2) and the lowest priority to unobservable inputs (Level 3). When determining the fair value measurements for assets and liabilities, First Financial looks to active markets to price identical assets or liabilities whenever possible and classifies such items in Level 1. When identical assets and liabilities are not traded in active markets, First Financial looks to observable market data for similar assets and liabilities and classifies such items as Level 2. Certain assets and liabilities are not actively traded in observable markets and First Financial must use alternative techniques, based on unobservable inputs, to determine the fair value and classifies such items as Level 3. The level within the fair value hierarchy is based on the lowest level of input that is significant in the fair value measurement. The estimated fair values of First Financial’s financial instruments not measured at fair value on a recurring or nonrecurring basis in the consolidated financial statements were as follows: Carrying Estimated fair value (Dollars in thousands) value Total Level 1 Level 2 Level 3 March 31, 2018 Financial assets Cash and short-term investments $ 126,781 $ 126,781 $ 126,781 $ 0 $ 0 Investment securities held-to-maturity 633,722 623,967 0 623,967 0 Other investments 53,070 N/A N/A N/A N/A Loans held for sale 8,048 8,048 0 8,048 0 Loans and leases 6,047,641 6,098,950 0 0 6,098,950 Accrued interest receivable 25,842 25,842 0 8,232 17,610 Financial liabilities Deposits 7,010,504 6,994,627 0 6,994,627 0 Short-term borrowings 658,332 658,332 658,332 0 0 Long-term debt 169,695 165,569 0 165,569 0 Accrued interest payable 4,091 4,091 375 3,716 0 Carrying Estimated fair value (Dollars in thousands) value Total Level 1 Level 2 Level 3 December 31, 2017 Financial assets Cash and short-term investments $ 184,624 $ 184,624 $ 184,624 $ 0 $ 0 Investment securities held-to-maturity 654,008 653,101 0 653,101 0 Other investments 53,140 N/A N/A N/A N/A Loans held for sale 11,502 11,502 0 11,502 0 Loans and leases 5,959,162 6,006,656 0 0 6,006,656 Accrued interest receivable 24,496 24,496 0 8,265 16,231 Financial liabilities Deposits 6,895,046 6,884,615 0 6,884,615 0 Short-term borrowings 814,565 814,565 814,565 0 0 Long-term debt 119,654 117,908 0 117,908 0 Accrued interest payable 5,104 5,104 204 4,900 0 N/A = Not applicable The methods utilized to estimate the fair value of financial instruments at December 31, 2017 did not necessarily represent an exit price. In accordance with our adoption of ASU 2016-01 in 2018, the methods utilized to measure the fair value of financial instruments at March 31, 2018 represent an approximation of exit price, however, an actual exit price may differ. The following methods, assumptions and valuation techniques were used by First Financial to measure different financial assets and liabilities at fair value on a recurring or nonrecurring basis. Investment securities. Investment securities classified as trading and available-for-sale are recorded at fair value on a recurring basis. Fair value measurement is based upon quoted market prices, when available (Level 1). If quoted market prices are not available, fair values are measured utilizing independent valuation techniques of identical or similar investment securities. First Financial compiles prices from various sources who 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 the specific investment securities but rather relying on the investment securities’ relationship to other benchmark quoted investment securities. Any investment securities not valued based upon the methods previously described are considered Level 3. First Financial utilizes values provided by third-party pricing vendors to price the investment securities portfolio in accordance with the fair value hierarchy of the Fair Value Topic and reviews the pricing methodologies utilized by the pricing vendors to ensure that the fair value determination is consistent with the applicable accounting guidance. First Financial’s pricing process includes a series of quality assurance activities where prices are compared to recent market conditions, historical prices and other independent pricing services. Further, the Company periodically validates the fair value of a sample of securities in the portfolio by comparing the fair values to prices from other independent sources for the same or similar securities. First Financial analyzes unusual or significant variances, conducts additional research with the pricing vendor, and if necessary, takes appropriate action based on its findings. The results of the quality assurance process are incorporated into the selection of pricing providers by the portfolio manager. Impaired loans. The fair value of impaired loans are specifically reviewed for purposes of determining the appropriate amount of impairment to be allocated to the ALLL. Fair value is generally measured based on the value of the collateral securing the loans. Collateral may be in the form of real estate or business assets including equipment, inventory and accounts receivable. The value of real estate collateral is determined utilizing an income or market valuation approach based on an appraisal conducted by an independent, licensed third-party appraiser (Level 3). The value of business equipment is based on an outside appraisal, if deemed significant, or the net book value on the applicable borrower financial statements. Likewise, values for inventory and accounts receivable collateral are based on borrower financial statement balances or aging reports on a discounted basis as appropriate (Level 3). Impaired loans are measured at fair value on a nonrecurring basis. Any fair value adjustments are recorded in the period incurred as provision for loan and lease losses on the Consolidated Statements of Income. OREO. Assets acquired through loan foreclosure are recorded at fair value less costs to sell, with any difference between the fair value of the property and the carrying value of the loan recorded as a charge-off. If the fair value is higher than the carrying amount of the loan, the excess is recognized first as a recovery and then as noninterest income. Subsequent declines in value are reported as adjustments to the carrying amount and are recorded in noninterest expense. The carrying value of OREO is not re-measured to fair value on a recurring basis, but is subject to fair value adjustments when the carrying value differs from the fair value, less estimated selling costs. Fair value is based on recent real estate appraisals and is updated at least annually. The Company classifies OREO in level 3 of the fair value hierarchy. Derivatives. The fair values of derivative instruments are based primarily on a net present value calculation of the cash flows related to the interest rate swaps at the reporting date, using primarily observable market inputs such as interest rate yield curves which represents the cost to terminate the swap if First Financial should choose to do so. Additionally, First Financial utilizes an internally-developed model to value the credit risk component of derivative assets and liabilities, which is recorded as an adjustment to the fair value of the derivative asset or liability on the reporting date. Derivative instruments are classified as Level 2 in the fair value hierarchy. The financial assets and liabilities measured at fair value on a recurring basis in the consolidated financial statements were as follows: Fair value measurements using (Dollars in thousands) Level 1 Level 2 Level 3 Assets/liabilities at fair value March 31, 2018 Assets Derivatives $ 0 $ 16,416 $ 0 $ 16,416 Investment securities available-for-sale 2,982 1,356,399 0 1,359,381 Total $ 2,982 $ 1,372,815 $ 0 $ 1,375,797 Liabilities Derivatives $ 0 $ 16,368 $ 0 $ 16,368 Fair value measurements using (Dollars in thousands) Level 1 Level 2 Level 3 Assets/liabilities at fair value December 31, 2017 Assets Derivatives $ 0 $ 12,757 $ 0 $ 12,757 Investment securities available-for-sale 2,969 1,346,439 0 1,349,408 Total $ 2,969 $ 1,359,196 $ 0 $ 1,362,165 Liabilities Derivatives $ 0 $ 12,755 $ 0 $ 12,755 Certain financial assets and liabilities are measured at fair value on a nonrecurring basis. Adjustments to the fair market value of these assets usually result from the application of fair value accounting or write-downs of individual assets. The following table summarizes financial assets and liabilities measured at fair value on a nonrecurring basis. Fair value measurements using (Dollars in thousands) Level 1 Level 2 Level 3 March 31, 2018 Assets Impaired loans $ 0 $ 0 $ 472 OREO 0 0 215 Fair value measurements using (Dollars in thousands) Level 1 Level 2 Level 3 December 31, 2017 Assets Impaired loans $ 0 $ 0 $ 2,671 OREO 0 0 1,086

BUSINESS COMBINATION Business C

BUSINESS COMBINATION Business Combination with MainSource Financial Group	3 Months Ended
	Mar. 31, 2018
Subsequent Events [Abstract]
Subsequent Event, Pro Forma Business Combinations or Disposals [Text Block]	On April 1, 2018, the Company completed its acquisition of MainSource Financial Group, Inc. and its banking subsidiary, MainSource Bank. Under the terms of the merger agreement, shareholders of MainSource received 1.3875 common shares of First Financial common stock for each share of MainSource common stock. Including outstanding options and warrants on MainSource common stock, total purchase consideration was $1.0 billion . The final fair values of assets and liabilities are not yet available. As of March 31, 2018, MainSource had total assets of $4.6 billion , gross loans of $3.0 billion and total deposits of $3.4 billion . The Company anticipates recording goodwill and core deposit intangibles with this acquisition.

SUMMARY OF SIGNIFICANT ACCOUNTI

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Policies)	3 Months Ended
	Mar. 31, 2018
Off-Balance-Sheet Credit Exposure, Policy [Policy Text Block]	Letters of credit are conditional commitments issued by First Financial to guarantee the performance of a client to a third party.  First Financial’s portfolio of letters of credit consists primarily of performance assurances made on behalf of clients who have a contractual commitment to produce or deliver goods or services.  The risk to First Financial arises from its obligation to make payment in the event of the client's contractual default to produce the contracted good or service to a third party.
Basis of Presentation Policy	The Consolidated Financial Statements of First Financial Bancorp., a financial holding company principally serving Ohio, Indiana and Kentucky, include the accounts and operations of First Financial and its wholly-owned subsidiary, First Financial Bank. All significant intercompany transactions and accounts have been eliminated in consolidation.  Certain reclassifications of prior periods' amounts have been made to conform to current year presentation. Such reclassifications had no effect on net earnings.
Use of Estimates, Policy	The preparation of financial statements in conformity with GAAP requires management to make estimates, assumptions and judgments that affect the amounts reported in the Consolidated Financial Statements and accompanying Notes. These estimates, assumptions and judgments are inherently subjective and may be susceptible to significant change. Actual realized amounts could differ materially from these estimates.
Loans and Leases Receivable, Past Due Status, Policy	Loans are considered past due or delinquent when the contractual principal or interest due in accordance with the terms of the loan agreement or any portion thereof remains unpaid after the date of the scheduled payment.
Loans and Leases Receivable, Nonaccrual Loan and Lease Status, Policy	Loans are classified as nonaccrual when, in the opinion of management, collection of principal or interest is doubtful or when principal or interest payments are 90 days or more past due. Generally, loans are classified as nonaccrual due to the continued failure to adhere to contractual payment terms by the borrower, coupled with other pertinent factors. When a loan is classified as nonaccrual, the accrual of interest income is discontinued and previously accrued but unpaid interest is reversed. Any payments received while a loan is on nonaccrual status are applied as a reduction to the carrying value of the loan. A loan classified as nonaccrual may return to accrual status if collection of future principal and interest payments is no longer doubtful. Purchased impaired loans are classified as performing, even though they may be contractually past due, as any nonpayment of contractual principal or interest is considered in the periodic re-estimation of expected cash flows and is included in the resulting recognition of current period provision for loan and lease losses or prospective yield adjustments.
Loans and Leases Receivable, Troubled Debt Restructuring Policy	A loan modification is considered a TDR when the borrower is experiencing financial difficulty and concessions are made by the Company that would not otherwise be considered for a borrower with similar credit characteristics. The most common types of modifications include interest rate reductions, maturity extensions and modifications to principal amortization, including interest-only structures. Modified terms are dependent upon the financial position and needs of the individual borrower. If the modification agreement is violated, the loan is managed by the Company’s credit administration group for resolution, which may result in foreclosure in the case of real estate.
Impaired Financing Receivable, Policy	First Financial individually reviews all impaired commercial loan relationships, as well as consumer loan TDRs, greater than $250,000
Loans and Leases Receivable, Real Estate Acquired Through Foreclosure, Policy	OREO consists of properties acquired by the Company primarily through the loan foreclosure or repossession process, or other resolution activity that results in partial or total satisfaction of problem loans.
Loans and Leases Receivable, Allowance for Loan Losses Policy	Management maintains the ALLL at a level that it considers sufficient to absorb probable incurred loan and lease losses inherent in the portfolio. Management determines the adequacy of the ALLL based on historical loss experience as well as other significant factors such as composition of the portfolio, economic conditions, geographic footprint, the results of periodic internal and external evaluations of delinquent, nonaccrual and classified loans and any other adverse situations that may affect a specific borrower's ability to repay, including the timing of future payments.
Goodwill and Intangible Assets, Goodwill, Policy	Assets and liabilities acquired in a business combination are recorded at their estimated fair values as of the acquisition date. The excess cost of the acquisition over the fair value of net assets acquired is recorded as goodwill.
Goodwill and Intangible Assets, Goodwill Impairment Policy	Goodwill is evaluated for impairment on an annual basis as of October 1 of each year, or whenever events or changes in circumstances indicate that the fair value of a reporting unit may be below its carrying value.
Goodwill and Intangible Assets, Policy	Core deposit intangibles represent the estimated fair value of acquired customer deposit relationships. Core deposit intangibles are recorded at fair value on the date of acquisition and are then amortized on an accelerated basis
Income Tax, Policy	The unrecognized tax benefits relate to state income tax exposures from taking tax positions where the Company believes it is likely that, upon examination, a state may take a position contrary to the position taken by the Company.
Commitments and Contingencies, Policy	First Financial offers a variety of financial instruments including standby letters of credit and outstanding commitments to extend credit to assist clients in meeting their requirement for liquidity and credit enhancement. GAAP does not require these financial instruments to be recorded in the Consolidated Financial Statements.
Fair Value Measurement, Policy [Policy Text Block]	Fair Value Measurement The fair value framework as disclosed in the Fair Value Topic includes a hierarchy which focuses on prioritizing the inputs used in valuation techniques. The fair value hierarchy gives the highest priority to quoted prices in active markets for identical assets or liabilities (Level 1), a lower priority to observable inputs other than quoted prices in active markets for identical assets and liabilities (Level 2) and the lowest priority to unobservable inputs (Level 3). When determining the fair value measurements for assets and liabilities, First Financial looks to active markets to price identical assets or liabilities whenever possible and classifies such items in Level 1. When identical assets and liabilities are not traded in active markets, First Financial looks to observable market data for similar assets and liabilities and classifies such items as Level 2. Certain assets and liabilities are not actively traded in observable markets and First Financial must use alternative techniques, based on unobservable inputs, to determine the fair value and classifies such items as Level 3. The level within the fair value hierarchy is based on the lowest level of input that is significant in the fair value measurement.
Fair Value of Financial Instruments, Policy	The following methods, assumptions and valuation techniques were used by First Financial to measure different financial assets and liabilities at fair value on a recurring or nonrecurring basis. Investment securities. Investment securities classified as trading and available-for-sale are recorded at fair value on a recurring basis. Fair value measurement is based upon quoted market prices, when available (Level 1). If quoted market prices are not available, fair values are measured utilizing independent valuation techniques of identical or similar investment securities. First Financial compiles prices from various sources who 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 the specific investment securities but rather relying on the investment securities’ relationship to other benchmark quoted investment securities. Any investment securities not valued based upon the methods previously described are considered Level 3. First Financial utilizes values provided by third-party pricing vendors to price the investment securities portfolio in accordance with the fair value hierarchy of the Fair Value Topic and reviews the pricing methodologies utilized by the pricing vendors to ensure that the fair value determination is consistent with the applicable accounting guidance. First Financial’s pricing process includes a series of quality assurance activities where prices are compared to recent market conditions, historical prices and other independent pricing services. Further, the Company periodically validates the fair value of a sample of securities in the portfolio by comparing the fair values to prices from other independent sources for the same or similar securities. First Financial analyzes unusual or significant variances, conducts additional research with the pricing vendor, and if necessary, takes appropriate action based on its findings. The results of the quality assurance process are incorporated into the selection of pricing providers by the portfolio manager. Impaired loans. The fair value of impaired loans are specifically reviewed for purposes of determining the appropriate amount of impairment to be allocated to the ALLL. Fair value is generally measured based on the value of the collateral securing the loans. Collateral may be in the form of real estate or business assets including equipment, inventory and accounts receivable. The value of real estate collateral is determined utilizing an income or market valuation approach based on an appraisal conducted by an independent, licensed third-party appraiser (Level 3). The value of business equipment is based on an outside appraisal, if deemed significant, or the net book value on the applicable borrower financial statements. Likewise, values for inventory and accounts receivable collateral are based on borrower financial statement balances or aging reports on a discounted basis as appropriate (Level 3). Impaired loans are measured at fair value on a nonrecurring basis. Any fair value adjustments are recorded in the period incurred as provision for loan and lease losses on the Consolidated Statements of Income. OREO. Assets acquired through loan foreclosure are recorded at fair value less costs to sell, with any difference between the fair value of the property and the carrying value of the loan recorded as a charge-off. If the fair value is higher than the carrying amount of the loan, the excess is recognized first as a recovery and then as noninterest income. Subsequent declines in value are reported as adjustments to the carrying amount and are recorded in noninterest expense. The carrying value of OREO is not re-measured to fair value on a recurring basis, but is subject to fair value adjustments when the carrying value differs from the fair value, less estimated selling costs. Fair value is based on recent real estate appraisals and is updated at least annually. The Company classifies OREO in level 3 of the fair value hierarchy. Derivatives.
Loan Commitments, Policy [Policy Text Block]	Loan commitments are agreements to extend credit to a client, absent any violation of conditions established in the commitment agreement.  Commitments generally have fixed expiration dates or other termination clauses and may require payment of a fee.  Since many of the commitments are expected to expire without being drawn upon, the total commitment amounts do not necessarily represent future cash requirements.  The amount of collateral obtained, if deemed necessary by First Financial upon extension of credit, is based on management’s credit evaluation of the client.  The collateral held varies, but may include securities, real estate, inventory, plant or equipment.
Other Contract-Mortgage
Derivatives, Methods of Accounting, Hedging Derivatives, Policy	First Financial enters into IRLCs and forward commitments for the future delivery of mortgage loans to third party investors, which are considered derivatives. When borrowers secure an IRLC with First Financial and the loan is intended to be sold, First Financial will enter into forward commitments for the future delivery of the loans to third party investors in order to hedge against the effect of changes in interest rates impacting IRLCs and loans held for sale.
Credit Risk
Derivatives, Methods of Accounting, Hedging Derivatives, Policy	First Financial manages market value credit risk through counterparty credit policies, which require the Company to maintain a total derivative notional position of less than 35% of assets, total credit exposure of less than 3% of capital and no single counterparty credit risk exposure greater than $20.0 million
Fair Value Hedges
Derivatives, Methods of Accounting, Hedging Derivatives, Policy	First Financial utilizes interest rate swaps as a means to offer commercial borrowers fixed rate funding while providing the Company with floating rate assets.

INVESTMENTS (Tables)

INVESTMENTS (Tables)	3 Months Ended
	Mar. 31, 2018
Investments, Debt and Equity Securities [Abstract]
Summary of Held-To-Maturity and Available-For-Sale Investment Securities	The following is a summary of held-to-maturity and available-for-sale investment securities as of March 31, 2018 : Held-to-maturity Available-for-sale (Dollars in thousands) Amortized Unrecognized gain Unrecognized loss Fair Amortized cost Unrealized gain Unrealized loss Fair U.S. Treasuries $ 0 $ 0 $ 0 $ 0 $ 98 $ 0 $ (2 ) $ 96 Securities of U.S. government agencies and corporations 10,627 0 (188 ) 10,439 25,689 244 (193 ) 25,740 Mortgage-backed securities - residential 155,208 1,225 (2,817 ) 153,616 288,757 375 (6,689 ) 282,443 Mortgage-backed securities - commercial 251,253 228 (5,348 ) 246,133 153,770 47 (2,875 ) 150,942 Collateralized mortgage obligations 135,143 86 (2,798 ) 132,431 305,496 558 (4,791 ) 301,263 Obligations of state and other political subdivisions 81,491 829 (972 ) 81,348 121,813 1,307 (1,696 ) 121,424 Asset-backed securities 0 0 0 0 391,943 1,351 (782 ) 392,512 Other securities 0 0 0 0 83,278 2,027 (344 ) 84,961 Total $ 633,722 $ 2,368 $ (12,123 ) $ 623,967 $ 1,370,844 $ 5,909 $ (17,372 ) $ 1,359,381 The following is a summary of held-to-maturity and available-for-sale investment securities as of December 31, 2017 : Held-to-maturity Available-for-sale (Dollars in thousands) Amortized Unrecognized gain Unrecognized Fair Amortized Unrealized Unrealized Fair U.S. Treasuries $ 0 $ 0 $ 0 $ 0 $ 98 $ 0 $ (1 ) $ 97 Securities of U.S. government agencies and corporations 11,168 0 (76 ) 11,092 15,695 220 0 15,915 Mortgage-backed securities - residential 162,093 2,042 (1,535 ) 162,600 290,793 849 (2,599 ) 289,043 Mortgage-backed securities - commercial 255,027 1,372 (3,000 ) 253,399 150,356 164 (1,417 ) 149,103 Collateralized mortgage obligations 143,545 354 (1,602 ) 142,297 306,095 1,158 (1,861 ) 305,392 Obligations of state and other political subdivisions 82,175 1,804 (266 ) 83,713 124,269 2,162 (676 ) 125,755 Asset-backed securities 0 0 0 0 377,655 1,628 (306 ) 378,977 Other securities 0 0 0 0 83,266 2,147 (287 ) 85,126 Total $ 654,008 $ 5,572 $ (6,479 ) $ 653,101 $ 1,348,227 $ 8,328 $ (7,147 ) $ 1,349,408
Summary of Investment Securities by Estimated Maturity	The following table provides a summary of investment securities by contractual maturity as of March 31, 2018 , except for residential and commercial mortgage-backed securities, collateralized mortgage obligations and asset-backed securities, which are shown as single totals due to the unpredictability of the timing in principal repayments. Held-to-maturity Available-for-sale (Dollars in thousands) Amortized cost Fair value Amortized cost Fair value By Contractual Maturity: Due in one year or less $ 165 $ 165 $ 2,296 $ 2,292 Due after one year through five years 4,277 4,279 37,023 36,960 Due after five years through ten years 2,499 2,632 82,431 83,521 Due after ten years 85,177 84,711 109,128 109,448 Mortgage-backed securities - residential 155,208 153,616 288,757 282,443 Mortgage-backed securities - commercial 251,253 246,133 153,770 150,942 Collateralized mortgage obligations 135,143 132,431 305,496 301,263 Asset-backed securities 0 0 391,943 392,512 Total $ 633,722 $ 623,967 $ 1,370,844 $ 1,359,381
Age of Gross Unrealized Losses and Associated Fair Value by Investment Category	The following tables provide the fair value and gross unrealized losses on investment securities in an unrealized loss position, aggregated by investment category and the length of time the individual securities have been in a continuous loss position: March 31, 2018 Less than 12 months 12 months or more Total (Dollars in thousands) Fair value Unrealized loss Fair Unrealized Fair Unrealized U.S. Treasuries $ 96 $ (2 ) $ 0 $ 0 $ 96 $ (2 ) Securities of U.S. Government agencies and corporations 26,347 (381 ) 0 0 26,347 (381 ) Mortgage-backed securities - residential 252,396 (3,712 ) 123,671 (5,794 ) 376,067 (9,506 ) Mortgage-backed securities - commercial 233,201 (4,185 ) 75,822 (4,038 ) 309,023 (8,223 ) Collateralized mortgage obligations 274,159 (3,915 ) 96,641 (3,674 ) 370,800 (7,589 ) Obligations of state and other political subdivisions 98,207 (1,879 ) 21,420 (789 ) 119,627 (2,668 ) Asset-backed securities 89,530 (613 ) 23,113 (169 ) 112,643 (782 ) Other securities 4,616 (29 ) 7,100 (315 ) 11,716 (344 ) Total $ 978,552 $ (14,716 ) $ 347,767 $ (14,779 ) $ 1,326,319 $ (29,495 ) December 31, 2017 Less than 12 months 12 months or more Total Fair Unrealized Fair Unrealized Fair Unrealized (Dollars in thousands) value loss value loss value loss U.S. Treasuries $ 97 $ (1 ) $ 0 $ 0 $ 97 $ (1 ) Securities of U.S. Government agencies and corporations 11,092 (76 ) 0 0 11,092 (76 ) Mortgage-backed securities - residential 175,183 (1,109 ) 108,782 (3,025 ) 283,965 (4,134 ) Mortgage-backed securities - commercial 132,818 (1,713 ) 72,139 (2,704 ) 204,957 (4,417 ) Collateralized mortgage obligations 164,909 (1,138 ) 101,436 (2,325 ) 266,345 (3,463 ) Obligations of state and other political subdivisions 38,450 (507 ) 21,639 (435 ) 60,089 (942 ) Asset-backed securities 44,941 (200 ) 24,396 (106 ) 69,337 (306 ) Other securities 2,605 (1 ) 7,124 (286 ) 9,729 (287 ) Total $ 570,095 $ (4,745 ) $ 335,516 $ (8,881 ) $ 905,611 $ (13,626 )

LOANS AND LEASES (Tables)

LOANS AND LEASES (Tables)	3 Months Ended
	Mar. 31, 2018
Receivables [Abstract]
Commercial and Consumer Credit Exposure by Risk Attribute	Commercial and consumer credit exposure by risk attribute was as follows: As of March 31, 2018 Commercial Real Estate Lease (Dollars in thousands) & industrial Construction Commercial financing Total Pass $ 1,911,912 $ 482,679 $ 2,502,882 $ 80,489 $ 4,977,962 Special Mention 5,228 11,947 6,422 0 23,597 Substandard 26,601 39 34,747 1,128 62,515 Doubtful 0 0 0 0 0 Total $ 1,943,741 $ 494,665 $ 2,544,051 $ 81,617 $ 5,064,074 (Dollars in thousands) Residential real estate Home equity Installment Credit card Total Performing $ 461,409 $ 479,470 $ 38,942 $ 46,472 $ 1,026,293 Nonperforming 7,175 4,173 306 0 11,654 Total $ 468,584 $ 483,643 $ 39,248 $ 46,472 $ 1,037,947 As of December 31, 2017 Commercial Real Estate Lease (Dollars in thousands) & industrial Construction Commercial financing Total Pass $ 1,882,464 $ 467,687 $ 2,446,999 $ 88,078 $ 4,885,228 Special Mention 6,226 0 4,436 0 10,662 Substandard 24,053 43 38,656 1,269 64,021 Doubtful 0 0 0 0 0 Total $ 1,912,743 $ 467,730 $ 2,490,091 $ 89,347 $ 4,959,911 (Dollars in thousands) Residential real estate Home equity Installment Credit card Total Performing $ 463,459 $ 489,148 $ 41,331 $ 46,691 $ 1,040,629 Nonperforming 7,932 4,456 255 0 12,643 Total $ 471,391 $ 493,604 $ 41,586 $ 46,691 $ 1,053,272
Loan Delinquency, including Nonaccrual Loans	Loan delinquency, including loans classified as nonaccrual, was as follows: As of March 31, 2018 (Dollars in thousands) 30 – 59 60 – 89 > 90 days Total Current Subtotal Purchased impaired Total > 90 days Loans Commercial & industrial $ 1,399 $ 4,857 $ 1,323 $ 7,579 $ 1,933,461 $ 1,941,040 $ 2,701 $ 1,943,741 $ 0 Lease financing 943 0 0 943 80,674 81,617 0 81,617 0 Construction real estate 0 0 0 0 494,389 494,389 276 494,665 0 Commercial real estate 236 3,317 12,255 15,808 2,475,106 2,490,914 53,137 2,544,051 0 Residential real estate 497 341 1,359 2,197 427,689 429,886 38,698 468,584 0 Home equity 1,395 508 2,000 3,903 476,446 480,349 3,294 483,643 0 Installment 284 74 271 629 38,018 38,647 601 39,248 0 Credit card 459 228 529 1,216 45,256 46,472 0 46,472 529 Total $ 5,213 $ 9,325 $ 17,737 $ 32,275 $ 5,971,039 $ 6,003,314 $ 98,707 $ 6,102,021 $ 529 As of December 31, 2017 (Dollars in thousands) 30 – 59 60 – 89 > 90 days Total Current Subtotal Purchased impaired Total > 90 days Loans Commercial & industrial $ 755 $ 1,657 $ 5,078 $ 7,490 $ 1,901,821 $ 1,909,311 $ 3,432 $ 1,912,743 $ 0 Lease financing 485 0 0 485 88,862 89,347 0 89,347 0 Construction real estate 234 0 0 234 467,216 467,450 280 467,730 0 Commercial real estate 1,716 201 8,777 10,694 2,419,969 2,430,663 59,428 2,490,091 0 Residential real estate 526 811 1,992 3,329 430,500 433,829 37,562 471,391 0 Home equity 2,716 394 1,753 4,863 485,127 489,990 3,614 493,604 0 Installment 179 29 205 413 40,529 40,942 644 41,586 0 Credit card 285 87 62 434 46,257 46,691 0 46,691 62 Total $ 6,896 $ 3,179 $ 17,867 $ 27,942 $ 5,880,281 $ 5,908,223 $ 104,960 $ 6,013,183 $ 62
Loans Restructured During Period	The following tables provide information on loan modifications classified as TDRs during the three months ended March 31, 2018 and 2017 : Three months ended March 31, 2018 March 31, 2017 (Dollars in thousands) Number of loans Pre-modification loan balance Period end balance Number of loans Pre-modification loan balance Period end balance Commercial & industrial 4 $ 928 $ 913 2 $ 3,502 $ 3,441 Construction real estate 0 0 0 0 0 0 Commercial real estate 2 72 72 0 0 0 Residential real estate 2 93 93 0 0 0 Home equity 0 0 0 0 0 0 Installment 0 0 0 0 0 0 Total 8 $ 1,093 $ 1,078 2 $ 3,502 $ 3,441
Loans Restructured, Modifications	The following table provides information on how TDRs were modified during the three months ended March 31, 2018 and 2017 : Three months ended March 31, (Dollars in thousands) 2018 2017 Extended maturities $ 888 $ 674 Adjusted interest rates 52 2,767 Combination of rate and maturity changes 0 0 Forbearance 0 0 Other (1) 138 0 Total $ 1,078 $ 3,441 (1) Includes covenant modifications and other concessions, or combination of concessions, that do not consist of interest rate adjustments, forbearance and maturity extensions
Nonaccrual, Restructured and Impaired Loans	The following table provides information on impaired loans, excluding purchased impaired loans: (Dollars in thousands) March 31, 2018 December 31, 2017 Impaired loans Nonaccrual loans (1) Commercial & industrial $ 6,275 $ 5,229 Lease financing 0 82 Construction real estate 26 29 Commercial real estate 16,878 10,616 Residential real estate 3,324 4,140 Home equity 3,484 3,743 Installment 296 243 Nonaccrual loans 30,283 24,082 Accruing troubled debt restructurings 14,943 17,545 Total impaired loans $ 45,226 $ 41,627 (1) Nonaccrual loans include nonaccrual TDRs of $6.0 million and $6.4 million as of March 31, 2018 and December 31, 2017 , respectively. Three months ended March 31, (Dollars in thousands) 2018 2017 Interest income effect on impaired loans Gross amount of interest that would have been recorded under original terms $ 802 $ 816 Interest included in income Nonaccrual loans 80 142 Troubled debt restructurings 124 226 Total interest included in income 204 368 Net impact on interest income $ 598 $ 448
Investment in Impaired Loans	First Financial's investment in impaired loans was as follows: As of March 31, 2018 As of December 31, 2017 (Dollars in thousands) Current balance Contractual principal balance Related allowance Current balance Contractual Related Loans with no related allowance recorded Commercial & industrial $ 8,571 $ 8,777 $ 0 $ 7,162 $ 8,460 $ 0 Lease financing 0 0 0 82 82 0 Construction real estate 26 58 0 29 60 0 Commercial real estate 24,377 28,871 0 18,423 20,837 0 Residential real estate 6,130 7,282 0 6,876 8,145 0 Home equity 4,072 4,884 0 4,356 5,399 0 Installment 306 469 0 255 422 0 Total 43,482 50,341 0 37,183 43,405 0 Loans with an allowance recorded Commercial & industrial 239 317 100 169 169 169 Lease financing 0 0 0 0 0 0 Construction real estate 0 0 0 0 0 0 Commercial real estate 359 359 26 3,119 3,120 448 Residential real estate 1,045 1,045 160 1,056 1,063 160 Home equity 101 101 2 100 100 2 Installment 0 0 0 0 0 0 Total 1,744 1,822 288 4,444 4,452 779 Total Commercial & industrial 8,810 9,094 100 7,331 8,629 169 Lease financing 0 0 0 82 82 0 Construction real estate 26 58 0 29 60 0 Commercial real estate 24,736 29,230 26 21,542 23,957 448 Residential real estate 7,175 8,327 160 7,932 9,208 160 Home equity 4,173 4,985 2 4,456 5,499 2 Installment 306 469 0 255 422 0 Total $ 45,226 $ 52,163 $ 288 $ 41,627 $ 47,857 $ 779 First Financial's average impaired loans by class and interest income recognized by class was as follows: Three months ended March 31, 2018 March 31, 2017 (Dollars in thousands) Average Interest Average Interest Loans with no related allowance recorded Commercial & industrial $ 7,867 $ 26 $ 15,607 $ 109 Lease financing 41 0 149 1 Construction real estate 28 1 538 0 Commercial real estate 21,400 99 19,939 160 Residential real estate 6,503 47 8,033 46 Home equity 4,214 20 4,111 24 Installment 281 0 413 2 Total 40,334 193 48,790 342 Loans with an allowance recorded Commercial & industrial 204 0 1,094 13 Lease financing 0 0 0 0 Construction real estate 0 0 0 0 Commercial real estate 1,739 3 4,374 5 Residential real estate 1,051 7 1,185 7 Home equity 101 1 101 1 Installment 0 0 0 0 Total 3,095 11 6,754 26 Total Commercial & industrial 8,071 26 16,701 122 Lease financing 41 0 149 1 Construction real estate 28 1 538 0 Commercial real estate 23,139 102 24,313 165 Residential real estate 7,554 54 9,218 53 Home equity 4,315 21 4,212 25 Installment 281 0 413 2 Total $ 43,429 $ 204 $ 55,544 $ 368
Changes in Other Real Estate Owned	Changes in OREO were as follows: Three months ended March 31, (Dollars in thousands) 2018 2017 Balance at beginning of period $ 2,781 $ 6,284 Additions Commercial & industrial 170 122 Residential real estate 459 165 Total additions 629 287 Disposals Commercial & industrial (2,104 ) (925 ) Residential real estate (118 ) (237 ) Total disposals (2,222 ) (1,162 ) Valuation adjustment Commercial & industrial (97 ) (46 ) Residential real estate (26 ) (63 ) Total valuation adjustment (123 ) (109 ) Balance at end of period $ 1,065 $ 5,300

ALLOWANCE FOR LOAN AND LEASE 28

ALLOWANCE FOR LOAN AND LEASE LOSSES (Tables)	3 Months Ended
	Mar. 31, 2018
Receivables [Abstract]
Allowance for Loan and Lease Losses by Classification	Changes in the allowance for loan and lease losses by loan category were as follows: Three months ended March 31, 2018 Real Estate (Dollars in thousands) Commercial & industrial Lease financing Construction Commercial Residential Home equity Installment Credit card Total Allowance for loan and lease losses: Balance at beginning of period $ 17,598 $ 675 $ 3,577 $ 20,930 $ 4,683 $ 4,935 $ 307 $ 1,316 $ 54,021 Provision for loan and lease losses 889 (49 ) 690 815 114 (294 ) (49 ) 187 2,303 Loans charged off (885 ) 0 0 (2,176 ) (96 ) (242 ) (16 ) (254 ) (3,669 ) Recoveries 436 0 0 752 26 429 48 34 1,725 Total net charge-offs (449 ) 0 0 (1,424 ) (70 ) 187 32 (220 ) (1,944 ) Ending allowance for loan and lease losses $ 18,038 $ 626 $ 4,267 $ 20,321 $ 4,727 $ 4,828 $ 290 $ 1,283 $ 54,380 As of March 31, 2018 Real Estate (Dollars in thousands) Commercial & industrial Lease financing Construction Commercial Residential Home equity Installment Credit card Total Ending allowance balance attributable to loans Individually evaluated for impairment $ 100 $ 0 $ 0 $ 26 $ 160 $ 2 $ 0 $ 0 $ 288 Collectively evaluated for impairment 17,938 626 4,267 20,295 4,567 4,826 290 1,283 54,092 Ending allowance for loan and lease losses $ 18,038 $ 626 $ 4,267 $ 20,321 $ 4,727 $ 4,828 $ 290 $ 1,283 $ 54,380 Loans Individually evaluated for impairment $ 8,810 $ 0 $ 26 $ 24,736 $ 7,175 $ 4,173 $ 306 $ 0 $ 45,226 Collectively evaluated for impairment 1,934,931 81,617 494,639 2,519,315 461,409 479,470 38,942 46,472 6,056,795 Total loans $ 1,943,741 $ 81,617 $ 494,665 $ 2,544,051 $ 468,584 $ 483,643 $ 39,248 $ 46,472 $ 6,102,021 Three months ended March 31, 2017 Real Estate (Dollars in thousands) Commercial & industrial Lease financing Construction Commercial Residential Home equity Installment Credit card Total Allowance for loan and lease losses: Balance at beginning of period $ 19,225 $ 716 $ 3,282 $ 26,540 $ 3,208 $ 3,043 $ 388 $ 1,559 $ 57,961 Provision for loan and lease losses (596 ) (100 ) 325 (2,566 ) 2,329 805 9 161 367 Loans charged off (1,743 ) 0 0 (485 ) (61 ) (180 ) (49 ) (232 ) (2,750 ) Recoveries 262 0 0 256 9 106 71 44 748 Total net charge-offs (1,481 ) 0 0 (229 ) (52 ) (74 ) 22 (188 ) (2,002 ) Ending allowance for loan and lease losses $ 17,148 $ 616 $ 3,607 $ 23,745 $ 5,485 $ 3,774 $ 419 $ 1,532 $ 56,326 As of December 31, 2017 Real Estate (Dollars in thousands) Commercial & industrial Lease financing Construction Commercial Residential Home equity Installment Credit card Total Ending allowance balance attributable to loans Individually evaluated for impairment $ 169 $ 0 $ 0 $ 448 $ 160 $ 2 $ 0 $ 0 $ 779 Collectively evaluated for impairment 17,429 675 3,577 20,482 4,523 4,933 307 1,316 53,242 Ending allowance for loan and lease losses $ 17,598 $ 675 $ 3,577 $ 20,930 $ 4,683 $ 4,935 $ 307 $ 1,316 $ 54,021 Loans Individually evaluated for impairment $ 7,331 $ 82 $ 29 $ 21,542 $ 7,932 $ 4,456 $ 255 $ 0 $ 41,627 Collectively evaluated for impairment 1,905,412 89,265 467,701 2,468,549 463,459 489,148 41,331 46,691 5,971,556 Total loans $ 1,912,743 $ 89,347 $ 467,730 $ 2,490,091 $ 471,391 $ 493,604 $ 41,586 $ 46,691 $ 6,013,183

BORROWINGS (Tables)

BORROWINGS (Tables)	3 Months Ended
	Mar. 31, 2018
Debt Disclosure [Abstract]
Summary of Long-term Debt	The following is a summary of First Financial's long-term debt: March 31, 2018 December 31, 2017 (Dollars in thousands) Amount Average rate Amount Average rate Subordinated notes $ 120,000 5.13 % $ 120,000 5.13 % Unamortized debt issuance costs (1,318 ) N/A (1,362 ) N/A FHLB borrowings 50,238 2.63 % 241 1.09 % Capital loan with municipality 775 0.00 % 775 0.00 % Total long-term debt $ 169,695 4.40 % $ 119,654 5.14 %

ACCUMULATED OTHER COMPREHENSI30

ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS) (Tables)	3 Months Ended
	Mar. 31, 2018
Equity [Abstract]
Related Tax Effects Allocated to Other Comprehensive Income and Accumulated Other Comprehensive Income (Loss)	The related tax effects allocated to other comprehensive income and reclassifications out of accumulated other comprehensive income (loss) are as follows: Three months ended March 31, 2018 Total other comprehensive income (loss) Total accumulated other comprehensive income (loss) (Dollars in thousands) Prior to Reclass Reclass from Pre-tax Tax-effect Net of tax Beginning Balance Net Activity Reclass of Stranded Tax Effects Ending Balance Unrealized gain (loss) on investment securities $ (12,536 ) $ 0 $ (12,536 ) $ 2,706 $ (9,830 ) $ (182 ) $ (9,830 ) $ (39 ) $ (10,051 ) Unrealized gain (loss) on derivatives 202 0 202 (46 ) 156 (577 ) 156 (124 ) (545 ) Retirement obligation 0 (419 ) 419 (96 ) 323 (19,631 ) 323 (4,779 ) (24,087 ) Total $ (12,334 ) $ (419 ) $ (11,915 ) $ 2,564 $ (9,351 ) $ (20,390 ) $ (9,351 ) $ (4,942 ) $ (34,683 ) Three months ended March 31, 2017 Total other comprehensive income (loss) Total accumulated other comprehensive income (loss) (Dollars in thousands) Prior to Reclass Reclass from Pre-tax Tax-effect Net of tax Beginning Balance Net Activity Ending Balance Unrealized gain (loss) on investment securities $ 2,832 $ 516 $ 2,316 $ (829 ) $ 1,487 $ (4,549 ) $ 1,487 $ (3,062 ) Unrealized gain (loss) on derivatives 203 0 203 (75 ) 128 (1,091 ) 128 (963 ) Retirement obligation 0 (335 ) 335 (146 ) 189 (22,803 ) 189 (22,614 ) Total $ 3,035 $ 181 $ 2,854 $ (1,050 ) $ 1,804 $ (28,443 ) $ 1,804 $ (26,639 )
Other Accumulated Comprehensive income reclassified from AOCI	The following table presents the activity reclassified from accumulated other comprehensive income into income during the three month periods ended March 31, 2018 and 2017, respectively: Amount reclassified from accumulated other comprehensive income (1) Three months ended March 31, (Dollars in thousands) 2018 2017 Affected Line Item in the Consolidated Statements of Income Realized gains and losses on securities available-for-sale $ 0 $ 516 Net gains on sales of investments securities Defined benefit pension plan Amortization of prior service cost (2) 103 103 Salaries and employee benefits Recognized net actuarial loss (2) (522 ) (438 ) Salaries and employee benefits Defined benefit pension plan total (419 ) (335 ) Total reclassifications for the period, before tax $ (419 ) $ 181 (1) Negative amounts are reductions to net income. (2)

DERIVATIVES (Tables)

DERIVATIVES (Tables)	3 Months Ended
	Mar. 31, 2018
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Summary of Derivative Financial Instruments and Balances	The following table details the classification and amounts recognized in the Consolidated Balance Sheets for client derivatives: March 31, 2018 December 31, 2017 Estimated fair value Estimated fair value (Dollars in thousands) Balance sheet classification Notional amount Gain Loss Notional amount Gain Loss Client derivatives - instruments associated with loans Matched interest rate swaps with borrower Accrued interest and other assets $ 908,216 $ 3,100 $ (13,225 ) $ 837,040 $ 7,153 $ (5,529 ) Matched interest rate swaps with counterparty Accrued interest and other liabilities 908,216 13,225 (3,102 ) 837,040 5,529 (7,158 ) Total $ 1,816,432 $ 16,325 $ (16,327 ) $ 1,674,080 $ 12,682 $ (12,687 )
Disclosure by Type of Financial Instrument	The following table discloses the gross and net amounts of client derivative liabilities recognized in the Consolidated Balance Sheets: March 31, 2018 December 31, 2017 (Dollars in thousands) Gross amounts of recognized liabilities Gross amounts offset in the Consolidated Balance Sheets Net amounts of assets presented in the Consolidated Balance Sheets Gross amounts of recognized liabilities Gross amounts offset in the Consolidated Balance Sheets Net amounts of assets presented in the Consolidated Balance Sheets Client derivatives Matched interest rate swaps with counterparty $ 16,327 $ 24,475 $ 40,802 $ 12,687 $ 2,279 $ 14,966
Derivative Financial Instruments, Average Remaining Maturity and the Weighted-Average Interest Rates being Paid and Received	The following table details the derivative financial instruments, the average remaining maturities and the weighted-average interest rates being paid and received by First Financial at March 31, 2018 : Weighted-average rate (Dollars in thousands) Notional amount Average maturity (years) Fair value Receive Pay Client derivatives Receive fixed, matched interest rate swaps with borrower $ 908,216 5.8 $ (10,125 ) 4.47 % 3.80 % Pay fixed, matched interest rate swaps with counterparty 908,216 5.8 10,123 3.80 % 4.47 % Total client derivatives $ 1,816,432 5.8 $ (2 ) 4.13 % 4.13 %

EMPLOYEE BENEFIT PLANS (Tables)

EMPLOYEE BENEFIT PLANS (Tables)	3 Months Ended
	Mar. 31, 2018
Retirement Benefits [Abstract]
Employee Benefit Plan Amounts Recognized in the Consolidated Balance Sheets and Consolidated Statements of Income	The following table sets forth information concerning amounts recognized in First Financial’s Consolidated Statements of Income related to the Company's pension plan: Three months ended March 31, (Dollars in thousands) 2018 2017 Service cost $ 1,295 $ 1,238 Interest cost 590 589 Expected return on assets (2,460 ) (2,481 ) Amortization of prior service cost (103 ) (103 ) Net actuarial loss 522 438 Net periodic benefit (income) cost $ (156 ) $ (319 )

EARNINGS PER COMMON SHARE (Tabl

EARNINGS PER COMMON SHARE (Tables)	3 Months Ended
	Mar. 31, 2018
Earnings Per Share [Abstract]
Computation of Basic and Diluted Earnings Per Share	The following table sets forth the computation of basic and diluted earnings per share: Three months ended March 31, (Dollars in thousands, except per share data) 2018 2017 Numerator Net income available to common shareholders $ 30,506 $ 24,414 Denominator Basic earnings per common share - weighted average shares 61,654,686 61,398,414 Effect of dilutive securities Employee stock awards 464,254 674,589 Warrants 61,804 67,381 Diluted earnings per common share - adjusted weighted average shares 62,180,744 62,140,384 Earnings per share available to common shareholders Basic $ 0.49 $ 0.40 Diluted $ 0.49 $ 0.39

FAIR VALUE DISCLOSURES (Tables)

FAIR VALUE DISCLOSURES (Tables)	3 Months Ended
	Mar. 31, 2018
Fair Value Disclosures [Abstract]
Estimated Fair Values of Financial Instruments	The estimated fair values of First Financial’s financial instruments not measured at fair value on a recurring or nonrecurring basis in the consolidated financial statements were as follows: Carrying Estimated fair value (Dollars in thousands) value Total Level 1 Level 2 Level 3 March 31, 2018 Financial assets Cash and short-term investments $ 126,781 $ 126,781 $ 126,781 $ 0 $ 0 Investment securities held-to-maturity 633,722 623,967 0 623,967 0 Other investments 53,070 N/A N/A N/A N/A Loans held for sale 8,048 8,048 0 8,048 0 Loans and leases 6,047,641 6,098,950 0 0 6,098,950 Accrued interest receivable 25,842 25,842 0 8,232 17,610 Financial liabilities Deposits 7,010,504 6,994,627 0 6,994,627 0 Short-term borrowings 658,332 658,332 658,332 0 0 Long-term debt 169,695 165,569 0 165,569 0 Accrued interest payable 4,091 4,091 375 3,716 0 Carrying Estimated fair value (Dollars in thousands) value Total Level 1 Level 2 Level 3 December 31, 2017 Financial assets Cash and short-term investments $ 184,624 $ 184,624 $ 184,624 $ 0 $ 0 Investment securities held-to-maturity 654,008 653,101 0 653,101 0 Other investments 53,140 N/A N/A N/A N/A Loans held for sale 11,502 11,502 0 11,502 0 Loans and leases 5,959,162 6,006,656 0 0 6,006,656 Accrued interest receivable 24,496 24,496 0 8,265 16,231 Financial liabilities Deposits 6,895,046 6,884,615 0 6,884,615 0 Short-term borrowings 814,565 814,565 814,565 0 0 Long-term debt 119,654 117,908 0 117,908 0 Accrued interest payable 5,104 5,104 204 4,900 0
Summary of Financial Assets and Liabilities Measured at Fair Value on a Recurring Basis	The financial assets and liabilities measured at fair value on a recurring basis in the consolidated financial statements were as follows: Fair value measurements using (Dollars in thousands) Level 1 Level 2 Level 3 Assets/liabilities at fair value March 31, 2018 Assets Derivatives $ 0 $ 16,416 $ 0 $ 16,416 Investment securities available-for-sale 2,982 1,356,399 0 1,359,381 Total $ 2,982 $ 1,372,815 $ 0 $ 1,375,797 Liabilities Derivatives $ 0 $ 16,368 $ 0 $ 16,368 Fair value measurements using (Dollars in thousands) Level 1 Level 2 Level 3 Assets/liabilities at fair value December 31, 2017 Assets Derivatives $ 0 $ 12,757 $ 0 $ 12,757 Investment securities available-for-sale 2,969 1,346,439 0 1,349,408 Total $ 2,969 $ 1,359,196 $ 0 $ 1,362,165 Liabilities Derivatives $ 0 $ 12,755 $ 0 $ 12,755
Summary of Financial Assets and Liabilities Measured at Fair Value on a Nonrecurring Basis	The following table summarizes financial assets and liabilities measured at fair value on a nonrecurring basis. Fair value measurements using (Dollars in thousands) Level 1 Level 2 Level 3 March 31, 2018 Assets Impaired loans $ 0 $ 0 $ 472 OREO 0 0 215 Fair value measurements using (Dollars in thousands) Level 1 Level 2 Level 3 December 31, 2017 Assets Impaired loans $ 0 $ 0 $ 2,671 OREO 0 0 1,086

RECENTLY ADOPTED AND ISSUED A35

RECENTLY ADOPTED AND ISSUED ACCOUNTING STANDARDS RECENTLY ADOPTED AND ISSUED ACCOUNTING STANDARDS - Additional Information (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2018USD ($)
Reclassification from AOCI, Current Period, Tax	$ 0
Retained earnings
Reclassification from AOCI, Current Period, Tax	$ 4,942

INVESTMENTS INVESTMENTS - Addit

INVESTMENTS INVESTMENTS - Additional Information (Details) $ in Millions	3 Months Ended
	Mar. 31, 2018USD ($)	Mar. 31, 2017USD ($)	Dec. 31, 2017
Gain (Loss) on Investments [Line Items]
NumberOfSecuritiesInSecurityPortfolio	774		775
NumberOfSecuritiesInUnrealizedLossPosition	359		237
Available-for-sale Securities, Gross Realized Gains (Losses), Sale Proceeds	$ 0	$ 22.2
Available-for-sale Securities, Gross Realized Gains		$ 0.5

INVESTMENTS - Summary of Held-T

INVESTMENTS - Summary of Held-To-Maturity and Available-For-Sale Investment Securities (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Investment Holdings [Line Items]
Total	$ 633,722	$ 654,008
Held-to-maturity Securities, Accumulated Unrecognized Holding Gain	2,368	5,572
Held-to-maturity Securities, Accumulated Unrecognized Holding Loss	(12,123)	(6,479)
Held-to-Maturity Market Value	623,967	653,101
Total	1,370,844	1,348,227
Available for Sale Securities Gross Unrealized Gain Accumulated In Investments	5,909	8,328
Available for Sale Securities Gross Unrealized Loss Accumulated In Investments	(17,372)	(7,147)
Investment securities available-for-sale	1,359,381	1,349,408
U.S. Treasuries
Investment Holdings [Line Items]
Total	0	0
Held-to-maturity Securities, Accumulated Unrecognized Holding Gain	0	0
Held-to-maturity Securities, Accumulated Unrecognized Holding Loss	0	0
Held-to-Maturity Market Value	0	0
Total	98	98
Available for Sale Securities Gross Unrealized Gain Accumulated In Investments	0	0
Available for Sale Securities Gross Unrealized Loss Accumulated In Investments	(2)	(1)
Investment securities available-for-sale	96	97
Securities of U.S. government agencies and corporations
Investment Holdings [Line Items]
Total	10,627	11,168
Held-to-maturity Securities, Accumulated Unrecognized Holding Gain	0	0
Held-to-maturity Securities, Accumulated Unrecognized Holding Loss	(188)	(76)
Held-to-Maturity Market Value	10,439	11,092
Total	25,689	15,695
Available for Sale Securities Gross Unrealized Gain Accumulated In Investments	244	220
Available for Sale Securities Gross Unrealized Loss Accumulated In Investments	(193)	0
Investment securities available-for-sale	25,740	15,915
Residential Mortgage Backed Securities [Member]
Investment Holdings [Line Items]
Total	155,208	162,093
Held-to-maturity Securities, Accumulated Unrecognized Holding Gain	1,225	2,042
Held-to-maturity Securities, Accumulated Unrecognized Holding Loss	(2,817)	(1,535)
Held-to-Maturity Market Value	153,616	162,600
Total	288,757	290,793
Available for Sale Securities Gross Unrealized Gain Accumulated In Investments	375	849
Available for Sale Securities Gross Unrealized Loss Accumulated In Investments	(6,689)	(2,599)
Investment securities available-for-sale	282,443	289,043
Commercial Mortgage Backed Securities [Member]
Investment Holdings [Line Items]
Total	251,253	255,027
Held-to-maturity Securities, Accumulated Unrecognized Holding Gain	228	1,372
Held-to-maturity Securities, Accumulated Unrecognized Holding Loss	(5,348)	(3,000)
Held-to-Maturity Market Value	246,133	253,399
Total	153,770	150,356
Available for Sale Securities Gross Unrealized Gain Accumulated In Investments	47	164
Available for Sale Securities Gross Unrealized Loss Accumulated In Investments	(2,875)	(1,417)
Investment securities available-for-sale	150,942	149,103
Collateralized Mortgage Backed Securities [Member]
Investment Holdings [Line Items]
Total	135,143	143,545
Held-to-maturity Securities, Accumulated Unrecognized Holding Gain	86	354
Held-to-maturity Securities, Accumulated Unrecognized Holding Loss	(2,798)	(1,602)
Held-to-Maturity Market Value	132,431	142,297
Total	305,496	306,095
Available for Sale Securities Gross Unrealized Gain Accumulated In Investments	558	1,158
Available for Sale Securities Gross Unrealized Loss Accumulated In Investments	(4,791)	(1,861)
Investment securities available-for-sale	301,263	305,392
Obligations of state and other political subdivisions
Investment Holdings [Line Items]
Total	81,491	82,175
Held-to-maturity Securities, Accumulated Unrecognized Holding Gain	829	1,804
Held-to-maturity Securities, Accumulated Unrecognized Holding Loss	(972)	(266)
Held-to-Maturity Market Value	81,348	83,713
Total	121,813	124,269
Available for Sale Securities Gross Unrealized Gain Accumulated In Investments	1,307	2,162
Available for Sale Securities Gross Unrealized Loss Accumulated In Investments	(1,696)	(676)
Investment securities available-for-sale	121,424	125,755
Asset-backed Securities [Member]
Investment Holdings [Line Items]
Total	0	0
Held-to-maturity Securities, Accumulated Unrecognized Holding Gain	0	0
Held-to-maturity Securities, Accumulated Unrecognized Holding Loss	0	0
Held-to-Maturity Market Value	0	0
Total	391,943	377,655
Available for Sale Securities Gross Unrealized Gain Accumulated In Investments	1,351	1,628
Available for Sale Securities Gross Unrealized Loss Accumulated In Investments	(782)	(306)
Investment securities available-for-sale	392,512	378,977
Other securities
Investment Holdings [Line Items]
Total	0	0
Held-to-maturity Securities, Accumulated Unrecognized Holding Gain	0	0
Held-to-maturity Securities, Accumulated Unrecognized Holding Loss	0	0
Held-to-Maturity Market Value	0	0
Total	83,278	83,266
Available for Sale Securities Gross Unrealized Gain Accumulated In Investments	2,027	2,147
Available for Sale Securities Gross Unrealized Loss Accumulated In Investments	(344)	(287)
Investment securities available-for-sale	$ 84,961	$ 85,126

INVESTMENTS - Summary of Invest

INVESTMENTS - Summary of Investment Securities by Estimated Maturity (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Held-to-Maturity Amortized Cost
Amortized Cost	$ 633,722	$ 654,008
Held-to-Maturity Market Value
Held-to-maturity Securities, Fair Value	623,967	653,101
Available-for-Sale Amortized Cost
Available-for-sale Securities, Amortized Cost Basis	1,370,844	1,348,227
Available-for-Sale Market Value
Investment securities available-for-sale	1,359,381	1,349,408
One Year or Less [Member]
Held-to-Maturity Amortized Cost
Amortized Cost	165
Held-to-Maturity Market Value
Held-to-maturity Securities, Fair Value	165
Available-for-Sale Amortized Cost
Available-for-sale Securities, Amortized Cost Basis	2,296
Available-for-Sale Market Value
Investment securities available-for-sale	2,292
After One Year Through Five Years [Member]
Held-to-Maturity Amortized Cost
Amortized Cost	4,277
Held-to-Maturity Market Value
Held-to-maturity Securities, Fair Value	4,279
Available-for-Sale Amortized Cost
Available-for-sale Securities, Amortized Cost Basis	37,023
Available-for-Sale Market Value
Investment securities available-for-sale	36,960
After Five Years Through Ten Years [Member]
Held-to-Maturity Amortized Cost
Amortized Cost	2,499
Held-to-Maturity Market Value
Held-to-maturity Securities, Fair Value	2,632
Available-for-Sale Amortized Cost
Available-for-sale Securities, Amortized Cost Basis	82,431
Available-for-Sale Market Value
Investment securities available-for-sale	83,521
After Ten Years [Member]
Held-to-Maturity Amortized Cost
Amortized Cost	85,177
Held-to-Maturity Market Value
Held-to-maturity Securities, Fair Value	84,711
Available-for-Sale Amortized Cost
Available-for-sale Securities, Amortized Cost Basis	109,128
Available-for-Sale Market Value
Investment securities available-for-sale	109,448
Residential Mortgage Backed Securities [Member]
Held-to-Maturity Amortized Cost
Amortized Cost	155,208	162,093
Held-to-Maturity Market Value
Held-to-maturity Securities, Fair Value	153,616	162,600
Available-for-Sale Amortized Cost
Available-for-sale Securities, Amortized Cost Basis	288,757	290,793
Available-for-Sale Market Value
Investment securities available-for-sale	282,443	289,043
Commercial Mortgage Backed Securities [Member]
Held-to-Maturity Amortized Cost
Amortized Cost	251,253	255,027
Held-to-Maturity Market Value
Held-to-maturity Securities, Fair Value	246,133	253,399
Available-for-Sale Amortized Cost
Available-for-sale Securities, Amortized Cost Basis	153,770	150,356
Available-for-Sale Market Value
Investment securities available-for-sale	150,942	149,103
Collateralized Mortgage Backed Securities [Member]
Held-to-Maturity Amortized Cost
Amortized Cost	135,143	143,545
Held-to-Maturity Market Value
Held-to-maturity Securities, Fair Value	132,431	142,297
Available-for-Sale Amortized Cost
Available-for-sale Securities, Amortized Cost Basis	305,496	306,095
Available-for-Sale Market Value
Investment securities available-for-sale	301,263	305,392
Asset-backed Securities [Member]
Held-to-Maturity Amortized Cost
Amortized Cost	0	0
Held-to-Maturity Market Value
Held-to-maturity Securities, Fair Value	0	0
Available-for-Sale Amortized Cost
Available-for-sale Securities, Amortized Cost Basis	391,943	377,655
Available-for-Sale Market Value
Investment securities available-for-sale	$ 392,512	$ 378,977

INVESTMENTS - Age of Gross Unre

INVESTMENTS - Age of Gross Unrealized Losses and Associated Fair Value by Investment Category (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Investments, Unrealized Loss Position [Line Items]
Less than 12 Months Fair Value	$ 978,552	$ 570,095
Less than 12 Months Unrealized Loss	(14,716)	(4,745)
12 Months or More Fair Value	347,767	335,516
12 Months or More Unrealized Loss	(14,779)	(8,881)
Total Fair Value	1,326,319	905,611
Total Unrealized Loss	(29,495)	(13,626)
U.S. Treasuries
Investments, Unrealized Loss Position [Line Items]
Less than 12 Months Fair Value	96	97
Less than 12 Months Unrealized Loss	(2)	(1)
12 Months or More Fair Value	0	0
12 Months or More Unrealized Loss	0	0
Total Fair Value	96	97
Total Unrealized Loss	(2)	(1)
Securities of U.S. government agencies and corporations
Investments, Unrealized Loss Position [Line Items]
Less than 12 Months Fair Value	26,347	11,092
Less than 12 Months Unrealized Loss	(381)	(76)
12 Months or More Fair Value	0	0
12 Months or More Unrealized Loss	0	0
Total Fair Value	26,347	11,092
Total Unrealized Loss	(381)	(76)
Residential Mortgage Backed Securities [Member]
Investments, Unrealized Loss Position [Line Items]
Less than 12 Months Fair Value	252,396	175,183
Less than 12 Months Unrealized Loss	(3,712)	(1,109)
12 Months or More Fair Value	123,671	108,782
12 Months or More Unrealized Loss	(5,794)	(3,025)
Total Fair Value	376,067	283,965
Total Unrealized Loss	(9,506)	(4,134)
Commercial Mortgage Backed Securities [Member]
Investments, Unrealized Loss Position [Line Items]
Less than 12 Months Fair Value	233,201	132,818
Less than 12 Months Unrealized Loss	(4,185)	(1,713)
12 Months or More Fair Value	75,822	72,139
12 Months or More Unrealized Loss	(4,038)	(2,704)
Total Fair Value	309,023	204,957
Total Unrealized Loss	(8,223)	(4,417)
Collateralized Mortgage Backed Securities [Member]
Investments, Unrealized Loss Position [Line Items]
Less than 12 Months Fair Value	274,159	164,909
Less than 12 Months Unrealized Loss	(3,915)	(1,138)
12 Months or More Fair Value	96,641	101,436
12 Months or More Unrealized Loss	(3,674)	(2,325)
Total Fair Value	370,800	266,345
Total Unrealized Loss	(7,589)	(3,463)
Obligations of state and other political subdivisions
Investments, Unrealized Loss Position [Line Items]
Less than 12 Months Fair Value	98,207	38,450
Less than 12 Months Unrealized Loss	(1,879)	(507)
12 Months or More Fair Value	21,420	21,639
12 Months or More Unrealized Loss	(789)	(435)
Total Fair Value	119,627	60,089
Total Unrealized Loss	(2,668)	(942)
Asset-backed Securities [Member]
Investments, Unrealized Loss Position [Line Items]
Less than 12 Months Fair Value	89,530	44,941
Less than 12 Months Unrealized Loss	(613)	(200)
12 Months or More Fair Value	23,113	24,396
12 Months or More Unrealized Loss	(169)	(106)
Total Fair Value	112,643	69,337
Total Unrealized Loss	(782)	(306)
Other securities
Investments, Unrealized Loss Position [Line Items]
Less than 12 Months Fair Value	4,616	2,605
Less than 12 Months Unrealized Loss	(29)	(1)
12 Months or More Fair Value	7,100	7,124
12 Months or More Unrealized Loss	(315)	(286)
Total Fair Value	11,716	9,729
Total Unrealized Loss	$ (344)	$ (287)

LOANS AND LEASES - Additional I

LOANS AND LEASES - Additional Information (Details) - USD ($)	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017	Dec. 31, 2016
Accounts, Notes, Loans and Financing Receivable [Line Items]
Restructured Loans, Nonaccrual Status	$ 6,000,000		$ 6,400,000
Write-downs	123,000	$ 109,000
Gain (loss) on sale of other real estate owned	(77,000)	(24,000)
Real Estate Acquired Through Foreclosure	1,065,000	5,300,000	2,781,000	$ 6,284,000
FDIC indemnification asset	0		$ 1,900,000
Commercial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Restructured Loans, Loan Relationships, Review Threshold Amount Minimum	250,000
Residential real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Restructured Loans, Loan Relationships, Review Threshold Amount Minimum	250,000
Write-downs	$ 26,000	$ 63,000

LOANS AND LEASES - Commercial a

LOANS AND LEASES - Commercial and Consumer Credit Exposure by Risk Attribute (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Financing Receivable, Recorded Investment [Line Items]
Commercial	$ 1,943,741	$ 1,912,743
Real Estate - Construction	494,665	467,730
Real Estate - Commercial	2,544,051	2,490,091
Lease financing	81,617	89,347
Total Commercial	5,064,074	4,959,911
Pass
Financing Receivable, Recorded Investment [Line Items]
Commercial	1,911,912	1,882,464
Real Estate - Construction	482,679	467,687
Real Estate - Commercial	2,502,882	2,446,999
Lease financing	80,489	88,078
Total Commercial	4,977,962	4,885,228
Special Mention
Financing Receivable, Recorded Investment [Line Items]
Commercial	5,228	6,226
Real Estate - Construction	11,947	0
Real Estate - Commercial	6,422	4,436
Lease financing	0	0
Total Commercial	23,597	10,662
Substandard
Financing Receivable, Recorded Investment [Line Items]
Commercial	26,601	24,053
Real Estate - Construction	39	43
Real Estate - Commercial	34,747	38,656
Lease financing	1,128	1,269
Total Commercial	62,515	64,021
Doubtful
Financing Receivable, Recorded Investment [Line Items]
Commercial	0	0
Real Estate - Construction	0	0
Real Estate - Commercial	0	0
Lease financing	0	0
Total Commercial	0	0
Residential real estate
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, before Fees, Gross	468,584	471,391
Residential real estate | Performing
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, before Fees, Gross	461,409	463,459
Residential real estate | Nonperforming
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, before Fees, Gross	7,175	7,932
Home equity
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, before Fees, Gross	483,643	493,604
Home equity | Performing
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, before Fees, Gross	479,470	489,148
Home equity | Nonperforming
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, before Fees, Gross	4,173	4,456
Installment
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, before Fees, Gross	39,248	41,586
Installment | Performing
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, before Fees, Gross	38,942	41,331
Installment | Nonperforming
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, before Fees, Gross	306	255
Credit card
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, before Fees, Gross	46,472	46,691
Credit card | Performing
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, before Fees, Gross	46,472	46,691
Credit card | Nonperforming
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, before Fees, Gross	0	0
Total consumer loans
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, before Fees, Gross	1,037,947	1,053,272
Total consumer loans | Performing
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, before Fees, Gross	1,026,293	1,040,629
Total consumer loans | Nonperforming
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, before Fees, Gross	$ 11,654	$ 12,643

LOANS AND LEASES - Loan Delinqu

LOANS AND LEASES - Loan Delinquency, including Nonaccrual Loans (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	$ 32,275	$ 27,942
Current	5,971,039	5,880,281
Loans and Leases Receivable, Gross	6,003,314	5,908,223
Purchased impaired loans	98,707	104,960
Total loans and leases	6,102,021	6,013,183
> 90 days past due and still accruing	529	62
Financing Receivables, 30 to 59 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	5,213	6,896
Financing Receivables, 60 to 89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	9,325	3,179
Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	17,737	17,867
Commercial
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	7,579	7,490
Current	1,933,461	1,901,821
Loans and Leases Receivable, Gross	1,941,040	1,909,311
Purchased impaired loans	2,701	3,432
Total loans and leases	1,943,741	1,912,743
> 90 days past due and still accruing	0	0
Commercial | Financing Receivables, 30 to 59 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	1,399	755
Commercial | Financing Receivables, 60 to 89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	4,857	1,657
Commercial | Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	1,323	5,078
Lease financing
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	943	485
Current	80,674	88,862
Loans and Leases Receivable, Gross	81,617	89,347
Purchased impaired loans	0	0
Total loans and leases	81,617	89,347
> 90 days past due and still accruing	0	0
Lease financing | Financing Receivables, 30 to 59 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	943	485
Lease financing | Financing Receivables, 60 to 89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	0	0
Lease financing | Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	0	0
Construction real estate
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	0	234
Current	494,389	467,216
Loans and Leases Receivable, Gross	494,389	467,450
Purchased impaired loans	276	280
Total loans and leases	494,665	467,730
> 90 days past due and still accruing	0	0
Construction real estate | Financing Receivables, 30 to 59 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	0	234
Construction real estate | Financing Receivables, 60 to 89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	0	0
Construction real estate | Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	0	0
Commercial real estate
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	15,808	10,694
Current	2,475,106	2,419,969
Loans and Leases Receivable, Gross	2,490,914	2,430,663
Purchased impaired loans	53,137	59,428
Total loans and leases	2,544,051	2,490,091
> 90 days past due and still accruing	0	0
Commercial real estate | Financing Receivables, 30 to 59 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	236	1,716
Commercial real estate | Financing Receivables, 60 to 89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	3,317	201
Commercial real estate | Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	12,255	8,777
Residential real estate
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	2,197	3,329
Current	427,689	430,500
Loans and Leases Receivable, Gross	429,886	433,829
Purchased impaired loans	38,698	37,562
Total loans and leases	468,584	471,391
> 90 days past due and still accruing	0	0
Residential real estate | Financing Receivables, 30 to 59 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	497	526
Residential real estate | Financing Receivables, 60 to 89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	341	811
Residential real estate | Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	1,359	1,992
Home equity
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	3,903	4,863
Current	476,446	485,127
Loans and Leases Receivable, Gross	480,349	489,990
Purchased impaired loans	3,294	3,614
Total loans and leases	483,643	493,604
> 90 days past due and still accruing	0	0
Home equity | Financing Receivables, 30 to 59 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	1,395	2,716
Home equity | Financing Receivables, 60 to 89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	508	394
Home equity | Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	2,000	1,753
Installment
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	629	413
Current	38,018	40,529
Loans and Leases Receivable, Gross	38,647	40,942
Purchased impaired loans	601	644
Total loans and leases	39,248	41,586
> 90 days past due and still accruing	0	0
Installment | Financing Receivables, 30 to 59 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	284	179
Installment | Financing Receivables, 60 to 89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	74	29
Installment | Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	271	205
Credit card
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	1,216	434
Current	45,256	46,257
Loans and Leases Receivable, Gross	46,472	46,691
Purchased impaired loans	0	0
Total loans and leases	46,472	46,691
> 90 days past due and still accruing	529	62
Credit card | Financing Receivables, 30 to 59 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	459	285
Credit card | Financing Receivables, 60 to 89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	228	87
Credit card | Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	$ 529	$ 62

LOANS AND LEASES - Restructured

LOANS AND LEASES - Restructured Loans (Details)	3 Months Ended		12 Months Ended
	Mar. 31, 2018USD ($)loansd	Mar. 31, 2017USD ($)loans	Dec. 31, 2017USD ($)loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Extended Maturities	$ 888,000	$ 674,000
Adjusted Interest Rates	52,000	2,767,000
Combined Rate And Maturity	0	0
Forebearance Agreements	0	0
Other	138,000	0
Total	$ 1,078,000	$ 3,441,000
Restructured loans, Number of Loans | loans	8	2
Restructured loans, Restructured loans, Pre-Modification Loan Balance	$ 1,093,000	$ 3,502,000
Restructured loans, Period End Balance	$ 1,078,000	3,441,000
Restructured loans with payment default within 12 months of modification, Number of Loans | loans	0		0
Restructured loans with payment default within 12 months of modification, Period End Balance	$ 0	$ 0
Number of Restructured Loans | loans	204		214
Total restructured loans	$ 21,000,000		$ 23,900,000
Restructured loans on accrual status	14,943,000		17,545,000
Restructured Loans, Nonaccrual Status	6,000,000		6,400,000
Allowance for loan and lease losses lncluded in reserves for restructured loans	2,000,000		1,300,000
Restructured loans uncollectible portion written off	100,000
Accruing TDRs performing in accordance with restructured terms for more than one year	$ 13,300,000		$ 17,200,000
Restructured loans performance threshold (days) | d	90
Commercial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Restructured loans, Number of Loans | loans	4	2
Restructured loans, Restructured loans, Pre-Modification Loan Balance	$ 928,000	$ 3,502,000
Restructured loans, Period End Balance	$ 913,000	$ 3,441,000
Construction real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Restructured loans, Number of Loans | loans	0	0
Restructured loans, Restructured loans, Pre-Modification Loan Balance	$ 0	$ 0
Restructured loans, Period End Balance	$ 0	$ 0
Commercial real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Restructured loans, Number of Loans | loans	2	0
Restructured loans, Restructured loans, Pre-Modification Loan Balance	$ 72,000	$ 0
Restructured loans, Period End Balance	$ 72,000	$ 0
Residential real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Restructured loans, Number of Loans | loans	2	0
Restructured loans, Restructured loans, Pre-Modification Loan Balance	$ 93,000	$ 0
Restructured loans, Period End Balance	93,000	$ 0
Restructured Loans, Loan Relationships, Review Threshold Amount Minimum	$ 250,000
Home equity
Accounts, Notes, Loans and Financing Receivable [Line Items]
Restructured loans, Number of Loans | loans	0	0
Restructured loans, Restructured loans, Pre-Modification Loan Balance	$ 0	$ 0
Restructured loans, Period End Balance	$ 0	$ 0
Installment
Accounts, Notes, Loans and Financing Receivable [Line Items]
Restructured loans, Number of Loans | loans	0	0
Restructured loans, Restructured loans, Pre-Modification Loan Balance	$ 0	$ 0
Restructured loans, Period End Balance	$ 0	$ 0

LOANS AND LEASES - Nonaccrual,

LOANS AND LEASES - Nonaccrual, Restructured and Impaired Loans (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Financing Receivable, Modifications [Line Items]
Average current balance	$ 43,429	$ 55,544
Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method	11	26
Impaired Financing Receivable, with No Related Allowance, Interest Income, Accrual Method	193	342
Nonaccrual loans	30,283		$ 24,082
Accruing trouble debt restructurings	14,943		17,545
Total impaired loans	45,226		41,627
Restructured loans - nonaccrual status	6,000		6,400
Interest income effect
Gross amount of interest that would have been recorded under original terms	802	816
Interest included in income
Nonaccrual loans	80	142
Troubled debt restructurings	124	226
Total interest included in income	204	368
Net impact on interest income	598	448
Commercial
Financing Receivable, Modifications [Line Items]
Average current balance	8,071	16,701
Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method	0	13
Impaired Financing Receivable, with No Related Allowance, Interest Income, Accrual Method	26	109
Nonaccrual loans	6,275		5,229
Total impaired loans	8,810		7,331
Interest included in income
Total interest included in income	26	122
Lease financing
Financing Receivable, Modifications [Line Items]
Average current balance	41	149
Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method	0	0
Impaired Financing Receivable, with No Related Allowance, Interest Income, Accrual Method	0	1
Nonaccrual loans	0		82
Total impaired loans	0		82
Interest included in income
Total interest included in income	0	1
Construction real estate
Financing Receivable, Modifications [Line Items]
Average current balance	28	538
Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method	0	0
Impaired Financing Receivable, with No Related Allowance, Interest Income, Accrual Method	1	0
Nonaccrual loans	26		29
Total impaired loans	26		29
Interest included in income
Total interest included in income	1	0
Commercial real estate
Financing Receivable, Modifications [Line Items]
Average current balance	23,139	24,313
Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method	3	5
Impaired Financing Receivable, with No Related Allowance, Interest Income, Accrual Method	99	160
Nonaccrual loans	16,878		10,616
Total impaired loans	24,736		21,542
Interest included in income
Total interest included in income	102	165
Residential real estate
Financing Receivable, Modifications [Line Items]
Average current balance	7,554	9,218
Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method	7	7
Impaired Financing Receivable, with No Related Allowance, Interest Income, Accrual Method	47	46
Nonaccrual loans	3,324		4,140
Total impaired loans	7,175		7,932
Interest included in income
Total interest included in income	54	53
Home equity
Financing Receivable, Modifications [Line Items]
Average current balance	4,315	4,212
Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method	1	1
Impaired Financing Receivable, with No Related Allowance, Interest Income, Accrual Method	20	24
Nonaccrual loans	3,484		3,743
Total impaired loans	4,173		4,456
Interest included in income
Total interest included in income	21	25
Installment
Financing Receivable, Modifications [Line Items]
Average current balance	281	413
Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method	0	0
Impaired Financing Receivable, with No Related Allowance, Interest Income, Accrual Method	0	2
Nonaccrual loans	296		243
Total impaired loans	306		255
Interest included in income
Total interest included in income	0	2
Loans with no related allowance recorded [member]
Financing Receivable, Modifications [Line Items]
Average current balance	40,334	48,790
Total impaired loans	43,482		37,183
Loans with no related allowance recorded [member] | Commercial
Financing Receivable, Modifications [Line Items]
Average current balance	7,867	15,607
Total impaired loans	8,571		7,162
Loans with no related allowance recorded [member] | Lease financing
Financing Receivable, Modifications [Line Items]
Average current balance	41	149
Total impaired loans	0		82
Loans with no related allowance recorded [member] | Construction real estate
Financing Receivable, Modifications [Line Items]
Average current balance	28	538
Total impaired loans	26		29
Loans with no related allowance recorded [member] | Commercial real estate
Financing Receivable, Modifications [Line Items]
Average current balance	21,400	19,939
Total impaired loans	24,377		18,423
Loans with no related allowance recorded [member] | Residential real estate
Financing Receivable, Modifications [Line Items]
Average current balance	6,503	8,033
Total impaired loans	6,130		6,876
Loans with no related allowance recorded [member] | Home equity
Financing Receivable, Modifications [Line Items]
Average current balance	4,214	4,111
Total impaired loans	4,072		4,356
Loans with no related allowance recorded [member] | Installment
Financing Receivable, Modifications [Line Items]
Average current balance	281	413
Total impaired loans	306		255
Impaired Financing Receivables With Related Allowance [Member]
Financing Receivable, Modifications [Line Items]
Total impaired loans	1,744
Impaired Financing Receivables With Related Allowance [Member] | Commercial
Financing Receivable, Modifications [Line Items]
Average current balance	204	1,094
Total impaired loans	239		169
Impaired Financing Receivables With Related Allowance [Member] | Lease financing
Financing Receivable, Modifications [Line Items]
Average current balance	0	0
Total impaired loans	0		0
Impaired Financing Receivables With Related Allowance [Member] | Construction real estate
Financing Receivable, Modifications [Line Items]
Average current balance	0	0
Total impaired loans	0		0
Impaired Financing Receivables With Related Allowance [Member] | Commercial real estate
Financing Receivable, Modifications [Line Items]
Average current balance	1,739	4,374
Total impaired loans	359		3,119
Impaired Financing Receivables With Related Allowance [Member] | Residential real estate
Financing Receivable, Modifications [Line Items]
Average current balance	1,051	1,185
Total impaired loans	1,045		1,056
Impaired Financing Receivables With Related Allowance [Member] | Home equity
Financing Receivable, Modifications [Line Items]
Average current balance	101	101
Total impaired loans	101		100
Impaired Financing Receivables With Related Allowance [Member] | Installment
Financing Receivable, Modifications [Line Items]
Average current balance	0	0
Total impaired loans	0		0
Impaired Financing Receivables With Related Allowance [Member]
Financing Receivable, Modifications [Line Items]
Average current balance	$ 3,095	$ 6,754
Total impaired loans			$ 4,444

LOANS AND LEASES - Investment i

LOANS AND LEASES - Investment in Impaired Loans (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Financing Receivable, Impaired [Line Items]
Financing Receivable, Recorded Investment, Nonaccrual Status	$ 30,283		$ 24,082
Current balance	45,226		41,627
Contractual Principal Balance	52,163		47,857
Related Allowance	288		779
Average current balance	43,429	$ 55,544
Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method	11	26
Impaired Financing Receivable, with No Related Allowance, Interest Income, Accrual Method	193	342
Interest income recognized	204	368
Commercial
Financing Receivable, Impaired [Line Items]
Financing Receivable, Recorded Investment, Nonaccrual Status	6,275		5,229
Current balance	8,810		7,331
Contractual Principal Balance	9,094		8,629
Related Allowance	100		169
Average current balance	8,071	16,701
Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method	0	13
Impaired Financing Receivable, with No Related Allowance, Interest Income, Accrual Method	26	109
Interest income recognized	26	122
Lease financing
Financing Receivable, Impaired [Line Items]
Financing Receivable, Recorded Investment, Nonaccrual Status	0		82
Current balance	0		82
Contractual Principal Balance	0		82
Related Allowance	0		0
Average current balance	41	149
Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method	0	0
Impaired Financing Receivable, with No Related Allowance, Interest Income, Accrual Method	0	1
Interest income recognized	0	1
Construction real estate
Financing Receivable, Impaired [Line Items]
Financing Receivable, Recorded Investment, Nonaccrual Status	26		29
Current balance	26		29
Contractual Principal Balance	58		60
Related Allowance	0		0
Average current balance	28	538
Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method	0	0
Impaired Financing Receivable, with No Related Allowance, Interest Income, Accrual Method	1	0
Interest income recognized	1	0
Commercial real estate
Financing Receivable, Impaired [Line Items]
Financing Receivable, Recorded Investment, Nonaccrual Status	16,878		10,616
Current balance	24,736		21,542
Contractual Principal Balance	29,230		23,957
Related Allowance	26		448
Average current balance	23,139	24,313
Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method	3	5
Impaired Financing Receivable, with No Related Allowance, Interest Income, Accrual Method	99	160
Interest income recognized	102	165
Residential real estate
Financing Receivable, Impaired [Line Items]
Financing Receivable, Recorded Investment, Nonaccrual Status	3,324		4,140
Current balance	7,175		7,932
Contractual Principal Balance	8,327		9,208
Related Allowance	160		160
Average current balance	7,554	9,218
Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method	7	7
Impaired Financing Receivable, with No Related Allowance, Interest Income, Accrual Method	47	46
Interest income recognized	54	53
Home equity
Financing Receivable, Impaired [Line Items]
Financing Receivable, Recorded Investment, Nonaccrual Status	3,484		3,743
Current balance	4,173		4,456
Contractual Principal Balance	4,985		5,499
Related Allowance	2		2
Average current balance	4,315	4,212
Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method	1	1
Impaired Financing Receivable, with No Related Allowance, Interest Income, Accrual Method	20	24
Interest income recognized	21	25
Installment
Financing Receivable, Impaired [Line Items]
Financing Receivable, Recorded Investment, Nonaccrual Status	296		243
Current balance	306		255
Contractual Principal Balance	469		422
Related Allowance	0		0
Average current balance	281	413
Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method	0	0
Impaired Financing Receivable, with No Related Allowance, Interest Income, Accrual Method	0	2
Interest income recognized	0	2
Loans with no related allowance recorded [member]
Financing Receivable, Impaired [Line Items]
Current balance	43,482		37,183
Contractual Principal Balance	50,341		43,405
Related Allowance	0		0
Average current balance	40,334	48,790
Loans with no related allowance recorded [member] | Commercial
Financing Receivable, Impaired [Line Items]
Current balance	8,571		7,162
Contractual Principal Balance	8,777		8,460
Related Allowance	0		0
Average current balance	7,867	15,607
Loans with no related allowance recorded [member] | Lease financing
Financing Receivable, Impaired [Line Items]
Current balance	0		82
Contractual Principal Balance	0		82
Related Allowance	0		0
Average current balance	41	149
Loans with no related allowance recorded [member] | Construction real estate
Financing Receivable, Impaired [Line Items]
Current balance	26		29
Contractual Principal Balance	58		60
Related Allowance	0		0
Average current balance	28	538
Loans with no related allowance recorded [member] | Commercial real estate
Financing Receivable, Impaired [Line Items]
Current balance	24,377		18,423
Contractual Principal Balance	28,871		20,837
Related Allowance	0		0
Average current balance	21,400	19,939
Loans with no related allowance recorded [member] | Residential real estate
Financing Receivable, Impaired [Line Items]
Current balance	6,130		6,876
Contractual Principal Balance	7,282		8,145
Related Allowance	0		0
Average current balance	6,503	8,033
Loans with no related allowance recorded [member] | Home equity
Financing Receivable, Impaired [Line Items]
Current balance	4,072		4,356
Contractual Principal Balance	4,884		5,399
Related Allowance	0		0
Average current balance	4,214	4,111
Loans with no related allowance recorded [member] | Installment
Financing Receivable, Impaired [Line Items]
Current balance	306		255
Contractual Principal Balance	469		422
Related Allowance	0		0
Average current balance	281	413
Impaired Financing Receivables With Related Allowance [Member]
Financing Receivable, Impaired [Line Items]
Current balance	1,744
Contractual Principal Balance	1,822
Related Allowance	288
Impaired Financing Receivables With Related Allowance [Member] | Commercial
Financing Receivable, Impaired [Line Items]
Current balance	239		169
Contractual Principal Balance	317		169
Related Allowance	100		169
Average current balance	204	1,094
Impaired Financing Receivables With Related Allowance [Member] | Lease financing
Financing Receivable, Impaired [Line Items]
Current balance	0		0
Contractual Principal Balance	0		0
Related Allowance	0		0
Average current balance	0	0
Impaired Financing Receivables With Related Allowance [Member] | Construction real estate
Financing Receivable, Impaired [Line Items]
Current balance	0		0
Contractual Principal Balance	0		0
Related Allowance	0		0
Average current balance	0	0
Impaired Financing Receivables With Related Allowance [Member] | Commercial real estate
Financing Receivable, Impaired [Line Items]
Current balance	359		3,119
Contractual Principal Balance	359		3,120
Related Allowance	26		448
Average current balance	1,739	4,374
Impaired Financing Receivables With Related Allowance [Member] | Residential real estate
Financing Receivable, Impaired [Line Items]
Current balance	1,045		1,056
Contractual Principal Balance	1,045		1,063
Related Allowance	160		160
Average current balance	1,051	1,185
Impaired Financing Receivables With Related Allowance [Member] | Home equity
Financing Receivable, Impaired [Line Items]
Current balance	101		100
Contractual Principal Balance	101		100
Related Allowance	2		2
Average current balance	101	101
Impaired Financing Receivables With Related Allowance [Member] | Installment
Financing Receivable, Impaired [Line Items]
Current balance	0		0
Contractual Principal Balance	0		0
Related Allowance	0		0
Average current balance	0	0
Impaired Financing Receivables With Related Allowance [Member]
Financing Receivable, Impaired [Line Items]
Current balance			4,444
Contractual Principal Balance			4,452
Related Allowance			$ 779
Average current balance	$ 3,095	$ 6,754

LOANS AND LEASES - Changes in O

LOANS AND LEASES - Changes in Other Real Estate Owned (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Accounts, Notes, Loans and Financing Receivable [Line Items]
FDIC indemnification asset	$ 0		$ 1,900
Balance at beginning of period	2,781	$ 6,284
Additions	629	287
Disposals	(2,222)	(1,162)
Write-downs	123	109
Balance at end of period	1,065	5,300
Commercial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Additions	170	122
Disposals	(2,104)	(925)
Write-downs	97	46
Residential real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Additions	459	165
Disposals	(118)	(237)
Write-downs	$ 26	$ 63

ALLOWANCE FOR LOAN AND LEASE 47

ALLOWANCE FOR LOAN AND LEASE LOSSES - Changes in the Allowance for Loan and Lease Losses (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Mar. 31, 2018	Dec. 31, 2017
Allowance for loan and lease losses:
Balance at beginning of period	$ 54,021	$ 57,961
Provision for loan and lease losses	2,303	367
Loans charged-off	(3,669)	(2,750)
Recoveries	1,725	748
Total net charge-offs	1,944	2,002
Balance at end of period	54,380	56,326
Ending allowance on loans individually evaluated for impairment			$ 288	$ 779
Ending allowance on loans collectively evaluated for impairment			54,092	53,242
Ending allowance for loan and lease losses	54,380	57,961	54,380	54,021
Loans and Leases:
Ending balance of loans individually evaluated for impairment			45,226	41,627
Ending balance of loans collectively evaluated for impairment			6,056,795	5,971,556
Loans and Leases Receivable, Net of Deferred Income			6,102,021	6,013,183
Commercial
Allowance for loan and lease losses:
Balance at beginning of period	17,598	19,225
Provision for loan and lease losses	889	(596)
Loans charged-off	(885)	(1,743)
Recoveries	436	262
Total net charge-offs	449	1,481
Balance at end of period	18,038	17,148
Ending allowance on loans individually evaluated for impairment			100	169
Ending allowance on loans collectively evaluated for impairment			17,938	17,429
Ending allowance for loan and lease losses	17,598	19,225	18,038	17,598
Loans and Leases:
Ending balance of loans individually evaluated for impairment			8,810	7,331
Ending balance of loans collectively evaluated for impairment			1,934,931	1,905,412
Loans and Leases Receivable, Net of Deferred Income			1,943,741	1,912,743
Lease financing
Allowance for loan and lease losses:
Balance at beginning of period	675	716
Provision for loan and lease losses	(49)	(100)
Loans charged-off	0	0
Recoveries	0	0
Total net charge-offs	0	0
Balance at end of period	626	616
Ending allowance on loans individually evaluated for impairment			0	0
Ending allowance on loans collectively evaluated for impairment			626	675
Ending allowance for loan and lease losses	626	716	626	675
Loans and Leases:
Ending balance of loans individually evaluated for impairment			0	82
Ending balance of loans collectively evaluated for impairment			81,617	89,265
Loans and Leases Receivable, Net of Deferred Income			81,617	89,347
Construction real estate
Allowance for loan and lease losses:
Balance at beginning of period	3,577	3,282
Provision for loan and lease losses	690	325
Loans charged-off	0	0
Recoveries	0	0
Total net charge-offs	0	0
Balance at end of period	4,267	3,607
Ending allowance on loans individually evaluated for impairment			0	0
Ending allowance on loans collectively evaluated for impairment			4,267	3,577
Ending allowance for loan and lease losses	4,267	3,282	4,267	3,577
Loans and Leases:
Ending balance of loans individually evaluated for impairment			26	29
Ending balance of loans collectively evaluated for impairment			494,639	467,701
Loans and Leases Receivable, Net of Deferred Income			494,665	467,730
Commercial real estate
Allowance for loan and lease losses:
Balance at beginning of period	20,930	26,540
Provision for loan and lease losses	815	(2,566)
Loans charged-off	(2,176)	(485)
Recoveries	752	256
Total net charge-offs	1,424	229
Balance at end of period	20,321	23,745
Ending allowance on loans individually evaluated for impairment			26	448
Ending allowance on loans collectively evaluated for impairment			20,295	20,482
Ending allowance for loan and lease losses	20,930	26,540	20,321	20,930
Loans and Leases:
Ending balance of loans individually evaluated for impairment			24,736	21,542
Ending balance of loans collectively evaluated for impairment			2,519,315	2,468,549
Loans and Leases Receivable, Net of Deferred Income			2,544,051	2,490,091
Residential real estate
Allowance for loan and lease losses:
Balance at beginning of period	4,683	3,208
Provision for loan and lease losses	114	2,329
Loans charged-off	(96)	(61)
Recoveries	26	9
Total net charge-offs	70	52
Balance at end of period	4,727	5,485
Ending allowance on loans individually evaluated for impairment			160	160
Ending allowance on loans collectively evaluated for impairment			4,567	4,523
Ending allowance for loan and lease losses	4,727	3,208	4,727	4,683
Loans and Leases:
Ending balance of loans individually evaluated for impairment			7,175	7,932
Ending balance of loans collectively evaluated for impairment			461,409	463,459
Loans and Leases Receivable, Net of Deferred Income			468,584	471,391
Home equity
Allowance for loan and lease losses:
Balance at beginning of period	4,935	3,043
Provision for loan and lease losses	(294)	805
Loans charged-off	(242)	(180)
Recoveries	429	106
Total net charge-offs	(187)	74
Balance at end of period	4,828	3,774
Ending allowance on loans individually evaluated for impairment			2	2
Ending allowance on loans collectively evaluated for impairment			4,826	4,933
Ending allowance for loan and lease losses	4,828	3,043	4,828	4,935
Loans and Leases:
Ending balance of loans individually evaluated for impairment			4,173	4,456
Ending balance of loans collectively evaluated for impairment			479,470	489,148
Loans and Leases Receivable, Net of Deferred Income			483,643	493,604
Installment
Allowance for loan and lease losses:
Balance at beginning of period	307	388
Provision for loan and lease losses	(49)	9
Loans charged-off	(16)	(49)
Recoveries	48	71
Total net charge-offs	(32)	(22)
Balance at end of period	290	419
Ending allowance on loans individually evaluated for impairment			0	0
Ending allowance on loans collectively evaluated for impairment			290	307
Ending allowance for loan and lease losses	307	388	290	307
Loans and Leases:
Ending balance of loans individually evaluated for impairment			306	255
Ending balance of loans collectively evaluated for impairment			38,942	41,331
Loans and Leases Receivable, Net of Deferred Income			39,248	41,586
Credit card
Allowance for loan and lease losses:
Balance at beginning of period	1,316	1,559
Provision for loan and lease losses	187	161
Loans charged-off	(254)	(232)
Recoveries	34	44
Total net charge-offs	(220)	(188)
Balance at end of period	1,283	1,532
Ending allowance on loans individually evaluated for impairment			0	0
Ending allowance on loans collectively evaluated for impairment			1,283	1,316
Ending allowance for loan and lease losses	$ 1,283	$ 1,559	1,283	1,316
Loans and Leases:
Ending balance of loans individually evaluated for impairment			0	0
Ending balance of loans collectively evaluated for impairment			46,472	46,691
Loans and Leases Receivable, Net of Deferred Income			$ 46,472	$ 46,691

GOODWILL AND OTHER INTANGIBLE48

GOODWILL AND OTHER INTANGIBLE ASSETS--Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Finite-Lived Intangible Assets [Line Items]
Goodwill	$ 204,100		$ 204,084
Intangible Assets, Net (Excluding Goodwill)	5,000		5,300
Finite-Lived Core Deposits, Gross	3,100		$ 3,300
Finite-Lived Intangible Assets, Amortization Expense	$ 300	$ 300
Core Deposits [Member]
Finite-Lived Intangible Assets [Line Items]
Intangible assets amortization method	accelerated basis
Estimated weighted average life (in years)	3 years 7 months 6 days

BORROWINGS Borrowings - - Addit

BORROWINGS Borrowings - - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Dec. 31, 2017
Debt Disclosure [Abstract]
Federal Home Loan Bank short-term borrowings	$ 601,600	$ 742,300
Line of Credit Facility, Maximum Borrowing Capacity	15,000
Commitments outstanding to extend credit	0	0
Subordinated debt	$ 120,000
Subordinated Borrowing, Interest Rate	5.125%
Advances from Federal Home Loan Banks	$ 50,238	$ 241
Long-term Federal Home Loan Bank Advances, Noncurrent	$ 50,000
Federal Home Loan Bank	2.63%	1.09%

BORROWINGS - Schedule of Long-t

BORROWINGS - Schedule of Long-term Debt (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Amount
Subordinated debt	$ 120,000	$ 120,000
FHLB long-term advances	50,238	241
Capital loan with municipality	775	775
Total long-term debt	$ 169,695	$ 119,654
Average Rate [Abstract]
Debt, Weighted Average Interest Rate	5.13%	5.13%
Federal Home Loan Bank	2.63%	1.09%
Weighted average rate on other long-term debt	0.00%	0.00%
Total long-term debt	4.40%	5.14%
Debt Instrument, Unamortized Discount (Premium) and Debt Issuance Costs, Net	$ (1,318)	$ (1,362)

ACCUMULATED OTHER COMPREHENSI51

ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017	Dec. 31, 2016
Other Comprehensive Income (Loss), before Reclassification Adjustments and Tax [Abstract]
Unrealized gain (loss) on investment securities	$ (12,536)	$ 2,832
Unrealized gain (loss) on derivatives	202	203
Retirement obligation	0	0
Total	(12,334)	3,035
Other Comprehensive Income (Loss) Reclassifications before Tax [Abstract]
Unrealized gain (loss) on investment securities	0	516
Unrealized gain (loss) on derivatives	0	0
Retirement obligation	(419)	(335)
Total	(419)	181
Transactions Pre-tax
Unrealized gain (loss) on investment securities	(12,536)	2,316
Unrealized gain (loss) on derivatives	202	203
Unfunded pension obligation	419	335
Total	(11,915)	2,854
Transactions Tax-effect
Unrealized gain (loss) on investment securities	2,706	(829)
Unrealized gain (loss) on derivatives	(46)	(75)
Retirement obligation	(96)	(146)
Total	2,564	(1,050)
Transactions Net of tax
Unrealized gain (loss) on investment securities	(9,830)	1,487
Unrealized gain (loss) on derivatives	156	128
Retirement obligation	323	189
Total	(9,351)	1,804
Stranded Tax Effects
Unrealized gain (loss) on investment securities	(39)
Unrealized gain (loss) on Derivatives	(124)
Retirement obligation	4,779
Total	(4,942)
Balances Net of tax
Unrealized gain (loss) on investment securities	(10,051)	(3,062)	$ (182)	$ (4,549)
Unrealized gain (loss) on cash flow hedges	(545)	(963)	(577)	(1,091)
Retirement obligation	(24,087)	(22,614)	(19,631)	(22,803)
Total	(34,683)	(26,639)	$ (20,390)	$ (28,443)
Accumulated other comprehensive income (loss)
Transactions Net of tax
Total	$ (9,351)	$ 1,804

ACCUMULATED OTHER COMPREHENSI52

ACCUMULATED OTHER COMPREHENSIVE INCOME AMOUNT RECLASSIFIED FROM ACCUMULATED OTHER COMPREHENSIVE INCOME (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Other Accumulated Comprehensive income reclassified from AOCI [Line Items]
Net gains (losses) on sales of investment securities	$ 0	$ 516
Defined Benefit Plan, Amortization of Prior Service Cost (Credit)	103	103
Defined Benefit Plan, Amortization of Gain (Loss)	(522)	(438)
Other Comprehensive Income, Reclassification, Amortization of Defined Benefit Plans items, Pre-tax	(419)	(335)
Total	$ (419)	$ 181

DERIVATIVES - Additional Inform

DERIVATIVES - Additional Information (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2018USD ($)entity	Dec. 31, 2017USD ($)entity
Derivative [Line Items]
Maximum derivative notional position as a percentage of assets	35.00%
Maximum credit exposure as a percentage of capital	3.00%
Maximum single counterparty credit risk exposure	$ 20,000
Inerest-bearing deposit liability	$ 1,816,432	$ 1,674,080
Number of counterparties | entity	14	13
Derivative Asset	$ 16,325	$ 12,682
Derivative Financial Instruments, Liabilities, Fair Value Disclosure	16,327	12,687
Interest Rate Lock Commitments [Member]
Derivative [Line Items]
Inerest-bearing deposit liability	13,000	12,300
Other Credit Derivatives [Member]
Derivative [Line Items]
Inerest-bearing deposit liability	10,100	15,400
Credit Risk Derivative Liabilities, at Fair Value	100	71
Credit Risk Contract [Member]
Derivative [Line Items]
Inerest-bearing deposit liability	95,600	95,900
Accrued interest and other liabilities | Derivative [Member]
Derivative [Line Items]
Inerest-bearing deposit liability	908,600	837,500
Derivative Asset	$ (10,400)
Derivative Financial Instruments, Liabilities, Fair Value Disclosure		$ 1,300

DERIVATIVES - Summary of Deriva

DERIVATIVES - Summary of Derivative Financial Instruments and Balances (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Derivatives, Fair Value [Line Items]
Inerest-bearing deposit liability	$ 1,816,432	$ 1,674,080
Derivative Asset	16,325	12,682
Estimate Fair Value Loss	(16,327)	(12,687)
Other Credit Derivatives [Member]
Derivatives, Fair Value [Line Items]
Inerest-bearing deposit liability	10,100	15,400
Credit Risk Derivative Liabilities, at Fair Value	100	71
Fair Value Hedges | Matched interest rate swaps | Accrued interest and other liabilities
Derivatives, Fair Value [Line Items]
Inerest-bearing deposit liability	908,216	837,040
Derivative Asset	13,225	5,529
Estimate Fair Value Loss	(3,102)	(7,158)
Fair Value Hedges | Matched interest rate swaps | Accrued interest and other assets
Derivatives, Fair Value [Line Items]
Inerest-bearing deposit liability	908,216	837,040
Derivative Asset	3,100	7,153
Estimate Fair Value Loss	$ (13,225)	$ (5,529)

DERIVATIVES DERIVATIVES - Discl

DERIVATIVES DERIVATIVES - Disclosure by Type of Financial Instrument (Details) - Fair Value Hedges - Matched interest rate swaps - Accrued interest and other liabilities - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Derivatives, Fair Value [Line Items]
Gross amounts of recognized liabilities	$ 16,327	$ 12,687
Derivative Liability, Fair Value, Gross Asset	24,475	2,279
Derivative Asset, Fair Value, Amount Not Offset Against Collateral	$ 40,802	$ 14,966

DERIVATIVES - Derivative Financ

DERIVATIVES - Derivative Financial Instruments, Average Remaining Maturity and the Weighted-Average Interest Rates being Paid and Received (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Dec. 31, 2017
Derivative [Line Items]
Notional Value	$ 1,816,432	$ 1,674,080
Interest Rate Swap
Derivative [Line Items]
Notional Value	$ 1,816,432
Average Maturity (years)	5 years 9 months 18 days
Fair Value	$ (2)
Weighted-Average Rate Receive	4.13%
Weighted-Average Rate Pay	4.13%
Interest Rate Swap | Derivative Financial Instruments Receive Fixed Pay Variable
Derivative [Line Items]
Notional Value	$ 908,216
Average Maturity (years)	5 years 9 months 18 days
Fair Value	$ (10,125)
Weighted-Average Rate Receive	4.47%
Weighted-Average Rate Pay	3.80%
Interest Rate Swap | Derivative Financial Instruments Receive Variable Pay Fixed
Derivative [Line Items]
Notional Value	$ 908,216
Average Maturity (years)	5 years 9 months 18 days
Fair Value	$ 10,123
Weighted-Average Rate Receive	3.80%
Weighted-Average Rate Pay	4.47%

COMMITMENTS AND CONTINGENCIES (

COMMITMENTS AND CONTINGENCIES (Details) - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Commitments and Contingencies Disclosure [Line Items]
Commitments outstanding to extend credit	$ 0		$ 0
Letters of credit issued to guarantee performance of a client to a third party	25,000		25,300
Affordable Housing Program Obligation	33,200		35,900
Affordable housing contingent commitment	0		0
Variable Interest Entity, Nonconsolidated, Carrying Amount, Assets	2,900		3,000
Variable Interest Entity, Reporting Entity Involvement, Maximum Loss Exposure, Amount	2,900		3,000
Amortization Method Qualified Affordable Housing Project Investments, Amortization	1,300	$ 1,000
Estimated Litigation Liability	0		0
Loans and Leases Receivable, Commitments, Fixed Rates	75,600		44,300
Loans and Leases Receivable, Commitments, Variable Rates	$ 2,000,000		$ 2,000,000
Loan Commitments, Fixed Interest Rate Range, Minimum	0.00%
Loan Commitments, Fixed Interest Rate Range, Maximum	21.00%
Loan Commitments, Fixed Rate, Maturities, Minimum	1 year
Loan Commitments, Fixed Rate, Maturities, Maximum	30 years
Commitments to Extend Credit
Commitments and Contingencies Disclosure [Line Items]
Commitments outstanding to extend credit	$ 2,000,000
Affordable housing investment [Member]
Commitments and Contingencies Disclosure [Line Items]
Low-income housing tax credit	1,100	800
Historic tax credit [Member]
Commitments and Contingencies Disclosure [Line Items]
Low-income housing tax credit	$ 100	$ 100

INCOME TAXES (Details)

INCOME TAXES (Details) - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Income tax expense	$ 7,653	$ 10,470
Effective tax rate	20.10%	30.00%
Employee Service Share-based Compensation, Tax Benefit from Compensation Expense	$ 400	$ 1,100
Effective Income Tax Rate Reconciliation, Change in Enacted Tax Rate, Percent			21.00%
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent			35.00%
Unrecognized Tax Benefits that Would Impact Effective Tax Rate	$ 2,900		$ 2,900

EMPLOYEE BENEFIT PLANS - Additi

EMPLOYEE BENEFIT PLANS - Additional Information (Details) - USD ($)	3 Months Ended		12 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Retirement Benefits [Abstract]
Defined Benefit Plan, Expected Future Employer Contributions, Remainder of Fiscal Year	$ 0
Payment for Pension Benefits	0		$ 0
Pension Cost (Reversal of Cost)	$ (156,000)	$ (319,000)

EMPLOYEE BENEFIT PLANS EMPLOYEE

EMPLOYEE BENEFIT PLANS EMPLOYEE BENEFIT PLANS - Employee benefit plan amounts recognized in the Consolidated Balance Sheets and Consolidated Statements of Income (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Retirement Benefits [Abstract]
Service cost	$ 1,295	$ 1,238
Interest cost	590	589
Expected return on plan assets	(2,460)	(2,481)
Amortization of prior service cost	(103)	(103)
Defined Benefit Plan, Amortization of Gain (Loss)	522	438
Net periodic benefit cost (income)	$ (156)	$ (319)

EARNINGS PER COMMON SHARE - Com

EARNINGS PER COMMON SHARE - Computation of Basic and Diluted Earnings Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Numerator for basic and diluted earnings per share -income available to common shareholders:
Net income	$ 30,506	$ 24,414
Denominator for basic earnings per share - weighted average shares	61,654,686	61,398,414
Effect of dilutive securities -
Employee stock awards	464,254	674,589
Warrants	61,804	67,381
Denominator for diluted earnings per share - adjusted weighted average shares	62,180,744	62,140,384
Basic	$ 0.49	$ 0.40
Diluted	$ 0.49	$ 0.39

EARNINGS PER COMMON SHARE - Add

EARNINGS PER COMMON SHARE - Additional Information (Details) - $ / shares	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Earnings Per Share Disclosure [Line Items]
Investment Warrants, Exercise Price	$ 12.11
Antidilutive Warrants
Earnings Per Share Disclosure [Line Items]
Stock options and warrants with an exercise price greater than the average market price of the common shares not included in the computation of net income per diluted share	101,808	112,233
Antidilutive Stock Options
Earnings Per Share Disclosure [Line Items]
Stock options and warrants with an exercise price greater than the average market price of the common shares not included in the computation of net income per diluted share	0	0

REVENUE RECOGNITION REVENUE R63

REVENUE RECOGNITION REVENUE RECOGNITION (Details) $ in Millions	3 Months Ended
	Mar. 31, 2018USD ($)
Revenue Recognition [Abstract]
Fees and Commissions, Credit and Debit Cards	$ 5.4
Credit card expense	$ 2

FAIR VALUE DISCLOSURES - Estima

FAIR VALUE DISCLOSURES - Estimated Fair Values of Financial Instruments (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative Financial Instruments, Liabilities, Fair Value Disclosure	$ 16,327	$ 12,687
Financial assets
Investment securities held-to-maturity	633,722	654,008
Other investments	53,070	53,140
Deposits
Noninterest-bearing	1,572,636	1,662,058
Savings	2,450,196	2,462,420
Time	1,545,273	1,317,105
Carrying value
Financial assets
Cash and short-term investments	126,781	184,624
Investment securities held-to-maturity	633,722	654,008
Other investments	53,070	53,140
Loans held for sale	8,048	11,502
Loans and leases	6,047,641	5,959,162
Interest Receivable	25,842	24,496
Deposits
Deposits	7,010,504	6,895,046
Short-term borrowings	658,332	814,565
Long-term debt	169,695	119,654
Interest Payable	4,091	5,104
Fair value
Financial assets
Cash and short-term investments	126,781	184,624
Investment securities held-to-maturity	623,967	653,101
Loans held for sale	8,048	11,502
Loans and leases	6,098,950	6,006,656
Interest Receivable	25,842	24,496
Deposits
Deposits	6,994,627	6,884,615
Short-term borrowings	658,332	814,565
Long-term debt	165,569	117,908
Interest Payable	4,091	5,104
Fair Value, Inputs, Level 1 [Member] | Fair value
Financial assets
Cash and short-term investments	126,781	184,624
Investment securities held-to-maturity	0	0
Loans held for sale	0	0
Loans and leases	0	0
Interest Receivable	0	0
Deposits
Deposits	0	0
Short-term borrowings	658,332	814,565
Long-term debt	0	0
Interest Payable	375	204
Fair Value, Inputs, Level 2 [Member] | Fair value
Financial assets
Cash and short-term investments	0	0
Investment securities held-to-maturity	623,967	653,101
Loans held for sale	8,048	11,502
Loans and leases	0	0
Interest Receivable	8,232	8,265
Deposits
Deposits	6,994,627	6,884,615
Short-term borrowings	0	0
Long-term debt	165,569	117,908
Interest Payable	3,716	4,900
Fair Value, Inputs, Level 3 [Member] | Fair value
Financial assets
Cash and short-term investments	0	0
Investment securities held-to-maturity	0	0
Loans held for sale	0	0
Loans and leases	6,098,950	6,006,656
Interest Receivable	17,610	16,231
Deposits
Deposits	0	0
Short-term borrowings	0	0
Long-term debt	0	0
Interest Payable	$ 0	$ 0

FAIR VALUE DISCLOSURES - Summar

FAIR VALUE DISCLOSURES - Summary of Financial Assets and Liabilities Measure at Fair Value on a Recurring Basis (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Assets
Derivatives	$ 16,325	$ 12,682
Investment securities available-for-sale	1,359,381	1,349,408
Liabilities
Derivatives	16,327	12,687
Fair Value, Measurements, Recurring
Assets
Derivatives	16,416	12,757
Investment securities available-for-sale	1,359,381	1,349,408
Total	1,375,797	1,362,165
Liabilities
Derivatives	16,368	12,755
Fair Value, Measurements, Recurring | Fair Value Measurements Using Level 1
Assets
Derivatives	0	0
Investment securities available-for-sale	2,982	2,969
Total	2,982	2,969
Liabilities
Derivatives	0	0
Fair Value, Measurements, Recurring | Fair Value Measurements Using Level 2
Assets
Derivatives	16,416	12,757
Investment securities available-for-sale	1,356,399	1,346,439
Total	1,372,815	1,359,196
Liabilities
Derivatives	16,368	12,755
Fair Value, Measurements, Recurring | Fair Value Measurements Using Level 3
Assets
Derivatives	0	0
Investment securities available-for-sale	0	0
Total	0	0
Liabilities
Derivatives	$ 0	$ 0

FAIR VALUE DISCLOSURES - Summ66

FAIR VALUE DISCLOSURES - Summary of Financial Assets and Liabilities Measured at Fair Value on a Nonrecurring Basis (Details) - Fair Value, Measurements, Nonrecurring - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Fair Value Measurements Using Level 1
Assets
Impaired loans	$ 0	$ 0
Other Real Estate Owned, Fair Value Disclosure	0	0
Fair Value Measurements Using Level 2
Assets
Impaired loans	0	0
Other Real Estate Owned, Fair Value Disclosure	0	0
Fair Value Measurements Using Level 3
Assets
Impaired loans	472	2,671
Other Real Estate Owned, Fair Value Disclosure	$ 215	$ 1,086

BUSINESS COMBINATION Business67

BUSINESS COMBINATION Business Combination - Additional Information - Narrative (Details) - USD ($) $ in Thousands	Apr. 01, 2018	Mar. 31, 2018	Dec. 31, 2017
Business Acquisition [Line Items]
Business Acquisition, Number Of Shares Received by Acquiree	1.3875
Business Combination, Consideration Transferred	$ 1,000,000
Assets		$ 8,898,429	$ 8,896,923
Loans and Leases Receivable, Net Amount		6,047,641	5,959,162
Deposits		7,010,504	$ 6,895,046
MainSource [Member]
Business Acquisition [Line Items]
Assets		4,600,000
Loans and Leases Receivable, Net Amount		3,000,000
Deposits		$ 3,400,000