Horizon Bancorp (HBNC) 10-K 28 Feb 18 2017 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Feb. 27, 2018	Jun. 30, 2017
Document And Entity Information [Abstract]
Document Type	10-K
Amendment Flag	false
Document Period End Date	Dec. 31, 2017
Document Fiscal Year Focus	2,017
Document Fiscal Period Focus	FY
Trading Symbol	HBNC
Entity Registrant Name	HORIZON BANCORP /IN/
Entity Central Index Key	706,129
Current Fiscal Year End Date	--12-31
Entity Well-known Seasoned Issuer	No
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Filer Category	Accelerated Filer
Entity Common Stock, Shares Outstanding		25,560,819
Entity Public Float			$ 554.7

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Assets
Cash and due from banks	$ 76,441	$ 70,832
Investment securities, available for sale	509,665	439,831
Investment securities, held to maturity (fair value of $201,085 and $194,086)	200,448	193,194
Loans held for sale	3,094	8,087
Loans, net of allowance for loan losses of $16,394 and $14,837	2,815,601	2,121,149
Premises and equipment, net	75,529	66,357
Federal Reserve and Federal Home Loan Bank stock	18,105	23,932
Goodwill	119,880	76,941
Other intangible assets	12,402	9,366
Interest receivable	16,244	12,713
Cash value of life insurance	75,931	74,134
Other assets	40,963	44,620
Total assets	3,964,303	3,141,156
Liabilities
Non-interest bearing	601,805	496,248
Interest bearing	2,279,198	1,974,962
Total deposits	2,881,003	2,471,210
Borrowings	564,157	267,489
Subordinated debentures	37,653	37,456
Interest payable	886	472
Other liabilities	23,526	23,674
Total liabilities	3,507,225	2,800,301
Commitments and contingent liabilities
Stockholders' Equity
Preferred stock, Authorized, 1,000,000 shares Issued 0 and 0 shares
Common stock, no par value Authorized 66,000,000 shares, Issued, 25,549,069 and 22,192,530 shares, Outstanding, 25,529,819 and 22,171,596 shares	0	0
Additional paid-in capital	275,059	182,326
Retained earnings	185,570	164,173
Accumulated other comprehensive loss	(3,551)	(5,644)
Total stockholders' equity	457,078	340,855
Total liabilities and stockholders' equity	$ 3,964,303	$ 3,141,156

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) $ in Thousands		Dec. 31, 2017USD ($)$ / sharesshares	Dec. 31, 2016USD ($)$ / sharesshares
Statement of Financial Position [Abstract]
Investment securities, held to maturity fair value | $		$ 201,085	$ 194,086
Allowance for loan losses | $		$ 16,394	$ 14,837
Preferred stock, shares authorized		1,000,000	1,000,000
Preferred stock, shares issued		0	0
Common stock, par value | $ / shares
Common stock, shares authorized	[1]	66,000,000	66,000,000
Common stock, shares issued	[1]	25,549,069	22,192,530
Common stock, shares outstanding	[1]	25,529,819	22,171,596
[1]	Adjusted for 3:2 stock split on November 14, 2016.

Consolidated Statements of Inco

Consolidated Statements of Income - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Interest Income
Loans receivable		$ 112,329	$ 91,569	$ 75,373
Investment securities
Taxable		9,086	10,039	8,721
Tax exempt		7,068	4,921	4,494
Total interest income		128,483	106,529	88,588
Interest Expense
Deposits		7,901	6,616	5,559
Borrowed funds		6,178	11,807	6,286
Subordinated debentures		2,304	2,114	2,009
Total interest expense		16,383	20,537	13,854
Net Interest Income		112,100	85,992	74,734
Provision for loan losses		2,470	1,842	3,162
Net Interest Income after Provision for Loan Losses		109,630	84,150	71,572
Non-interest Income
Service charges on deposit accounts		6,383	5,762	4,807
Wire transfer fees		658	806	633
Interchange fees		5,104	4,165	3,623
Fiduciary activities		7,894	6,621	5,637
Gain on sale of investment securities (includes $38, $1,836 and $189 for the years ended December 31, 2017, 2016 and 2015 related to accumulated other comprehensive earnings reclassifications)		38	1,836	189
Gain on sale of mortgage loans		7,906	11,675	10,055
Mortgage servicing income net of impairment		1,583	1,908	993
Increase in cash value of bank owned life insurance		1,797	1,643	1,249
Death benefit on bank owned life insurance				145
Other income		1,773	1,039	1,103
Total non-interest income		33,136	35,455	28,434
Non-interest Expense
Salaries and employee benefits		51,375	44,013	37,712
Net occupancy expenses		9,535	8,322	6,400
Data processing		5,914	5,367	4,251
Professional fees		2,490	2,752	2,070
Outside services and consultants		7,018	7,863	5,735
Loan expense		4,970	5,582	5,379
FDIC insurance expense		1,046	1,559	1,499
Other losses		368	684	432
Other expense		12,097	10,750	8,747
Total non-interest expense		94,813	86,892	72,225
Income Before Income Tax		47,953	32,713	27,781
Income tax expense (includes $13, $643 and $66 for the years ended December 31, 2017, 2016 and 2015 related to income tax expense from reclassification items)		14,836	8,801	7,232
Net Income		33,117	23,912	20,549
Preferred stock dividend			(42)	(125)
Net Income Available to Common Shareholders		$ 33,117	$ 23,870	$ 20,424
Basic Earnings Per Share	[1]	$ 1.44	$ 1.19	$ 1.30
Diluted Earnings Per Share	[1]	$ 1.43	$ 1.19	$ 1.26
[1]	Adjusted for 3:2 stock split on November 14, 2016

Consolidated Statements of Inc5

Consolidated Statements of Income (Parenthetical) $ in Thousands	12 Months Ended
	Dec. 31, 2017USD ($)	Dec. 31, 2016USD ($)	Dec. 31, 2015USD ($)
Income Statement [Abstract]
Accumulated other comprehensive earnings reclassifications	$ 38	$ 1,836	$ 189
Income tax expense from reclassification	$ 13	$ 643	$ 66

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Statement of Comprehensive Income [Abstract]
Net income	$ 33,117	$ 23,912	$ 20,549
Change in fair value of derivative instruments:
Change in fair value of derivative instruments for the period	1,404	9	195
Income tax effect	(491)	(3)	(68)
Changes from derivative instruments	913	6	127
Change in securities:
Unrealized appreciation (depreciation) for the period on AFS securities	2,110	(5,091)	(2,910)
Amortization from transfer of securities from available for sale to held to maturity securities	(256)	(653)	(549)
Reclassification adjustment for securities (gains) losses realized in income	(38)	(1,836)	(189)
Income tax effect	(636)	2,653	1,277
Unrealized gains (losses) on securities	1,180	(4,927)	(2,371)
Other Comprehensive Income (Loss), Net of Tax	2,093	(4,921)	(2,244)
Comprehensive Income	$ 35,210	$ 18,991	$ 18,305

Consolidated Statements of Stoc

Consolidated Statements of Stockholders' Equity - USD ($) $ in Thousands	Total	Kosciusko Financial Inc [Member]	LaPorte Bancorp Inc [Member]	Lafayette Community Bancorp [Member]	Wolverine Bancorp Inc [Member]	Preferred Stock [Member]	Additional Paid-in Capital [Member]	Additional Paid-in Capital [Member]Kosciusko Financial Inc [Member]	Additional Paid-in Capital [Member]LaPorte Bancorp Inc [Member]	Additional Paid-in Capital [Member]Lafayette Community Bancorp [Member]	Additional Paid-in Capital [Member]Wolverine Bancorp Inc [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income (Loss) [Member]
Beginning Balances at Dec. 31, 2014	$ 194,414					$ 12,500	$ 45,916					$ 134,477	$ 1,521
Net income	20,549											20,549
Other comprehensive income (loss), net of tax	(2,244)												(2,244)
Amortization of unearned compensation	355						355
Stock issued stock plans	554						554
Exercise of stock warrants	3,751						3,751
Stock option expense	288						288
Stock issued from acquisition	55,506						55,506
Cash dividends on preferred stock	(125)											(125)
Cash dividends on common stock	(6,216)											(6,216)
Ending Balances at Dec. 31, 2015	266,832					12,500	106,370					148,685	(723)
Net income	23,912											23,912
Other comprehensive income (loss), net of tax	(4,921)												(4,921)
Redemption of preferred stock	(12,500)					$ (12,500)
Amortization of unearned compensation	284						284
Stock issued stock plans	572						572
Stock option expense	324						324
Stock issued from acquisition		$ 14,470	$ 60,306					$ 14,470	$ 60,306
Cash dividends on preferred stock	(42)											(42)
Cash dividends on common stock	(8,382)											(8,382)
Ending Balances at Dec. 31, 2016	340,855						182,326					164,173	(5,644)
Net income	33,117											33,117
Other comprehensive income (loss), net of tax	2,093												2,093
Amortization of unearned compensation	135						135
Exercise of stock options	1,604						1,604
Stock option expense	325						325
Stock issued from acquisition				$ 28,558	$ 62,111					$ 28,558	$ 62,111
Cash dividends on common stock	(11,720)											(11,720)
Ending Balances at Dec. 31, 2017	$ 457,078						$ 275,059					$ 185,570	$ (3,551)

Consolidated Statements of Sto8

Consolidated Statements of Stockholders' Equity (Parenthetical) - Retained Earnings [Member] - $ / shares	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Cash dividends on preferred stock, rate		1.00%	1.00%
Cash dividends on common stock, per share	$ 0.50	$ 0.41	$ 0.39

Consolidated Statements of Cash

Consolidated Statements of Cash Flows $ in Thousands	12 Months Ended
	Dec. 31, 2017USD ($)	Dec. 31, 2016USD ($)	Dec. 31, 2015USD ($)
Operating Activities
Net income	$ 33,117	$ 23,912	$ 20,549
Items not requiring (providing) cash
Provision for loan losses	2,470	1,842	3,162
Depreciation and amortization	5,936	5,275	4,152
Share based compensation	325	324	288
Mortgage servicing rights net impairment	80	110	59
Premium amortization on securities, net	6,024	6,162	3,420
Gain on sale of investment securities	(38)	(1,836)	(189)
Gain on sale of mortgage loans	(7,906)	(11,675)	(10,055)
Proceeds from sales of loans	231,410	328,377	310,700
Loans originated for sale	(218,511)	(316,875)	(302,419)
Change in cash value of life insurance	(1,797)	(1,618)	(1,224)
Loss (gain) on sale of other real estate owned	(4)	261	(289)
Net change in
Interest receivable	(2,591)	(544)	(1,010)
Interest payable	152	(275)	(11)
Other assets	6,173	489	8,569
Other liabilities	(5,776)	(8,381)	(472)
Net cash provided by operating activities	49,064	25,548	35,230
Investing Activities
Purchases of securities available for sale	(149,376)	(225,555)	(244,195)
Proceeds from sales, maturities, calls, and principal repayments of securities available for sale	85,587	269,587	121,724
Purchases of securities held to maturity	(31,794)	(45,832)	(32,605)
Proceeds from maturities of securities held to maturity	13,376	30,843	7,155
Change in Federal Reserve and FHLB stock	8,922	(5,448)	268
Net change in loans	(251,821)	32,099	(156,340)
Proceeds on the sale of OREO and repossessed assets	4,238	2,572	3,014
Change in premises and equipment, net	(2,689)	(1,383)	(5,622)
Net cash provided by (used in) investing activities	(279,874)	226,390	(124,188)
Net change in
Deposits	(13,360)	46,590	46,747
Borrowings	259,895	(255,994)	49,421
Redemption of preferred stock		(12,500)
Proceeds from issuance of stock	1,604	572	4,305
Dividends paid on common shares	(11,720)	(8,382)	(6,216)
Dividends paid on preferred shares		(42)	(125)
Net cash provided by (used in) financing activities	236,419	(229,756)	94,132
Net Change in Cash and Cash Equivalents	5,609	22,182	5,174
Cash and Cash Equivalents, Beginning of Period	70,832	48,650	43,476
Cash and Cash Equivalents, End of Period	76,441	70,832	48,650
Additional Supplemental Information
Interest paid	15,969	20,572	13,844
Income taxes paid	10,195	6,916	4,123
Transfer of loans to other real estate owned	2,411	3,679	5,567
Peoples Bancorp Inc [Member]
Investing Activities
Net cash received in acquisition			182,413
The Company purchased all of the capital stock of Wolverine for $93,773 on October 17, 2017, Lafayette for $34,465 on September 1, 2017, CNB Bancorp for $5,311 on November 7, 2016, LaPorte Bancorp for $98,634 on July 18, 2016, Kosciusko for $22,983 on June 1, 2016, Peoples for $78,147 on July 1, 2015. In conjunction with the acquisition, liabilities were assumed as follows:
Fair value of assets acquired			485,077
Less: common stock issued			55,506
Cash paid for the capital stock			22,641
Liabilities assumed			$ 406,930
Kosciusko Financial Inc [Member]
Investing Activities
Net cash received in acquisition		30,437
The Company purchased all of the capital stock of Wolverine for $93,773 on October 17, 2017, Lafayette for $34,465 on September 1, 2017, CNB Bancorp for $5,311 on November 7, 2016, LaPorte Bancorp for $98,634 on July 18, 2016, Kosciusko for $22,983 on June 1, 2016, Peoples for $78,147 on July 1, 2015. In conjunction with the acquisition, liabilities were assumed as follows:
Fair value of assets acquired		155,873
Less: common stock issued		14,470
Cash paid for the capital stock		8,513
Liabilities assumed		132,890
LaPorte Bancorp Inc [Member]
Net change in
Acquisition of LaPorte, measurement period adjustments	704
Investing Activities
Net cash received in acquisition		116,521
The Company purchased all of the capital stock of Wolverine for $93,773 on October 17, 2017, Lafayette for $34,465 on September 1, 2017, CNB Bancorp for $5,311 on November 7, 2016, LaPorte Bancorp for $98,634 on July 18, 2016, Kosciusko for $22,983 on June 1, 2016, Peoples for $78,147 on July 1, 2015. In conjunction with the acquisition, liabilities were assumed as follows:
Fair value of assets acquired		546,770
Less: common stock issued		60,306
Cash paid for the capital stock		38,328
Liabilities assumed		448,136
Central National Bank & Trust [Member]
Investing Activities
Net cash received in acquisition		22,549
The Company purchased all of the capital stock of Wolverine for $93,773 on October 17, 2017, Lafayette for $34,465 on September 1, 2017, CNB Bancorp for $5,311 on November 7, 2016, LaPorte Bancorp for $98,634 on July 18, 2016, Kosciusko for $22,983 on June 1, 2016, Peoples for $78,147 on July 1, 2015. In conjunction with the acquisition, liabilities were assumed as follows:
Fair value of assets acquired		56,219
Cash paid for the capital stock		5,311
Liabilities assumed		$ 50,908
Single Branch of First Farmers Bank & Trust Co [Member]
Investing Activities
Net cash received in acquisition	11,000
Lafayette Community Bancorp [Member]
Investing Activities
Net cash received in acquisition	20,425
Gain on remeasurement of equity interest in Lafayette	(530)
The Company purchased all of the capital stock of Wolverine for $93,773 on October 17, 2017, Lafayette for $34,465 on September 1, 2017, CNB Bancorp for $5,311 on November 7, 2016, LaPorte Bancorp for $98,634 on July 18, 2016, Kosciusko for $22,983 on June 1, 2016, Peoples for $78,147 on July 1, 2015. In conjunction with the acquisition, liabilities were assumed as follows:
Fair value of assets acquired	186,844
Less: common stock issued	30,044
Cash paid for the capital stock	4,421
Liabilities assumed	152,379
Wolverine Bancorp Inc [Member]
Investing Activities
Net cash received in acquisition	12,788
The Company purchased all of the capital stock of Wolverine for $93,773 on October 17, 2017, Lafayette for $34,465 on September 1, 2017, CNB Bancorp for $5,311 on November 7, 2016, LaPorte Bancorp for $98,634 on July 18, 2016, Kosciusko for $22,983 on June 1, 2016, Peoples for $78,147 on July 1, 2015. In conjunction with the acquisition, liabilities were assumed as follows:
Fair value of assets acquired	394,090
Less: common stock issued	62,111
Cash paid for the capital stock	31,662
Liabilities assumed	$ 300,317

Consolidated Statements of Ca10

Consolidated Statements of Cash Flows (Parenthetical) - USD ($) $ in Thousands	Oct. 17, 2017	Sep. 01, 2017	Nov. 07, 2016	Jul. 18, 2016	Jun. 01, 2016	Jul. 01, 2015
Peoples Bancorp Inc [Member]
Capital stock purchased						$ 78,147
Kosciusko Financial Inc [Member]
Capital stock purchased					$ 22,983
LaPorte Bancorp Inc [Member]
Capital stock purchased				$ 98,634
Central National Bank & Trust [Member]
Capital stock purchased			$ 5,311
Lafayette Community Bancorp [Member]
Capital stock purchased		$ 34,465
Wolverine Bancorp Inc [Member]
Capital stock purchased	$ 93,773

Nature of Operations and Summar

Nature of Operations and Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2017
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Nature of Operations and Summary of Significant Accounting Policies	Note 1 - Nature of Operations and Summary of Significant Accounting Policies Nature of Business The Bank is a full-service commercial bank offering a broad range of commercial and retail banking and other services incident to banking along with a trust department that offers corporate and individual trust and agency services and investment management services. The Bank maintains 62 full service offices. The Bank has wholly owned direct and indirect subsidiaries: Horizon Investments, Inc. (“Horizon Investments”), Horizon Properties, Inc. (“Horizon Properties”), Horizon Insurance Services, Inc. (“Horizon Insurance”) and Horizon Grantor Trust. Horizon Investments manages the investment portfolio of the Bank. Horizon Properties manages the real estate investment trust. Horizon Insurance is used by the Company’s Wealth Management to sell certain insurance products. Horizon Grantor Trust holds title to certain company owned life insurance policies. Horizon conducts no business except that incident to its ownership of the subsidiaries. Horizon formed Horizon Bancorp Capital Trust II in 2004 (“Trust II”) and Horizon Bancorp Capital Trust III in 2006 (“Trust III”) for the purpose of participating in pooled trust preferred securities offerings. The Company assumed additional debentures as the result of the following acquisitions: Alliance Financial Corporation in 2005, which formed Alliance Financial Statutory Trust I (“Alliance Trust”); American Trust & Savings Bank in 2010, which formed Am Tru Statutory Trust I (“Am Tru Trust”); Heartland Bancshares, Inc. in 2013, which formed Heartland (IN) Statutory Trust II (“Heartland Trust”); and LaPorte Bancorp, Inc. in 2016, which acquired City Savings Statutory Trust I (“City Savings Trust”) in 2007. See Note 15 of the Consolidated Financial Statements for further discussion regarding these previously consolidated entities that are now reported separately. The business of Horizon is not seasonal to any material degree. Basis of Reporting Use of Estimates Material estimates that are particularly susceptible to significant change relate to the determination of the allowance for loan losses, valuation of other real estate owned, goodwill and intangible assets, mortgage servicing rights, other-than-temporary impairments and fair values of financial instruments. Fair Value Measurements As defined in codification, fair value is the price to sell an asset or transfer a liability in an orderly transaction between market participants. It represents an exit price at the measurement date. Market participants are buyers and sellers, who are independent, knowledgeable, and willing and able to transact in the principal (or most advantageous) market for the asset or liability being measured. Current market conditions, including imbalances between supply and demand, are considered in determining fair value. Horizon values its assets and liabilities in the principal market where it sells the particular asset or transfers the liability with the greatest volume and level of activity. In the absence of a principal market, the valuation is based on the most advantageous market for the asset or liability (i.e., the market where the asset could be sold or the liability transferred at a price that maximizes the amount to be received for the asset or minimizes the amount to be paid to transfer the liability). In measuring the fair value of an asset, Horizon assumes the highest and best use of the asset by a market participant to maximize the value of the asset, and does not consider the intended use of the asset. When measuring the fair value of a liability, Horizon assumes that the nonperformance risk associated with the liability is the same before and after the transfer. Nonperformance risk is the risk that an obligation will not be satisfied and encompasses not only Horizon’s own credit risk (i.e., the risk that Horizon will fail to meet its obligation), but also other risks such as settlement risk. Horizon considers the effect of its own credit risk on the fair value for any period in which fair value is measured. There are three acceptable valuation techniques that can be used to measure fair value: the market approach, the income approach and the cost approach. Selection of the appropriate technique for valuing a particular asset or liability takes into consideration the exit market, the nature of the asset or liability being valued, and how a market participant would value the same asset or liability. Ultimately, determination of the appropriate valuation method requires significant judgment, and sufficient knowledge and expertise are required to apply the valuation techniques. Valuation inputs refer to the assumptions market participants would use in pricing a given asset or liability using one of the three valuation techniques. Inputs can be observable or unobservable. Observable inputs are those assumptions which market participants would use in pricing the particular asset or liability. These inputs are based on market data and are obtained from a source independent of Horizon. Unobservable inputs are assumptions based on Horizon’s own information or estimate of assumptions used by market participants in pricing the asset or liability. Unobservable inputs are based on the best and most current information available on the measurement date. All inputs, whether observable or unobservable, are ranked in accordance with a prescribed fair value hierarchy which gives the highest ranking to quoted prices (unadjusted) in active markets for identical assets or liabilities (Level 1) and the lowest ranking to unobservable inputs (Level 3). Fair values for assets or liabilities classified as Level 2 are based on one or a combination of the following factors: (i) quoted prices for similar assets; (ii) observable inputs for the asset or liability, such as interest rates or yield curves; or (iii) inputs derived principally from or corroborated by observable market data. The level in the fair value hierarchy within which the fair value measurement in its entirety falls is determined based on the lowest level input that is significant to the fair value measurement in its entirety. The Company considers an input to be significant if it drives 10% or more of the total fair value of a particular asset or liability. Assets and liabilities are considered to be fair valued on a recurring basis if fair value is measured regularly (i.e., daily, weekly, monthly or quarterly). Recurring valuation occurs at a minimum on the measurement date. Assets and liabilities are considered to be fair valued on a nonrecurring basis if the fair value measurement of the instrument does not necessarily result in a change in the amount recorded on the balance sheet. Generally, nonrecurring valuation is the result of the application of other accounting pronouncements which require assets or liabilities to be assessed for impairment or recorded at the lower of cost or fair value. The fair value of assets or liabilities transferred in or out of Level 3 is measured on the transfer date, with any additional changes in fair value subsequent to the transfer considered to be realized or unrealized gains or losses. Investment Securities Available for Sale Investment Securities Held to Maturity Loans Held for Sale Interest and Fees on Loans Concentrations of Credit Risk Mortgage Warehouse Loans The transaction does not qualify as a sale under ASC 860, Transfers and Servicing and therefore is accounted for as a secured borrowing with pledge of collateral pursuant to the agreement with the mortgage company. When the individual loan is sold to the end investor by the mortgage company, the proceeds from the sale of the loan are received by Horizon and used to pay off the loan balance with Horizon along with any accrued interest and any related fees. The remaining balance from the sale is forwarded to the mortgage company. These individual loans typically are sold by the mortgage company within 30 days and are seldom held more than 90 days. Interest income is accrued during this period and collected at the time each loan is sold. Fee income for each loan sold is collected when the loan is sold and no costs are deferred due to the term between each loan funding and related payoff, which is typically less than 30 days. Based on the agreements with each mortgage company, at any time a mortgage company can reacquire from Horizon its outstanding loan balance on an individual mortgage and regain possession of the original note. Horizon also has the option to request that the mortgage company reacquire an individual mortgage. Should this occur, Horizon would return the original note and reassign the assignment of the mortgage to the mortgage company. Also, in the event that the end investor would not be able to honor the sales commitment and the mortgage company would not be able to reacquire its loan on an individual mortgage, Horizon would be able to exercise its rights under the agreement. Allowance for Loan Losses The general allowance is calculated by applying loss factors to pools of outstanding loans. Loss factors are based on historical loss experience and may be adjusted for significant factors that, in management’s judgment, affect the collectability of the portfolio as of the evaluation date. Specific allowances are established in cases where management has identified conditions or circumstances related to a credit that management believes indicate the probability that a loss will be incurred in excess of the amount determined by the application of the formula allowance. The qualitative allowance is based upon management’s evaluation of various conditions, the effects of which are not directly measured in the determination of the general and specific allowances. The evaluation of the inherent loss with respect to these conditions is subject to a higher degree of uncertainty because they are not identified with specific credits. The conditions evaluated in connection with the qualitative allowance may include factors such as local, regional and national economic conditions and forecasts, concentrations of credit and changes in the composition of the portfolio. Loan Impairment non-accrual charged-off Loans are considered impaired if the borrower does not exhibit the ability to pay or the full principal or interest payments are not expected or made in accordance with the original terms of the loan. Impaired loans are measured and carried at the lower of cost or the present value of expected future cash flows discounted at the loan’s effective interest rate, at the loan’s observable market price or at the fair value of the collateral if the loan is collateral dependent. Smaller balance homogenous loans are evaluated for impairment in the aggregate. Such loans include residential first mortgage loans secured by one to four family residences, residential construction loans and automobile, home equity and second mortgages. Commercial loans and mortgage loans secured by other properties are evaluated individually for impairment. Loans Acquired in Business Combinations past-due 310-30) 310-30, The expected cash flows of the acquired loan pools in excess of the fair values recorded is referred to as the accretable yield and is recognized in interest income over the remaining estimated lives of the loan pools. The Company continues to evaluate the fair value of the loans including cash flows expected to be collected. Increases in the Company’s cash flow expectation are recognized as increases to the accretable yield while decreases are recognized as impairments through the allowance for loan losses. Performing loans acquired (FASB ASC 310-20) Premises and Equipment Federal Reserve and Federal Home Loan Bank of Indianapolis (FHLBI) Stock Mortgage Servicing Rights (ASC 860-50), Fair value is based on market prices for comparable mortgage servicing contracts, when available, or alternatively, is based on a valuation model that calculates the present value of estimated future net servicing income. The valuation model incorporates assumptions that market participants would use in estimating future net servicing income, such as the cost to service, the discount rate, the custodial earnings rate, an inflation rate, ancillary income, prepayment speeds and default rates and losses. These variables change from quarter to quarter as market conditions and projected interest rates change, and may have an adverse impact on the value of the mortgage servicing right and may result in a reduction to noninterest income. Each class of separately recognized servicing assets subsequently measured using the amortization method are evaluated and measured for impairment. Impairment is determined by stratifying rights into tranches based on predominant characteristics, such as interest rate, loan type and investor type. Impairment is recognized through a valuation allowance for an individual tranche, to the extent that fair value is less than the carrying amount of the servicing assets for that tranche. The valuation allowance is adjusted to reflect changes in the measurement of impairment after the initial measurement of impairment. Changes in valuation allowances are reported with mortgage servicing income net of impairment on the income statement. Fair value in excess of the carrying amount of servicing assets for that stratum is not recognized. Servicing fee income is recorded for fees earned for servicing loans. The fees are based on a contractual percentage of the outstanding principal or a fixed amount per loan and are recorded as income when earned. The amortization of mortgage servicing rights is netted against loan servicing fee income. Intangible Assets Bank Owned Life Insurance (BOLI) Income Taxes Income Taxes Uncertain tax positions are recognized if it is more likely than not, based on the technical merits, that the tax position will be realized or sustained upon examination. The term more likely than not means a likelihood of more than 50 percent; the terms examined and upon examination also include resolution of the related appeals or litigation processes, if any. A tax position that meets the more-likely-than-not more-likely-than-not The Company recognizes interest and penalties on income taxes as a component of income tax expense. The Company files consolidated income tax returns with its subsidiaries. Trust Assets and Income Transfer of Financial Assets Earnings per Common Share Years Ended December 31 2017 2016 2015 Basic earnings per share Net income $ 33,117 $ 23,912 $ 20,549 Less: Preferred stock dividends — 42 125 Net income available to common shareholders $ 33,117 $ 23,870 $ 20,424 Weighted average common shares outstanding (1) 23,035,824 19,987,728 15,765,444 Basic earnings per share $ 1.44 $ 1.19 $ 1.30 Diluted earnings per share Net income available to common shareholders $ 33,117 $ 23,870 $ 20,424 Weighted average common shares outstanding (1) 23,035,824 19,987,728 15,765,444 Effect of dilutive securities: Warrants — — 330,474 Restricted stock 31,321 26,553 48,015 Stock options 106,481 68,129 53,379 Weighted average shares outstanding 23,173,626 20,082,410 16,197,312 Diluted earnings per share $ 1.43 $ 1.19 $ 1.26 (1) Adjusted for 3:2 stock split on November 14, 2016 At December 31, 2017 and 2016, there were zero shares and at December 31, 2015 there were 3,750 shares that were not included in the computation of diluted earnings per share because they were non-dilutive. Dividend Restrictions Consolidated Statements of Cash Flows Comprehensive Income available-for-sale available-for-sale held-to-maturity. Share-Based Compensation 12-month Reclassifications Recent Accounting Pronouncements Financial Accounting Standards Board (FASB) Accounting Standards Update (ASU) No. 2018-02, Income Statement – Reporting Comprehensive Income (Topic 220): Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income The FASB has issued ASU No. 2018-02, Income Statement – Reporting Comprehensive Income (Topic 220): Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income FASB ASU No. 2017-12, Derivatives and Hedging (Topic 815), Targeted Improvements to Accounting for Hedging Activities The FASB has issued ASU No. 2017-12, Derivatives and Hedging (Topic 815), Targeted Improvements to Accounting for Hedging Activities FASB ASU No. 2017-08, Receivables – Nonrefundable Fees and Other Costs (Subtopic 310-20), The FASB has issued ASU No. 2017-08, Receivables – Nonrefundable Fees and Other Costs (Subtopic 310-20), FASB ASU No. 2017-04, Intangibles – Goodwill and Other (Topic 350), Simplifying the Test for Goodwill Impairment The FASB has issued ASU No. 2017-04, Intangibles – Goodwill and Other (Topic 350), Simplifying the Test for Goodwill Impairment FASB ASU No. 2017-01, Business Combinations (Topic 805), Clarifying the Definition of a Business The FASB has issued ASU No. 2017-01, Business Combinations (Topic 805), Clarifying the Definition of a Business. FASB ASU No. 2016-13, Financial Instruments – Credit Losses (Topic 326), Measurement of Credit Losses on Financial Instruments The FASB has issued ASU No. 2016-13, Financial Instrument – Credit Losses (Topic 326), Measurement of Credit Losses on Financial Instruments. available-for-sale one-time one-time FASB ASU No. 2016-09, Compensation – Stock Compensation (Topic 718), Improvements to Employee Share-Based Payment Accounting The FASB has issued ASU No. 2016-09, Compensation – Stock Compensation (Topic 718), Improvements to Employee Share-Based Payment Accounting. FASB ASU No. 2016-02, Leases (Topic 842) The FASB has issued ASU No. 2016-02, Leases (Topic 842). right-of-use FASB ASU No. 2016-01, Financial Instruments – Overall (Subtopic 825-10), The FASB has issued ASU No. 2016-01, Financial Instruments – Overall (Subtopic 825-10), not-for-profit The new guidance makes targeted improvements to existing U.S. GAAP by: • Requiring equity investments (except those accounted for under the equity method of accounting, or those that result in consolidation of the investee) to be measured at fair value with changes in fair value recognized in net income; • Requiring public business entities to use the exit price notion when measuring the fair value of financial instruments for disclosure purposes; • Requiring separate presentation of financial assets and financial liabilities by measurement category and form of financial asset (i.e., securities or loans and receivables) on the balance sheet or the accompanying notes to the financial statements; • Eliminating the requirement to disclose the fair value of financial instruments measured at amortized cost for organizations that are not public business entities; • Eliminating the requirement for public business entities to disclose the method(s) and significant assumptions used to estimate the fair value that is required to be disclosed for financial instruments measured at amortized cost on the balance sheet; and • Requiring a reporting organization to present separately in other comprehensive income the portion of the total change in the fair value of a liability resulting from a change in the instrument-specific credit risk (also referred to as “own credit”) when the organization has elected to measure the liability at fair value in accordance with the fair value option for financial instruments. The new guidance is effective for public companies for fiscal years beginning after December 15, 2017, including interim periods within those fiscal years. The new guidance permits early adoption of the own credit provision. In addition, the new guidance permits early adoption of the provision that exempts private companies and not-for-profit FASB ASU No. 2014-09, Revenue from Contracts with Customers (Topic 606) The FASB has issued ASU No. 2014-09, Revenue from Contracts with Customers (Topic 606) non-interest In May 2016, the FASB issued ASU No. 2016-12, Revenue from Contracts with Customers (Topic 606), Narrow-Scope Improvements and Practical Expedients In December 2016, the FASB issued ASU No. 2016-20, Revenue from Contracts with Customers (Topic 606), Technical Corrections and Improvements No. 2014-09 No. 2014-09. No. 2014-09.

Acquisitions

Acquisitions	12 Months Ended
	Dec. 31, 2017
Business Combinations [Abstract]
Acquisitions	Note 2 – Acquisitions Wolverine Bancorp, Inc. On October 17, 2017, Horizon completed the acquisition of Wolverine Bancorp, Inc., a Maryland corporation (“Wolverine”) and Horizon Bank’s acquisition of Wolverine Bank, a federally chartered savings bank and wholly-owned subsidiary of Wolverine, through mergers effective October 17, 2017. Under the terms of the Merger Agreement, shareholders of Wolverine received 1.0152 shares of Horizon common stock and $14.00 in cash for each outstanding share of Wolverine common stock. Wolverine shares outstanding at the closing to be exchanged were 2,129,331, and the shares of Horizon common stock issued to Wolverine shareholders totaled 2,160,697. Based upon the October 16, 2017 closing price of $29.06 per share of Horizon common stock immediately prior to the effectiveness of the merger, less the consideration used to pay off Wolverine Bancorp’s ESOP loan receivable, the transaction has an implied valuation of approximately $93.8 million. The Company incurred approximately $1.9 million in costs related to the acquisition as of December 31, 2017. These expenses are classified in the non-interest Under the acquisition method of accounting, the total purchase price is allocated to net tangible and intangible assets based on their current estimated fair values on the date of the acquisition. Based on preliminary valuations of the fair value of tangible and intangible assets acquired and liabilities assumed, which are based on estimates and assumptions that are subject to change, the final purchase price for the Wolverine acquisition is allocated as follows: ASSETS Cash and due from banks $ 44,450 Investment securities, available for sale — Commercial 276,167 Residential mortgage 30,603 Consumer 3,897 Total loans 310,667 Premises and equipment, net 2,941 FHLB stock 2,700 Goodwill 26,827 Core deposit intangible 2,024 Interest receivable 584 Other assets 3,897 Total assets purchased $ 394,090 Common shares issued $ 62,111 Cash paid 31,662 Total estimated purchase price $ 93,773 LIABILITIES Deposits Non-interest $ 25,221 NOW accounts 8,026 Savings and money market 129,044 Certificates of deposits 94,688 Total deposits 256,979 Borrowings 36,970 Interest payable 214 Other liabilities 6,154 Total liabilities assumed $ 300,317 Of the total purchase price of $93.8 million, $2.0 million has been allocated to core deposit intangible. Additionally, $26.8 million has been allocated to goodwill and none of the purchase price is deductible. The core deposit intangible will be amortized over 10 years on a straight line basis. The Company acquired various loans in the acquisition that had evidence of deterioration of credit quality since origination and it was probable, at acquisition, that all contractually required payments would not be collected. Loans purchased with evidence of credit deterioration since origination and for which it is probable that all contractually required payments will not be collected are considered to be credit impaired. Evidence of credit quality deterioration as of the purchase date may include information such as past-due non-accrual loan-to-value 310-30) Loans with specific credit-related deterioration, since origination, are recorded at fair value, reflecting the present value of the amounts expected to be collected. Income recognition of these loans is based on reasonable expectation about the timing and amount of cash flows to be collected. The following table details the acquired loans that are accounted for in accordance with ASC 310-30 Contractually required principal and interest at acquisition $ 21,912 Contractual cash flows not expected to be collected (nonaccretable differences) 1,832 Expected cash flows at acquisition 20,080 Interest component of expected cash flows (accretable discount) 2,267 Fair value of acquired loans accounted for under ASC 310-30 $ 17,813 Final estimates of certain loans, those for which specific credit-related deterioration, since origination, are recorded at fair value, reflecting the present value of the amounts expected to be collected. Income recognition of these loans is based on reasonable expectation about the timing and amount of cash flows to be collected. Lafayette Community Bancorp On September 1, 2017, Horizon completed the acquisition of Lafayette Community Bancorp, an Indiana corporation (“Lafayette”) and Horizon Bank’s acquisition of Lafayette Community Bank, a state-chartered bank and wholly-owned subsidiary of Lafayette, through mergers effective September 1, 2017. Under the terms of the Merger Agreement, shareholders of Lafayette received 0.5878 shares of Horizon common stock and $1.73 in cash for each outstanding share of Lafayette common stock. Lafayette shareholders owning fewer than 100 shares of common stock received $17.25 in cash for each common share. Lafayette shares outstanding at the closing to be exchanged were 1,856,679, and the shares of Horizon common stock issued to Lafayette shareholders totaled 1,091,259. Based upon the August 31, 2017 closing price of $26.17 per share of Horizon common stock immediately prior to the effectiveness of the merger, the transaction has an implied valuation of approximately $34.5 million. The Company has had approximately $1.7 million in costs related to the acquisition as of December 31, 2017. These expenses are classified in the non-interest Horizon held 5% ownership in Lafayette immediately preceding the merger date. In accordance with ASC 805-10 Under the acquisition method of accounting, the total purchase price is allocated to net tangible and intangible assets based on their current estimated fair values on the date of the acquisition. Based on preliminary valuations of the fair value of tangible and intangible assets acquired and liabilities assumed, which are based on assumptions that are subject to change, the purchase price for the Lafayette acquisition is detailed in the following table. ASSETS Cash and due from banks $ 24,846 Investment securities, available for sale 6 Commercial 116,258 Residential mortgage 12,761 Consumer 5,280 Total loans 134,299 Premises and equipment, net 7,818 FHLB stock 395 Goodwill 15,408 Core deposit intangible 2,085 Interest receivable 338 Other assets 1,649 Total assets purchased $ 186,844 Common shares issued $ 30,044 (1) Cash paid 4,421 Total estimated purchase price $ 34,465 LIABILITIES Deposits Non-interest $ 34,990 NOW accounts 30,174 Savings and money market 53,663 Certificates of deposits 32,520 Total deposits 151,347 Borrowings — Interest payable 42 Other liabilities 990 Total liabilities assumed $ 152,379 (1) This includes $955,000 of common shares previously held by Horizon. Of the total estimated purchase price of $34.5 million, $2.1 million has been allocated to core deposit intangible. Additionally, $15.4 million has been allocated to goodwill and none of the purchase price is deductible. The core deposit intangible will be amortized over 10 years on a straight-line basis. The Company acquired various loans in the acquisition that had evidence of deterioration of credit quality since origination and it was probable, at acquisition, that all contractually required payments would not be collected. Loans purchased with evidence of credit deterioration since origination and for which it is probable that all contractually required payments will not be collected are considered to be credit impaired. Evidence of credit quality deterioration as of the purchase date may include information such as past-due non-accrual loan-to-value 310-30) Loans with specific credit-related deterioration, since origination, are recorded at fair value, reflecting the present value of the amounts expected to be collected. Income recognition of these loans is based on reasonable expectation about the timing and amount of cash flows to be collected. The following table details an estimate of the acquired loans that are accounted for in accordance with ASC 310-30 Contractually required principal and interest at acquisition $ 6,128 Contractual cash flows not expected to be collected (nonaccretable differences) 1,326 Expected cash flows at acquisition 4,802 Interest component of expected cash flows (accretable discount) 933 Fair value of acquired loans accounted for under ASC 310-30 $ 3,869 Final estimates of certain loans, those for which specific credit-related deterioration, since origination, are recorded at fair value, reflecting the present value of the amounts expected to be collected. Income recognition of these loans is based on reasonable expectation about the timing and amount of cash flows to be collected. Bargersville Branch Purchase On February 3, 2017, Horizon completed the purchase and assumption of certain assets and liabilities of a single branch of First Farmers Bank & Trust Company, in Bargersville, Indiana. Net cash of $11.0 million was received in the transaction, representing the deposit balances assumed at closing, net of amounts paid for loans acquired in the transaction of $3.4 million and a 3.0% premium on deposits. Customer deposit balances were recorded at $14.8 million and a core deposit intangible of $452,000 was recorded in the transaction, which will be amortized over 10 years on a straight line basis. There was no goodwill generated in the transaction. CNB Bancorp On November 7, 2016, Horizon completed the acquisition of CNB Bancorp, an Indiana corporation headquartered in Attica, Indiana (“CNB”) and the Bank’s acquisition of The Central National Bank and Trust Company (“Central National Bank & Trust”), through mergers effective November 7, 2016. Under terms of the acquisition, shareholders of CNB received merger consideration in the form of cash. The total value of the consideration for the acquisition was $5.3 million. The Company had approximately $779,000 in costs related to the acquisition as of December 31, 2016. These expenses are classified in the non-interest Under the purchase method of accounting, the total estimated purchase price is allocated to CNB’s net tangible and intangible assets based on their current estimated fair values on the date of the acquisition. Based on management’s preliminary valuation of the fair value of tangible and intangible assets acquired and liabilities assumed, which are based on estimates and assumptions that are subject to change, the final purchase price for the CNB acquisition is allocated as follows: ASSETS Cash and due from banks $ 27,860 Investment securities, available for sale 16,393 Commercial 2,267 Residential mortgage 6,624 Consumer 1,579 Total loans 10,470 Premises and equipment, net 444 FHLB stock 50 Goodwill 609 Core deposit intangible 190 Interest receivable 154 Other assets 49 Total assets purchased $ 56,219 Cash paid 5,311 Total estimated purchase price $ 5,311 LIABILITIES Deposits Non-interest $ 24,079 NOW accounts 9,038 Savings and money market 13,829 Certificates of deposits 3,342 Total deposits 50,288 Borrowings 459 Interest payable 7 Other liabilities 154 Total liabilities assumed $ 50,908 Of the total purchase price of $5.3 million, $190,000 has been allocated to core deposit intangible. Additionally, $609,000 has been allocated to goodwill and none of the purchase price is deductible. The core deposit intangible will be amortized over 10 years on a straight line basis. The Company acquired the $10.8 million performing loan portfolio with an estimated fair value of $10.5 million. No loans were purchased with evidence of credit deterioration since origination and for which it is probable that all contractually required payments will not be collected or which are considered to be credit impaired. LaPorte Bancorp, Inc. On July 18, 2016, Horizon completed the acquisition of LaPorte Bancorp, Inc., a Maryland corporation (“LaPorte Bancorp”) and the Bank’s acquisition of The LaPorte Savings Bank, a state-chartered savings bank and wholly owned subsidiary of LaPorte Bancorp, through mergers effective July 18, 2016. Under the terms of the merger agreement, shareholders of LaPorte Bancorp had the option to receive $17.50 per share in cash or 0.9435 shares of Horizon common stock for each share of LaPorte Bancorp’s common stock, subject to allocation provisions to assure that in aggregate, LaPorte Bancorp shareholders received total consideration that consisted of 65% stock and 35% cash. As a result of LaPorte Bancorp shareholder stock and cash elections and the related proration provisions of the merger agreement, Horizon issued 3,421,488 shares of its common stock in the merger. Based upon the July 18, 2016 closing price of $18.36 per share of Horizon common stock, less the consideration used to pay off LaPorte Bancorp’s ESOP loan receivable, the transaction has an implied valuation of approximately $98.6 million. The Company had approximately $4.0 million in costs related to the acquisition as of December 31, 2016. These expenses are classified in the non-interest Under the acquisition method of accounting, the total purchase price is allocated to net tangible and intangible assets based on their current estimated fair values on the date of the acquisition. Based on preliminary valuations of the fair value of tangible and intangible assets acquired and liabilities assumed, which are based on assumptions that are subject to change, the purchase price for the LaPorte Bancorp acquisition is detailed in the following table. ASSETS Cash and due from banks $ 154,849 Investment securities, available for sale 23,779 Commercial 153,750 Residential mortgage 42,603 Consumer 16,801 Mortgage Warehousing 99,752 Total loans 312,906 Premises and equipment, net 6,022 FHLB stock 4,029 Goodwill 20,993 Core deposit intangible 2,514 Interest receivable 844 Cash value of life insurance 15,267 Other assets 8,334 Total assets purchased $ 549,537 Common shares issued $ 60,306 Cash paid 38,328 Total estimated purchase price $ 98,634 LIABILITIES Deposits Non-interest $ 66,733 NOW accounts 99,346 Savings and money market 117,688 Certificates of deposits 87,605 Total deposits 371,372 Borrowings 64,793 Interest payable 178 Subordinated debt 4,504 Other liabilities 10,056 Total liabilities assumed $ 450,903 Of the total estimated purchase price of $98.6 million, $2.5 million has been allocated to core deposit intangible. Additionally, $21.0 million has been allocated to goodwill and none of the purchase price is deductible. The core deposit intangible will be amortized over 10 years on a straight line basis. The Company acquired various loans in the acquisition that had evidence of deterioration of credit quality since origination and it was probable, at acquisition, that all contractually required payments would not be collected. Loans purchased with evidence of credit deterioration since origination and for which it is probable that all contractually required payments will not be collected are considered to be credit impaired. Evidence of credit quality deterioration as of the purchase date may include information such as past-due non-accrual loan-to-value 310-30) Loans with specific credit-related deterioration, since origination, are recorded at fair value, reflecting the present value of the amounts expected to be collected. Income recognition of these loans is based on reasonable expectation about the timing and amount of cash flows to be collected. The following table details the acquired loans that are accounted for in accordance with ASC 310-30 Contractually required principal and interest at acquisition $ 12,545 Contractual cash flows not expected to be collected (nonaccretable differences) 4,492 Expected cash flows at acquisition 8,053 Interest component of expected cash flows (accretable discount) 1,258 Fair value of acquired loans accounted for under ASC 310-30 $ 6,795 Final estimates of certain loans, those for which specific credit-related deterioration, since origination, are recorded at fair value, reflecting the present value of the amounts expected to be collected. Income recognition of these loans is based on reasonable expectation about the timing and amount of cash flows to be collected. Kosciusko Financial, Inc. On June 1, 2016, Horizon completed the acquisition of Kosciusko Financial, Inc., an Indiana corporation (“Kosciusko”) and the Bank’s acquisition of Farmers State Bank, a state-chartered bank and wholly owned subsidiary of Kosciusko, through mergers effective June 1, 2016. Under the terms of the merger agreement, shareholders of Kosciusko had the option to receive $81.75 per share in cash or 4.5183 shares of Horizon common stock for each share of Kosciusko’s common stock, subject to allocation provisions to assure that in aggregate, Kosciusko shareholders received total consideration that consisted of 65% stock and 35% cash. Kosciusko shareholders owning fewer than 100 shares of common stock received $81.75 in cash for each common share. As a result of Kosciusko shareholder stock and cash elections and the related proration provisions of the merger agreement, Horizon issued 873,430 shares of its common stock in the merger. Based upon the June 1, 2016 closing price of $16.57 per share of Horizon common stock, the transaction has an implied valuation of approximately $23.0 million. The Company had approximately $2.0 million in costs related to the acquisition. These expenses are classified in the non-interest Under the acquisition method of accounting, the total purchase price is allocated to net tangible and intangible assets based on their current estimated fair values on the date of the acquisition. Based on preliminary valuations of the fair value of tangible and intangible assets acquired and liabilities assumed, which are based on assumptions that are subject to change, the purchase price for the Kosciusko acquisition is detailed in the following table. ASSETS Cash and due from banks $ 38,950 Investment securities, available for sale 1,191 Commercial 70,006 Residential mortgage 26,244 Consumer 6,319 Total loans 102,569 Premises and equipment, net 1,466 FRB and FHLB stock 582 Goodwill 6,443 Core deposit intangible 526 Interest receivable 636 Cash value of life insurance 2,745 Other assets 765 Total assets purchased $ 155,873 Common shares issued $ 14,470 Cash paid 8,513 Total estimated purchase price $ 22,983 LIABILITIES Deposits Non-interest $ 27,871 NOW accounts 35,213 Savings and money market 26,953 Certificates of deposits 32,771 Total deposits 122,808 Borrowings 9,038 Interest payable 55 Other liabilities 989 Total liabilities assumed $ 132,890 Of the total estimated purchase price of $23.0 million, $526,000 has been allocated to core deposit intangible. Additionally, $6.4 million has been allocated to goodwill and none of the purchase price is deductible. The core deposit intangible will be amortized over 10 years on a straight line basis. The Company acquired various loans in the acquisition that had evidence of deterioration of credit quality since origination and it was probable, at acquisition, that all contractually required payments would not be collected. Loans purchased with evidence of credit deterioration since origination and for which it is probable that all contractually required payments will not be collected are considered to be credit impaired. Evidence of credit quality deterioration as of the purchase date may include information such as past-due non-accrual loan-to-value 310-30) Loans with specific credit-related deterioration, since origination, are recorded at fair value, reflecting the present value of the amounts expected to be collected. Income recognition of these loans is based on reasonable expectation about the timing and amount of cash flows to be collected. The following table details the acquired loans that are accounted for in accordance with ASC 310-30 Contractually required principal and interest at acquisition $ 2,682 Contractual cash flows not expected to be collected (nonaccretable differences) 25 Expected cash flows at acquisition 2,657 Interest component of expected cash flows (accretable discount) 634 Fair value of acquired loans accounted for under ASC 310-30 $ 2,023 Final estimates of certain loans, those for which specific credit-related deterioration, since origination, are recorded at fair value, reflecting the present value of the amounts expected to be collected. Income recognition of these loans is based on reasonable expectation about the timing and amount of cash flows to be collected. Peoples Bancorp On July 1, 2015, Horizon completed the acquisition of Peoples Bancorp, an Indiana corporation (“Peoples”) and the Bank’s acquisition of Peoples Federal Savings Bank of DeKalb County (“Peoples FSB”), through mergers effective July 1, 2015. Under the terms of the acquisition, the exchange ratio was 1.425 shares of Horizon common stock and $9.75 in cash for each outstanding share of Peoples common stock. Peoples shareholders owning fewer than 100 shares of common stock received $33.14 in cash for each common share. Peoples shares outstanding at the closing were 2,311,858, and the shares of Horizon common stock issued to Peoples shareholders totaled 3,288,303. Horizon’s stock price was $16.88 per share at the close of business on July 1, 2015. Based upon these numbers, the total value of the consideration for the acquisition was $78.1 million. The Company had approximately $4.9 million in costs related to the acquisition as of December 31, 2015. These expenses are classified in the non-interest Under the purchase method of accounting, the total estimated purchase price is allocated to Peoples net tangible and intangible assets based on their current estimated fair values on the date of the acquisition. Based on management’s preliminary valuation of the fair value of tangible and intangible assets acquired and liabilities assumed, which are based on estimates and assumptions that are subject to change, the final purchase price for the Peoples acquisition is allocated as follows: ASSETS Cash and due from banks $ 205,054 Investment securities, available for sale 2,038 Commercial 67,435 Residential mortgage 137,331 Consumer 19,593 Total loans 224,359 Premises and equipment, net 5,524 FRB and FHLB stock 2,743 Goodwill 21,424 Core deposit intangible 4,394 Interest receivable 1,279 Cash value of life insurance 13,898 Other assets 4,364 Total assets purchased $ 485,077 Common shares issued $ 55,506 Cash paid 22,641 Total estimated purchase price $ 78,147 LIABILITIES Deposits Non-interest $ 28,251 NOW accounts 65,771 Savings and money market 125,176 Certificates of deposits 131,889 Total deposits 351,087 Borrowings 48,884 Interest payable 21 Other liabilities 6,938 Total liabilities assumed $ 406,930 Of the total purchase price of $78.1 million, $4.4 million has been allocated to core deposit intangible. Additionally, $21.4 million has been allocated to goodwill and none of the purchase price is deductible. The core deposit intangible will be amortized over 10 years on a straight line basis. The Company acquired the $228.6 million loan portfolio at a fair value discount of $4.8 million. The performing portion of the portfolio, $223.4 million, had an estimated fair value of $220.0 million. The excess of expected cash flows above the fair value of the performing portion of loans will be accreted to interest income over the remaining lives of the loans in accordance with ASC 310-20. The Company acquired various loans in the acquisition that had evidence of deterioration of credit quality since origination and it was probable, at acquisition, that all contractually required payments would not be collected. The loans purchased with evidence of credit deterioration since origination and for which it is probable that all contractually required payments will not be collected are considered to be credit impaired. Evidence of credit quality deterioration as of the purchase date may include information such as past-due non-accrual loan-to-value 310-30) Loan with specific credit-related deterioration, since origination, are recorded at fair value, reflecting the present value of the amounts expected to be collected. Income recognition of these loans is based on reasonable expectation about the timing and amount of cash flows to be collected. The following table details the acquired loans that are accounted for in accordance with ASC 310-30 Contractually required principal and interest at acquisition $ 5,730 Contractual cash flows not expected to be collected (nonaccretable differences) 715 Expected cash flows at acquisition 5,015 Interest component of expected cash flows (accretable discount) 647 Fair value of acquired loans accounted for under ASC 310-30 $ 4,368 The results of operations of Wolverine, Lafayette, CNB, LaPorte Bancorp, Kosciusko and Peoples have been included in the Company’s consolidated financial statements since the acquisition dates. The following schedule includes pro-forma December 31 December 31 December 31 2017 2016 2015 Summary of Operations: Net Interest Income $ 125,442 $ 115,860 119,732 Provision for loan losses (12 ) 1,082 4,027 Net Interest Income after Provision for Loan Losses 125,454 114,778 115,705 Non-interest 33,959 43,330 37,976 Non-interest 109,605 119,522 112,309 Income before Income Taxes 49,808 38,586 41,372 Income Tax Expense 16,204 12,072 10,764 Net Income 33,604 26,514 30,608 Net Income Available to Common Shareholders $ 33,604 $ 26,472 30,483 Basic Earnings Per Share $ 1.46 $ 1.32 $ 1.93 Diluted Earnings Per Share $ 1.45 $ 1.32 $ 1.88 The pro-forma pro-forma non-recurring pro-forma non-recurring pro-forma non-recurring The pro-forma

Cash Equivalents

Cash Equivalents	12 Months Ended
	Dec. 31, 2017
Cash and Cash Equivalents [Abstract]
Cash Equivalents	Note 3 – Cash Equivalents The Company considers all liquid investments with original maturities of three months or less to be cash equivalents. At December 31, 2017 and 2016, cash equivalents consisted primarily of money market accounts with brokers and certificates of deposit. At December 31, 2017, the Company’s cash accounts exceeded federally insured limits by approximately $12.5 million.

Securities

Securities	12 Months Ended
	Dec. 31, 2017
Investments, Debt and Equity Securities [Abstract]
Securities	Note 4 – Securities The fair value of securities is as follows: Gross Gross December 31, 2017 Amortized Unrealized Unrealized Fair Cost Gains Losses Value Available for sale U.S. Treasury and federal agencies $ 19,277 $ — $ (225 ) $ 19,052 State and municipal 148,045 2,189 (670 ) 149,564 Federal agency collateralized mortgage obligations 132,871 45 (2,551 ) 130,365 Federal agency mortgage-backed pools 211,487 155 (2,985 ) 208,657 Private labeled mortgage-backed pools 1,650 — (8 ) 1,642 Corporate notes 272 113 — 385 Total available for sale investment securities $ 513,602 $ 2,502 $ (6,439 ) $ 509,665 Held to maturity State and municipal $ 179,836 $ 3,493 $ (2,932 ) $ 180,397 Federal agency collateralized mortgage obligations 5,734 17 (69 ) 5,682 Federal agency mortgage-backed pools 14,878 216 (88 ) 15,006 Total held to maturity investment securities $ 200,448 $ 3,726 $ (3,089 ) $ 201,085 Gross Gross December 31, 2016 Amortized Unrealized Unrealized Fair Cost Gains Losses Value Available for sale U.S. Treasury and federal agencies $ 8,051 $ 2 $ (64 ) $ 7,989 State and municipal 117,327 324 (1,059 ) 116,592 Federal agency collateralized mortgage obligations 139,040 254 (2,099 ) 137,195 Federal agency mortgage-backed pools 180,183 251 (3,707 ) 176,726 Corporate notes 1,238 91 — 1,329 Total available for sale investment securities $ 445,839 $ 922 $ (6,929 ) $ 439,831 Held to maturity State and municipal $ 165,607 $ 2,700 $ (2,485 ) $ 165,822 Federal agency collateralized mortgage obligations 6,530 31 (71 ) 6,490 Federal agency mortgage-backed pools 21,057 897 (180 ) 21,774 Total held to maturity investment securities $ 193,194 $ 3,628 $ (2,736 ) $ 194,086 Based on evaluation of available evidence, including recent changes in market interest rates, credit rating information, and information obtained from regulatory filings, management believes the declines in fair value for these securities are temporary. While these securities are held in the available for sale portfolio and held-to-maturity, Should the impairment of any of these securities become other than temporary, the cost basis of the investment will be reduced and the resulting loss recognized in net income in the period the other-than-temporary impairment is identified. At December 31, 2017, no individual investment security had an unrealized loss that was determined to be other-than-temporary. The unrealized losses on the Company’s investments in securities of state and municipal governmental agencies, U.S. Treasury and federal agencies, federal agency collateralized mortgage obligations, and federal agency mortgage-backed pools were caused by interest rate volatility and not a decline in credit quality. The contractual terms of those investments do not permit the issuer to settle the securities at a price less than the amortized cost basis of the investments. The Company expects to recover the amortized cost basis over the term of the securities. Because the Company does not intend to sell the investments and it is not likely that the Company will be required to sell the investments before recovery of their amortized cost basis, which may be at maturity, the Company did not consider those investments to be other-than-temporarily impaired at December 31, 2017. The Company elected to transfer 319 available-for-sale held-to-maturity 320-10-55-24, pre-tax The amortized cost and fair value of securities available for sale and held-to-maturity December 31, 2017 December 31, 2016 Amortized Fair Amortized Fair Cost Value Cost Value Available for sale Within one year $ 13,347 $ 13,326 $ 7,455 $ 7,480 One to five years 40,468 40,193 37,483 37,479 Five to ten years 50,473 51,156 21,112 20,984 After ten years 63,306 64,326 60,566 59,967 167,594 169,001 126,616 125,910 Federal agency collateralized mortgage obligations 132,871 130,365 139,040 137,195 Federal agency mortgage-backed pools 211,487 208,657 180,183 176,726 Private labeled mortgage-backed pools 1,650 1,642 — — Total available for sale investment securities $ 513,602 $ 509,665 $ 445,839 $ 439,831 Held to maturity Within one year $ 1,948 $ 1,934 $ — $ — One to five years 40,603 41,531 24,594 25,271 Five to ten years 89,801 91,249 87,645 88,805 After ten years 47,484 45,683 53,368 51,746 179,836 180,397 165,607 165,822 Federal agency collateralized mortgage obligations 5,734 5,682 6,530 6,490 Federal agency mortgage-backed pools 14,878 15,006 21,057 21,774 Total held to maturity investment securities $ 200,448 $ 201,085 $ 193,194 $ 194,086 The following table shows the gross unrealized losses and the fair value of the Company’s investments, aggregated by investment category and length of time that individual securities have been in a continuous unrealized loss position. Less than 12 Months 12 Months or More Total Fair Unrealized Fair Unrealized Fair Unrealized December 31, 2017 Value Losses Value Losses Value Losses U.S. Treasury and federal agencies $ 15,882 $ (180 ) $ 2,870 $ (45 ) $ 18,752 $ (225 ) State and municipal 54,312 (2,758 ) 30,691 (844 ) 85,003 (3,602 ) Federal agency collateralized mortgage obligations 54,006 (589 ) 73,462 (2,031 ) 127,468 (2,620 ) Federal agency mortgage-backed pools 103,926 (1,019 ) 86,846 (2,054 ) 190,772 (3,073 ) Private labeled mortgage-backed pools 1,642 (8 ) — — 1,642 (8 ) Total temporarily impaired securities $ 229,768 $ (4,554 ) $ 193,869 $ (4,974 ) $ 423,637 $ (9,528 ) Less than 12 Months 12 Months or More Total Fair Unrealized Fair Unrealized Fair Unrealized December 31, 2016 Value Losses Value Losses Value Losses U.S. Treasury and federal agencies $ 6,987 $ (64 ) $ — $ — $ 6,987 $ (64 ) State and municipal 142,466 (3,544 ) — — 142,466 (3,544 ) Federal agency collateralized mortgage obligations 112,414 (1,918 ) 10,199 (252 ) 122,613 (2,170 ) Federal agency mortgage-backed pools 163,768 (3,887 ) — — 163,768 (3,887 ) Total temporarily impaired securities $ 425,635 $ (9,413 ) $ 10,199 $ (252 ) $ 435,834 $ (9,665 ) U.S. Treasury, federal agency, state and municipal The unrealized losses on the Company’s investments in U.S. Treasury, federal agency and state and municipals were caused by interest rate changes. The contractual terms of those investments do not permit the issuer to settle the securities at a price less than the amortized cost bases of the investments. Because the Company does not intend to sell the investments and it is not more likely than not the Company will be required to sell the investments before recovery of their amortized cost bases, which may be maturity, the Company does not consider those investments to be other-than-temporarily impaired at December 31, 2017. Federal agency mortgage-backed pools and collateralized mortgage obligations The unrealized losses on the Company’s investment in federal agency mortgage backed pools and collateralized mortgage obligations securities were caused by interest rate changes. The Company expects to recover the amortized cost basis over the term of the securities. Because the decline in market value is attributable to changes in interest rates and not credit quality, and because the Company does not intend to sell the investments and it is not more likely than not the Company will be required to sell the investments before recovery of their amortized cost bases, which may be maturity, the Company does not consider those investments to be other-than-temporarily impaired at December 31, 2017. Information regarding security proceeds, gross gains and gross losses are presented below. Years ended December 31 2017 2016 2015 Sales of securities available for sale Proceeds $ 5,490 $ 182,549 $ 43,051 Gross gains 151 2,646 254 Gross losses (113 ) (810 ) (65 ) The tax effect of the proceeds from the sale of securities available for sale was $13,000, $643,000 and $66,000 for the years ended December 31, 2017, 2016 and 2015, respectively. The Company pledges securities to secure retail and corporate repurchase agreements to the Federal Reserve for borrowing availability and as settlements for the fair value of swap agreements. At December 31, 2017, the Company had pledged $74.0 million of fair value or $75.6 million of amortized cost, in securities as collateral for $61.1 million in repurchase agreements, $94.6 million of fair value or $93.1 million of amortized cost, in securities as collateral for borrowing availability at the Federal Reserve with $11.0 million current outstanding borrowings and $13.1 million of fair value or $13.1 million of amortized cost, in securities as collateral for $917,000 in settlements on the fair value of swap agreements.

Loans

Loans	12 Months Ended
	Dec. 31, 2017
Receivables [Abstract]
Loans	Note 5 – Loans December 31 December 31 2017 2016 Commercial Working capital and equipment $ 696,612 $ 539,403 Real estate, including agriculture 854,003 485,620 Tax exempt 36,324 15,486 Other 30,931 29,447 Total 1,617,870 1,069,956 Real estate 1–4 family 599,217 526,024 Other 7,543 5,850 Total 606,760 531,874 Consumer Auto 251,020 174,773 Recreation 8,752 5,669 Real estate/home improvement 63,811 53,898 Home equity 165,240 144,508 Unsecured 3,743 3,875 Other 20,291 15,706 Total 512,857 398,429 Mortgage warehouse 94,508 135,727 Total loans 2,831,995 2,135,986 Allowance for loan losses (16,394 ) (14,837 ) Loans, net $ 2,815,601 $ 2,121,149 Commercial Commercial loans are primarily based on the identified cash flows of the borrower and secondarily on the underlying collateral provided by the borrower. The cash flows of borrowers, however, may not be as expected, and the collateral securing these loans may fluctuate in value. Most commercial loans are secured by the assets being financed or other business assets such as accounts receivable or inventory and may incorporate a personal guarantee; however, some short-term loans may be made on an unsecured basis. In the case of loans secured by accounts receivable, the availability of funds for the repayment of these loans may be substantially dependent on the ability of the borrower to collect amounts due from its customers. Commercial real estate loans are viewed primarily as cash flow loans and secondarily as loans secured by real estate. Commercial real estate lending typically involves larger loan principal amounts and the repayment of these loans is generally dependent on the successful operation of the property securing the loan or the business conducted on the property securing the loan. Commercial real estate loans may be more adversely affected by conditions in the real estate markets, the general economy or fluctuations in interest rates. The properties securing the Company’s commercial real estate portfolio are diverse in terms of property type, and are monitored for concentrations of credit. Management monitors and evaluates commercial real estate loans based on collateral, cash flow and risk grade criteria. As a general rule, the Company avoids financing single purpose projects unless other underwriting factors are present to help mitigate risk. In addition, management tracks the level of owner-occupied commercial real estate loans versus non-owner Real Estate and Consumer With respect to residential loans that are secured by 1-4 loan-to-value 1-4 Mortgage Warehousing Horizon’s mortgage warehouse lending has specific mortgage companies as customers of Horizon Bank. Individual mortgage loans originated by these mortgage companies are funded as a secured borrowing with a pledge of collateral under Horizon’s agreement with the mortgage company. Each mortgage loan funded by Horizon undergoes an underwriting review by Horizon to the end investor guidelines and is assigned to Horizon until the loan is sold to the secondary market by the mortgage company. In addition, Horizon takes possession of each original note and forwards such note to the end investor once the mortgage company has sold the loan. At the time a loan is transferred to the secondary market, the mortgage company reacquires the loan under its option within the agreement. Due to the reacquire feature contained in the agreement, the transaction does not qualify as a sale and therefore is accounted for as a secured borrowing with a pledge of collateral pursuant to the agreement with the mortgage company. When the individual loan is sold to the end investor by the mortgage company, the proceeds from the sale of the loan are received by Horizon and used to pay off the loan balance with Horizon along with any accrued interest and any related fees. The remaining balance from the sale is forwarded to the mortgage company. These individual loans typically are sold by the mortgage company within 30 days and are seldom held more than 90 days. Interest income is accrued during this period and collected at the time each loan is sold. Fee income for each loan sold is collected when the loan is sold, and no costs are deferred due to the term between each loan funding and related payoff, which is typically less than 30 days. Based on the agreements with each mortgage company, at any time a mortgage company can reacquire from Horizon its outstanding loan balance on an individual mortgage and regain possession of the original note. Horizon also has the option to request that the mortgage company reacquire an individual mortgage. Should this occur, Horizon would return the original note and reassign the assignment of the mortgage to the mortgage company. Also, in the event that the end investor would not be able to honor the purchase commitment and the mortgage company would not be able to reacquire its loan on an individual mortgage, Horizon would be able to exercise its rights under the agreement. The following table shows the recorded investment of individual loan categories. Loan Deferred Recorded December 31, 2017 Balance Interest Due Fees / (Costs) Investment Owner occupied real estate $ 547,596 $ 1,441 $ 1,917 $ 550,954 Non owner occupied real estate 664,281 1,100 2,478 667,859 Residential spec homes 16,431 63 80 16,574 Development & spec land loans 48,674 116 579 49,369 Commercial and industrial 335,227 2,524 607 338,358 Total commercial 1,612,209 5,244 5,661 1,623,114 Residential mortgage 588,358 1,776 2,375 592,509 Residential construction 16,027 39 — 16,066 Mortgage warehouse 94,508 480 — 94,988 Total real estate 698,893 2,295 2,375 703,563 Direct installment 89,617 270 (552 ) 89,335 Direct installment purchased 82 — — 82 Indirect installment 227,323 528 168 228,019 Home equity 197,578 889 (1,359 ) 197,108 Total consumer 514,600 1,687 (1,743 ) 514,544 Total loans 2,825,702 9,226 6,293 2,841,221 Allowance for loan losses (16,394 ) — — (16,394 ) Net loans $ 2,809,308 $ 9,226 $ 6,293 $ 2,824,827 Loan Deferred Recorded December 31, 2016 Balance Interest Due Fees / (Costs) Investment Owner occupied real estate $ 337,548 $ 899 $ 1,022 $ 339,469 Non owner occupied real estate 461,897 624 2,176 464,697 Residential spec homes 5,006 8 (2 ) 5,012 Development & spec land loans 31,228 56 119 31,403 Commercial and industrial 230,520 1,906 442 232,868 Total commercial 1,066,199 3,493 3,757 1,073,449 Residential mortgage 508,233 1,492 3,030 512,755 Residential construction 20,611 33 — 20,644 Mortgage warehouse 135,727 480 — 136,207 Total real estate 664,571 2,005 3,030 669,606 Direct installment 71,150 199 (385 ) 70,964 Direct installment purchased 119 — — 119 Indirect installment 153,204 345 — 153,549 Home equity 175,126 703 (785 ) 175,044 Total consumer 399,599 1,247 (1,170 ) 399,676 Total loans 2,130,369 6,745 5,617 2,142,731 Allowance for loan losses (14,837 ) — — (14,837 ) Net loans $ 2,115,532 $ 6,745 $ 5,617 $ 2,127,894

Accounting for Certain Loans Ac

Accounting for Certain Loans Acquired in a Transfer	12 Months Ended
	Dec. 31, 2017
Transfers and Servicing [Abstract]
Accounting for Certain Loans Acquired in a Transfer	Note 6 – Accounting for Certain Loans Acquired in a Transfer The Company acquired loans in acquisitions with evidence of deterioration of credit quality since origination and it was probable, at acquisition, that all contractually required payments would not be collected. Loans purchased with evidence of credit deterioration since origination and for which it is probable that all contractually required payments will not be collected are considered to be credit impaired. Evidence of credit quality deterioration as of the purchase date may include information such as past-due non-accrual loan-to-value 310-30) The carrying amounts of those loans included in the balance sheet amounts of loans receivable are as follows: December 31 December 31 December 31 December 31 December 31 December 31 December 31 December 31 2017 2017 2017 2017 2017 2017 2017 2017 Heartland Summit Peoples Kosciusko LaPorte Lafayette Wolverine Total Commercial $ 390 $ 3,653 $ 315 $ 838 $ 1,034 $ 4,271 $ 16,697 $ 27,198 Real estate 229 870 126 403 1,004 — — 2,632 Consumer — — — — 33 — — 33 Outstanding balance $ 619 $ 4,523 $ 441 $ 1,241 $ 2,071 $ 4,271 $ 16,697 $ 29,863 Carrying amount, net of allowance of $0 $ 29,863 December 31 December 31 December 31 December 31 December 31 December 31 December 31 December 31 2016 2016 2016 2016 2016 2016 2016 2016 Heartland Summit Peoples Kosciusko LaPorte Lafayette Wolverine Total Commercial $ 774 $ 5,245 $ 692 $ 1,652 $ 3,200 $ — $ — $ 11,563 Real estate 534 967 165 457 1,114 — — 3,237 Consumer 2 — — — 41 — — 43 Outstanding balance $ 1,310 $ 6,213 $ 856 $ 2,109 $ 4,355 $ — $ — $ 14,843 Carrying amount, net of allowance of $0 $ 14,843 Accretable yield, or income expected to be collected are as follows: Twelve Months Ended December 31, 2017 Heartland Summit Peoples Kosciusko LaPorte Lafayette Wolverine Total Balance at January 1 $ 557 $ 502 $ 389 $ 530 $ 1,479 $ — $ — $ 3,457 Additions — — — — — 933 2,267 3,200 Accretion (99 ) (353 ) (388 ) (101 ) (235 ) — — (1,176 ) Reclassification from nonaccretable difference — — — — — — — — Disposals (6 ) (2 ) (1 ) (43 ) (264 ) — — (316 ) Balance at December 31 $ 452 $ 147 $ — $ 386 $ 980 $ 933 $ 2,267 $ 5,165 Twelve Months Ended December 31, 2016 Heartland Summit Peoples Kosciusko LaPorte Lafayette Wolverine Total Balance at January 1 $ 795 $ 708 $ 555 $ — $ — $ — $ — $ 2,058 Additions — — — 634 1,636 — — 2,270 Accretion (164 ) (171 ) (106 ) (72 ) (147 ) — — (660 ) Reclassification from nonaccretable difference — — — — — — — — Disposals (74 ) (35 ) (60 ) (32 ) (10 ) — — (211 ) Balance at December 31 $ 557 $ 502 $ 389 $ 530 $ 1,479 $ — $ — $ 3,457 During the years ended December 31, 2017 and 2016, the Company increased the allowance for loan losses by a charge to the income statement of $0 and $71,000, respectively. $71,000 and $0 of allowances for loan losses were reversed for the years ended December 31, 2017 and 2016, respectively.

Allowance for Loan Losses

Allowance for Loan Losses	12 Months Ended
	Dec. 31, 2017
Receivables [Abstract]
Allowance for Loan Losses	Note 7 – Allowance for Loan Losses The historical loss experience is determined by portfolio segment and is based on the actual loss history experienced by the Company over the prior one to five years. Management believes using the highest of the one, two or five-year historical loss experience is an appropriate methodology in the current economic environment, as it captures loss rates that are comparable to the current period being analyzed. The actual allowance for loan loss activity is provided below. December 31 December 31 December 31 2017 2016 2015 Balance at beginning of the period $ 14,837 $ 14,534 $ 16,501 Loans charged-off: Commercial Owner occupied real estate 68 181 2,208 Non owner occupied real estate 20 471 556 Residential development — — — Development & Spec Land Loans 1 — — Commercial and industrial 288 106 673 Total commercial 377 758 3,437 Real estate Residential mortgage 89 213 288 Residential construction — — — Mortgage warehouse — — — Total real estate 89 213 288 Consumer Direct Installment 389 329 367 Direct Installment Purchased — — — Indirect Installment 1,193 1,051 1,081 Home Equity 205 309 926 Total consumer 1,787 1,689 2,374 Total loans charged-off 2,253 2,660 6,099 Recoveries of loans previously charged-off: Commercial Owner occupied real estate 9 31 104 Non owner occupied real estate 32 55 1 Residential development 8 8 — Development & Spec Land Loans — — 35 Commercial and industrial 219 116 52 Total commercial 268 210 192 Real estate Residential mortgage 44 97 69 Residential construction — — — Mortgage warehouse — — — Total real estate 44 97 69 Consumer Direct Installment 531 81 106 Direct Installment Purchased — — — Indirect Installment 497 529 489 Home Equity — 204 114 Total consumer 1,028 814 709 Total loan recoveries 1,340 1,121 970 Net loans charged-off 913 1,539 5,129 Provision charged to operating expense Commercial 2,164 (68 ) 2,531 Real estate (81 ) (23 ) 62 Consumer 387 1,933 569 Total provision charged to operating expense 2,470 1,842 3,162 Balance at the end of the period $ 16,394 $ 14,837 $ 14,534 Certain loans are individually evaluated for impairment, and the Company’s general practice is to proactively charge down impaired loans to the fair value, which is the appraised value less estimated selling costs, of the underlying collateral. Consistent with regulatory guidance, charge-offs on all loan segments are taken when specific loans, or portions thereof, are considered uncollectible. The Company’s policy is to promptly charge these loans off in the period the uncollectible loss is reasonably determined. For all loan portfolio segments except 1-4 charges-off charge-off The Company charges-off 1-4 1-4 charges-off open-end The following table presents the balance in the allowance for loan losses and the recorded investment in loans by portfolio segment and based on impairment analysis: Mortgage December 31, 2017 Commercial Real Estate Warehousing Consumer Total Allowance For Loan Losses Ending allowance balance attributable to loans: Individually evaluated for impairment $ 184 $ — $ — $ — $ 184 Collectively evaluated for impairment 8,450 2,188 1,030 4,542 16,210 Loans acquired with deteriorated credit quality — — — — — Total ending allowance balance $ 8,634 $ 2,188 $ 1,030 $ 4,542 $ 16,394 Loans: Individually evaluated for impairment $ 7,187 $ — $ — $ — $ 7,187 Collectively evaluated for impairment 1,615,927 608,575 94,988 514,544 2,834,034 Loans acquired with deteriorated credit quality — — — — — Total ending loans balance $ 1,623,114 $ 608,575 $ 94,988 $ 514,544 $ 2,841,221 Mortgage December 31, 2016 Commercial Real Estate Warehousing Consumer Total Allowance For Loan Losses Ending allowance balance attributable to loans: Individually evaluated for impairment $ 4 $ — $ — $ — $ 4 Collectively evaluated for impairment 6,575 2,090 1,254 4,914 14,833 Loans acquired with deteriorated credit quality — — — — — Total ending allowance balance $ 6,579 $ 2,090 $ 1,254 $ 4,914 $ 14,837 Loans: Individually evaluated for impairment $ 2,250 $ — $ — $ — $ 2,250 Collectively evaluated for impairment 1,071,199 533,399 136,207 399,676 2,140,481 Loans acquired with deteriorated credit quality — — — — — Total ending loans balance $ 1,073,449 $ 533,399 $ 136,207 $ 399,676 $ 2,142,731

Non-performing Assets and Impai

Non-performing Assets and Impaired Loans	12 Months Ended
	Dec. 31, 2017
Text Block [Abstract]
Non-performing Assets and Impaired Loans	Note 8 – Non-performing The following table presents the nonaccrual, loans past due over 90 days still on accrual, and troubled debt restructured (“TDRs”) by class of loans: Loans Past Due Over 90 Non- Total Non- Days Still Performing Performing Performing December 31, 2017 Non-accrual Accruing TDRs TDRs Loans Commercial Owner occupied real estate $ 4,742 $ — $ 11 $ 1 $ 4,754 Non owner occupied real estate 115 — 440 — 555 Residential development — — — — — Development & Spec Land Loans 176 — — — 176 Commercial and industrial 1,656 — — — 1,656 Total commercial 6,689 — 451 1 7,141 Real estate Residential mortgage 3,693 — 351 1,450 5,494 Residential construction — — — 222 222 Mortgage warehouse — — — — — Total real estate 3,693 — 351 1,672 5,716 Consumer Direct Installment 373 — — — 373 Direct Installment Purchased — — — — — Indirect Installment 1,041 167 — — 1,208 Home Equity 1,480 — 211 285 1,976 Total Consumer 2,894 167 211 285 3,557 Total $ 13,276 $ 167 $ 1,013 $ 1,958 $ 16,414 Loans Past Due Over 90 Non- Total Non- Days Still Performing Performing Performing December 31, 2016 Non-accrual Accruing TDRs TDRs Loans Commercial Owner occupied real estate $ 1,532 $ 183 $ — $ — $ 1,715 Non owner occupied real estate 440 — — — 440 Residential development — — — — — Development & Spec Land Loans 118 — — — 118 Commercial and industrial 159 — — — 159 Total commercial 2,249 183 — — 2,432 Real estate Residential mortgage 2,959 — 576 1,254 4,789 Residential construction — — 233 — 233 Mortgage warehouse — — — — — Total real estate 2,959 — 809 1,254 5,022 Consumer Direct Installment 512 — — — 512 Direct Installment Purchased — — — — — Indirect Installment 659 49 — — 708 Home Equity 1,557 9 205 238 2,009 Total Consumer 2,728 58 205 238 3,229 Total $ 7,936 $ 241 $ 1,014 $ 1,492 $ 10,683 Included in the $13.3 million of non-accrual non-performing From time to time, the Bank obtains information that may lead management to believe that the collection of payments may be doubtful on a particular loan. In recognition of this, it is management’s policy to convert the loan from an “earning asset” to a non-accruing non-accrual non-accrual non-accrual Non-accrual non-accrual A loan becomes impaired when, based on current information, it is probable that a creditor will be unable to collect all amounts due according to the contractual terms of the loan agreement. When a loan is classified as impaired, the degree of impairment must be recognized by estimating future cash flows from the debtor. The present value of these cash flows is computed at a discount rate based on the interest rate contained in the loan agreement. However, if a particular loan has a determinable market value for its collateral, the creditor may use that value. Also, if the loan is secured and considered collateral dependent, the creditor may use the fair value of the collateral. Interest income on loans individually classified as impaired is recognized on a cash basis after all past due and current principal payments have been made. Smaller-balance, homogeneous loans are evaluated for impairment in total. Such loans include residential first mortgage loans secured by 1–4 family residences, residential construction loans, automobile, home equity, second mortgage loans and mortgage warehouse loans. Commercial loans and mortgage loans secured by other properties are evaluated individually for impairment. When analysis of borrower operating results and financial condition indicate that underlying cash flows of a borrower’s business are not adequate to meet its debt service requirements, the loan is evaluated for impairment. Often this is associated with a delay or shortfall in payments of 30 days or more. Loans are generally moved to non-accrual Loans for which it is probable that the Company will not collect all principal and interest due according to contractual terms, including TDRs, are measured for impairment. Allowable methods for determining the amount of impairment include the three methods described above. The Company’s TDRs are considered impaired loans and included in the allowance methodology using the guidance for impaired loans. At December 31, 2017, the type of concessions the Company has made on restructured loans has been temporary rate reductions and/or reductions in monthly payments and there have been no restructured loans with modified recorded balances. Any modification to a loan that is a concession and is not in the normal course of lending is considered a restructured loan. A restructured loan is returned to accruing status after six consecutive payments but is still reported as TDR unless the loan bears interest at a market rate. As of December 31, 2017, the Company had $3.0 million in TDRs and $2.0 million were performing according to the restructured terms and two TDRs were returned to accrual status during 2017. There was $50,000 of specific reserves allocated to TDRs at December 31, 2017 based on the collateral deficiencies. The following table presents commercial loans individually evaluated for impairment by class of loans: Twelve Months Ending Average Cash/Accrual Unpaid Allowance For Balance in Interest Principal Recorded Loan Loss Impaired Income December 31, 2017 Balance Investment Allocated Loans Recognized With no recorded allowance Commercial Owner occupied real estate $ 3,824 $ 3,849 $ — $ 1,673 $ 11 Non owner occupied real estate 554 570 — 345 — Residential development — — — — — Development & Spec Land Loans 176 174 — 233 4 Commercial and industrial 1,656 1,663 — 1,445 25 Total commercial 6,210 6,256 — 3,696 40 With an allowance recorded Commercial Owner occupied real estate 931 931 184 78 46 Non owner occupied real estate — — — — — Residential development — — — — — Development & Spec Land Loans — — — — — Commercial and industrial — — — — — Total commercial 931 931 184 78 46 Total $ 7,141 $ 7,187 $ 184 $ 3,774 $ 86 Twelve Months Ending Average Cash/Accrual Unpaid Allowance For Balance in Interest Principal Recorded Loan Loss Impaired Income December 31, 2016 Balance Investment Allocated Loans Recognized With no recorded allowance Commercial Owner occupied real estate $ 1,533 $ 1,533 $ — $ 1,619 $ 58 Non owner occupied real estate 440 440 — 871 18 Residential development — — — — — Development & Spec Land Loans 118 118 — 61 16 Commercial and industrial 128 127 — 349 1 Total commercial 2,219 2,218 — 2,900 93 With an allowance recorded Commercial Owner occupied real estate — — — — — Non owner occupied real estate — — — — — Residential development — — — — — Development & Spec Land Loans — — — — — Commercial and industrial 31 32 4 5 2 Total commercial 31 32 4 5 2 Total $ 2,250 $ 2,250 $ 4 $ 2,905 $ 95 Twelve Months Ending Average Cash/Accrual Unpaid Allowance For Balance in Interest Principal Recorded Loan Loss Impaired Income December 31, 2015 Balance Investment Allocated Loans Recognized With no recorded allowance Commercial Owner occupied real estate $ 1,340 $ 1,339 $ — $ 1,001 $ 22 Non owner occupied real estate 4,938 4,953 — 5,417 8 Residential development — — — — — Development & Spec Land Loans 71 71 — 6 3 Commercial and industrial 79 79 — 275 4 Total commercial 6,428 6,442 — 6,699 37 With an allowance recorded Commercial Owner occupied real estate 410 410 105 243 8 Non owner occupied real estate 70 70 32 6 13 Residential development — — — — — Development & Spec Land Loans — — — — — Commercial and industrial 97 97 65 162 — Total commercial 577 577 202 411 21 Total $ 7,005 $ 7,019 $ 202 $ 7,110 $ 58 The following table presents the payment status by class of loans: 30 - 59 Days 60 - 89 Days 90 Days or Loans Not Past December 31, 2017 Past Due Past Due Greater Past Due Total Past Due Due Total Commercial Owner occupied real estate $ 1,613 $ 1,950 $ — $ 3,563 $ 544,033 $ 547,596 Non owner occupied real estate 512 122 — 634 663,647 664,281 Residential development — — — — 16,431 16,431 Development & Spec Land Loans 31 — — 31 48,643 48,674 Commercial and industrial 520 1 — 521 334,706 335,227 Total commercial 2,676 2,073 — 4,749 1,607,460 1,612,209 Real estate Residential mortgage 1,248 49 — 1,297 587,061 588,358 Residential construction 63 — — 63 15,964 16,027 Mortgage warehouse — — — — 94,508 94,508 Total real estate 1,311 49 — 1,360 697,533 698,893 Consumer Direct Installment 78 10 — 88 89,529 89,617 Direct Installment Purchased — — — — 82 82 Indirect Installment 1,859 244 167 2,270 225,053 227,323 Home Equity 502 527 — 1,029 196,549 197,578 Total consumer 2,439 781 167 3,387 511,213 514,600 Total $ 6,426 $ 2,903 $ 167 $ 9,496 $ 2,816,206 $ 2,825,702 Percentage of total loans 0.23 % 0.10 % 0.01 % 0.34 % 99.66 % 30 - 59 Days 60 - 89 Days 90 Days or Loans Not Past December 31, 2016 Past Due Past Due Greater Past Due Total Past Due Due Total Commercial Owner occupied real estate $ 1,068 $ — $ 183 $ 1,251 $ 336,297 $ 337,548 Non owner occupied real estate 357 — — 357 461,540 461,897 Residential development — — — — 5,006 5,006 Development & Spec Land Loans 1 — — 1 31,227 31,228 Commercial and industrial 982 — — 982 229,538 230,520 Total commercial 2,408 — 183 2,591 1,063,608 1,066,199 Real estate Residential mortgage 886 123 — 1,009 507,224 508,233 Residential construction — — — — 20,611 20,611 Mortgage warehouse — — — — 135,727 135,727 Total real estate 886 123 — 1,009 663,562 664,571 Consumer Direct Installment 139 4 — 143 71,007 71,150 Direct Installment Purchased — — — — 119 119 Indirect Installment 1,339 237 49 1,625 151,579 153,204 Home Equity 912 267 9 1,188 173,938 175,126 Total consumer 2,390 508 58 2,956 396,643 399,599 Total $ 5,684 $ 631 $ 241 $ 6,556 $ 2,123,813 $ 2,130,369 Percentage of total loans 0.27 % 0.03 % 0.01 % 0.31 % 99.69 % The entire balance of a loan is considered delinquent if the minimum payment contractually required to be made is not received by the specified due date. Horizon Bank’s processes for determining credit quality differ slightly depending on whether a new loan or a renewed loan is being underwritten, or whether an existing loan is being re-evaluated • For new and renewed commercial loans, the Bank’s Credit Department, which acts independently of the loan officer, assigns the credit quality grade to the loan. Loan grades for loans with an aggregate credit exposure that exceeds the authorities in the respective markets (ranging from $1,000,000 to $3,500,000) are validated by the Loan Committee, which is chaired by the Chief Credit Officer (CCO). • Commercial loan officers are responsible for reviewing their loan portfolios and report any adverse material change to the CCO or Loan Committee. When circumstances warrant a change in the credit quality grade, loan officers are required to notify the CCO and the Credit Department of the change in the loan grade. Downgrades are accepted immediately by the CCO, however, lenders must present their factual information to either the Loan Committee or the CCO when recommending an upgrade. • The CCO, or his designee, meets weekly with loan officers to discuss the status of past-due • Monthly, senior management meets with the Watch Committee, which reviews all of the past due, classified, and impaired loans and the relative trends of these assets. This committee also reviews the actions taken by management regarding foreclosure mitigation, loan extensions, troubled debt restructures, other real estate owned and personal property repossessions. The information reviewed in this meeting acts as a precursor for developing management’s analysis of the adequacy of the Allowance for Loan and Lease Losses. For residential real estate and consumer loans, Horizon uses a grading system based on delinquency. Loans that are 90 days or more past due, on non-accrual, non-accrual. Horizon Bank employs a nine-grade rating system to determine the credit quality of commercial loans. The first five grades represent acceptable quality, and the last four grades mirror the criticized and classified grades used by the bank regulatory agencies (special mention, substandard, doubtful, and loss). The loan grade definitions are detailed below. Risk Grade 1: Excellent (Pass) Loans secured by liquid collateral, such as certificates of deposit, reputable bank letters of credit, or other cash equivalents; loans that are guaranteed or otherwise backed by the full faith and credit of the United States government or an agency thereof, such as the Small Business Administration; or loans to any publicly held company with a current long-term debt rating of A or better. Risk Grade 2: Good (Pass) Loans to businesses that have strong financial statements containing an unqualified opinion from a CPA firm and at least three consecutive years of profits; loans supported by unaudited financial statements containing strong balance sheets, five consecutive years of profits, a five-year satisfactory relationship with the Bank, and key balance sheet and income statement trends that are either stable or positive; loans secured by publicly traded marketable securities where there is no impediment to liquidation; loans to individuals backed by liquid personal assets and unblemished credit history; or loans to publicly held companies with current long-term debt ratings of Baa or better. Risk Grade 3: Satisfactory (Pass) Loans supported by financial statements (audited or unaudited) that indicate average or slightly below average risk and having some deficiency or vulnerability to changing economic conditions; loans with some weakness but offsetting features of other support are readily available; loans that are meeting the terms of repayment, but which may be susceptible to deterioration if adverse factors are encountered. Loans may be graded Satisfactory when there is no recent information on which to base a current risk evaluation and the following conditions apply: • At inception, the loan was properly underwritten, did not • At inception, the loan was secured with collateral possessing a loan value adequate to protect the Bank from loss. • The loan has exhibited two or more years of satisfactory repayment with a reasonable reduction of the principal balance. • During the period that the loan has been outstanding, there has been no evidence of any credit weakness. Some examples of weakness include slow payment, lack of cooperation by the borrower, breach of loan covenants, or the borrower is in an industry known to be experiencing problems. If any of these credit weaknesses is observed, a lower risk grade may be warranted. Risk Grade 4 Satisfactory/Monitored: Loans in this category are considered to be of acceptable credit quality, but contain greater credit risk than Satisfactory loans. Borrower displays acceptable liquidity, leverage, and earnings performance within the Bank’s minimum underwriting guidelines. The level of risk is acceptable but conditioned on the proper level of loan officer supervision. Loans that normally fall into this grade include acquisition, construction and development loans and income producing properties that have not reached stabilization. Risk Grade 4W Management Watch: Loans in this category are considered to be of acceptable quality, but with above normal risk. Borrower displays potential indicators of weakness in the primary source of repayment resulting in a higher reliance on secondary sources of repayment. Balance sheet may exhibit weak liquidity and/or high leverage. There is inconsistent earnings performance without the ability to sustain adverse economic conditions. Borrower may be operating in a declining industry or the property type, as for a commercial real estate loan, may be high risk or in decline. These loans require an increased level of loan officer supervision and monitoring to assure that any deterioration is addressed in a timely fashion. Risk Grade 5: Special Mention Loans which possess some credit deficiency or potential weakness which deserves close attention. Such loans pose an unwarranted financial risk that, if not corrected, could weaken the loan by adversely impacting the future repayment ability of the borrower. The key distinctions of a Special Mention classification are that (1) it is indicative of an unwarranted level of risk and (2) weaknesses are considered “potential,” not “defined,” impairments to the primary source of repayment. These loans may be to borrowers with adverse trends in financial performance, collateral value and/or marketability, or balance sheet strength. Risk Grade 6: Substandard One or more of the following characteristics may be exhibited in loans classified Substandard: • Loans which possess a defined credit weakness. The likelihood that a loan will be paid from the primary source of repayment is uncertain. Financial deterioration is under way and very close attention is warranted to ensure that the loan is collected without loss. • Loans are inadequately protected by the current net worth and paying capacity of the obligor. • The primary source of repayment is gone, and the Bank is forced to rely on a secondary source of repayment, such as collateral liquidation or guarantees. • Loans have a distinct possibility that the Bank will sustain some loss if deficiencies are not corrected. • Unusual courses of action are needed to maintain a high probability of repayment. • The borrower is not generating enough cash flow to repay loan principal; however, it continues to make interest payments. • The lender is forced into a subordinated or unsecured position due to flaws in documentation. • Loans have been restructured so that payment schedules, terms, and collateral represent concessions to the borrower when compared to the normal loan terms. • The lender is seriously contemplating foreclosure or legal action due to the apparent deterioration in the loan. • There is a significant deterioration in market conditions to which the borrower is highly vulnerable. Risk Grade 7: Doubtful One or more of the following characteristics may be present in loans classified Doubtful: • Loans have all of the weaknesses of those classified as Substandard. However, based on existing conditions, these weaknesses make full collection of principal highly improbable. • The primary source of repayment is gone, and there is considerable doubt as to the quality of the secondary source of repayment. • The possibility of loss is high but because of certain important pending factors which may strengthen the loan, loss classification is deferred until the exact status of repayment is known. Risk Grade 8: Loss Loans are considered uncollectible and of such little value that continuing to carry them as assets is not feasible. Loans will be classified Loss when it is neither practical nor desirable to defer writing off or reserving all or a portion of a basically worthless asset, even though partial recovery may be possible at some time in the future. The following table presents loans by credit grades. Special December 31, 2017 Pass Mention Substandard Doubtful Total Commercial Owner occupied real estate $ 520,907 $ 8,622 $ 18,067 $ — $ 547,596 Non owner occupied real estate 655,410 3,864 5,007 — 664,281 Residential development 16,431 — — — 16,431 Development & Spec Land Loans 47,562 886 226 — 48,674 Commercial and industrial 314,190 7,448 13,589 — 335,227 Total commercial 1,554,500 20,820 36,889 — 1,612,209 Real estate Residential mortgage 582,864 — 5,494 — 588,358 Residential construction 15,805 — 222 — 16,027 Mortgage warehouse 94,508 — — — 94,508 Total real estate 693,177 — 5,716 — 698,893 Consumer Direct Installment 89,244 — 373 — 89,617 Direct Installment Purchased 82 — — — 82 Indirect Installment 226,115 — 1,208 — 227,323 Home Equity 195,602 — 1,976 — 197,578 Total Consumer 511,043 — 3,557 — 514,600 Total $ 2,758,720 $ 20,820 $ 46,162 $ — $ 2,825,702 Percentage of total loans 97.63 % 0.74 % 1.63 % 0.00 % Special December 31, 2016 Pass Mention Substandard Doubtful Total Commercial Owner occupied real estate $ 322,924 $ 4,960 $ 9,664 $ — $ 337,548 Non owner occupied real estate 455,648 341 5,908 — 461,897 Residential development 5,006 — — — 5,006 Development & Spec Land Loans 31,057 — 171 — 31,228 Commercial and industrial 220,424 3,728 6,368 — 230,520 Total commercial 1,035,059 9,029 22,111 — 1,066,199 Real estate Residential mortgage 503,444 — 4,789 — 508,233 Residential construction 20,378 — 233 — 20,611 Mortgage warehouse 135,727 — — — 135,727 Total real estate 659,549 — 5,022 — 664,571 Consumer Direct Installment 70,638 — 512 — 71,150 Direct Installment Purchased 119 — — — 119 Indirect Installment 152,496 — 708 — 153,204 Home Equity 173,117 — 2,009 — 175,126 Total Consumer 396,370 — 3,229 — 399,599 Total $ 2,090,978 $ 9,029 $ 30,362 $ — $ 2,130,369 Percentage of total loans 98.15 % 0.42 % 1.43 % 0.00 %

Premises and Equipment

Premises and Equipment	12 Months Ended
	Dec. 31, 2017
Property, Plant and Equipment [Abstract]
Premises and Equipment	Note 9 – Premises and Equipment December 31 December 31 2017 2016 Land $ 21,633 $ 20,032 Buildings and improvements 68,447 59,607 Furniture and equipment 22,288 19,965 Total cost 112,368 99,604 Accumulated depreciation (36,839 ) (33,247 ) Net premise and equipment $ 75,529 $ 66,357

Loan Servicing

Loan Servicing	12 Months Ended
	Dec. 31, 2017
Text Block [Abstract]
Loan Servicing	Note 10 – Loan Servicing Loans serviced for others are not included in the accompanying consolidated balance sheets. The unpaid principal balances of loans serviced for others totaled approximately $1.310 billion and $1.301 billion at December 31, 2017 and 2016. The aggregate fair value of capitalized mortgage servicing rights was approximately $12.8 million, $12.1 million, and $10.8 million at December 31, 2017, 2016 and 2015, compared to the carrying values of $11.6 million, $11.1 million and $8.9 million, respectively. The fair value of capitalized mortgage servicing rights was approximately $7.6 million on January 1, 2015. Comparable market values and a valuation model that calculates the present value of future cash flows were used to estimate fair value. For purposes of measuring impairment, risk characteristics including product type, investor type and interest rates, were used to stratify the originated mortgage servicing rights. December 31 December 31 December 31 2017 2016 2015 Mortgage servicing rights Balances, January 1 $ 11,681 $ 9,271 $ 7,980 Servicing rights capitalized 2,109 3,426 2,974 Amortization of servicing rights (1,601 ) (1,016 ) (1,683 ) Balances, December 31 12,189 11,681 9,271 Impairment allowance Balances, January 1 (507 ) (397 ) (338 ) Additions (85 ) (236 ) (130 ) Reductions 5 126 71 Balances, December 31 (587 ) (507 ) (397 ) Mortgage servicing rights, net $ 11,602 $ 11,174 $ 8,874 During 2017, 2016 and 2015, the Bank recorded additional impairment of approximately $80,000, $110,000 and $59,000, respectively.

Goodwill and Intangible Assets

Goodwill and Intangible Assets	12 Months Ended
	Dec. 31, 2017
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill and Intangible Assets	Note 11 – Goodwill and Intangible Assets On October 17, 2017, the Wolverine acquisition resulted in goodwill of $26.8 million. On September 1, 2017, the Lafayette acquisition resulted in goodwill of $15.4 million. On November 7, 2016, the CNB acquisition resulted in goodwill of $609,000. On July 18, 2016, the LaPorte acquisition resulted in goodwill of $21.0 million. On June 1, 2016, the Kosciusko acquisition resulted in goodwill of $6.4 million. Additionally, on July 1, 2015, the Peoples acquisition resulted in goodwill of $21.4 million. No impairment loss was recorded in 2017 or 2016. The Company tested goodwill for impairment during 2017 and 2016. In both valuations, the fair value exceeded the Company’s carrying value, therefore, it was concluded goodwill is not impaired. For additional details related to impairment testing, see the “Goodwill and Intangible Assets” section of “Management’s Discussion and Analysis of Financial Condition and Results of Operations” included as Item 7 of this Annual Report on Form 10K. 2017 2016 Balance, January 1 $ 76,941 $ 49,600 Goodwill acquired 42,939 27,341 Balance, December 31 $ 119,880 $ 76,941 Goodwill acquired in 2017 includes a $704,000 measurement period adjustment related to the 2016 acquisition of LaPorte. As a result of the acquisition of Alliance Bank Corporation in 2005; American Trust & Savings Bank in 2010; Heartland in 2012; Summit in 2014; Peoples in 2015; Kosciusko, LaPorte and CNB in 2016; and Lafayette and Wolverine in 2017; the Company has recorded certain amortizable intangible assets related to core deposit intangibles. These core deposit intangibles are being amortized over seven to ten years using an accelerated method. Amortizable intangible assets are summarized as follows: December 31, 2017 December 31, 2016 Gross Carrying Accumulated Gross Carrying Accumulated Amount Amortization Amount Amortization Amortizable intangible assets Core deposit intangible $ 20,711 $ (8,309 ) $ 16,151 $ (6,785 ) Amortization expense for intangible assets totaled $1.5 million, $1.2 million, and $988,000 for the years ended December 31, 2017, 2016 and 2015. Estimated amortization for the years ending December 31 is as follows: 2018 $ 2,012 2019 1,787 2020 1,481 2021 1,394 2022 1,375 Thereafter 4,353 $ 12,402

Deposits

Deposits	12 Months Ended
	Dec. 31, 2017
Banking and Thrift [Abstract]
Deposits	Note 12 – Deposits December 31 December 31 2017 2016 Noninterest-bearing demand deposits $ 601,805 $ 496,248 Interest-bearing demand deposits 909,638 850,641 Money market (variable rate) 378,108 290,896 Savings deposits 424,500 357,582 Certificates of deposit of $250,000 or more 130,585 105,361 Other certificates and time deposits 436,367 370,482 Total deposits $ 2,881,003 $ 2,471,210 Certificates and other time deposits for both retail and brokered maturing in years ending December 31 are as follows: Retail Brokered Total 2018 $ 258,488 $ 19,010 $ 277,498 2019 152,027 12,558 164,585 2020 56,838 7,058 63,896 2021 16,128 3,386 19,514 2022 16,758 1,900 18,658 Thereafter 22,222 579 22,801 $ 522,461 $ 44,491 $ 566,952

Borrowings

Borrowings	12 Months Ended
	Dec. 31, 2017
Debt Disclosure [Abstract]
Borrowings	Note 13 – Borrowings December 31 December 31 2017 2016 Federal Home Loan Bank advances, variable and fixed rates ranging from 0.93% to 7.53%, due at various dates through November 15, 2024 $ 336,308 $ 124,034 Securities sold under agreements to repurchase 61,097 57,144 Federal Reserve Bank discount window 11,000 — Federal funds purchased 143,252 66,811 Notes payable,variable rate of 2.75%, due at various dates through July 13, 2019 12,500 19,500 Total borrowings $ 564,157 $ 267,489 The Federal Home Loan Bank advances are secured by first and second mortgage loans and mortgage warehouse loans totaling approximately $503.8 million. Advances are subject to restrictions or penalties in the event of prepayment. At December 31, 2017, the Bank had available approximately $127.2 million in credit lines with various money center banks, including the FHLB. Contractual maturities in years ending December 31 are as follows: 2018 $ 430,078 2019 69,252 2020 37,472 2021 5,042 2022 12,154 Thereafter 10,159 $ 564,157

Repurchase Agreements

Repurchase Agreements	12 Months Ended
	Dec. 31, 2017
Text Block [Abstract]
Repurchase Agreements	Note 14 – Repurchase Agreements The Company transfers various securities to customers in exchange for cash at the end of each business day and agrees to acquire the securities at the end of the next business day for the cash exchanged plus interest. The process is repeated at the end of each business day until the agreement is terminated. The securities underlying the agreement remain under the Bank’s control. Securities sold under agreements to repurchase are secured by federal agency collateralized mortgage obligations and mortgage-backed pools. The following table shows repurchase agreements accounted for as secured borrowings (in thousands): Remaining Contractual Maturity of the Agreements December 31, 2017 Overnight Up to one One to Three to five years Five to ten Beyond ten Total Repurchase Agreements and repurchase-to-maturity Repurchase Agreements $ 61,097 $ — $ — $ — $ — $ — $ 61,097 Securities pledged for Repurchase Agreements Federal agency collateralized mortgage obligations 38,421 $ — $ — $ — $ — $ — $ 38,421 Federal agency mortgage-backed pools 35,577 — — — — — 35,577 Total $ 73,998 $ — $ — $ — $ — $ — $ 73,998 Securities sold under agreements to repurchase consist of obligations of the Bank to other parties. The obligations are secured by federal agency collateralized mortgage obligations and federal agency mortgage-backed pools and such collateral is held in safekeeping by third parties. The maximum amount of outstanding agreements at any month end during 2017 and 2016 totaled $63.1 million and $157.7 million and the daily average of such agreements totaled $55.2 million and $134.2 million. The agreements at December 31, 2017, are overnight agreements.

Subordinated Debentures

Subordinated Debentures	12 Months Ended
	Dec. 31, 2017
Text Block [Abstract]
Subordinated Debentures	Note 15 – Subordinated Debentures In October of 2004, Horizon formed Horizon Statutory Trust II (“Trust II”), a wholly owned statutory business trust. Trust II sold $10.3 million of Trust Preferred Capital Securities as a participant in a pooled trust preferred securities offering. The proceeds from the sale of the trust preferred securities were used by the trust to purchase an equivalent amount of subordinated debentures from Horizon. The junior subordinated debentures are the sole assets of Trust II and are fully and unconditionally guaranteed by Horizon. The junior subordinated debentures and the trust preferred securities pay interest and dividends on a quarterly basis. The junior subordinated debentures and the securities bear interest at a rate of 90-day In December of 2006, Horizon formed Horizon Bancorp Capital Trust III (“Trust III”), a wholly owned statutory business trust. Trust III sold $12.4 million of Trust Preferred Capital Securities as a participant in a pooled trust preferred securities offering. The proceeds from the sale of the trust preferred securities were used by the trust to purchase an equivalent amount of subordinated debentures from Horizon. The junior subordinated debentures are the sole assets of Trust III and are fully and unconditionally guaranteed by Horizon. The junior subordinated debentures and the trust preferred securities pay interest and dividends on a quarterly basis. The junior subordinated debentures and the securities bear interest at a rate of 90-day The Company assumed additional debentures as the result of the acquisition of Alliance Bank Corporation in 2005. In June 2004, Alliance formed Alliance Financial Statutory Trust I a wholly owned business trust (“Alliance Trust”), to sell $5.2 million in trust preferred securities. The proceeds from the sale of the trust preferred securities were used by the trust to purchase an equivalent amount of subordinated debentures from Alliance. The junior subordinated debentures are the sole assets of Alliance Trust and are fully and unconditionally guaranteed by Horizon. The junior subordinated debentures and the trust preferred securities pay interest and dividends on a quarterly basis. The junior subordinated debentures and the securities bear interest at a rate of 90-day The Company assumed additional debentures as the result of the American Trust & Savings Bank purchase and assumption in 2010. In March 2004, Am Tru Inc., the holding company for American Trust & Savings Bank, formed Am Tru Statutory Trust I a wholly owned business trust (“Am Tru Trust”), to sell $3.5 million in trust preferred securities. The proceeds from the sale of the trust preferred securities were used by the trust to purchase an equivalent amount of subordinated debentures from Am Tru Inc. The junior subordinated debentures are the sole assets of Am Tru Trust and are fully and unconditionally guaranteed by Horizon. The junior subordinated debentures and the trust preferred securities pay interest and dividends on a quarterly basis. The junior subordinated debentures and the securities bear interest at a rate of 90-day The Company assumed additional debentures as the result of the Heartland merger in July 2012. In December 2006, Heartland formed Heartland (IN) Statutory Trust II a wholly owned business trust (“Heartland Trust”), to sell $3.0 million in trust preferred securities. The proceeds from the sale of the trust preferred securities were used by the trust to purchase an equivalent amount of subordinated debentures from Heartland. The junior subordinated debentures are the sole assets of Heartland Trust and are fully and unconditionally guaranteed by Horizon. The junior subordinated debentures and the trust preferred securities pay interest and dividends on a quarterly basis. The junior subordinated debentures and the securities bear interest at a rate of 90-day The Company assumed additional debentures as the result of the LaPorte merger in July 2016. In October 2007, LaPorte assumed debentures as the result of its acquisition of City Savings Financial Corporation (“City Savings”). In June 2003, City Savings formed City Savings Statutory Trust I a wholly owned business trust (“City Savings Trust”), to sell $5.0 million in trust preferred securities. The proceeds from the sale of the trust preferred securities were used by the trust to purchase an equivalent amount of subordinated debentures from City Savings. The junior subordinated debentures are the sole assets of City Savings Trust and are fully and unconditionally guaranteed by Horizon. The junior subordinated debentures and the trust preferred securities pay interest and dividends on a quarterly basis. The junior subordinated debentures and the securities bear interest at a rate of 90-day The Trust Preferred Capital Securities, subject to certain limitations, are included in Tier 1 Capital for regulatory purposes. Dividends on the Trust Preferred Capital Securities are recorded as interest expense.

Employee Stock Ownership Plan

Employee Stock Ownership Plan	12 Months Ended
	Dec. 31, 2017
Text Block [Abstract]
Employee Stock Ownership Plan	Note 16 – Employee Stock Ownership Plan Effective January 1, 2007, Horizon converted its stock bonus plan to an employee stock ownership plan (“ESOP”). Prior to that date, Horizon maintained an employee stock bonus plan that covered substantially all employees. The stock bonus plan was noncontributory, and Horizon made matching contributions of amounts contributed by the employees to the Employee Thrift Plan and discretionary contributions. Prior to the establishment of the employee stock bonus plan, Horizon maintained an ESOP that was terminated in 1999. The prior ESOP accounts of active employees and the discretionary accounts of active employees remain in the new ESOP. The Matching contribution accounts under the stock bonus plan were transferred to the Employees Thrift Plan. The ESOP exists for the benefit of substantially all employees. Contributions to the ESOP are by Horizon and are determined by the Board of Directors at its discretion. The contributions may be made in the form of cash or common stock. Shares are allocated among participants each December 31 on the basis of each participant’s eligible compensation to total eligible compensation. Eligible compensation is limited to $265,000 for each participant. Dividends on shares held by the plan, at the discretion of each participant, may be distributed to an individual participant or left in the plan to purchase additional shares. Total cash contributions and expense recorded for the ESOP was $600,000 in 2017, $550,000 in 2016 and $450,000 in 2015. The ESOP, which is not leveraged, owns a total of 963,628 shares of Horizon’s stock or 3.8% of the outstanding shares.

Employee Thrift and Defined Ben

Employee Thrift and Defined Benefit Plan	12 Months Ended
	Dec. 31, 2017
Postemployment Benefits [Abstract]
Employee Thrift and Defined Benefit Plan	Note 17 – Employee Thrift and Defined Benefit Plan The Employee Thrift Plan (“Plan”) provides that all employees of Horizon with the requisite hours of service are eligible for the Plan. The Plan permits voluntary employee contributions and Horizon may make discretionary matching and profit sharing contributions. Each eligible employee is vested according to a schedule based upon years of service. Employee voluntary contributions are vested at all times. The Bank’s expense related to the Plan totaled approximately $942,000 in 2017, $785,000 in 2016 and $848,000 in 2015. The Plan owns a total of 497,948 shares of Horizon’s stock or 1.9% of the outstanding shares. The Company acquired a pension fund known as the Pentegra Defined Benefit Plan (“Pentegra Plan”) in the Peoples acquisition. Prior to August 1, 2007, Peoples provided pension benefits for substantially all of its employees through its participation in the Pentegra Plan. Peoples chose to freeze the Pentegra Plan effective August 1, 2007. The trustees of the Financial Institutions Retirement Fund administer the Pentegra Plan, employer identification number 13-5645888 The risks of participating in these multiemployer plans are different from single-employer plans in the following aspects: • Assets contributed to the multiemployer plan by one employer may be used to provide benefits to employees of other participating employers. • If a participating employer stops contributing to the plan, the unfunded obligations of the plan may be borne by the remaining participating employers. • If the Company chooses to stop participating in the multiemployer plan, the Company may be required to pay the plan an amount based on the underfunded status of the plan, referred to as a withdrawal liability. There was no expense to the Company in 2017 and 2016 for this Pentegra Plan. The Company intends on terminating this Pentegra Plan during 2018 and has recorded a $3.4 million withdrawal liability for the termination of the Pentegra Plan.

Income Tax

Income Tax	12 Months Ended
	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Income Tax	Note 18 – Income Tax December 31 December 31 December 31 2017 2016 2015 Income tax expense Currently payable Federal $ 12,079 $ 7,467 $ 5,511 Deferred Federal 331 1,334 1,721 Revaluation of deferred tax assets 2,426 — — Total income tax expense $ 14,836 $ 8,801 $ 7,232 Reconciliation of federal statutory to actual tax expense Federal statutory income tax at 35% $ 16,783 $ 11,450 $ 9,724 Tax exempt interest (2,699 ) (1,882 ) (1,708 ) Tax exempt income (638 ) (575 ) (488 ) Stock compensation (546 ) — — Revaluation of deferred tax assets 2,426 — — Other tax exempt income (456 ) (608 ) (199 ) Nondeductible and other (34 ) 416 (97 ) Actual tax expense $ 14,836 $ 8,801 $ 7,232 December 31 December 31 2017 2016 Assets Allowance for loan losses $ 3,396 $ 5,581 Net operating loss (from acquisitions) 1,658 2,368 Director and employee benefits 2,276 3,124 Unrealized loss on AFS securities and fair value hedge 1,147 937 Accrued Pension 852 1,323 Fair value adjustment on acquistions 1,087 2,340 Other 1,083 1,593 Total assets 11,499 17,266 Liabilities Depreciation (1,680 ) (1,916 ) State tax (210 ) (341 ) Federal Home Loan Bank stock dividends (339 ) (474 ) Difference in basis of intangible assets (2,831 ) (4,654 ) Other (125 ) (431 ) Total liabilities (5,185 ) (7,816 ) Valuation allowance (1,613 ) (2,018 ) Net deferred tax asset $ 4,701 $ 7,432 The Tax Cuts and Jobs Act (the “Act”) was enacted in December 2017. The Act reduces the U.S. federal corporate tax rate from 35 percent to 21 percent. As of December 31, 2017, we have substantially completed our accounting for the tax effects of enactment of the Act; however, in certain cases, we have made a reasonable estimate of the effects on our existing deferred tax balances. We do not believe the actual results will vary materially from those estimates. The effect of the Tax Cuts and Jobs Act listed above reflects the revaluation of our net deferred tax asset based on a U.S. federal tax rate of 21 percent. As of December 31, 2017, the Company had approximately $25.2 million of state tax loss carryforward available to offset future franchise taxable income. Also, at December 31, 2017, the Company had approximately $74,000 of Federal loss carryforward available to offset future federal income tax. The state loss carryforward begins to expire in 2024. The Federal loss carryforward begins to expire in 2032. Due to these losses being incurred by acquired institutions, prior to the acquisitions by Horizon, the annual losses which can be used are subject to an annual limitation. Management believes that the Company will be able to utilize the benefits recorded for both state and federal loss carryforwards within the allotted time periods, except for the amount represented by the valuation allowance. The valuation allowance has been recorded for the possible inability to use a portion of the state net operating loss carryover. Retained earnings of the Bank include approximately $12.8 million for which no deferred income tax liability has been recognized. This amount represents an allocation of previously acquired institutions income to bad debt deductions as of December 31, 1987 for tax purposes only. Reductions of amounts so allocated for purposes other than tax bad debt losses including redemption of bank stock or excess dividends, or loss of “bank” status would create income for tax purposes only, which would be subject to the then-current corporate income tax rate. The unrecorded deferred income tax liability on the above amount for the Company was approximately $2.7 million at December 31, 2017. The Company files income tax returns in the U.S. federal jurisdiction. With a few exceptions, the Company is no longer subject to U.S. federal, state and local or non-U.S.

Accumulated Other Comprehensive

Accumulated Other Comprehensive Loss	12 Months Ended
	Dec. 31, 2017
Equity [Abstract]
Accumulated Other Comprehensive Loss	Note 19 – Accumulated Other Comprehensive Loss The components of accumulated other comprehensive loss included in capital are as follows: December 31 December 31 2017 2016 Unrealized loss on securities available for sale $ (3,937 ) $ (6,007 ) Unamortized gain on securities held to maturity, previously transferred from AFS 200 456 Unrealized loss on derivative instruments (1,728 ) (3,132 ) Tax effect 1,914 3,039 Total accumulated other comprehensive loss $ (3,551 ) $ (5,644 )

Commitments, Off-Balance Sheet

Commitments, Off-Balance Sheet Risk and Contingencies	12 Months Ended
	Dec. 31, 2017
Commitments and Contingencies Disclosure [Abstract]
Commitments, Off-Balance Sheet Risk and Contingencies	Note 20 – Commitments, Off-Balance Because of the nature of its activities, Horizon is subject to claims and lawsuits that arise primarily in the ordinary course of business. It is the opinion of management that the disposition or ultimate resolution of such claims and lawsuits will not have a material adverse effect on the consolidated financial position, results of operations and cash flows of the Company. The Bank was not required to have any cash on deposit with the Federal Reserve Bank to meet regulatory reserve and clearing balance requirements at December 31, 2017. These balances would be included in cash and cash equivalents and would not earn interest. The Bank is a party to financial instruments with off-balance At December 31, 2017 and 2016, commitments to make loans amounted to approximately $802.9 million and $808.3 million and commitments under outstanding standby letters of credit amounted to approximately $3.4 million and $1.0 million. Since many commitments to make loans and standby letters of credit expire without being used, the amount does not necessarily represent future cash advances. No losses are anticipated as a result of these transactions. Collateral obtained upon exercise of the commitment is determined using management’s credit evaluation.

Regulatory Capital

Regulatory Capital	12 Months Ended
	Dec. 31, 2017
Banking and Thrift [Abstract]
Regulatory Capital	Note 21 – Regulatory Capital Horizon and the Bank are subject to various regulatory capital requirements administered by the federal banking agencies and are assigned to a capital category. Failure to meet the minimum regulatory capital requirements can initiate certain mandatory and possible additional discretionary actions by regulators, which if undertaken, could have a direct material effect on the Company’s financial statements. Under capital adequacy guidelines and the regulatory framework for prompt corrective actions, the Company and Bank must meet specific capital guidelines involving quantitative measures of the Bank’s assets, liabilities, and certain off-balance-sheet Quantitative measures established by regulation to ensure capital adequacy require the Company and the Bank to maintain minimum amounts and ratios of total and Tier I capital (as defined in the regulations) to risk-weighted assets (as defined), and of Tier I capital (as defined) to average assets (as defined), or leverage ratio. For December 31, 2017 and 2016, Basel III rules require the Company and Bank to maintain minimum amounts and ratios of common equity Tier I capital (as defined in the regulation) to risk-weighted assets (as defined). Additionally, under Basel III rules, the decision was made to opt-out To be categorized as well capitalized, the Company and Bank must maintain minimum Total risk-based, Tier I risk-based, common equity Tier I risk-based and Tier I leverage ratios as set forth in the table below. As of December 31, 2017 and December 31, 2016, the Company and Bank met all capital adequacy requirements to be considered well capitalized. There have been no conditions or events since the year ending December 31, 2017 that management believes have changed the Bank’s classification as well capitalized. There is no threshold for well-capitalized status for bank holding companies. Horizon and the Bank’s actual and required capital ratios as of December 31, 2017 and 2016 were as follows: Required For Capital 1 Required For Capital 1 Adequacy Purposes Well Capitalized Under Prompt 1 Actual Adequacy Purposes with Capital Buffer Corrective Action Provisions Amount Ratio Amount Ratio Amount Ratio Amount Ratio As of December 31, 2017 Total capital 1 Consolidated $ 384,800 12.91 % $ 238,543 8.00 % $ 275,816 9.25 % N/A N/A Bank 382,788 12.85 % 238,386 8.00 % 275,634 9.25 % $ 297,982 10.00 % Tier 1 capital 1 Consolidated 368,355 12.35 % 178,907 6.00 % 216,180 7.25 % N/A N/A Bank 366,343 12.29 % 178,790 6.00 % 216,038 7.25 % 238,386 8.00 % Common equity tier 1 capital 1 Consolidated 329,892 11.06 % 134,181 4.50 % 171,454 5.75 % N/A N/A Bank 366,343 12.29 % 134,092 4.50 % 171,340 5.75 % 193,689 6.50 % Tier 1 capital 1 Consolidated 368,355 9.92 % 148,503 4.00 % 148,503 4.00 % N/A N/A Bank 366,343 9.89 % 148,116 4.00 % 148,116 4.00 % 185,145 5.00 % As of December 31, 2016 Total capital 1 Consolidated $ 316,576 13.87 % $ 182,596 8.00 % $ 196,976 8.63 % N/A N/A Bank 319,013 13.98 % 182,541 8.00 % 196,916 8.63 % $ 228,176 10.00 % Tier 1 capital 1 Consolidated 301,739 13.22 % 136,947 6.00 % 151,326 6.63 % N/A N/A Bank 304,176 13.33 % 136,905 6.00 % 151,280 6.63 % 182,540 8.00 % Common equity tier 1 capital 1 Consolidated 263,313 11.50 % 103,036 4.50 % 117,460 5.13 % N/A N/A Bank 304,176 13.33 % 102,679 4.50 % 117,054 5.13 % 148,314 6.50 % Tier 1 capital 1 Consolidated 301,739 10.44 % 115,609 4.00 % 115,609 4.00 % N/A N/A Bank 304,176 9.93 % 122,521 4.00 % 122,521 4.00 % 153,151 5.00 % 1 As defined by regulatory agencies The above minimum capital requirements exclude the capital conservation buffer required to avoid limitations on capital distributions, including dividend payments and certain discretionary bonus payments to executive officers. The capital conservation buffer is being phased in from 0.0% for 2015 to 2.50% by 2019. The capital conservation buffer was 1.25% at December 31, 2017. The net unrealized gain or loss on available for sale securities is not included in computing regulatory capital.

Share-Based Compensation

Share-Based Compensation	12 Months Ended
	Dec. 31, 2017
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Share-Based Compensation	Note 22 – Share-Based Compensation On January 21, 2003, the Board of Directors adopted the Horizon Bancorp 2003 Omnibus Equity Incentive Plan (“2003 Plan”), which was approved by stockholders on May 8, 2003. Under the 2003 Plan, Horizon could issue up to 506,250 common shares, plus the number of shares that are tendered to or withheld by Horizon in connection with the exercise of options plus that number of shares that are purchased by Horizon with the cash proceeds received upon option exercises. The 2003 Plan limited the number of shares available to 506,250 for incentive stock options and to 253,125 for the grant of non-option A summary of option activity under the 2003 Plan as of December 31, 2017, and changes during the year then ended, is presented below: Weighted- Average Weighted- Remaining Aggregate Average Contractual Intrinsic Shares Exercise Price Term Value Outstanding, beginning of year 36,635 $ 7.25 Granted — — Exercised (9,185 ) 6.86 Forfeited — — Outstanding, end of year 27,450 7.37 2.73 $ 560,691 Exercisable, end of year 27,450 7.37 2.73 560,691 On June 18, 2013, the Board of Directors adopted the Horizon Bancorp 2013 Omnibus Equity Incentive Plan (“2013 Plan”), which was approved by the Company’s shareholders on May 8, 2014. Under the 2013 Plan, Horizon may issue up to 1,037,550 common shares, plus the number of shares that are tendered to or withheld by Horizon in connection with the exercise of options plus that number of shares that are purchased by Horizon with the cash proceeds received upon option exercises. The 2013 Plan limits the number of shares available to 150,000 for incentive stock options and to 600,000 for the grant of non-option The restricted shares can vest over a period of time established by the Committee at the time of each grant, but the restricted shares already granted under the 2013 Plan generally vest at the end of each grant’s vesting period. Holders of restricted shares receive dividends and may vote the shares. The restricted shares are recorded at fair market value (on the date granted) as a separate component of stockholders’ equity. The cost of these shares is being amortized against earnings using the straight-line method over the vesting period. The performance shares that are awarded become earned and vested based on the achievement of certain performance goals during a performance period as established by the Committee at the time of each grant. The performance goals are based on a comparison of the Company’s average performance over the performance period for the return on common equity, compounded annual growth rate of total assets, and return on average assets, all as relative to the average performance for publicly traded banks with total assets between $1 billion and $5 billion on the SNL Bank Index. Holders of performance share awards receive pass-through dividends but do not have any voting rights before the performance shares are earned and vested. The options shares granted under the 2013 Plan vest at a rate designated per the individual agreements. The fair value of options granted is estimated on the date of the grant using an option-pricing model with the following weighted-average assumptions: December 31 2017 2016 2015 Dividend yields 1.75 % 2.34 % 2.35 % Volatility factors of expected market price of common stock 28.52 % 28.60 % 28.97 % Risk-free interest rates 2.42 % 1.83 % 2.10 % Expected life of options 8 years 8 years 8 years A summary of option activity under the 2013 Plan as of December 31, 2017, and changes during the year then ended, is presented below: Weighted- Average Weighted- Remaining Aggregate Average Contractual Intrinsic Shares Exercise Price Term Value Outstanding, beginning of year 286,586 $ 15.08 Granted 43,502 25.14 Exercised (108,434 ) 14.77 Forfeited (5,871 ) 15.64 Outstanding, end of year 215,783 17.25 7.69 $ 2,276,823 Exercisable, end of year 88,036 14.77 6.62 1,147,538 The weighted average grant-date fair value of options granted during the years 2017, 2016 and 2015 was $7.25, $3.89 and $4.09. A summary of the status of Horizon’s non-vested Weighted Average Grant Date Shares Fair Value Non-vested 70,959 $ 15.59 Vested (6,754 ) 14.80 Granted 41,786 25.49 Forfeited (9,461 ) 15.05 Non-vested, 96,530 19.98 Grants vest at the end of three, four or five years of continuous employment. Total compensation cost recognized in the income statement for option-based payment arrangements during 2017 was $325,000 and the related tax benefit recognized was approximately $114,000. Total compensation cost recognized in the income statement for option-based payment arrangements during 2016 and 2015 was $324,000 and $288,000 and the related tax benefit recognized was $113,000 and $101,000, respectively. Total compensation cost recognized in the income statement for restricted share and performance share based payment arrangements during 2017, 2016 and 2015 was $135,000, $284,000, and $355,000. The recognized tax benefit related thereto was approximately $47,000, $99,000, and $124,000 for the years ended December 31, 2017, 2016 and 2015. Cash received from option exercise under all share-based payment arrangements for the years ended December 31, 2017, 2016 and 2015 was $1.6 million, $214,000, and $403,000. The actual tax benefit realized for the tax deductions from option exercise of the share-based payment arrangements totaled $522,000, $158,000, and $151,000, for the years ended December 31, 2017, 2016 and 2015. As of December 31, 2017, there was $911,000 of total unrecognized compensation cost related to all non-vested On December 19, 2017, the Board of Directors proposed adoption of the Amended and Restated 2013 Omnibus Equity Incentive Plan, primarily to allow awards of “Other Stock Based Awards,” which includes awards valued in whole or in part by reference to Horizon’s common shares. The Amended and Restated 2013 Omnibus Equity Incentive Plan must be approved by the shareholders in order to become effective, and the shareholders will vote on its adoption at the Annual Meeting to be held on May 3, 2018.

Derivative Financial Instrument

Derivative Financial Instruments	12 Months Ended
	Dec. 31, 2017
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivative Financial Instruments	Note 23 – Derivative Financial Instruments Cash Flow Hedges As a strategy to maintain acceptable levels of exposure to the risk of changes in future cash flow due to interest rate fluctuations, the Company entered into interest rate swap agreements for a portion of its floating rate debt. The agreements provide for the Company to receive interest from the counterparty at three month LIBOR and to pay interest to the counterparty at a weighted average fixed rate of 5.81% on a notional amount of $30.5 million at December 31, 2017 and 2016. Under the agreements, the Company pays or receives the net interest amount monthly, with the monthly settlements included in interest expense. The Company assumed additional interest rate swap agreements as the result of the LaPorte acquisition in July 2016. The agreements provide for the Company to receive interest from the counterparty at one month LIBOR and to pay interest to the counterparty at a weighted average fixed rate of 2.31% on a notional amount of $30.0 million at December 31, 2017 and 2016. Under the agreements, the Company pays or receives the net interest amount monthly, with the monthly settlements included in interest expense. Management has designated the interest rate swap agreements as cash flow hedging instruments. For derivative instruments that are designated and qualify as a cash flow hedge, the effective portion of the gain or loss on the derivative is reported as a component of other comprehensive income and reclassified into earnings in the same period or periods during which the hedged transaction affects earnings. Gains and losses on the derivative representing either hedge ineffectiveness or hedge components excluded from the assessment of effectiveness are recognized in current earnings. At December 31, 2017, the Company’s cash flow hedge was effective and is not expected to have a significant impact on the Company’s net income over the next 12 months. Fair Value Hedges Fair value hedges are intended to reduce the interest rate risk associated with the underlying hedged item. The Company enters into fixed rate loan agreements as part of its lending policy. To mitigate the risk of changes in fair value based on fluctuations in interest rates, the Company has entered into interest rate swap agreements on individual loans, converting the fixed rate loans to a variable rate. For derivative instruments that are designated and qualify as a fair value hedge, the gain or loss on the derivative as well as the offsetting gain or loss on the hedged item attributable to the hedged risk are recognized in current earnings. At December 31, 2017, the Company’s fair value hedges were effective and are not expected to have a significant impact on the Company’s net income over the next 12 months. The change in fair value of both the hedge instruments and the underlying loan agreements are recorded as gains or losses in interest income. The fair value hedges are considered to be highly effective and any hedge ineffectiveness was deemed not material. The notional amounts of the loan agreements being hedged were $154.6 million at December 31, 2017 and $122.4 million at December 31, 2016. Other Derivative Instruments The Company enters into non-hedging The change in fair value of both the forward sale commitments and commitments to originate mortgage loans were recorded and the net gains or losses included in the Company’s gain on sale of loans. The following tables summarize the fair value of derivative financial instruments utilized by Horizon: Asset Derivatives Liability Derivatives December 31, 2017 December 31, 2017 Derivatives designated as hedging Balance Sheet Location Fair Value Balance Sheet Location Fair Value Interest rate contracts Loans $ — Other liabilities $ 811 Interest rate contracts Other Assets 811 Other liabilities 1,728 Total derivatives designated as hedging instruments 811 2,539 Derivatives not designated as hedging instruments Mortgage loan contracts Other assets 143 Other liabilities 3 Total derivatives not designated as hedging instruments 143 3 Total derivatives $ 954 $ 2,542 Asset Derivatives Liability Derivatives December 31, 2016 December 31, 2016 Derivatives designated as hedging Balance Sheet Location Fair Value Balance Sheet Location Fair Value Interest rate contracts Loans $ — Other liabilities $ 6 Interest rate contracts Other Assets 6 Other liabilities 3,132 Total derivatives designated as hedging instruments 6 3,138 Derivatives not designated as hedging instruments Mortgage loan contracts Other assets 602 Other liabilities 22 Total derivatives not designated as hedging instruments 602 22 Total derivatives $ 608 $ 3,160 The effect of the derivative instruments on the consolidated statement of income for the 12-month Amount of Loss Recognized in Other Comprehensive Income on Derivative (Effective Derivative in cash flow Years Ended December 31 hedging relationship 2017 2016 2015 Interest rate contracts $ 913 $ 6 $ 127 FASB Accounting Standards Codification (“ASC”) Topic 820-10-20 820-10-55 Amount of Gain (Loss) Recognized on Derivative Derivative in fair value Location of gain (loss) Years Ended December 31 hedging relationship recognized on derivative 2017 2016 2015 Interest rate contracts Interest income - loans $ (817 ) $ (1,776 ) $ 574 Interest rate contracts Interest income - loans 817 1,776 (574 ) Total $ — $ — $ — Amount of Gain (Loss) Recognized on Derivative Derivative not designated Location of gain (loss) Years Ended December 31 as hedging relationship recognized on derivative 2017 2016 2015 Mortgage contracts Other income - gain on sale of loans $ (439 ) $ (62 ) $ 195

Disclosures about fair value of

Disclosures about fair value of assets and liabilities	12 Months Ended
	Dec. 31, 2017
Text Block [Abstract]
Disclosures about fair value of assets and liabilities	Note 24 – Disclosures about fair value of assets and liabilities The Fair Value Measurements topic of the FASB ASC defines fair value, establishes a framework for measuring fair value and expands disclosures about fair value measurements. There are three levels of inputs that may be used to measure fair value: Level 1 Quoted prices in active markets for identical assets or liabilities Level 2 Observable inputs other than Level 1 prices, such as quoted prices for similar assets or liabilities; quoted prices in markets that are not active; or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the assets or liabilities Level 3 Unobservable inputs that are supported by little or no market activity and that are significant to the fair value of the assets or liabilities Following is a description of the valuation methodologies used for instruments measured at fair value on a recurring basis and recognized in the accompanying consolidated financial statements, as well as the general classification of such instruments pursuant to the valuation hierarchy. There have been no significant changes in the valuation techniques during the period ended December 31, 2017. For assets classified within Level 3 of the fair value hierarchy, the process used to develop the reported fair value is described below. Available for sale securities When quoted market prices are available in an active market, securities are classified within Level 1 of the valuation hierarchy. If quoted market prices are not available, then fair values are estimated by using pricing models, quoted prices of securities with similar characteristics or discounted cash flows. Level 2 securities include U.S. Treasury and federal agency securities, state and municipal securities, federal agency mortgage obligations and mortgage-backed pools, private-label mortgage-backed pools and corporate notes. Level 2 securities are valued by a third party pricing service commonly used in the banking industry utilizing observable inputs. Observable inputs include dealer quotes, market spreads, cash flow analysis, the U.S. Treasury yield curve, trade execution data, market consensus prepayment spreads and available credit information and the bond’s terms and conditions. The pricing provider utilizes evaluated pricing models that vary based on asset class. These models incorporate available market information including quoted prices of securities with similar characteristics and, because many fixed-income securities do not trade on a daily basis, apply available information through processes such as benchmark curves, benchmarking of like securities, sector grouping, and matrix pricing. In addition, model processes, such as an option adjusted spread model is used to develop prepayment and interest rate scenarios for securities with prepayment features. Hedged loans Certain fixed rate loans have been converted to variable rate loans by entering into interest rate swap agreements. The fair value of those fixed rate loans is based on discounting the estimated cash flows using interest rates determined by the respective interest rate swap agreement. Loans are classified within Level 2 of the valuation hierarchy based on the unobservable inputs used. Interest rate swap agreements The fair value of the Company’s interest rate swap agreements is estimated by a third party using inputs that are primarily unobservable including a yield curve, adjusted for liquidity and credit risk, contracted terms and discounted cash flow analysis, and therefore, are classified within Level 2 of the valuation hierarchy. The following table presents the fair value measurements of assets and liabilities recognized in the accompanying financial statements measured at fair value on a recurring basis and the level within the FASB ASC fair value hierarchy in which the fair value measurements fall at the following: Quoted Prices in Significant Significant Fair Value (Level 1) (Level 2) (Level 3) December 31, 2017 Available-for-sale U.S. Treasury and federal agencies $ 19,052 $ — $ 19,052 $ — State and municipal 149,564 — 149,564 — Federal agency collateralized mortgage obligations 130,365 — 130,365 — Federal agency mortgage-backed pools 208,657 — 208,657 — Private labeled mortgage-backed pools 1,642 — 1,642 — Corporate notes 385 — 385 — Total available-for-sale 509,665 — 509,665 — Hedged loans 154,575 — 154,575 — Forward sale commitments 143 — 143 — Interest rate swap agreements (917 ) — (917 ) — Commitments to originate loans (3 ) — (3 ) — December 31, 2016 Available-for-sale U.S. Treasury and federal agencies $ 7,989 $ — $ 7,989 $ — State and municipal 116,592 — 116,592 — Federal agency collateralized mortgage obligations 137,195 — 137,195 — Federal agency mortgage-backed pools 176,726 — 176,726 — Corporate notes 1,329 — 1,329 — Total available-for-sale 439,831 — 439,831 — Hedged loans 122,345 — 122,345 — Forward sale commitments 602 — 602 — Interest rate swap agreements (3,138 ) — (3,138 ) — Commitments to originate loans (22 ) — (22 ) — Realized gains and losses included in net income for the periods are reported in the consolidated statements of income as follows: Non Interest Income Years Ended December 31 Total gains and losses from: 2017 2016 2015 Hedged loans $ (817 ) $ (1,776 ) $ 574 Fair value interest rate swap agreements 817 1,776 (574 ) Derivative loan commitments (439 ) (62 ) 195 $ (439 ) $ (62 ) $ 195 Certain other assets are measured at fair value on a nonrecurring basis in the ordinary course of business and are subject to fair value adjustments in certain circumstances (for example, when there is evidence of impairment): Quoted Prices in Significant Significant Fair Value (Level 1) (Level 2) (Level 3) December 31, 2017 Impaired loans $ 6,957 $ — $ — $ 6,957 Mortgage servicing rights 11,602 — — 11,602 December 31, 2016 Impaired loans $ 2,246 $ — $ — $ 2,246 Mortgage servicing rights 11,174 — — 11,174 Impaired (collateral dependent): If the impaired loan is identified as collateral dependent, then the fair value method of measuring the amount of impairment is utilized. This method requires obtaining a current independent appraisal of the collateral and applying a discount factor to the value. Impaired loans that are collateral dependent are classified within Level 3 of the fair value hierarchy when impairment is determined using the fair value method. Mortgage Servicing Rights (MSRs): month-end The following table presents qualitative information about unobservable inputs used in recurring and nonrecurring Level 3 fair value measurements, other than goodwill, at December 31, 2017 and 2016. Fair Value at Valuation Range (Weighted December 31, 2017 Technique Unobservable Inputs Average) Impaired loans $ 6,957 Collateral based measurement Discount to reflect current market conditions and ultimate collectability 0% - 46.8% (2.6%) Mortgage servicing rights $ 11,602 Discounted cashflows Discount rate, Constant prepayment rate, Probability of default 9.6% - 10.8% (9.7%), 9.2% - 27.7% (10.5%), 0% - 1.5% (0.2%) Fair Value at Valuation Range (Weighted December 31, 2016 Technique Unobservable Inputs Average) Impaired loans $ 2,246 Collateral based measurement Discount to reflect current market conditions and ultimate collectability 10% - 16% (13%) Mortgage servicing rights $ 11,174 Discounted cashflows Discount rate, Constant prepayment rate, Probability of default 10% - 16% (13%), 4% - 7% (4.6%), 1% - 10% (4.5%)

Fair Value of Financial Instrum

Fair Value of Financial Instruments	12 Months Ended
	Dec. 31, 2017
Fair Value Disclosures [Abstract]
Fair Value of Financial Instruments	Note 25 – Fair Value of Financial Instruments The estimated fair value amounts of the Company’s financial instruments were determined using available market information, current pricing information applicable to Horizon and various valuation methodologies. Where market quotations were not available, considerable management judgment was involved in the determination of estimated fair values. Therefore, the estimated fair value of financial instruments shown below may not be representative of the amounts at which they could be exchanged in a current or future transaction. Due to the inherent uncertainties of expected cash flows of financial instruments, the use of alternate valuation assumptions and methods could have a significant effect on the estimated fair value amounts. The estimated fair values of financial instruments, as shown below, are not intended to reflect the estimated liquidation or market value of Horizon taken as a whole. The disclosed fair value estimates are limited to Horizon’s significant financial instruments at December 31, 2017 and December 31, 2016. These include financial instruments recognized as assets and liabilities on the consolidated balance sheet as well as certain off-balance The following methods and assumptions were used to estimate the fair value of each class of financial instrument: Cash and Due from Banks Held-to-Maturity Loans Held for Sale Net Loans FHLB and FRB Stock Interest Receivable/Payable Deposits Borrowings Subordinated Debentures Commitments to Extend Credit and Standby Letters of Credit The following table presents estimated fair values of the Company’s financial instruments and the level within the fair value hierarchy in which the fair value measurements fall. December 31, 2017 Quoted Prices in Active Significant Markets for Other Significant Identical Observable Unobservable Carrying Assets Inputs Inputs Amount (Level 1) (Level 2) (Level 3) Assets Cash and due from banks $ 76,441 $ 76,441 $ — $ — Investment securities, held to maturity 200,448 — 201,085 — Loans held for sale 3,094 — — 3,094 Loans excluding loan level hedges, net 2,661,026 — — 2,585,879 Stock in FHLB 18,105 — 18,105 — Interest receivable 16,244 — 16,244 — Liabilities Non-interest $ 601,805 $ 601,805 $ — $ — Interest-bearing deposits 2,279,198 — 2,156,487 — Borrowings 564,157 — 560,057 — Subordinated debentures 37,653 — 35,994 — Interest payable 886 — 886 — December 31, 2016 Carrying Quoted Prices (Level 1) Significant Significant (Level 3) Assets Cash and due from banks $ 70,832 $ 70,832 $ — $ — Investment securities, held to maturity 193,194 — 194,086 — Loans held for sale 8,087 — — 8,087 Loans excluding loan level hedges, net 1,998,804 — — 1,965,928 Stock in FHLB and FRB 23,932 — 23,932 — Interest receivable 12,713 — 12,713 — Liabilities Non-interest $ 496,248 $ 496,248 $ — $ — Interest-bearing deposits 1,974,962 — 1,839,167 — Borrowings 267,489 — 261,141 — Subordinated debentures 37,456 — 36,371 — Interest payable 472 — 472 —

General Litigation

General Litigation	12 Months Ended
	Dec. 31, 2017
Commitments and Contingencies Disclosure [Abstract]
General Litigation	Note 26 – General Litigation The Company is subject to claims and lawsuits that arise primarily in the ordinary course of business. It is the opinion of management that the disposition or ultimate resolution of such claims and lawsuits will not have a material adverse effect on the consolidated financial position, results of operations and cash flows of the Company.

Condensed Financial Information

Condensed Financial Information (Parent Company Only)	12 Months Ended
	Dec. 31, 2017
Condensed Financial Information of Parent Company Only Disclosure [Abstract]
Condensed Financial Information (Parent Company Only)	Note 27 – Condensed Financial Information (Parent Company Only) Presented below is condensed financial information as to financial position, results of operations and cash flows of Horizon Bancorp: Condensed Balance Sheets December 31 December 31 2017 2016 Assets Total cash and cash equivalents $ 13,361 $ 15,736 Investment in Subsidiaries 497,623 386,389 Other assets 1,318 2,504 Total assets $ 512,302 $ 404,629 Liabilities Borrowings $ 12,500 $ 19,500 Subordinated debentures 37,653 37,456 Other liabilities 5,071 6,818 Stockholders’ Equity 457,078 340,855 Total liabilities and stockholders’ equity $ 512,302 $ 404,629 Condensed Statements of Income Years Ended December 31 2017 2016 2015 Operating Income (Expense) Dividend income from Bank $ 27,000 $ 20,000 $ 30,470 Investment income — 33 15 Other income 540 42 24 Interest expense (2,791 ) (2,376 ) (2,009 ) Employee benefit expense (1,094 ) (1,158 ) (1,093 ) Other expense (326 ) 1,279 910 Income Before Undistributed Income of Subsidiaries 23,329 17,820 28,317 Undistributed Income of Subsidiaries 8,804 5,938 (8,168 ) Income Before Tax 32,133 23,758 20,149 Income Tax Benefit 984 154 400 Net Income 33,117 23,912 20,549 Preferred stock dividend — (42 ) (125 ) Net Income Available to Common Shareholders $ 33,117 $ 23,870 $ 20,424 Condensed Statements of Comprehensive Income Years Ended December 31 2017 2016 2015 Net Income $ 33,117 $ 23,912 $ 20,549 Other Comprehensive Income (Loss) Change in fair value of derivative instruments, net of taxes 913 6 127 Unrealized appreciation for the period on held-to-maturity (166 ) (424 ) (357 ) Unrealized appreciation (depreciation) on available-for-sale 1,371 (3,310 ) (1,891 ) Less: reclassification adjustment for realized gains included in net income, net of taxes (25 ) (1,193 ) (123 ) 2,093 (4,921 ) (2,244 ) Comprehensive Income $ 35,210 $ 18,991 $ 18,305 Condensed Statements of Cash Flows Years Ended December 31 2017 2016 2015 Operating Activities Net income $ 33,117 $ 23,912 $ 20,549 Items not requiring (providing) cash Equity in undistributed net income of subsidiaries (8,804 ) (5,938 ) 8,168 Change in Share based compensation 325 284 288 Amortization of unearned compensation 135 324 355 Other assets 388 888 (634 ) Other liabilities (1,675 ) (244 ) (13 ) Net cash provided by operating activities 23,486 19,226 28,713 Investing Activities Acquisition of Peoples — — (19,365 ) Acquisition of Kosciusko — (6,741 ) — Acquisition of LaPorte — (17,108 ) — Acquisition of CNB — (5,296 ) — Acquisition of Lafayette (1,254 ) — — Acquisition of Wolverine (7,688 ) — — Net cash used in investing activities (8,942 ) (29,145 ) (19,365 ) Financing Activities Redemption of preferred stock — (12,500 ) — Net change in borrowings (6,803 ) 19,500 — Dividends paid on preferred shares — (42 ) (125 ) Dividends paid on common shares (11,720 ) (8,382 ) (6,216 ) Exercise of stock options 1,604 572 4,305 Net cash used in financing activities (16,919 ) (852 ) (2,036 ) Net Change in Cash and Cash Equivalents (2,375 ) (10,771 ) 7,312 Cash and Cash Equivalents at Beginning of Year 15,736 26,507 19,195 Cash and Cash Equivalents at End of Year $ 13,361 $ 15,736 $ 26,507

Quarterly Results of Operations

Quarterly Results of Operations (Unaudited)	12 Months Ended
	Dec. 31, 2017
Quarterly Financial Information Disclosure [Abstract]
Quarterly Results of Operations (Unaudited)	Note 28 – Quarterly Results of Operations (Unaudited) The following is a summary of the quarterly consolidated results of operations: Three Months Ended 2017 March 31 June 30 September 30 December 31 Interest income $ 28,834 $ 30,805 $ 32,070 $ 36,774 Interest expense 3,266 3,607 4,191 5,319 Net interest income 25,568 27,198 27,879 31,455 Provision for loan losses 330 330 710 1,100 Gain on sale of securities 35 (3 ) 6 — Net income 8,224 9,072 8,171 7,650 Net income available to common shareholders $ 8,224 $ 9,072 $ 8,171 $ 7,650 Earnings per share: Basic $ 0.37 $ 0.41 $ 0.36 $ 0.30 Diluted 0.37 0.41 0.36 0.30 Average shares outstanding: Basic 22,175,526 22,176,465 22,580,160 25,140,800 Diluted 22,326,071 22,322,390 22,715,273 25,262,010 Three Months Ended 2016 March 31 June 30 September 30 December 31 Interest income $ 23,528 $ 24,650 $ 28,962 $ 29,390 Interest expense 3,754 3,781 4,552 8,450 Net interest income 19,774 20,869 24,410 20,940 Provision for loan losses 532 232 455 623 Gain on sale of securities 108 767 — 961 Net income 5,381 6,326 6,602 5,603 Net income available to common shareholders $ 5,339 $ 6,326 $ 6,602 $ 5,603 Earnings per share: Basic $ 0.30 $ 0.35 $ 0.31 $ 0.25 Diluted 0.30 0.34 0.30 0.25 Average shares outstanding: Basic 17,924,124 18,268,880 21,538,752 22,155,549 Diluted 18,012,726 18,364,167 21,651,953 22,283,722

Nature of Operations and Summ39

Nature of Operations and Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2017
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Nature of Business	Nature of Business The Bank is a full-service commercial bank offering a broad range of commercial and retail banking and other services incident to banking along with a trust department that offers corporate and individual trust and agency services and investment management services. The Bank maintains 62 full service offices. The Bank has wholly owned direct and indirect subsidiaries: Horizon Investments, Inc. (“Horizon Investments”), Horizon Properties, Inc. (“Horizon Properties”), Horizon Insurance Services, Inc. (“Horizon Insurance”) and Horizon Grantor Trust. Horizon Investments manages the investment portfolio of the Bank. Horizon Properties manages the real estate investment trust. Horizon Insurance is used by the Company’s Wealth Management to sell certain insurance products. Horizon Grantor Trust holds title to certain company owned life insurance policies. Horizon conducts no business except that incident to its ownership of the subsidiaries. Horizon formed Horizon Bancorp Capital Trust II in 2004 (“Trust II”) and Horizon Bancorp Capital Trust III in 2006 (“Trust III”) for the purpose of participating in pooled trust preferred securities offerings. The Company assumed additional debentures as the result of the following acquisitions: Alliance Financial Corporation in 2005, which formed Alliance Financial Statutory Trust I (“Alliance Trust”); American Trust & Savings Bank in 2010, which formed Am Tru Statutory Trust I (“Am Tru Trust”); Heartland Bancshares, Inc. in 2013, which formed Heartland (IN) Statutory Trust II (“Heartland Trust”); and LaPorte Bancorp, Inc. in 2016, which acquired City Savings Statutory Trust I (“City Savings Trust”) in 2007. See Note 15 of the Consolidated Financial Statements for further discussion regarding these previously consolidated entities that are now reported separately. The business of Horizon is not seasonal to any material degree.
Basis of Reporting	Basis of Reporting
Use of Estimates	Use of Estimates Material estimates that are particularly susceptible to significant change relate to the determination of the allowance for loan losses, valuation of other real estate owned, goodwill and intangible assets, mortgage servicing rights, other-than-temporary impairments and fair values of financial instruments.
Fair Value Measurements	Fair Value Measurements As defined in codification, fair value is the price to sell an asset or transfer a liability in an orderly transaction between market participants. It represents an exit price at the measurement date. Market participants are buyers and sellers, who are independent, knowledgeable, and willing and able to transact in the principal (or most advantageous) market for the asset or liability being measured. Current market conditions, including imbalances between supply and demand, are considered in determining fair value. Horizon values its assets and liabilities in the principal market where it sells the particular asset or transfers the liability with the greatest volume and level of activity. In the absence of a principal market, the valuation is based on the most advantageous market for the asset or liability (i.e., the market where the asset could be sold or the liability transferred at a price that maximizes the amount to be received for the asset or minimizes the amount to be paid to transfer the liability). In measuring the fair value of an asset, Horizon assumes the highest and best use of the asset by a market participant to maximize the value of the asset, and does not consider the intended use of the asset. When measuring the fair value of a liability, Horizon assumes that the nonperformance risk associated with the liability is the same before and after the transfer. Nonperformance risk is the risk that an obligation will not be satisfied and encompasses not only Horizon’s own credit risk (i.e., the risk that Horizon will fail to meet its obligation), but also other risks such as settlement risk. Horizon considers the effect of its own credit risk on the fair value for any period in which fair value is measured. There are three acceptable valuation techniques that can be used to measure fair value: the market approach, the income approach and the cost approach. Selection of the appropriate technique for valuing a particular asset or liability takes into consideration the exit market, the nature of the asset or liability being valued, and how a market participant would value the same asset or liability. Ultimately, determination of the appropriate valuation method requires significant judgment, and sufficient knowledge and expertise are required to apply the valuation techniques. Valuation inputs refer to the assumptions market participants would use in pricing a given asset or liability using one of the three valuation techniques. Inputs can be observable or unobservable. Observable inputs are those assumptions which market participants would use in pricing the particular asset or liability. These inputs are based on market data and are obtained from a source independent of Horizon. Unobservable inputs are assumptions based on Horizon’s own information or estimate of assumptions used by market participants in pricing the asset or liability. Unobservable inputs are based on the best and most current information available on the measurement date. All inputs, whether observable or unobservable, are ranked in accordance with a prescribed fair value hierarchy which gives the highest ranking to quoted prices (unadjusted) in active markets for identical assets or liabilities (Level 1) and the lowest ranking to unobservable inputs (Level 3). Fair values for assets or liabilities classified as Level 2 are based on one or a combination of the following factors: (i) quoted prices for similar assets; (ii) observable inputs for the asset or liability, such as interest rates or yield curves; or (iii) inputs derived principally from or corroborated by observable market data. The level in the fair value hierarchy within which the fair value measurement in its entirety falls is determined based on the lowest level input that is significant to the fair value measurement in its entirety. The Company considers an input to be significant if it drives 10% or more of the total fair value of a particular asset or liability. Assets and liabilities are considered to be fair valued on a recurring basis if fair value is measured regularly (i.e., daily, weekly, monthly or quarterly). Recurring valuation occurs at a minimum on the measurement date. Assets and liabilities are considered to be fair valued on a nonrecurring basis if the fair value measurement of the instrument does not necessarily result in a change in the amount recorded on the balance sheet. Generally, nonrecurring valuation is the result of the application of other accounting pronouncements which require assets or liabilities to be assessed for impairment or recorded at the lower of cost or fair value. The fair value of assets or liabilities transferred in or out of Level 3 is measured on the transfer date, with any additional changes in fair value subsequent to the transfer considered to be realized or unrealized gains or losses.
Investment Securities Available for Sale	Investment Securities Available for Sale
Investment Securities Held to Maturity	Investment Securities Held to Maturity
Loans Held for Sale	Loans Held for Sale
Interest and Fees on Loans	Interest and Fees on Loans
Concentrations of Credit Risk	Concentrations of Credit Risk
Mortgage Warehouse Loans	Mortgage Warehouse Loans The transaction does not qualify as a sale under ASC 860, Transfers and Servicing and therefore is accounted for as a secured borrowing with pledge of collateral pursuant to the agreement with the mortgage company. When the individual loan is sold to the end investor by the mortgage company, the proceeds from the sale of the loan are received by Horizon and used to pay off the loan balance with Horizon along with any accrued interest and any related fees. The remaining balance from the sale is forwarded to the mortgage company. These individual loans typically are sold by the mortgage company within 30 days and are seldom held more than 90 days. Interest income is accrued during this period and collected at the time each loan is sold. Fee income for each loan sold is collected when the loan is sold and no costs are deferred due to the term between each loan funding and related payoff, which is typically less than 30 days. Based on the agreements with each mortgage company, at any time a mortgage company can reacquire from Horizon its outstanding loan balance on an individual mortgage and regain possession of the original note. Horizon also has the option to request that the mortgage company reacquire an individual mortgage. Should this occur, Horizon would return the original note and reassign the assignment of the mortgage to the mortgage company. Also, in the event that the end investor would not be able to honor the sales commitment and the mortgage company would not be able to reacquire its loan on an individual mortgage, Horizon would be able to exercise its rights under the agreement.
Allowance for Loan Losses	Allowance for Loan Losses The general allowance is calculated by applying loss factors to pools of outstanding loans. Loss factors are based on historical loss experience and may be adjusted for significant factors that, in management’s judgment, affect the collectability of the portfolio as of the evaluation date. Specific allowances are established in cases where management has identified conditions or circumstances related to a credit that management believes indicate the probability that a loss will be incurred in excess of the amount determined by the application of the formula allowance. The qualitative allowance is based upon management’s evaluation of various conditions, the effects of which are not directly measured in the determination of the general and specific allowances. The evaluation of the inherent loss with respect to these conditions is subject to a higher degree of uncertainty because they are not identified with specific credits. The conditions evaluated in connection with the qualitative allowance may include factors such as local, regional and national economic conditions and forecasts, concentrations of credit and changes in the composition of the portfolio.
Loan Impairment	Loan Impairment non-accrual charged-off Loans are considered impaired if the borrower does not exhibit the ability to pay or the full principal or interest payments are not expected or made in accordance with the original terms of the loan. Impaired loans are measured and carried at the lower of cost or the present value of expected future cash flows discounted at the loan’s effective interest rate, at the loan’s observable market price or at the fair value of the collateral if the loan is collateral dependent. Smaller balance homogenous loans are evaluated for impairment in the aggregate. Such loans include residential first mortgage loans secured by one to four family residences, residential construction loans and automobile, home equity and second mortgages. Commercial loans and mortgage loans secured by other properties are evaluated individually for impairment.
Loans Acquired in Business Combinations	Loans Acquired in Business Combinations past-due 310-30) 310-30, The expected cash flows of the acquired loan pools in excess of the fair values recorded is referred to as the accretable yield and is recognized in interest income over the remaining estimated lives of the loan pools. The Company continues to evaluate the fair value of the loans including cash flows expected to be collected. Increases in the Company’s cash flow expectation are recognized as increases to the accretable yield while decreases are recognized as impairments through the allowance for loan losses. Performing loans acquired (FASB ASC 310-20)
Premises and Equipment	Premises and Equipment
Federal Reserve and Federal Home Loan Bank of Indianapolis (FHLBI) Stock	Federal Reserve and Federal Home Loan Bank of Indianapolis (FHLBI) Stock
Mortgage Servicing Rights	Mortgage Servicing Rights (ASC 860-50), Fair value is based on market prices for comparable mortgage servicing contracts, when available, or alternatively, is based on a valuation model that calculates the present value of estimated future net servicing income. The valuation model incorporates assumptions that market participants would use in estimating future net servicing income, such as the cost to service, the discount rate, the custodial earnings rate, an inflation rate, ancillary income, prepayment speeds and default rates and losses. These variables change from quarter to quarter as market conditions and projected interest rates change, and may have an adverse impact on the value of the mortgage servicing right and may result in a reduction to noninterest income. Each class of separately recognized servicing assets subsequently measured using the amortization method are evaluated and measured for impairment. Impairment is determined by stratifying rights into tranches based on predominant characteristics, such as interest rate, loan type and investor type. Impairment is recognized through a valuation allowance for an individual tranche, to the extent that fair value is less than the carrying amount of the servicing assets for that tranche. The valuation allowance is adjusted to reflect changes in the measurement of impairment after the initial measurement of impairment. Changes in valuation allowances are reported with mortgage servicing income net of impairment on the income statement. Fair value in excess of the carrying amount of servicing assets for that stratum is not recognized. Servicing fee income is recorded for fees earned for servicing loans. The fees are based on a contractual percentage of the outstanding principal or a fixed amount per loan and are recorded as income when earned. The amortization of mortgage servicing rights is netted against loan servicing fee income.
Intangible Assets	Intangible Assets
Bank Owned Life Insurance (BOLI)	Bank Owned Life Insurance (BOLI)
Income Taxes	Income Taxes Income Taxes Uncertain tax positions are recognized if it is more likely than not, based on the technical merits, that the tax position will be realized or sustained upon examination. The term more likely than not means a likelihood of more than 50 percent; the terms examined and upon examination also include resolution of the related appeals or litigation processes, if any. A tax position that meets the more-likely-than-not more-likely-than-not The Company recognizes interest and penalties on income taxes as a component of income tax expense. The Company files consolidated income tax returns with its subsidiaries.
Trust Assets and Income	Trust Assets and Income
Transfer of Financial Assets	Transfer of Financial Assets
Earnings per Common Share	Earnings per Common Share Years Ended December 31 2017 2016 2015 Basic earnings per share Net income $ 33,117 $ 23,912 $ 20,549 Less: Preferred stock dividends — 42 125 Net income available to common shareholders $ 33,117 $ 23,870 $ 20,424 Weighted average common shares outstanding (1) 23,035,824 19,987,728 15,765,444 Basic earnings per share $ 1.44 $ 1.19 $ 1.30 Diluted earnings per share Net income available to common shareholders $ 33,117 $ 23,870 $ 20,424 Weighted average common shares outstanding (1) 23,035,824 19,987,728 15,765,444 Effect of dilutive securities: Warrants — — 330,474 Restricted stock 31,321 26,553 48,015 Stock options 106,481 68,129 53,379 Weighted average shares outstanding 23,173,626 20,082,410 16,197,312 Diluted earnings per share $ 1.43 $ 1.19 $ 1.26 (1) Adjusted for 3:2 stock split on November 14, 2016 At December 31, 2017 and 2016, there were zero shares and at December 31, 2015 there were 3,750 shares that were not included in the computation of diluted earnings per share because they were non-dilutive.
Dividend Restrictions	Dividend Restrictions
Consolidated Statements of Cash Flows	Consolidated Statements of Cash Flows
Comprehensive Income	Comprehensive Income available-for-sale available-for-sale held-to-maturity.
Share-Based Compensation	Share-Based Compensation 12-month
Reclassifications	Reclassifications
Recent Accounting Pronouncements	Recent Accounting Pronouncements Financial Accounting Standards Board (FASB) Accounting Standards Update (ASU) No. 2018-02, Income Statement – Reporting Comprehensive Income (Topic 220): Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income The FASB has issued ASU No. 2018-02, Income Statement – Reporting Comprehensive Income (Topic 220): Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income FASB ASU No. 2017-12, Derivatives and Hedging (Topic 815), Targeted Improvements to Accounting for Hedging Activities The FASB has issued ASU No. 2017-12, Derivatives and Hedging (Topic 815), Targeted Improvements to Accounting for Hedging Activities FASB ASU No. 2017-08, Receivables – Nonrefundable Fees and Other Costs (Subtopic 310-20), The FASB has issued ASU No. 2017-08, Receivables – Nonrefundable Fees and Other Costs (Subtopic 310-20), FASB ASU No. 2017-04, Intangibles – Goodwill and Other (Topic 350), Simplifying the Test for Goodwill Impairment The FASB has issued ASU No. 2017-04, Intangibles – Goodwill and Other (Topic 350), Simplifying the Test for Goodwill Impairment FASB ASU No. 2017-01, Business Combinations (Topic 805), Clarifying the Definition of a Business The FASB has issued ASU No. 2017-01, Business Combinations (Topic 805), Clarifying the Definition of a Business. FASB ASU No. 2016-13, Financial Instruments – Credit Losses (Topic 326), Measurement of Credit Losses on Financial Instruments The FASB has issued ASU No. 2016-13, Financial Instrument – Credit Losses (Topic 326), Measurement of Credit Losses on Financial Instruments. available-for-sale one-time one-time FASB ASU No. 2016-09, Compensation – Stock Compensation (Topic 718), Improvements to Employee Share-Based Payment Accounting The FASB has issued ASU No. 2016-09, Compensation – Stock Compensation (Topic 718), Improvements to Employee Share-Based Payment Accounting. FASB ASU No. 2016-02, Leases (Topic 842) The FASB has issued ASU No. 2016-02, Leases (Topic 842). right-of-use FASB ASU No. 2016-01, Financial Instruments – Overall (Subtopic 825-10), The FASB has issued ASU No. 2016-01, Financial Instruments – Overall (Subtopic 825-10), not-for-profit The new guidance makes targeted improvements to existing U.S. GAAP by: • Requiring equity investments (except those accounted for under the equity method of accounting, or those that result in consolidation of the investee) to be measured at fair value with changes in fair value recognized in net income; • Requiring public business entities to use the exit price notion when measuring the fair value of financial instruments for disclosure purposes; • Requiring separate presentation of financial assets and financial liabilities by measurement category and form of financial asset (i.e., securities or loans and receivables) on the balance sheet or the accompanying notes to the financial statements; • Eliminating the requirement to disclose the fair value of financial instruments measured at amortized cost for organizations that are not public business entities; • Eliminating the requirement for public business entities to disclose the method(s) and significant assumptions used to estimate the fair value that is required to be disclosed for financial instruments measured at amortized cost on the balance sheet; and • Requiring a reporting organization to present separately in other comprehensive income the portion of the total change in the fair value of a liability resulting from a change in the instrument-specific credit risk (also referred to as “own credit”) when the organization has elected to measure the liability at fair value in accordance with the fair value option for financial instruments. The new guidance is effective for public companies for fiscal years beginning after December 15, 2017, including interim periods within those fiscal years. The new guidance permits early adoption of the own credit provision. In addition, the new guidance permits early adoption of the provision that exempts private companies and not-for-profit FASB ASU No. 2014-09, Revenue from Contracts with Customers (Topic 606) The FASB has issued ASU No. 2014-09, Revenue from Contracts with Customers (Topic 606) non-interest In May 2016, the FASB issued ASU No. 2016-12, Revenue from Contracts with Customers (Topic 606), Narrow-Scope Improvements and Practical Expedients In December 2016, the FASB issued ASU No. 2016-20, Revenue from Contracts with Customers (Topic 606), Technical Corrections and Improvements No. 2014-09 No. 2014-09. No. 2014-09.

Nature of Operations and Summ40

Nature of Operations and Summary of Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2017
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Summary of Computation of Basic and Diluted Earnings Per Share	The following table shows computation of basic and diluted earnings per share. Years Ended December 31 2017 2016 2015 Basic earnings per share Net income $ 33,117 $ 23,912 $ 20,549 Less: Preferred stock dividends — 42 125 Net income available to common shareholders $ 33,117 $ 23,870 $ 20,424 Weighted average common shares outstanding (1) 23,035,824 19,987,728 15,765,444 Basic earnings per share $ 1.44 $ 1.19 $ 1.30 Diluted earnings per share Net income available to common shareholders $ 33,117 $ 23,870 $ 20,424 Weighted average common shares outstanding (1) 23,035,824 19,987,728 15,765,444 Effect of dilutive securities: Warrants — — 330,474 Restricted stock 31,321 26,553 48,015 Stock options 106,481 68,129 53,379 Weighted average shares outstanding 23,173,626 20,082,410 16,197,312 Diluted earnings per share $ 1.43 $ 1.19 $ 1.26 (1) Adjusted for 3:2 stock split on November 14, 2016

Acquisitions (Tables)

Acquisitions (Tables)	12 Months Ended
	Dec. 31, 2017
Pro Forma Result of Comparable Prior Reporting Period	The following schedule includes pro-forma December 31 December 31 December 31 2017 2016 2015 Summary of Operations: Net Interest Income $ 125,442 $ 115,860 119,732 Provision for loan losses (12 ) 1,082 4,027 Net Interest Income after Provision for Loan Losses 125,454 114,778 115,705 Non-interest 33,959 43,330 37,976 Non-interest 109,605 119,522 112,309 Income before Income Taxes 49,808 38,586 41,372 Income Tax Expense 16,204 12,072 10,764 Net Income 33,604 26,514 30,608 Net Income Available to Common Shareholders $ 33,604 $ 26,472 30,483 Basic Earnings Per Share $ 1.46 $ 1.32 $ 1.93 Diluted Earnings Per Share $ 1.45 $ 1.32 $ 1.88
Wolverine Bancorp Inc [Member]
Schedule of Purchase Price of Assets Acquired and Liabilities Assumed	Based on preliminary valuations of the fair value of tangible and intangible assets acquired and liabilities assumed, which are based on estimates and assumptions that are subject to change, the final purchase price for the Wolverine acquisition is allocated as follows: ASSETS Cash and due from banks $ 44,450 Investment securities, available for sale — Commercial 276,167 Residential mortgage 30,603 Consumer 3,897 Total loans 310,667 Premises and equipment, net 2,941 FHLB stock 2,700 Goodwill 26,827 Core deposit intangible 2,024 Interest receivable 584 Other assets 3,897 Total assets purchased $ 394,090 Common shares issued $ 62,111 Cash paid 31,662 Total estimated purchase price $ 93,773 LIABILITIES Deposits Non-interest $ 25,221 NOW accounts 8,026 Savings and money market 129,044 Certificates of deposits 94,688 Total deposits 256,979 Borrowings 36,970 Interest payable 214 Other liabilities 6,154 Total liabilities assumed $ 300,317
Schedule of Acquired Loans Accounted for in Accordance with ASC 310-30	The following table details the acquired loans that are accounted for in accordance with ASC 310-30 Contractually required principal and interest at acquisition $ 21,912 Contractual cash flows not expected to be collected (nonaccretable differences) 1,832 Expected cash flows at acquisition 20,080 Interest component of expected cash flows (accretable discount) 2,267 Fair value of acquired loans accounted for under ASC 310-30 $ 17,813
Central National Bank & Trust [Member]
Schedule of Purchase Price of Assets Acquired and Liabilities Assumed	Based on management’s preliminary valuation of the fair value of tangible and intangible assets acquired and liabilities assumed, which are based on estimates and assumptions that are subject to change, the final purchase price for the CNB acquisition is allocated as follows: ASSETS Cash and due from banks $ 27,860 Investment securities, available for sale 16,393 Commercial 2,267 Residential mortgage 6,624 Consumer 1,579 Total loans 10,470 Premises and equipment, net 444 FHLB stock 50 Goodwill 609 Core deposit intangible 190 Interest receivable 154 Other assets 49 Total assets purchased $ 56,219 Cash paid 5,311 Total estimated purchase price $ 5,311 LIABILITIES Deposits Non-interest $ 24,079 NOW accounts 9,038 Savings and money market 13,829 Certificates of deposits 3,342 Total deposits 50,288 Borrowings 459 Interest payable 7 Other liabilities 154 Total liabilities assumed $ 50,908
LaPorte Bancorp Inc [Member]
Schedule of Purchase Price of Assets Acquired and Liabilities Assumed	Based on preliminary valuations of the fair value of tangible and intangible assets acquired and liabilities assumed, which are based on assumptions that are subject to change, the purchase price for the LaPorte Bancorp acquisition is detailed in the following table. ASSETS Cash and due from banks $ 154,849 Investment securities, available for sale 23,779 Commercial 153,750 Residential mortgage 42,603 Consumer 16,801 Mortgage Warehousing 99,752 Total loans 312,906 Premises and equipment, net 6,022 FHLB stock 4,029 Goodwill 20,993 Core deposit intangible 2,514 Interest receivable 844 Cash value of life insurance 15,267 Other assets 8,334 Total assets purchased $ 549,537 Common shares issued $ 60,306 Cash paid 38,328 Total estimated purchase price $ 98,634 LIABILITIES Deposits Non-interest $ 66,733 NOW accounts 99,346 Savings and money market 117,688 Certificates of deposits 87,605 Total deposits 371,372 Borrowings 64,793 Interest payable 178 Subordinated debt 4,504 Other liabilities 10,056 Total liabilities assumed $ 450,903
Schedule of Acquired Loans Accounted for in Accordance with ASC 310-30	The following table details the acquired loans that are accounted for in accordance with ASC 310-30 Contractually required principal and interest at acquisition $ 12,545 Contractual cash flows not expected to be collected (nonaccretable differences) 4,492 Expected cash flows at acquisition 8,053 Interest component of expected cash flows (accretable discount) 1,258 Fair value of acquired loans accounted for under ASC 310-30 $ 6,795
Kosciusko Financial Inc [Member]
Schedule of Purchase Price of Assets Acquired and Liabilities Assumed	Based on preliminary valuations of the fair value of tangible and intangible assets acquired and liabilities assumed, which are based on assumptions that are subject to change, the purchase price for the Kosciusko acquisition is detailed in the following table. ASSETS Cash and due from banks $ 38,950 Investment securities, available for sale 1,191 Commercial 70,006 Residential mortgage 26,244 Consumer 6,319 Total loans 102,569 Premises and equipment, net 1,466 FRB and FHLB stock 582 Goodwill 6,443 Core deposit intangible 526 Interest receivable 636 Cash value of life insurance 2,745 Other assets 765 Total assets purchased $ 155,873 Common shares issued $ 14,470 Cash paid 8,513 Total estimated purchase price $ 22,983 LIABILITIES Deposits Non-interest $ 27,871 NOW accounts 35,213 Savings and money market 26,953 Certificates of deposits 32,771 Total deposits 122,808 Borrowings 9,038 Interest payable 55 Other liabilities 989 Total liabilities assumed $ 132,890
Schedule of Acquired Loans Accounted for in Accordance with ASC 310-30	The following table details the acquired loans that are accounted for in accordance with ASC 310-30 Contractually required principal and interest at acquisition $ 2,682 Contractual cash flows not expected to be collected (nonaccretable differences) 25 Expected cash flows at acquisition 2,657 Interest component of expected cash flows (accretable discount) 634 Fair value of acquired loans accounted for under ASC 310-30 $ 2,023
Peoples Bancorp Inc [Member]
Schedule of Purchase Price of Assets Acquired and Liabilities Assumed	Based on management’s preliminary valuation of the fair value of tangible and intangible assets acquired and liabilities assumed, which are based on estimates and assumptions that are subject to change, the final purchase price for the Peoples acquisition is allocated as follows: ASSETS Cash and due from banks $ 205,054 Investment securities, available for sale 2,038 Commercial 67,435 Residential mortgage 137,331 Consumer 19,593 Total loans 224,359 Premises and equipment, net 5,524 FRB and FHLB stock 2,743 Goodwill 21,424 Core deposit intangible 4,394 Interest receivable 1,279 Cash value of life insurance 13,898 Other assets 4,364 Total assets purchased $ 485,077 Common shares issued $ 55,506 Cash paid 22,641 Total estimated purchase price $ 78,147 LIABILITIES Deposits Non-interest $ 28,251 NOW accounts 65,771 Savings and money market 125,176 Certificates of deposits 131,889 Total deposits 351,087 Borrowings 48,884 Interest payable 21 Other liabilities 6,938 Total liabilities assumed $ 406,930
Schedule of Acquired Loans Accounted for in Accordance with ASC 310-30	The following table details the acquired loans that are accounted for in accordance with ASC 310-30 Contractually required principal and interest at acquisition $ 5,730 Contractual cash flows not expected to be collected (nonaccretable differences) 715 Expected cash flows at acquisition 5,015 Interest component of expected cash flows (accretable discount) 647 Fair value of acquired loans accounted for under ASC 310-30 $ 4,368
Lafayette Community Bancorp [Member]
Schedule of Purchase Price of Assets Acquired and Liabilities Assumed	Based on preliminary valuations of the fair value of tangible and intangible assets acquired and liabilities assumed, which are based on assumptions that are subject to change, the purchase price for the Lafayette acquisition is detailed in the following table. ASSETS Cash and due from banks $ 24,846 Investment securities, available for sale 6 Commercial 116,258 Residential mortgage 12,761 Consumer 5,280 Total loans 134,299 Premises and equipment, net 7,818 FHLB stock 395 Goodwill 15,408 Core deposit intangible 2,085 Interest receivable 338 Other assets 1,649 Total assets purchased $ 186,844 Common shares issued $ 30,044 (1) Cash paid 4,421 Total estimated purchase price $ 34,465 LIABILITIES Deposits Non-interest $ 34,990 NOW accounts 30,174 Savings and money market 53,663 Certificates of deposits 32,520 Total deposits 151,347 Borrowings — Interest payable 42 Other liabilities 990 Total liabilities assumed $ 152,379 (1) This includes $955,000 of common shares previously held by Horizon.
Schedule of Acquired Loans Accounted for in Accordance with ASC 310-30	The following table details an estimate of the acquired loans that are accounted for in accordance with ASC 310-30 Contractually required principal and interest at acquisition $ 6,128 Contractual cash flows not expected to be collected (nonaccretable differences) 1,326 Expected cash flows at acquisition 4,802 Interest component of expected cash flows (accretable discount) 933 Fair value of acquired loans accounted for under ASC 310-30 $ 3,869

Securities (Tables)

Securities (Tables)	12 Months Ended
	Dec. 31, 2017
Investments, Debt and Equity Securities [Abstract]
Fair Value of Securities	The fair value of securities is as follows: Gross Gross December 31, 2017 Amortized Unrealized Unrealized Fair Cost Gains Losses Value Available for sale U.S. Treasury and federal agencies $ 19,277 $ — $ (225 ) $ 19,052 State and municipal 148,045 2,189 (670 ) 149,564 Federal agency collateralized mortgage obligations 132,871 45 (2,551 ) 130,365 Federal agency mortgage-backed pools 211,487 155 (2,985 ) 208,657 Private labeled mortgage-backed pools 1,650 — (8 ) 1,642 Corporate notes 272 113 — 385 Total available for sale investment securities $ 513,602 $ 2,502 $ (6,439 ) $ 509,665 Held to maturity State and municipal $ 179,836 $ 3,493 $ (2,932 ) $ 180,397 Federal agency collateralized mortgage obligations 5,734 17 (69 ) 5,682 Federal agency mortgage-backed pools 14,878 216 (88 ) 15,006 Total held to maturity investment securities $ 200,448 $ 3,726 $ (3,089 ) $ 201,085 Gross Gross December 31, 2016 Amortized Unrealized Unrealized Fair Cost Gains Losses Value Available for sale U.S. Treasury and federal agencies $ 8,051 $ 2 $ (64 ) $ 7,989 State and municipal 117,327 324 (1,059 ) 116,592 Federal agency collateralized mortgage obligations 139,040 254 (2,099 ) 137,195 Federal agency mortgage-backed pools 180,183 251 (3,707 ) 176,726 Corporate notes 1,238 91 — 1,329 Total available for sale investment securities $ 445,839 $ 922 $ (6,929 ) $ 439,831 Held to maturity State and municipal $ 165,607 $ 2,700 $ (2,485 ) $ 165,822 Federal agency collateralized mortgage obligations 6,530 31 (71 ) 6,490 Federal agency mortgage-backed pools 21,057 897 (180 ) 21,774 Total held to maturity investment securities $ 193,194 $ 3,628 $ (2,736 ) $ 194,086
Amortized Cost and Fair Value of Securities Available for Sale and Held to Maturity	The amortized cost and fair value of securities available for sale and held-to-maturity December 31, 2017 December 31, 2016 Amortized Fair Amortized Fair Cost Value Cost Value Available for sale Within one year $ 13,347 $ 13,326 $ 7,455 $ 7,480 One to five years 40,468 40,193 37,483 37,479 Five to ten years 50,473 51,156 21,112 20,984 After ten years 63,306 64,326 60,566 59,967 167,594 169,001 126,616 125,910 Federal agency collateralized mortgage obligations 132,871 130,365 139,040 137,195 Federal agency mortgage-backed pools 211,487 208,657 180,183 176,726 Private labeled mortgage-backed pools 1,650 1,642 — — Total available for sale investment securities $ 513,602 $ 509,665 $ 445,839 $ 439,831 Held to maturity Within one year $ 1,948 $ 1,934 $ — $ — One to five years 40,603 41,531 24,594 25,271 Five to ten years 89,801 91,249 87,645 88,805 After ten years 47,484 45,683 53,368 51,746 179,836 180,397 165,607 165,822 Federal agency collateralized mortgage obligations 5,734 5,682 6,530 6,490 Federal agency mortgage-backed pools 14,878 15,006 21,057 21,774 Total held to maturity investment securities $ 200,448 $ 201,085 $ 193,194 $ 194,086
Gross Unrealized Losses and Fair Value of Company's Investments	The following table shows the gross unrealized losses and the fair value of the Company’s investments, aggregated by investment category and length of time that individual securities have been in a continuous unrealized loss position. Less than 12 Months 12 Months or More Total Fair Unrealized Fair Unrealized Fair Unrealized December 31, 2017 Value Losses Value Losses Value Losses U.S. Treasury and federal agencies $ 15,882 $ (180 ) $ 2,870 $ (45 ) $ 18,752 $ (225 ) State and municipal 54,312 (2,758 ) 30,691 (844 ) 85,003 (3,602 ) Federal agency collateralized mortgage obligations 54,006 (589 ) 73,462 (2,031 ) 127,468 (2,620 ) Federal agency mortgage-backed pools 103,926 (1,019 ) 86,846 (2,054 ) 190,772 (3,073 ) Private labeled mortgage-backed pools 1,642 (8 ) — — 1,642 (8 ) Total temporarily impaired securities $ 229,768 $ (4,554 ) $ 193,869 $ (4,974 ) $ 423,637 $ (9,528 ) Less than 12 Months 12 Months or More Total Fair Unrealized Fair Unrealized Fair Unrealized December 31, 2016 Value Losses Value Losses Value Losses U.S. Treasury and federal agencies $ 6,987 $ (64 ) $ — $ — $ 6,987 $ (64 ) State and municipal 142,466 (3,544 ) — — 142,466 (3,544 ) Federal agency collateralized mortgage obligations 112,414 (1,918 ) 10,199 (252 ) 122,613 (2,170 ) Federal agency mortgage-backed pools 163,768 (3,887 ) — — 163,768 (3,887 ) Total temporarily impaired securities $ 425,635 $ (9,413 ) $ 10,199 $ (252 ) $ 435,834 $ (9,665 )
Sales of Securities Available for Sale	Information regarding security proceeds, gross gains and gross losses are presented below. Years ended December 31 2017 2016 2015 Sales of securities available for sale Proceeds $ 5,490 $ 182,549 $ 43,051 Gross gains 151 2,646 254 Gross losses (113 ) (810 ) (65 )

Loans (Tables)

Loans (Tables)	12 Months Ended
	Dec. 31, 2017
Amounts of Loans	December 31 December 31 2017 2016 Commercial Working capital and equipment $ 696,612 $ 539,403 Real estate, including agriculture 854,003 485,620 Tax exempt 36,324 15,486 Other 30,931 29,447 Total 1,617,870 1,069,956 Real estate 1–4 family 599,217 526,024 Other 7,543 5,850 Total 606,760 531,874 Consumer Auto 251,020 174,773 Recreation 8,752 5,669 Real estate/home improvement 63,811 53,898 Home equity 165,240 144,508 Unsecured 3,743 3,875 Other 20,291 15,706 Total 512,857 398,429 Mortgage warehouse 94,508 135,727 Total loans 2,831,995 2,135,986 Allowance for loan losses (16,394 ) (14,837 ) Loans, net $ 2,815,601 $ 2,121,149
Recorded Investment of Individual Loan Categories	The following table shows the recorded investment of individual loan categories. Loan Deferred Recorded December 31, 2017 Balance Interest Due Fees / (Costs) Investment Owner occupied real estate $ 547,596 $ 1,441 $ 1,917 $ 550,954 Non owner occupied real estate 664,281 1,100 2,478 667,859 Residential spec homes 16,431 63 80 16,574 Development & spec land loans 48,674 116 579 49,369 Commercial and industrial 335,227 2,524 607 338,358 Total commercial 1,612,209 5,244 5,661 1,623,114 Residential mortgage 588,358 1,776 2,375 592,509 Residential construction 16,027 39 — 16,066 Mortgage warehouse 94,508 480 — 94,988 Total real estate 698,893 2,295 2,375 703,563 Direct installment 89,617 270 (552 ) 89,335 Direct installment purchased 82 — — 82 Indirect installment 227,323 528 168 228,019 Home equity 197,578 889 (1,359 ) 197,108 Total consumer 514,600 1,687 (1,743 ) 514,544 Total loans 2,825,702 9,226 6,293 2,841,221 Allowance for loan losses (16,394 ) — — (16,394 ) Net loans $ 2,809,308 $ 9,226 $ 6,293 $ 2,824,827 Loan Deferred Recorded December 31, 2016 Balance Interest Due Fees / (Costs) Investment Owner occupied real estate $ 337,548 $ 899 $ 1,022 $ 339,469 Non owner occupied real estate 461,897 624 2,176 464,697 Residential spec homes 5,006 8 (2 ) 5,012 Development & spec land loans 31,228 56 119 31,403 Commercial and industrial 230,520 1,906 442 232,868 Total commercial 1,066,199 3,493 3,757 1,073,449 Residential mortgage 508,233 1,492 3,030 512,755 Residential construction 20,611 33 — 20,644 Mortgage warehouse 135,727 480 — 136,207 Total real estate 664,571 2,005 3,030 669,606 Direct installment 71,150 199 (385 ) 70,964 Direct installment purchased 119 — — 119 Indirect installment 153,204 345 — 153,549 Home equity 175,126 703 (785 ) 175,044 Total consumer 399,599 1,247 (1,170 ) 399,676 Total loans 2,130,369 6,745 5,617 2,142,731 Allowance for loan losses (14,837 ) — — (14,837 ) Net loans $ 2,115,532 $ 6,745 $ 5,617 $ 2,127,894
Loans Purchased With Evidence of Credit Deterioration [Member]
Amounts of Loans	The carrying amounts of those loans included in the balance sheet amounts of loans receivable are as follows: December 31 December 31 December 31 December 31 December 31 December 31 December 31 December 31 2017 2017 2017 2017 2017 2017 2017 2017 Heartland Summit Peoples Kosciusko LaPorte Lafayette Wolverine Total Commercial $ 390 $ 3,653 $ 315 $ 838 $ 1,034 $ 4,271 $ 16,697 $ 27,198 Real estate 229 870 126 403 1,004 — — 2,632 Consumer — — — — 33 — — 33 Outstanding balance $ 619 $ 4,523 $ 441 $ 1,241 $ 2,071 $ 4,271 $ 16,697 $ 29,863 Carrying amount, net of allowance of $0 $ 29,863 December 31 December 31 December 31 December 31 December 31 December 31 December 31 December 31 2016 2016 2016 2016 2016 2016 2016 2016 Heartland Summit Peoples Kosciusko LaPorte Lafayette Wolverine Total Commercial $ 774 $ 5,245 $ 692 $ 1,652 $ 3,200 $ — $ — $ 11,563 Real estate 534 967 165 457 1,114 — — 3,237 Consumer 2 — — — 41 — — 43 Outstanding balance $ 1,310 $ 6,213 $ 856 $ 2,109 $ 4,355 $ — $ — $ 14,843 Carrying amount, net of allowance of $0 $ 14,843

Accounting for Certain Loans 44

Accounting for Certain Loans Acquired in a Transfer (Tables)	12 Months Ended
	Dec. 31, 2017
Loans Purchased With Evidence of Credit Deterioration [Member]
Accretable Yield or Income Expected to be Collected	Accretable yield, or income expected to be collected are as follows: Twelve Months Ended December 31, 2017 Heartland Summit Peoples Kosciusko LaPorte Lafayette Wolverine Total Balance at January 1 $ 557 $ 502 $ 389 $ 530 $ 1,479 $ — $ — $ 3,457 Additions — — — — — 933 2,267 3,200 Accretion (99 ) (353 ) (388 ) (101 ) (235 ) — — (1,176 ) Reclassification from nonaccretable difference — — — — — — — — Disposals (6 ) (2 ) (1 ) (43 ) (264 ) — — (316 ) Balance at December 31 $ 452 $ 147 $ — $ 386 $ 980 $ 933 $ 2,267 $ 5,165 Twelve Months Ended December 31, 2016 Heartland Summit Peoples Kosciusko LaPorte Lafayette Wolverine Total Balance at January 1 $ 795 $ 708 $ 555 $ — $ — $ — $ — $ 2,058 Additions — — — 634 1,636 — — 2,270 Accretion (164 ) (171 ) (106 ) (72 ) (147 ) — — (660 ) Reclassification from nonaccretable difference — — — — — — — — Disposals (74 ) (35 ) (60 ) (32 ) (10 ) — — (211 ) Balance at December 31 $ 557 $ 502 $ 389 $ 530 $ 1,479 $ — $ — $ 3,457

Allowance for Loan Losses (Tabl

Allowance for Loan Losses (Tables)	12 Months Ended
	Dec. 31, 2017
Receivables [Abstract]
Allowance for Loan Losses	The historical loss experience is determined by portfolio segment and is based on the actual loss history experienced by the Company over the prior one to five years. Management believes using the highest of the one, two or five-year historical loss experience is an appropriate methodology in the current economic environment, as it captures loss rates that are comparable to the current period being analyzed. The actual allowance for loan loss activity is provided below. December 31 December 31 December 31 2017 2016 2015 Balance at beginning of the period $ 14,837 $ 14,534 $ 16,501 Loans charged-off: Commercial Owner occupied real estate 68 181 2,208 Non owner occupied real estate 20 471 556 Residential development — — — Development & Spec Land Loans 1 — — Commercial and industrial 288 106 673 Total commercial 377 758 3,437 Real estate Residential mortgage 89 213 288 Residential construction — — — Mortgage warehouse — — — Total real estate 89 213 288 Consumer Direct Installment 389 329 367 Direct Installment Purchased — — — Indirect Installment 1,193 1,051 1,081 Home Equity 205 309 926 Total consumer 1,787 1,689 2,374 Total loans charged-off 2,253 2,660 6,099 Recoveries of loans previously charged-off: Commercial Owner occupied real estate 9 31 104 Non owner occupied real estate 32 55 1 Residential development 8 8 — Development & Spec Land Loans — — 35 Commercial and industrial 219 116 52 Total commercial 268 210 192 Real estate Residential mortgage 44 97 69 Residential construction — — — Mortgage warehouse — — — Total real estate 44 97 69 Consumer Direct Installment 531 81 106 Direct Installment Purchased — — — Indirect Installment 497 529 489 Home Equity — 204 114 Total consumer 1,028 814 709 Total loan recoveries 1,340 1,121 970 Net loans charged-off 913 1,539 5,129 Provision charged to operating expense Commercial 2,164 (68 ) 2,531 Real estate (81 ) (23 ) 62 Consumer 387 1,933 569 Total provision charged to operating expense 2,470 1,842 3,162 Balance at the end of the period $ 16,394 $ 14,837 $ 14,534
Allowance for Loan Losses and Recorded Investment in Loans by Portfolio Segment	The following table presents the balance in the allowance for loan losses and the recorded investment in loans by portfolio segment and based on impairment analysis: Mortgage December 31, 2017 Commercial Real Estate Warehousing Consumer Total Allowance For Loan Losses Ending allowance balance attributable to loans: Individually evaluated for impairment $ 184 $ — $ — $ — $ 184 Collectively evaluated for impairment 8,450 2,188 1,030 4,542 16,210 Loans acquired with deteriorated credit quality — — — — — Total ending allowance balance $ 8,634 $ 2,188 $ 1,030 $ 4,542 $ 16,394 Loans: Individually evaluated for impairment $ 7,187 $ — $ — $ — $ 7,187 Collectively evaluated for impairment 1,615,927 608,575 94,988 514,544 2,834,034 Loans acquired with deteriorated credit quality — — — — — Total ending loans balance $ 1,623,114 $ 608,575 $ 94,988 $ 514,544 $ 2,841,221 Mortgage December 31, 2016 Commercial Real Estate Warehousing Consumer Total Allowance For Loan Losses Ending allowance balance attributable to loans: Individually evaluated for impairment $ 4 $ — $ — $ — $ 4 Collectively evaluated for impairment 6,575 2,090 1,254 4,914 14,833 Loans acquired with deteriorated credit quality — — — — — Total ending allowance balance $ 6,579 $ 2,090 $ 1,254 $ 4,914 $ 14,837 Loans: Individually evaluated for impairment $ 2,250 $ — $ — $ — $ 2,250 Collectively evaluated for impairment 1,071,199 533,399 136,207 399,676 2,140,481 Loans acquired with deteriorated credit quality — — — — — Total ending loans balance $ 1,073,449 $ 533,399 $ 136,207 $ 399,676 $ 2,142,731

Non-performing Assets and Imp46

Non-performing Assets and Impaired Loans (Tables)	12 Months Ended
	Dec. 31, 2017
Text Block [Abstract]
Non-accrual, Loans Past Due Over 90 Days Still on Accrual, and Troubled Debt Restructured ("TDRs") by Class of Loans	The following table presents the nonaccrual, loans past due over 90 days still on accrual, and troubled debt restructured (“TDRs”) by class of loans: Loans Past Due Over 90 Non- Total Non- Days Still Performing Performing Performing December 31, 2017 Non-accrual Accruing TDRs TDRs Loans Commercial Owner occupied real estate $ 4,742 $ — $ 11 $ 1 $ 4,754 Non owner occupied real estate 115 — 440 — 555 Residential development — — — — — Development & Spec Land Loans 176 — — — 176 Commercial and industrial 1,656 — — — 1,656 Total commercial 6,689 — 451 1 7,141 Real estate Residential mortgage 3,693 — 351 1,450 5,494 Residential construction — — — 222 222 Mortgage warehouse — — — — — Total real estate 3,693 — 351 1,672 5,716 Consumer Direct Installment 373 — — — 373 Direct Installment Purchased — — — — — Indirect Installment 1,041 167 — — 1,208 Home Equity 1,480 — 211 285 1,976 Total Consumer 2,894 167 211 285 3,557 Total $ 13,276 $ 167 $ 1,013 $ 1,958 $ 16,414 Loans Past Due Over 90 Non- Total Non- Days Still Performing Performing Performing December 31, 2016 Non-accrual Accruing TDRs TDRs Loans Commercial Owner occupied real estate $ 1,532 $ 183 $ — $ — $ 1,715 Non owner occupied real estate 440 — — — 440 Residential development — — — — — Development & Spec Land Loans 118 — — — 118 Commercial and industrial 159 — — — 159 Total commercial 2,249 183 — — 2,432 Real estate Residential mortgage 2,959 — 576 1,254 4,789 Residential construction — — 233 — 233 Mortgage warehouse — — — — — Total real estate 2,959 — 809 1,254 5,022 Consumer Direct Installment 512 — — — 512 Direct Installment Purchased — — — — — Indirect Installment 659 49 — — 708 Home Equity 1,557 9 205 238 2,009 Total Consumer 2,728 58 205 238 3,229 Total $ 7,936 $ 241 $ 1,014 $ 1,492 $ 10,683
Commercial Loans Individually Evaluated for Impairment by Class of Loans	The following table presents commercial loans individually evaluated for impairment by class of loans: Twelve Months Ending Average Cash/Accrual Unpaid Allowance For Balance in Interest Principal Recorded Loan Loss Impaired Income December 31, 2017 Balance Investment Allocated Loans Recognized With no recorded allowance Commercial Owner occupied real estate $ 3,824 $ 3,849 $ — $ 1,673 $ 11 Non owner occupied real estate 554 570 — 345 — Residential development — — — — — Development & Spec Land Loans 176 174 — 233 4 Commercial and industrial 1,656 1,663 — 1,445 25 Total commercial 6,210 6,256 — 3,696 40 With an allowance recorded Commercial Owner occupied real estate 931 931 184 78 46 Non owner occupied real estate — — — — — Residential development — — — — — Development & Spec Land Loans — — — — — Commercial and industrial — — — — — Total commercial 931 931 184 78 46 Total $ 7,141 $ 7,187 $ 184 $ 3,774 $ 86 Twelve Months Ending Average Cash/Accrual Unpaid Allowance For Balance in Interest Principal Recorded Loan Loss Impaired Income December 31, 2016 Balance Investment Allocated Loans Recognized With no recorded allowance Commercial Owner occupied real estate $ 1,533 $ 1,533 $ — $ 1,619 $ 58 Non owner occupied real estate 440 440 — 871 18 Residential development — — — — — Development & Spec Land Loans 118 118 — 61 16 Commercial and industrial 128 127 — 349 1 Total commercial 2,219 2,218 — 2,900 93 With an allowance recorded Commercial Owner occupied real estate — — — — — Non owner occupied real estate — — — — — Residential development — — — — — Development & Spec Land Loans — — — — — Commercial and industrial 31 32 4 5 2 Total commercial 31 32 4 5 2 Total $ 2,250 $ 2,250 $ 4 $ 2,905 $ 95 Twelve Months Ending Average Cash/Accrual Unpaid Allowance For Balance in Interest Principal Recorded Loan Loss Impaired Income December 31, 2015 Balance Investment Allocated Loans Recognized With no recorded allowance Commercial Owner occupied real estate $ 1,340 $ 1,339 $ — $ 1,001 $ 22 Non owner occupied real estate 4,938 4,953 — 5,417 8 Residential development — — — — — Development & Spec Land Loans 71 71 — 6 3 Commercial and industrial 79 79 — 275 4 Total commercial 6,428 6,442 — 6,699 37 With an allowance recorded Commercial Owner occupied real estate 410 410 105 243 8 Non owner occupied real estate 70 70 32 6 13 Residential development — — — — — Development & Spec Land Loans — — — — — Commercial and industrial 97 97 65 162 — Total commercial 577 577 202 411 21 Total $ 7,005 $ 7,019 $ 202 $ 7,110 $ 58
Payment Status by Class of Loan	The following table presents the payment status by class of loans: 30 - 59 Days 60 - 89 Days 90 Days or Loans Not Past December 31, 2017 Past Due Past Due Greater Past Due Total Past Due Due Total Commercial Owner occupied real estate $ 1,613 $ 1,950 $ — $ 3,563 $ 544,033 $ 547,596 Non owner occupied real estate 512 122 — 634 663,647 664,281 Residential development — — — — 16,431 16,431 Development & Spec Land Loans 31 — — 31 48,643 48,674 Commercial and industrial 520 1 — 521 334,706 335,227 Total commercial 2,676 2,073 — 4,749 1,607,460 1,612,209 Real estate Residential mortgage 1,248 49 — 1,297 587,061 588,358 Residential construction 63 — — 63 15,964 16,027 Mortgage warehouse — — — — 94,508 94,508 Total real estate 1,311 49 — 1,360 697,533 698,893 Consumer Direct Installment 78 10 — 88 89,529 89,617 Direct Installment Purchased — — — — 82 82 Indirect Installment 1,859 244 167 2,270 225,053 227,323 Home Equity 502 527 — 1,029 196,549 197,578 Total consumer 2,439 781 167 3,387 511,213 514,600 Total $ 6,426 $ 2,903 $ 167 $ 9,496 $ 2,816,206 $ 2,825,702 Percentage of total loans 0.23 % 0.10 % 0.01 % 0.34 % 99.66 % 30 - 59 Days 60 - 89 Days 90 Days or Loans Not Past December 31, 2016 Past Due Past Due Greater Past Due Total Past Due Due Total Commercial Owner occupied real estate $ 1,068 $ — $ 183 $ 1,251 $ 336,297 $ 337,548 Non owner occupied real estate 357 — — 357 461,540 461,897 Residential development — — — — 5,006 5,006 Development & Spec Land Loans 1 — — 1 31,227 31,228 Commercial and industrial 982 — — 982 229,538 230,520 Total commercial 2,408 — 183 2,591 1,063,608 1,066,199 Real estate Residential mortgage 886 123 — 1,009 507,224 508,233 Residential construction — — — — 20,611 20,611 Mortgage warehouse — — — — 135,727 135,727 Total real estate 886 123 — 1,009 663,562 664,571 Consumer Direct Installment 139 4 — 143 71,007 71,150 Direct Installment Purchased — — — — 119 119 Indirect Installment 1,339 237 49 1,625 151,579 153,204 Home Equity 912 267 9 1,188 173,938 175,126 Total consumer 2,390 508 58 2,956 396,643 399,599 Total $ 5,684 $ 631 $ 241 $ 6,556 $ 2,123,813 $ 2,130,369 Percentage of total loans 0.27 % 0.03 % 0.01 % 0.31 % 99.69 %
Loans by Credit Grades	The following table presents loans by credit grades. Special December 31, 2017 Pass Mention Substandard Doubtful Total Commercial Owner occupied real estate $ 520,907 $ 8,622 $ 18,067 $ — $ 547,596 Non owner occupied real estate 655,410 3,864 5,007 — 664,281 Residential development 16,431 — — — 16,431 Development & Spec Land Loans 47,562 886 226 — 48,674 Commercial and industrial 314,190 7,448 13,589 — 335,227 Total commercial 1,554,500 20,820 36,889 — 1,612,209 Real estate Residential mortgage 582,864 — 5,494 — 588,358 Residential construction 15,805 — 222 — 16,027 Mortgage warehouse 94,508 — — — 94,508 Total real estate 693,177 — 5,716 — 698,893 Consumer Direct Installment 89,244 — 373 — 89,617 Direct Installment Purchased 82 — — — 82 Indirect Installment 226,115 — 1,208 — 227,323 Home Equity 195,602 — 1,976 — 197,578 Total Consumer 511,043 — 3,557 — 514,600 Total $ 2,758,720 $ 20,820 $ 46,162 $ — $ 2,825,702 Percentage of total loans 97.63 % 0.74 % 1.63 % 0.00 % Special December 31, 2016 Pass Mention Substandard Doubtful Total Commercial Owner occupied real estate $ 322,924 $ 4,960 $ 9,664 $ — $ 337,548 Non owner occupied real estate 455,648 341 5,908 — 461,897 Residential development 5,006 — — — 5,006 Development & Spec Land Loans 31,057 — 171 — 31,228 Commercial and industrial 220,424 3,728 6,368 — 230,520 Total commercial 1,035,059 9,029 22,111 — 1,066,199 Real estate Residential mortgage 503,444 — 4,789 — 508,233 Residential construction 20,378 — 233 — 20,611 Mortgage warehouse 135,727 — — — 135,727 Total real estate 659,549 — 5,022 — 664,571 Consumer Direct Installment 70,638 — 512 — 71,150 Direct Installment Purchased 119 — — — 119 Indirect Installment 152,496 — 708 — 153,204 Home Equity 173,117 — 2,009 — 175,126 Total Consumer 396,370 — 3,229 — 399,599 Total $ 2,090,978 $ 9,029 $ 30,362 $ — $ 2,130,369 Percentage of total loans 98.15 % 0.42 % 1.43 % 0.00 %

Premises and Equipment (Tables)

Premises and Equipment (Tables)	12 Months Ended
	Dec. 31, 2017
Property, Plant and Equipment [Abstract]
Summary of Premises and Equipment	December 31 December 31 2017 2016 Land $ 21,633 $ 20,032 Buildings and improvements 68,447 59,607 Furniture and equipment 22,288 19,965 Total cost 112,368 99,604 Accumulated depreciation (36,839 ) (33,247 ) Net premise and equipment $ 75,529 $ 66,357

Loan Servicing (Tables)

Loan Servicing (Tables)	12 Months Ended
	Dec. 31, 2017
Text Block [Abstract]
Originated Mortgage Servicing Rights	December 31 December 31 December 31 2017 2016 2015 Mortgage servicing rights Balances, January 1 $ 11,681 $ 9,271 $ 7,980 Servicing rights capitalized 2,109 3,426 2,974 Amortization of servicing rights (1,601 ) (1,016 ) (1,683 ) Balances, December 31 12,189 11,681 9,271 Impairment allowance Balances, January 1 (507 ) (397 ) (338 ) Additions (85 ) (236 ) (130 ) Reductions 5 126 71 Balances, December 31 (587 ) (507 ) (397 ) Mortgage servicing rights, net $ 11,602 $ 11,174 $ 8,874

Goodwill and Intangible Assets

Goodwill and Intangible Assets (Tables)	12 Months Ended
	Dec. 31, 2017
Goodwill and Intangible Assets Disclosure [Abstract]
Changes in Carrying Amount of Goodwill	For additional details related to impairment testing, see the “Goodwill and Intangible Assets” section of “Management’s Discussion and Analysis of Financial Condition and Results of Operations” included as Item 7 of this Annual Report on Form 10K. 2017 2016 Balance, January 1 $ 76,941 $ 49,600 Goodwill acquired 42,939 27,341 Balance, December 31 $ 119,880 $ 76,941
Amortizable Intangible Assets	Amortizable intangible assets are summarized as follows: December 31, 2017 December 31, 2016 Gross Carrying Accumulated Gross Carrying Accumulated Amount Amortization Amount Amortization Amortizable intangible assets Core deposit intangible $ 20,711 $ (8,309 ) $ 16,151 $ (6,785 )
Estimated Amortization	Estimated amortization for the years ending December 31 is as follows: 2018 $ 2,012 2019 1,787 2020 1,481 2021 1,394 2022 1,375 Thereafter 4,353 $ 12,402

Deposits (Tables)

Deposits (Tables)	12 Months Ended
	Dec. 31, 2017
Banking and Thrift [Abstract]
Deposits	December 31 December 31 2017 2016 Noninterest-bearing demand deposits $ 601,805 $ 496,248 Interest-bearing demand deposits 909,638 850,641 Money market (variable rate) 378,108 290,896 Savings deposits 424,500 357,582 Certificates of deposit of $250,000 or more 130,585 105,361 Other certificates and time deposits 436,367 370,482 Total deposits $ 2,881,003 $ 2,471,210
Certificates and Other Time Deposits for Both Retail and Brokered	Certificates and other time deposits for both retail and brokered maturing in years ending December 31 are as follows: Retail Brokered Total 2018 $ 258,488 $ 19,010 $ 277,498 2019 152,027 12,558 164,585 2020 56,838 7,058 63,896 2021 16,128 3,386 19,514 2022 16,758 1,900 18,658 Thereafter 22,222 579 22,801 $ 522,461 $ 44,491 $ 566,952

Borrowings (Tables)

Borrowings (Tables)	12 Months Ended
	Dec. 31, 2017
Debt Disclosure [Abstract]
Borrowings	December 31 December 31 2017 2016 Federal Home Loan Bank advances, variable and fixed rates ranging from 0.93% to 7.53%, due at various dates through November 15, 2024 $ 336,308 $ 124,034 Securities sold under agreements to repurchase 61,097 57,144 Federal Reserve Bank discount window 11,000 — Federal funds purchased 143,252 66,811 Notes payable,variable rate of 2.75%, due at various dates through July 13, 2019 12,500 19,500 Total borrowings $ 564,157 $ 267,489
Contractual Maturities	Contractual maturities in years ending December 31 are as follows: 2018 $ 430,078 2019 69,252 2020 37,472 2021 5,042 2022 12,154 Thereafter 10,159 $ 564,157

Repurchase Agreements (Tables)

Repurchase Agreements (Tables)	12 Months Ended
	Dec. 31, 2017
Text Block [Abstract]
Summary of Repurchase Agreements Accounted as Secured Borrowings	The following table shows repurchase agreements accounted for as secured borrowings (in thousands): Remaining Contractual Maturity of the Agreements December 31, 2017 Overnight Up to one One to Three to five years Five to ten Beyond ten Total Repurchase Agreements and repurchase-to-maturity Repurchase Agreements $ 61,097 $ — $ — $ — $ — $ — $ 61,097 Securities pledged for Repurchase Agreements Federal agency collateralized mortgage obligations 38,421 $ — $ — $ — $ — $ — $ 38,421 Federal agency mortgage-backed pools 35,577 — — — — — 35,577 Total $ 73,998 $ — $ — $ — $ — $ — $ 73,998

Income Tax (Tables)

Income Tax (Tables)	12 Months Ended
	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Reconciliation of Income Taxes	December 31 December 31 December 31 2017 2016 2015 Income tax expense Currently payable Federal $ 12,079 $ 7,467 $ 5,511 Deferred Federal 331 1,334 1,721 Revaluation of deferred tax assets 2,426 — — Total income tax expense $ 14,836 $ 8,801 $ 7,232 Reconciliation of federal statutory to actual tax expense Federal statutory income tax at 35% $ 16,783 $ 11,450 $ 9,724 Tax exempt interest (2,699 ) (1,882 ) (1,708 ) Tax exempt income (638 ) (575 ) (488 ) Stock compensation (546 ) — — Revaluation of deferred tax assets 2,426 — — Other tax exempt income (456 ) (608 ) (199 ) Nondeductible and other (34 ) 416 (97 ) Actual tax expense $ 14,836 $ 8,801 $ 7,232
Reconciliation of Deferred Tax Assets & Liabilities	December 31 December 31 2017 2016 Assets Allowance for loan losses $ 3,396 $ 5,581 Net operating loss (from acquisitions) 1,658 2,368 Director and employee benefits 2,276 3,124 Unrealized loss on AFS securities and fair value hedge 1,147 937 Accrued Pension 852 1,323 Fair value adjustment on acquistions 1,087 2,340 Other 1,083 1,593 Total assets 11,499 17,266 Liabilities Depreciation (1,680 ) (1,916 ) State tax (210 ) (341 ) Federal Home Loan Bank stock dividends (339 ) (474 ) Difference in basis of intangible assets (2,831 ) (4,654 ) Other (125 ) (431 ) Total liabilities (5,185 ) (7,816 ) Valuation allowance (1,613 ) (2,018 ) Net deferred tax asset $ 4,701 $ 7,432

Accumulated Other Comprehensi54

Accumulated Other Comprehensive Loss (Tables)	12 Months Ended
	Dec. 31, 2017
Equity [Abstract]
Components of Accumulated Other Comprehensive Loss	The components of accumulated other comprehensive loss included in capital are as follows: December 31 December 31 2017 2016 Unrealized loss on securities available for sale $ (3,937 ) $ (6,007 ) Unamortized gain on securities held to maturity, previously transferred from AFS 200 456 Unrealized loss on derivative instruments (1,728 ) (3,132 ) Tax effect 1,914 3,039 Total accumulated other comprehensive loss $ (3,551 ) $ (5,644 )

Regulatory Capital (Tables)

Regulatory Capital (Tables)	12 Months Ended
	Dec. 31, 2017
Banking and Thrift [Abstract]
Summary of Regulatory Capital Requirement	Horizon and the Bank’s actual and required capital ratios as of December 31, 2017 and 2016 were as follows: Required For Capital 1 Required For Capital 1 Adequacy Purposes Well Capitalized Under Prompt 1 Actual Adequacy Purposes with Capital Buffer Corrective Action Provisions Amount Ratio Amount Ratio Amount Ratio Amount Ratio As of December 31, 2017 Total capital 1 Consolidated $ 384,800 12.91 % $ 238,543 8.00 % $ 275,816 9.25 % N/A N/A Bank 382,788 12.85 % 238,386 8.00 % 275,634 9.25 % $ 297,982 10.00 % Tier 1 capital 1 Consolidated 368,355 12.35 % 178,907 6.00 % 216,180 7.25 % N/A N/A Bank 366,343 12.29 % 178,790 6.00 % 216,038 7.25 % 238,386 8.00 % Common equity tier 1 capital 1 Consolidated 329,892 11.06 % 134,181 4.50 % 171,454 5.75 % N/A N/A Bank 366,343 12.29 % 134,092 4.50 % 171,340 5.75 % 193,689 6.50 % Tier 1 capital 1 Consolidated 368,355 9.92 % 148,503 4.00 % 148,503 4.00 % N/A N/A Bank 366,343 9.89 % 148,116 4.00 % 148,116 4.00 % 185,145 5.00 % As of December 31, 2016 Total capital 1 Consolidated $ 316,576 13.87 % $ 182,596 8.00 % $ 196,976 8.63 % N/A N/A Bank 319,013 13.98 % 182,541 8.00 % 196,916 8.63 % $ 228,176 10.00 % Tier 1 capital 1 Consolidated 301,739 13.22 % 136,947 6.00 % 151,326 6.63 % N/A N/A Bank 304,176 13.33 % 136,905 6.00 % 151,280 6.63 % 182,540 8.00 % Common equity tier 1 capital 1 Consolidated 263,313 11.50 % 103,036 4.50 % 117,460 5.13 % N/A N/A Bank 304,176 13.33 % 102,679 4.50 % 117,054 5.13 % 148,314 6.50 % Tier 1 capital 1 Consolidated 301,739 10.44 % 115,609 4.00 % 115,609 4.00 % N/A N/A Bank 304,176 9.93 % 122,521 4.00 % 122,521 4.00 % 153,151 5.00 % 1 As defined by regulatory agencies

Share-Based Compensation (Table

Share-Based Compensation (Tables)	12 Months Ended
	Dec. 31, 2017
Fair Value of Options Granted	The fair value of options granted is estimated on the date of the grant using an option-pricing model with the following weighted-average assumptions: December 31 2017 2016 2015 Dividend yields 1.75 % 2.34 % 2.35 % Volatility factors of expected market price of common stock 28.52 % 28.60 % 28.97 % Risk-free interest rates 2.42 % 1.83 % 2.10 % Expected life of options 8 years 8 years 8 years
Summary of Status of Non-vested, Restricted and Performance Shares	A summary of the status of Horizon’s non-vested Weighted Average Grant Date Shares Fair Value Non-vested 70,959 $ 15.59 Vested (6,754 ) 14.80 Granted 41,786 25.49 Forfeited (9,461 ) 15.05 Non-vested, 96,530 19.98
Stock Options 2003 Plan [Member]
Summary of Option Activity under 2003 Plan	A summary of option activity under the 2003 Plan as of December 31, 2017, and changes during the year then ended, is presented below: Weighted- Average Weighted- Remaining Aggregate Average Contractual Intrinsic Shares Exercise Price Term Value Outstanding, beginning of year 36,635 $ 7.25 Granted — — Exercised (9,185 ) 6.86 Forfeited — — Outstanding, end of year 27,450 7.37 2.73 $ 560,691 Exercisable, end of year 27,450 7.37 2.73 560,691
Stock Options 2013 Plan [Member]
Summary of Option Activity under 2003 Plan	A summary of option activity under the 2013 Plan as of December 31, 2017, and changes during the year then ended, is presented below: Weighted- Average Weighted- Remaining Aggregate Average Contractual Intrinsic Shares Exercise Price Term Value Outstanding, beginning of year 286,586 $ 15.08 Granted 43,502 25.14 Exercised (108,434 ) 14.77 Forfeited (5,871 ) 15.64 Outstanding, end of year 215,783 17.25 7.69 $ 2,276,823 Exercisable, end of year 88,036 14.77 6.62 1,147,538

Derivative Financial Instrume57

Derivative Financial Instruments (Tables)	12 Months Ended
	Dec. 31, 2017
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Fair Value of Derivative Financial Instruments	The following tables summarize the fair value of derivative financial instruments utilized by Horizon: Asset Derivatives Liability Derivatives December 31, 2017 December 31, 2017 Derivatives designated as hedging Balance Sheet Location Fair Value Balance Sheet Location Fair Value Interest rate contracts Loans $ — Other liabilities $ 811 Interest rate contracts Other Assets 811 Other liabilities 1,728 Total derivatives designated as hedging instruments 811 2,539 Derivatives not designated as hedging instruments Mortgage loan contracts Other assets 143 Other liabilities 3 Total derivatives not designated as hedging instruments 143 3 Total derivatives $ 954 $ 2,542 Asset Derivatives Liability Derivatives December 31, 2016 December 31, 2016 Derivatives designated as hedging Balance Sheet Location Fair Value Balance Sheet Location Fair Value Interest rate contracts Loans $ — Other liabilities $ 6 Interest rate contracts Other Assets 6 Other liabilities 3,132 Total derivatives designated as hedging instruments 6 3,138 Derivatives not designated as hedging instruments Mortgage loan contracts Other assets 602 Other liabilities 22 Total derivatives not designated as hedging instruments 602 22 Total derivatives $ 608 $ 3,160
Effect of Derivative Instruments on Condensed Consolidated Statement of Income Derivative in Cash Flow Hedging Relationship	The effect of the derivative instruments on the consolidated statement of income for the 12-month Amount of Loss Recognized in Other Comprehensive Income on Derivative (Effective Derivative in cash flow Years Ended December 31 hedging relationship 2017 2016 2015 Interest rate contracts $ 913 $ 6 $ 127
Effect of Derivative Instruments on Consolidated Statement of Income Derivative in Fair Value Hedging Relationship	Amount of Gain (Loss) Recognized on Derivative Derivative in fair value Location of gain (loss) Years Ended December 31 hedging relationship recognized on derivative 2017 2016 2015 Interest rate contracts Interest income - loans $ (817 ) $ (1,776 ) $ 574 Interest rate contracts Interest income - loans 817 1,776 (574 ) Total $ — $ — $ — Amount of Gain (Loss) Recognized on Derivative Derivative not designated Location of gain (loss) Years Ended December 31 as hedging relationship recognized on derivative 2017 2016 2015 Mortgage contracts Other income - gain on sale of loans $ (439 ) $ (62 ) $ 195

Disclosures about fair value 58

Disclosures about fair value of assets and liabilities (Tables)	12 Months Ended
	Dec. 31, 2017
Text Block [Abstract]
Fair Value Measurements of Assets and Liabilities Recognized on a Recurring Basis	The following table presents the fair value measurements of assets and liabilities recognized in the accompanying financial statements measured at fair value on a recurring basis and the level within the FASB ASC fair value hierarchy in which the fair value measurements fall at the following: Quoted Prices in Significant Significant Fair Value (Level 1) (Level 2) (Level 3) December 31, 2017 Available-for-sale U.S. Treasury and federal agencies $ 19,052 $ — $ 19,052 $ — State and municipal 149,564 — 149,564 — Federal agency collateralized mortgage obligations 130,365 — 130,365 — Federal agency mortgage-backed pools 208,657 — 208,657 — Private labeled mortgage-backed pools 1,642 — 1,642 — Corporate notes 385 — 385 — Total available-for-sale 509,665 — 509,665 — Hedged loans 154,575 — 154,575 — Forward sale commitments 143 — 143 — Interest rate swap agreements (917 ) — (917 ) — Commitments to originate loans (3 ) — (3 ) — December 31, 2016 Available-for-sale U.S. Treasury and federal agencies $ 7,989 $ — $ 7,989 $ — State and municipal 116,592 — 116,592 — Federal agency collateralized mortgage obligations 137,195 — 137,195 — Federal agency mortgage-backed pools 176,726 — 176,726 — Corporate notes 1,329 — 1,329 — Total available-for-sale 439,831 — 439,831 — Hedged loans 122,345 — 122,345 — Forward sale commitments 602 — 602 — Interest rate swap agreements (3,138 ) — (3,138 ) — Commitments to originate loans (22 ) — (22 ) —
Realized Gains and Losses Included in Net Income for Periods in Consolidated Statements of Income	Realized gains and losses included in net income for the periods are reported in the consolidated statements of income as follows: Non Interest Income Years Ended December 31 Total gains and losses from: 2017 2016 2015 Hedged loans $ (817 ) $ (1,776 ) $ 574 Fair value interest rate swap agreements 817 1,776 (574 ) Derivative loan commitments (439 ) (62 ) 195 $ (439 ) $ (62 ) $ 195
Other Assets Measured at Fair Value on Nonrecurring Basis	Certain other assets are measured at fair value on a nonrecurring basis in the ordinary course of business and are subject to fair value adjustments in certain circumstances (for example, when there is evidence of impairment): Quoted Prices in Significant Significant Fair Value (Level 1) (Level 2) (Level 3) December 31, 2017 Impaired loans $ 6,957 $ — $ — $ 6,957 Mortgage servicing rights 11,602 — — 11,602 December 31, 2016 Impaired loans $ 2,246 $ — $ — $ 2,246 Mortgage servicing rights 11,174 — — 11,174
Qualitative Information About Unobservable Inputs Used in Recurring and Nonrecurring Level 3 Fair Value Measurements, Other than Goodwill	The following table presents qualitative information about unobservable inputs used in recurring and nonrecurring Level 3 fair value measurements, other than goodwill, at December 31, 2017 and 2016. Fair Value at Valuation Range (Weighted December 31, 2017 Technique Unobservable Inputs Average) Impaired loans $ 6,957 Collateral based measurement Discount to reflect current market conditions and ultimate collectability 0% - 46.8% (2.6%) Mortgage servicing rights $ 11,602 Discounted cashflows Discount rate, Constant prepayment rate, Probability of default 9.6% - 10.8% (9.7%), 9.2% - 27.7% (10.5%), 0% - 1.5% (0.2%) Fair Value at Valuation Range (Weighted December 31, 2016 Technique Unobservable Inputs Average) Impaired loans $ 2,246 Collateral based measurement Discount to reflect current market conditions and ultimate collectability 10% - 16% (13%) Mortgage servicing rights $ 11,174 Discounted cashflows Discount rate, Constant prepayment rate, Probability of default 10% - 16% (13%), 4% - 7% (4.6%), 1% - 10% (4.5%)

Fair Value of Financial Instr59

Fair Value of Financial Instruments (Tables)	12 Months Ended
	Dec. 31, 2017
Fair Value Disclosures [Abstract]
Summary of Estimated Fair Values of Financial Instruments	The following table presents estimated fair values of the Company’s financial instruments and the level within the fair value hierarchy in which the fair value measurements fall. December 31, 2017 Quoted Prices in Active Significant Markets for Other Significant Identical Observable Unobservable Carrying Assets Inputs Inputs Amount (Level 1) (Level 2) (Level 3) Assets Cash and due from banks $ 76,441 $ 76,441 $ — $ — Investment securities, held to maturity 200,448 — 201,085 — Loans held for sale 3,094 — — 3,094 Loans excluding loan level hedges, net 2,661,026 — — 2,585,879 Stock in FHLB 18,105 — 18,105 — Interest receivable 16,244 — 16,244 — Liabilities Non-interest $ 601,805 $ 601,805 $ — $ — Interest-bearing deposits 2,279,198 — 2,156,487 — Borrowings 564,157 — 560,057 — Subordinated debentures 37,653 — 35,994 — Interest payable 886 — 886 — December 31, 2016 Carrying Quoted Prices (Level 1) Significant Significant (Level 3) Assets Cash and due from banks $ 70,832 $ 70,832 $ — $ — Investment securities, held to maturity 193,194 — 194,086 — Loans held for sale 8,087 — — 8,087 Loans excluding loan level hedges, net 1,998,804 — — 1,965,928 Stock in FHLB and FRB 23,932 — 23,932 — Interest receivable 12,713 — 12,713 — Liabilities Non-interest $ 496,248 $ 496,248 $ — $ — Interest-bearing deposits 1,974,962 — 1,839,167 — Borrowings 267,489 — 261,141 — Subordinated debentures 37,456 — 36,371 — Interest payable 472 — 472 —

Condensed Financial Informati60

Condensed Financial Information (Parent Company Only) (Tables)	12 Months Ended
	Dec. 31, 2017
Condensed Financial Information of Parent Company Only Disclosure [Abstract]
Condensed Balance Sheets	Condensed Balance Sheets December 31 December 31 2017 2016 Assets Total cash and cash equivalents $ 13,361 $ 15,736 Investment in Subsidiaries 497,623 386,389 Other assets 1,318 2,504 Total assets $ 512,302 $ 404,629 Liabilities Borrowings $ 12,500 $ 19,500 Subordinated debentures 37,653 37,456 Other liabilities 5,071 6,818 Stockholders’ Equity 457,078 340,855 Total liabilities and stockholders’ equity $ 512,302 $ 404,629
Condensed Statements of Income	Condensed Statements of Income Years Ended December 31 2017 2016 2015 Operating Income (Expense) Dividend income from Bank $ 27,000 $ 20,000 $ 30,470 Investment income — 33 15 Other income 540 42 24 Interest expense (2,791 ) (2,376 ) (2,009 ) Employee benefit expense (1,094 ) (1,158 ) (1,093 ) Other expense (326 ) 1,279 910 Income Before Undistributed Income of Subsidiaries 23,329 17,820 28,317 Undistributed Income of Subsidiaries 8,804 5,938 (8,168 ) Income Before Tax 32,133 23,758 20,149 Income Tax Benefit 984 154 400 Net Income 33,117 23,912 20,549 Preferred stock dividend — (42 ) (125 ) Net Income Available to Common Shareholders $ 33,117 $ 23,870 $ 20,424
Condensed Statements of Comprehensive Income	Condensed Statements of Comprehensive Income Years Ended December 31 2017 2016 2015 Net Income $ 33,117 $ 23,912 $ 20,549 Other Comprehensive Income (Loss) Change in fair value of derivative instruments, net of taxes 913 6 127 Unrealized appreciation for the period on held-to-maturity (166 ) (424 ) (357 ) Unrealized appreciation (depreciation) on available-for-sale 1,371 (3,310 ) (1,891 ) Less: reclassification adjustment for realized gains included in net income, net of taxes (25 ) (1,193 ) (123 ) 2,093 (4,921 ) (2,244 ) Comprehensive Income $ 35,210 $ 18,991 $ 18,305
Condensed Statements of Cash Flows	Condensed Statements of Cash Flows Years Ended December 31 2017 2016 2015 Operating Activities Net income $ 33,117 $ 23,912 $ 20,549 Items not requiring (providing) cash Equity in undistributed net income of subsidiaries (8,804 ) (5,938 ) 8,168 Change in Share based compensation 325 284 288 Amortization of unearned compensation 135 324 355 Other assets 388 888 (634 ) Other liabilities (1,675 ) (244 ) (13 ) Net cash provided by operating activities 23,486 19,226 28,713 Investing Activities Acquisition of Peoples — — (19,365 ) Acquisition of Kosciusko — (6,741 ) — Acquisition of LaPorte — (17,108 ) — Acquisition of CNB — (5,296 ) — Acquisition of Lafayette (1,254 ) — — Acquisition of Wolverine (7,688 ) — — Net cash used in investing activities (8,942 ) (29,145 ) (19,365 ) Financing Activities Redemption of preferred stock — (12,500 ) — Net change in borrowings (6,803 ) 19,500 — Dividends paid on preferred shares — (42 ) (125 ) Dividends paid on common shares (11,720 ) (8,382 ) (6,216 ) Exercise of stock options 1,604 572 4,305 Net cash used in financing activities (16,919 ) (852 ) (2,036 ) Net Change in Cash and Cash Equivalents (2,375 ) (10,771 ) 7,312 Cash and Cash Equivalents at Beginning of Year 15,736 26,507 19,195 Cash and Cash Equivalents at End of Year $ 13,361 $ 15,736 $ 26,507

Quarterly Results of Operatio61

Quarterly Results of Operations (Unaudited) (Tables)	12 Months Ended
	Dec. 31, 2017
Quarterly Financial Information Disclosure [Abstract]
Summary of Quarterly Consolidated Results of Operations	The following is a summary of the quarterly consolidated results of operations: Three Months Ended 2017 March 31 June 30 September 30 December 31 Interest income $ 28,834 $ 30,805 $ 32,070 $ 36,774 Interest expense 3,266 3,607 4,191 5,319 Net interest income 25,568 27,198 27,879 31,455 Provision for loan losses 330 330 710 1,100 Gain on sale of securities 35 (3 ) 6 — Net income 8,224 9,072 8,171 7,650 Net income available to common shareholders $ 8,224 $ 9,072 $ 8,171 $ 7,650 Earnings per share: Basic $ 0.37 $ 0.41 $ 0.36 $ 0.30 Diluted 0.37 0.41 0.36 0.30 Average shares outstanding: Basic 22,175,526 22,176,465 22,580,160 25,140,800 Diluted 22,326,071 22,322,390 22,715,273 25,262,010 Three Months Ended 2016 March 31 June 30 September 30 December 31 Interest income $ 23,528 $ 24,650 $ 28,962 $ 29,390 Interest expense 3,754 3,781 4,552 8,450 Net interest income 19,774 20,869 24,410 20,940 Provision for loan losses 532 232 455 623 Gain on sale of securities 108 767 — 961 Net income 5,381 6,326 6,602 5,603 Net income available to common shareholders $ 5,339 $ 6,326 $ 6,602 $ 5,603 Earnings per share: Basic $ 0.30 $ 0.35 $ 0.31 $ 0.25 Diluted 0.30 0.34 0.30 0.25 Average shares outstanding: Basic 17,924,124 18,268,880 21,538,752 22,155,549 Diluted 18,012,726 18,364,167 21,651,953 22,283,722

Nature of Operations and Summ62

Nature of Operations and Summary of Significant Accounting Policies - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2017USD ($)FacilitiesBusinessshares	Dec. 31, 2016USD ($)shares	Dec. 31, 2015USD ($)shares
Schedule Of Accounting Policies [Line Items]
Full service facilities maintained by bank | Facilities	62
Number of business conduct | Business	0
Factor considered to be significant for fair value measurement	10.00%
Accrual of interest discontinued description	Principal or interest is past due 90 days or more, and the loan is not well secured or in the process of collection, or when serious doubt exists as to the collectability of a loan, the accrual of interest is discontinued.
Commercial loans as a percentage of total loan	57.00%
Residential real estate loans as a percentage of total loan	21.00%
Installment loans as a percentage of total loan	18.00%
Mortgage warehouse loans as a percentage of total loan	3.00%
Period in which loan sold by mortgage company	30 days
Minimum period loan held by mortgage company	90 days
Mortgage warehousing maximum pay off period	30 days
Costs are deferred due to the term	$ 0
Impaired loans charged off	90 days
Status of Non-Accrual of Loan	90 days
Impairment of Loan	30 days
Intangibles, Gross	$ 12,400,000
Goodwill	$ 119,880,000	$ 76,941,000	$ 49,600,000
Uncertain tax positions recognized	50.00%
Shares, non-dilutive | shares	0	0	3,750
Amount available for payment of dividend	$ 8,500,000
Cash and cash equivalents maximum maturity period	1 day
Compensation expense	$ 1,700,000	$ 608,000	$ 643,000
Reclassifications effect on net income	$ 0
Buildings and Improvements [Member] | Minimum [Member]
Schedule Of Accounting Policies [Line Items]
Useful Life for depreciation	3 years
Buildings and Improvements [Member] | Maximum [Member]
Schedule Of Accounting Policies [Line Items]
Useful Life for depreciation	40 years
Furniture and Equipment [Member] | Minimum [Member]
Schedule Of Accounting Policies [Line Items]
Useful Life for depreciation	2 years
Furniture and Equipment [Member] | Maximum [Member]
Schedule Of Accounting Policies [Line Items]
Useful Life for depreciation	20 years
Accounting Standards Update 2018-02 [Member]
Schedule Of Accounting Policies [Line Items]
Stranded tax effects included in AOCI	$ 766,000

Nature of Operations and Summ63

Nature of Operations and Summary of Significant Accounting Policies - Summary of Computation of Basic and Diluted Earnings Per Share (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017		Dec. 31, 2016		Dec. 31, 2015
Basic earnings per share
Net income	$ 7,650	$ 8,171	$ 9,072	$ 8,224	$ 5,603	$ 6,602	$ 6,326	$ 5,381	$ 33,117		$ 23,912		$ 20,549
Less: Preferred stock dividends											42		125
Net Income Available to Common Shareholders	$ 7,650	$ 8,171	$ 9,072	$ 8,224	$ 5,603	$ 6,602	$ 6,326	$ 5,339	$ 33,117		$ 23,870		$ 20,424
Weighted average common shares outstanding	25,140,800	22,580,160	22,176,465	22,175,526	22,155,549	21,538,752	18,268,880	17,924,124	23,035,824		19,987,728		15,765,444
Basic Earnings Per Share	$ 0.30	$ 0.36	$ 0.41	$ 0.37	$ 0.25	$ 0.31	$ 0.35	$ 0.30	$ 1.44	[1]	$ 1.19	[1]	$ 1.30	[1]
Diluted earnings per share
Net income available to common shareholders									$ 33,117		$ 23,870		$ 20,424
Weighted average common shares outstanding	25,140,800	22,580,160	22,176,465	22,175,526	22,155,549	21,538,752	18,268,880	17,924,124	23,035,824		19,987,728		15,765,444
Effect of dilutive securities:
Warrants													330,474
Weighted average shares outstanding	25,262,010	22,715,273	22,322,390	22,326,071	22,283,722	21,651,953	18,364,167	18,012,726	23,173,626		20,082,410		16,197,312
Diluted Earnings Per Share	$ 0.30	$ 0.36	$ 0.41	$ 0.37	$ 0.25	$ 0.30	$ 0.34	$ 0.30	$ 1.43	[1]	$ 1.19	[1]	$ 1.26	[1]
Restricted Stock [Member]
Effect of dilutive securities:
Effect of dilutive securities									31,321		26,553		48,015
Stock Options [Member]
Effect of dilutive securities:
Effect of dilutive securities									106,481		68,129		53,379
[1]	Adjusted for 3:2 stock split on November 14, 2016

Nature of Operations and Summ64

Nature of Operations and Summary of Significant Accounting Policies - Summary of Computation of Basic and Diluted Earnings Per Share (Parenthetical) (Detail)	Nov. 14, 2016
Accounting Policies [Abstract]
Stock split ratio	1.5

Acquisitions - Additional Infor

Acquisitions - Additional Information (Detail) - USD ($)		Oct. 17, 2017	Sep. 01, 2017	Feb. 03, 2017	Jul. 18, 2016	Jun. 01, 2016	Jul. 01, 2015	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Aug. 31, 2017	Nov. 07, 2016
Business Acquisition [Line Items]
Common stock, shares outstanding	[1]							25,529,819	22,171,596
Acquisition of goodwill								$ 119,880,000	$ 76,941,000	$ 49,600,000
Ownership interest percentage			5.00%
Operating revenue, net of tax								2,600,000	4,300,000	2,300,000
Non-recurring expense, net of tax								$ 2,700,000	4,800,000	3,300,000
Peoples Bancorp Inc [Member]
Business Acquisition [Line Items]
Exchange ratio per share							142.50%
Common stock, shares outstanding							2,311,858
Common stock issued							3,288,303
Market closing price per share							$ 16.88
Costs related to the acquisition										$ 4,900,000
Total estimated purchase price							$ 78,147,000
Net intangible assets acquired							4,394,000
Acquisition of goodwill							21,424,000
Purchase price of the business assets, portion deductible							$ 0
Core deposit intangible amortization period										10 years
Share of common stock outstanding per share							$ 9.75
Payments received as cash consideration										$ (182,413,000)
Performing portion of the loan portfolio acquired							$ 223,400,000
Estimated fair value of performing portion of the loan portfolio							220,000,000
Loan portfolio acquired							228,600,000
Discount on loan portfolio acquired							$ 4,800,000
Peoples Bancorp Inc [Member] | Maximum [Member]
Business Acquisition [Line Items]
Number of shares owned							100
Share of common stock outstanding per share							$ 33.14
Kosciusko Financial Inc [Member]
Business Acquisition [Line Items]
Exchange ratio per share						451.83%
Cash paid for each share						$ 81.75
Common stock issued						873,430
Market closing price per share						$ 16.57
Estimated transaction value						$ 23,000,000
Costs related to the acquisition						2,000,000
Total estimated purchase price						22,983,000
Net intangible assets acquired						526,000
Acquisition of goodwill						6,443,000
Purchase price of the business assets, portion deductible						$ 0
Core deposit intangible amortization period								10 years
Payments received as cash consideration									(30,437,000)
Business combination stock transferred, percentage of consideration						65.00%
Business combination cash transferred, percentage of consideration						35.00%
Kosciusko Financial Inc [Member] | Maximum [Member]
Business Acquisition [Line Items]
Number of shares owned						100
Share of common stock outstanding per share						$ 81.75
LaPorte Bancorp Inc [Member]
Business Acquisition [Line Items]
Exchange ratio per share					94.35%
Cash paid for each share					$ 17.50
Common stock issued					3,421,488
Market closing price per share					$ 18.36
Estimated transaction value					$ 98,600,000
Costs related to the acquisition									$ 4,000,000
Total estimated purchase price					98,634,000
Net intangible assets acquired					2,514,000
Acquisition of goodwill					20,993,000
Purchase price of the business assets, portion deductible					$ 0
Core deposit intangible amortization period									10 years
Payments received as cash consideration									$ (116,521,000)
Business combination stock transferred, percentage of consideration					65.00%
Business combination cash transferred, percentage of consideration					35.00%
Central National Bank & Trust [Member]
Business Acquisition [Line Items]
Costs related to the acquisition									$ 779,000
Total estimated purchase price												$ 5,311,000
Net intangible assets acquired												190,000
Acquisition of goodwill												609,000
Purchase price of the business assets, portion deductible												5,311,000
Core deposit intangible amortization period									10 years
Payments received as cash consideration									$ (22,549,000)
Performing portion of the loan portfolio acquired												10,800,000
Estimated fair value of performing portion of the loan portfolio												$ 10,500,000
Wolverine Bancorp Inc [Member]
Business Acquisition [Line Items]
Exchange ratio per share		101.52%
Cash paid for each share		$ 14
Common stock, shares outstanding		2,129,331
Common stock issued		2,160,697
Market closing price per share		$ 29.06
Estimated transaction value		$ 93,800,000
Costs related to the acquisition		1,900,000
Total estimated purchase price		93,773,000
Net intangible assets acquired		2,024,000
Acquisition of goodwill		26,827,000
Purchase price of the business assets, portion deductible		$ 0
Core deposit intangible amortization period								10 years
Payments received as cash consideration								$ (12,788,000)
Lafayette Community Bancorp [Member]
Business Acquisition [Line Items]
Exchange ratio per share			58.78%
Cash paid for each share			$ 1.73
Common stock, shares outstanding			1,856,679
Common stock issued			1,091,259
Market closing price per share											$ 26.17
Estimated transaction value											$ 34,500,000
Costs related to the acquisition			$ 1,700,000
Total estimated purchase price			34,465,000
Net intangible assets acquired			2,085,000
Acquisition of goodwill			15,408,000
Purchase price of the business assets, portion deductible			0
Core deposit intangible amortization period								10 years
Gain on remeasurement of equity interest			$ 530,000					$ 530,000
Payments received as cash consideration								$ (20,425,000)
Lafayette Community Bancorp [Member] | Maximum [Member]
Business Acquisition [Line Items]
Number of shares owned			100
Share of common stock outstanding per share			$ 17.25
First Farmers Bank & Trust Co [Member]
Business Acquisition [Line Items]
Net intangible assets acquired				$ 452,000,000
Acquisition of goodwill				$ 0
Core deposit intangible amortization period				10 years
Payments received as cash consideration				$ 11,000,000
Business acquisition, loans assumed				$ 3,400,000
Premium on deposits paid				3.00%
Business acquisition, customer deposit balances				$ 14,800,000
[1]	Adjusted for 3:2 stock split on November 14, 2016.

Acquisitions - Schedule of Fina

Acquisitions - Schedule of Final Purchase Price of Assets Acquired and Liabilities Assumed (Detail) - USD ($) $ in Thousands	Dec. 31, 2017	Oct. 17, 2017	Dec. 31, 2016	Nov. 07, 2016	Dec. 31, 2015	Jul. 01, 2015
ASSETS
Goodwill	$ 119,880		$ 76,941		$ 49,600
Central National Bank & Trust [Member]
ASSETS
Cash and due from banks				$ 27,860
Investment securities, available for sale				16,393
Total loans				10,470
Premises and equipment, net				444
FHLB stock				50
Goodwill				609
Core deposit intangible				190
Interest receivable				154
Other assets				49
Total assets purchased				56,219
Cash paid			$ 5,311	5,311
Total estimated purchase price				5,311
Deposits
Non-interest bearing				24,079
NOW accounts				9,038
Savings and money market				13,829
Certificates of deposits				3,342
Total deposits				50,288
Borrowings				459
Interest payable				7
Other liabilities				154
Total liabilities assumed				50,908
Central National Bank & Trust [Member] | Residential Mortgage [Member]
ASSETS
Total loans				6,624
Central National Bank & Trust [Member] | Commercial [Member]
ASSETS
Total loans				2,267
Central National Bank & Trust [Member] | Consumer [Member]
ASSETS
Total loans				$ 1,579
Peoples Bancorp Inc [Member]
ASSETS
Cash and due from banks						$ 205,054
Investment securities, available for sale						2,038
Total loans						224,359
Premises and equipment, net						5,524
FRB and FHLB stock						2,743
Goodwill						21,424
Core deposit intangible						4,394
Interest receivable						1,279
Cash value of life insurance						13,898
Other assets						4,364
Total assets purchased						485,077
Common shares issued					55,506	55,506
Cash paid					$ 22,641	22,641
Total estimated purchase price						78,147
Deposits
Non-interest bearing						28,251
NOW accounts						65,771
Savings and money market						125,176
Certificates of deposits						131,889
Total deposits						351,087
Borrowings						48,884
Interest payable						21
Other liabilities						6,938
Total liabilities assumed						406,930
Peoples Bancorp Inc [Member] | Residential Mortgage [Member]
ASSETS
Total loans						137,331
Peoples Bancorp Inc [Member] | Commercial [Member]
ASSETS
Total loans						67,435
Peoples Bancorp Inc [Member] | Consumer [Member]
ASSETS
Total loans						$ 19,593
Wolverine Bancorp Inc [Member]
ASSETS
Cash and due from banks		$ 44,450
Total loans		310,667
Premises and equipment, net		2,941
FHLB stock		2,700
Goodwill		26,827
Core deposit intangible		2,024
Interest receivable		584
Other assets		3,897
Total assets purchased		394,090
Common shares issued	62,111	62,111
Cash paid	$ 31,662	31,662
Total estimated purchase price		93,773
Deposits
Non-interest bearing		25,221
NOW accounts		8,026
Savings and money market		129,044
Certificates of deposits		94,688
Total deposits		256,979
Borrowings		36,970
Interest payable		214
Other liabilities		6,154
Total liabilities assumed		300,317
Wolverine Bancorp Inc [Member] | Residential Mortgage [Member]
ASSETS
Total loans		30,603
Wolverine Bancorp Inc [Member] | Commercial [Member]
ASSETS
Total loans		276,167
Wolverine Bancorp Inc [Member] | Consumer [Member]
ASSETS
Total loans		$ 3,897

Acquisitions - Schedule of Acqu

Acquisitions - Schedule of Acquired Loans Accounted for in Accordance with ASC 310-30 (Detail) - USD ($) $ in Thousands	Oct. 17, 2017	Sep. 01, 2017	Jul. 18, 2016	Jun. 01, 2016	Jul. 01, 2015
LaPorte Bancorp Inc [Member]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities Acquired During Period [Line Items]
Contractually required principal and interest at acquisition			$ 12,545
Contractual cash flows not expected to be collected (nonaccretable differences)			4,492
Expected cash flows at acquisition			8,053
Interest component of expected cash flows (accretable discount)			1,258
Fair value of acquired loans accounted for under ASC 310-30			$ 6,795
Kosciusko Financial Inc [Member]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities Acquired During Period [Line Items]
Contractually required principal and interest at acquisition				$ 2,682
Contractual cash flows not expected to be collected (nonaccretable differences)				25
Expected cash flows at acquisition				2,657
Interest component of expected cash flows (accretable discount)				634
Fair value of acquired loans accounted for under ASC 310-30				$ 2,023
Peoples Bancorp Inc [Member]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities Acquired During Period [Line Items]
Contractually required principal and interest at acquisition					$ 5,730
Contractual cash flows not expected to be collected (nonaccretable differences)					715
Expected cash flows at acquisition					5,015
Interest component of expected cash flows (accretable discount)					647
Fair value of acquired loans accounted for under ASC 310-30					$ 4,368
Wolverine Bancorp Inc [Member]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities Acquired During Period [Line Items]
Contractually required principal and interest at acquisition	$ 21,912
Contractual cash flows not expected to be collected (nonaccretable differences)	1,832
Expected cash flows at acquisition	20,080
Interest component of expected cash flows (accretable discount)	2,267
Fair value of acquired loans accounted for under ASC 310-30	$ 17,813
Lafayette Community Bancorp [Member]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities Acquired During Period [Line Items]
Contractually required principal and interest at acquisition		$ 6,128
Contractual cash flows not expected to be collected (nonaccretable differences)		1,326
Expected cash flows at acquisition		4,802
Interest component of expected cash flows (accretable discount)		933
Fair value of acquired loans accounted for under ASC 310-30		$ 3,869

Acquisitions - Schedule of Purc

Acquisitions - Schedule of Purchase Price of Assets Acquired and Liabilities Assumed (Detail) - USD ($) $ in Thousands	Dec. 31, 2017	Sep. 01, 2017	Dec. 31, 2016	Jul. 18, 2016	Jun. 01, 2016	Dec. 31, 2015
ASSETS
Goodwill	$ 119,880		$ 76,941			$ 49,600
LaPorte Bancorp Inc [Member]
ASSETS
Cash and due from banks				$ 154,849
Investment securities, available for sale				23,779
Total loans				312,906
Premises and equipment, net				6,022
FHLB stock				4,029
Goodwill				20,993
Core deposit intangible				2,514
Interest receivable				844
Cash value of life insurance				15,267
Other assets				8,334
Total assets purchased				549,537
Common shares issued			60,306	60,306
Cash paid			38,328	38,328
Total estimated purchase price				98,634
Deposits
Non-interest bearing				66,733
NOW accounts				99,346
Savings and money market				117,688
Certificates of deposits				87,605
Total deposits				371,372
Borrowings				64,793
Interest payable				178
Subordinated debt				4,504
Other liabilities				10,056
Total liabilities assumed				450,903
LaPorte Bancorp Inc [Member] | Residential Mortgage [Member]
ASSETS
Total loans				42,603
LaPorte Bancorp Inc [Member] | Mortgage Warehousing [Member]
ASSETS
Total loans				99,752
LaPorte Bancorp Inc [Member] | Commercial [Member]
ASSETS
Total loans				153,750
LaPorte Bancorp Inc [Member] | Consumer [Member]
ASSETS
Total loans				$ 16,801
Kosciusko Financial Inc [Member]
ASSETS
Cash and due from banks					$ 38,950
Investment securities, available for sale					1,191
Total loans					102,569
Premises and equipment, net					1,466
FHLB stock					582
Goodwill					6,443
Core deposit intangible					526
Interest receivable					636
Cash value of life insurance					2,745
Other assets					765
Total assets purchased					155,873
Common shares issued			14,470		14,470
Cash paid			$ 8,513		8,513
Total estimated purchase price					22,983
Deposits
Non-interest bearing					27,871
NOW accounts					35,213
Savings and money market					26,953
Certificates of deposits					32,771
Total deposits					122,808
Borrowings					9,038
Interest payable					55
Other liabilities					989
Total liabilities assumed					132,890
Kosciusko Financial Inc [Member] | Residential Mortgage [Member]
ASSETS
Total loans					26,244
Kosciusko Financial Inc [Member] | Commercial [Member]
ASSETS
Total loans					70,006
Kosciusko Financial Inc [Member] | Consumer [Member]
ASSETS
Total loans					$ 6,319
Lafayette Community Bancorp [Member]
ASSETS
Cash and due from banks		$ 24,846
Investment securities, available for sale		6
Total loans		134,299
Premises and equipment, net		7,818
FHLB stock		395
Goodwill		15,408
Core deposit intangible		2,085
Interest receivable		338
Other assets		1,649
Total assets purchased		186,844
Common shares issued	30,044	30,044
Cash paid	$ 4,421	4,421
Total estimated purchase price		34,465
Deposits
Non-interest bearing		34,990
NOW accounts		30,174
Savings and money market		53,663
Certificates of deposits		32,520
Total deposits		151,347
Interest payable		42
Other liabilities		990
Total liabilities assumed		152,379
Lafayette Community Bancorp [Member] | Residential Mortgage [Member]
ASSETS
Total loans		12,761
Lafayette Community Bancorp [Member] | Commercial [Member]
ASSETS
Total loans		116,258
Lafayette Community Bancorp [Member] | Consumer [Member]
ASSETS
Total loans		$ 5,280

Acquisitions - Schedule of Pu69

Acquisitions - Schedule of Purchase Price of Assets Acquired and Liabilities Assumed (Parenthetical) (Detail)	Jul. 18, 2016USD ($)
Lafayette Community Bancorp [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Common shares previously held	$ 955,000

Acquisitions - Pro Forma Result

Acquisitions - Pro Forma Result of Comparable Prior Reporting Period (Detail) - Peoples Bancorp Inc [Member] - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Business Acquisition [Line Items]
Net Interest Income	$ 125,442	$ 115,860	$ 119,732
Provision for loan losses	(12)	1,082	4,027
Net Interest Income after Provision for Loan Losses	125,454	114,778	115,705
Non-interest Income	33,959	43,330	37,976
Non-interest Expense	109,605	119,522	112,309
Income before Income Taxes	49,808	38,586	41,372
Income Tax Expense	16,204	12,072	10,764
Net Income	33,604	26,514	30,608
Net Income Available to Common Shareholders	$ 33,604	$ 26,472	$ 30,483
Basic Earnings Per Share	$ 1.46	$ 1.32	$ 1.93
Diluted Earnings Per Share	$ 1.45	$ 1.32	$ 1.88

Cash Equivalents - Additional I

Cash Equivalents - Additional Information (Detail) $ in Millions	12 Months Ended
	Dec. 31, 2017USD ($)
Cash and Cash Equivalents [Abstract]
Cash equivalent maximum maturity period	3 months
Increase in Cash account over the insured limit	$ 12.5

Securities - Fair Value of Secu

Securities - Fair Value of Securities (Detail) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Schedule of Available-for-sale Securities [Line Items]
Total available for sale investment securities, Amortized Cost	$ 513,602	$ 445,839
Gross Unrealized Gains	2,502	922
Gross Unrealized Losses	(6,439)	(6,929)
Available-for-sale Securities, Fair Value	509,665	439,831
Held-to-maturity, Amortized Cost	200,448	193,194
Held-to-maturity, Gross Unrealized Gains	3,726	3,628
Held-to-maturity, Gross Unrealized Losses	(3,089)	(2,736)
Held-to-maturity, Fair Value	201,085	194,086
State and Municipal [Member]
Schedule of Available-for-sale Securities [Line Items]
Total available for sale investment securities, Amortized Cost	148,045	117,327
Gross Unrealized Gains	2,189	324
Gross Unrealized Losses	(670)	(1,059)
Available-for-sale Securities, Fair Value	149,564	116,592
Held-to-maturity, Amortized Cost	179,836	165,607
Held-to-maturity, Gross Unrealized Gains	3,493	2,700
Held-to-maturity, Gross Unrealized Losses	(2,932)	(2,485)
Held-to-maturity, Fair Value	180,397	165,822
Federal Agency Collateralized Mortgage Obligations [Member]
Schedule of Available-for-sale Securities [Line Items]
Total available for sale investment securities, Amortized Cost	132,871	139,040
Gross Unrealized Gains	45	254
Gross Unrealized Losses	(2,551)	(2,099)
Available-for-sale Securities, Fair Value	130,365	137,195
Held-to-maturity, Amortized Cost	5,734	6,530
Held-to-maturity, Gross Unrealized Gains	17	31
Held-to-maturity, Gross Unrealized Losses	(69)	(71)
Held-to-maturity, Fair Value	5,682	6,490
Federal Agency Mortgage-backed Pools [Member]
Schedule of Available-for-sale Securities [Line Items]
Total available for sale investment securities, Amortized Cost	211,487	180,183
Gross Unrealized Gains	155	251
Gross Unrealized Losses	(2,985)	(3,707)
Available-for-sale Securities, Fair Value	208,657	176,726
Held-to-maturity, Amortized Cost	14,878	21,057
Held-to-maturity, Gross Unrealized Gains	216	897
Held-to-maturity, Gross Unrealized Losses	(88)	(180)
Held-to-maturity, Fair Value	15,006	21,774
U.S. Treasury and Federal Agencies [Member]
Schedule of Available-for-sale Securities [Line Items]
Total available for sale investment securities, Amortized Cost	19,277	8,051
Gross Unrealized Gains		2
Gross Unrealized Losses	(225)	(64)
Available-for-sale Securities, Fair Value	19,052	7,989
Private Labeled Mortgage-backed Pools [Member]
Schedule of Available-for-sale Securities [Line Items]
Total available for sale investment securities, Amortized Cost	1,650
Gross Unrealized Losses	(8)
Available-for-sale Securities, Fair Value	1,642
Corporate Notes [Member]
Schedule of Available-for-sale Securities [Line Items]
Total available for sale investment securities, Amortized Cost	272	1,238
Gross Unrealized Gains	113	91
Available-for-sale Securities, Fair Value	$ 385	$ 1,329

Securities - Additional Informa

Securities - Additional Information (Detail)	Apr. 01, 2014USD ($)Security	Dec. 31, 2017USD ($)	Dec. 31, 2016USD ($)	Dec. 31, 2015USD ($)
Investments, Debt and Equity Securities [Abstract]
Unrealized loss, other than temporary securities		$ 0
Number of securities | Security	319
Aggregate fair value of securities	$ 167,100,000
Gain/Loss from net unrealized holdings, Net of tax	1,300,000
Unrealized gain or loss, Held to maturity	$ 0
Tax effect of the proceeds from sale of securities		13,000	$ 643,000	$ 66,000
Pledged of Fair Value of Securities as collateral		74,000,000
Amortization cost of securities as Collateral not Separately Reported		75,600,000
Debt Instrument Repurchase Agreement		61,100,000
Securities Pledged for Federal Home Loan Bank At Fair Value		94,600,000
Securities for Federal Home Loan Bank Not Separately Reported		93,100,000
Securities Pledged For Derivative At Fair Value		13,100,000
Securities Pledged For Derivative At Amortized Cost		13,100,000
Debt Instrument Derivative Swap Agreement		917,000
Debt Instrument Federal Home Loan Bank		$ 11,000,000

Securities - Amortized Cost and

Securities - Amortized Cost and Fair Value of Securities Available for Sale and Held to Maturity (Detail) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Schedule of Available-for-sale Securities [Line Items]
Amortized cost within one year	$ 13,347	$ 7,455
Amortized cost one to five years	40,468	37,483
Amortized cost for five to ten years	50,473	21,112
Amortized cost for after ten years	63,306	60,566
Total amortized cost	167,594	126,616
Total available for sale investment securities, Amortized Cost	513,602	445,839
Within one year, amortized cost	1,948
One to five years, amortized cost	40,603	24,594
Five to ten years, amortized cost	89,801	87,645
After ten years, amortized cost	47,484	53,368
Total amortized cost	179,836	165,607
Total held to maturity investment securities, amortized cost	200,448	193,194
Fair value within one year	13,326	7,480
Fair value for one to five years	40,193	37,479
Fair value for five to ten years	51,156	20,984
Fair value for after ten years	64,326	59,967
Total fair value	169,001	125,910
Investment securities, available for sale	509,665	439,831
Within one year, fair value	1,934
One to five years, fair value	41,531	25,271
five to ten years, fair value	91,249	88,805
After ten years, fair value	45,683	51,746
Total fair value	180,397	165,822
Held-to-maturity, Fair Value	201,085	194,086
Federal Agency Collateralized Mortgage Obligations [Member]
Schedule of Available-for-sale Securities [Line Items]
Total available for sale investment securities, Amortized Cost	132,871	139,040
Total held to maturity investment securities, amortized cost	5,734	6,530
Investment securities, available for sale	130,365	137,195
Held-to-maturity, Fair Value	5,682	6,490
Federal Agency Mortgage-backed Pools [Member]
Schedule of Available-for-sale Securities [Line Items]
Total available for sale investment securities, Amortized Cost	211,487	180,183
Total held to maturity investment securities, amortized cost	14,878	21,057
Investment securities, available for sale	208,657	176,726
Held-to-maturity, Fair Value	15,006	$ 21,774
Private Labeled Mortgage-backed Pools [Member]
Schedule of Available-for-sale Securities [Line Items]
Total available for sale investment securities, Amortized Cost	1,650
Investment securities, available for sale	$ 1,642

Securities - Gross Unrealized L

Securities - Gross Unrealized Losses and Fair Value of Company's Investments (Detail) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Schedule of Available-for-sale Securities [Line Items]
Fair Value less than 12 months	$ 229,768	$ 425,635
Fair value more than 12 months	193,869	10,199
Total fair value	423,637	435,834
Unrealized losses less than 12 months	(4,554)	(9,413)
Unrealized losses more than 12 months	(4,974)	(252)
Total unrealized losses	(9,528)	(9,665)
U.S. Treasury and Federal Agencies [Member]
Schedule of Available-for-sale Securities [Line Items]
Fair Value less than 12 months	15,882	6,987
Fair value more than 12 months	2,870
Total fair value	18,752	6,987
Unrealized losses less than 12 months	(180)	(64)
Unrealized losses more than 12 months	(45)
Total unrealized losses	(225)	(64)
State and Municipal [Member]
Schedule of Available-for-sale Securities [Line Items]
Fair Value less than 12 months	54,312	142,466
Fair value more than 12 months	30,691
Total fair value	85,003	142,466
Unrealized losses less than 12 months	(2,758)	(3,544)
Unrealized losses more than 12 months	(844)
Total unrealized losses	(3,602)	(3,544)
Federal Agency Collateralized Mortgage Obligations [Member]
Schedule of Available-for-sale Securities [Line Items]
Fair Value less than 12 months	54,006	112,414
Fair value more than 12 months	73,462	10,199
Total fair value	127,468	122,613
Unrealized losses less than 12 months	(589)	(1,918)
Unrealized losses more than 12 months	(2,031)	(252)
Total unrealized losses	(2,620)	(2,170)
Federal Agency Mortgage-backed Pools [Member]
Schedule of Available-for-sale Securities [Line Items]
Fair Value less than 12 months	103,926	163,768
Fair value more than 12 months	86,846
Total fair value	190,772	163,768
Unrealized losses less than 12 months	(1,019)	(3,887)
Unrealized losses more than 12 months	(2,054)
Total unrealized losses	(3,073)	$ (3,887)
Private Labeled Mortgage-backed Pools [Member]
Schedule of Available-for-sale Securities [Line Items]
Fair Value less than 12 months	1,642
Total fair value	1,642
Unrealized losses less than 12 months	(8)
Total unrealized losses	$ (8)

Securities - Sales of Securitie

Securities - Sales of Securities Available for Sale (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Investments, Debt and Equity Securities [Abstract]
Proceeds	$ 5,490	$ 182,549	$ 43,051
Gross gains	151	2,646	254
Gross losses	$ (113)	$ (810)	$ (65)

Loans - Amounts of Loans (Detai

Loans - Amounts of Loans (Detail) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Accounts, Notes, Loans and Financing Receivable [Line Items]
Mortgage warehouse	$ 94,508	$ 135,727
Total loans	2,831,995	2,135,986
Allowance for loan losses	(16,394)	(14,837)	$ (14,534)	$ (16,501)
Loans, net	2,815,601	2,121,149
Commercial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Commercial/Consumer, Total	1,617,870	1,069,956
Real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Real Estate, Total	606,760	531,874
Consumer [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Commercial/Consumer, Total	512,857	398,429
Working Capital and Equipment [Member] | Commercial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Commercial/Consumer, Total	696,612	539,403
Real Estate Including Agriculture [Member] | Commercial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Commercial/Consumer, Total	854,003	485,620
Tax Exempt Loans Receivable [Member] | Commercial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Commercial/Consumer, Total	36,324	15,486
Other Commercial Loans [Member] | Commercial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Commercial/Consumer, Total	30,931	29,447
1-4 Family [Member] | Real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Real Estate, Total	599,217	526,024
Other Real Estate Loans [Member] | Real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Real Estate, Total	7,543	5,850
Auto [Member] | Consumer [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Commercial/Consumer, Total	251,020	174,773
Recreation Consumer Loans Receivable [Member] | Consumer [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Commercial/Consumer, Total	8,752	5,669
Real Estate Home Improvement Loans Receivable [Member] | Consumer [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Commercial/Consumer, Total	63,811	53,898
Home Equity Loan [Member] | Consumer [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Commercial/Consumer, Total	165,240	144,508
Unsecured Debt [Member] | Consumer [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Commercial/Consumer, Total	3,743	3,875
Other Consumer Loans [Member] | Consumer [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Commercial/Consumer, Total	$ 20,291	$ 15,706

Loans - Additional Information

Loans - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2017
Receivables [Abstract]
Period of loan sold	30 days
Minimum period seldom held	90 days
Mortgage warehousing maximum pay off period	30 days

Loans - Recorded Investment of

Loans - Recorded Investment of Individual Loan Categories (Detail) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan Balance	$ 2,825,702	$ 2,130,369
Net loans	2,809,308	2,115,532
Interest Due	9,226	6,745
Deferred Fees / (Costs)	6,293	5,617
Recorded Investment	2,841,221	2,142,731
Recorded Investment	2,824,827	2,127,894
Allowance for loan losses	(16,394)	(14,837)	$ (14,534)	$ (16,501)
Commercial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan Balance	1,612,209	1,066,199
Interest Due	5,244	3,493
Deferred Fees / (Costs)	5,661	3,757
Recorded Investment	1,623,114	1,073,449
Real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan Balance	698,893	664,571
Interest Due	2,295	2,005
Deferred Fees / (Costs)	2,375	3,030
Recorded Investment	703,563	669,606
Consumer [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan Balance	514,600	399,599
Interest Due	1,687	1,247
Deferred Fees / (Costs)	(1,743)	(1,170)
Recorded Investment	514,544	399,676
Owner Occupied Real Estate [Member] | Commercial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan Balance	547,596	337,548
Interest Due	1,441	899
Deferred Fees / (Costs)	1,917	1,022
Recorded Investment	550,954	339,469
Non Owner Occupied Real Estate [Member] | Commercial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan Balance	664,281	461,897
Interest Due	1,100	624
Deferred Fees / (Costs)	2,478	2,176
Recorded Investment	667,859	464,697
Residential Spec Homes [Member] | Commercial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan Balance	16,431	5,006
Interest Due	63	8
Deferred Fees / (Costs)	80	(2)
Recorded Investment	16,574	5,012
Development & Spec Land Loans [Member] | Commercial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan Balance	48,674	31,228
Interest Due	116	56
Deferred Fees / (Costs)	579	119
Recorded Investment	49,369	31,403
Commercial and Industrial [Member] | Commercial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan Balance	335,227	230,520
Interest Due	2,524	1,906
Deferred Fees / (Costs)	607	442
Recorded Investment	338,358	232,868
Residential Mortgage [Member] | Real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan Balance	588,358	508,233
Interest Due	1,776	1,492
Deferred Fees / (Costs)	2,375	3,030
Recorded Investment	592,509	512,755
Residential Construction [Member] | Real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan Balance	16,027	20,611
Interest Due	39	33
Recorded Investment	16,066	20,644
Mortgage Warehousing [Member] | Real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan Balance	94,508	135,727
Interest Due	480	480
Recorded Investment	94,988	136,207
Direct Installment [Member] | Consumer [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan Balance	89,617	71,150
Interest Due	270	199
Deferred Fees / (Costs)	(552)	(385)
Recorded Investment	89,335	70,964
Direct Installment Purchased [Member] | Consumer [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan Balance	82	119
Recorded Investment	82	119
Indirect Installment [Member] | Consumer [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan Balance	227,323	153,204
Interest Due	528	345
Deferred Fees / (Costs)	168
Recorded Investment	228,019	153,549
Home Equity Loan [Member] | Consumer [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan Balance	197,578	175,126
Interest Due	889	703
Deferred Fees / (Costs)	(1,359)	(785)
Recorded Investment	$ 197,108	$ 175,044

Accounting for Certain Loans 80

Accounting for Certain Loans Acquired in a Transfer - Amounts of Loans (Detail) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Accounts, Notes, Loans and Financing Receivable [Line Items]
Outstanding balance	$ 2,831,995	$ 2,135,986
Carrying amount, net of allowance	2,809,308	2,115,532
Loans Purchased With Evidence of Credit Deterioration [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Outstanding balance	29,863	14,843
Carrying amount, net of allowance	29,863	14,843
Loans Purchased With Evidence of Credit Deterioration [Member] | Commercial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Outstanding balance	27,198	11,563
Loans Purchased With Evidence of Credit Deterioration [Member] | Real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Outstanding balance	2,632	3,237
Loans Purchased With Evidence of Credit Deterioration [Member] | Consumer [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Outstanding balance	33	43
Loans Purchased With Evidence of Credit Deterioration [Member] | Heartland [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Outstanding balance	619	1,310
Loans Purchased With Evidence of Credit Deterioration [Member] | Heartland [Member] | Commercial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Outstanding balance	390	774
Loans Purchased With Evidence of Credit Deterioration [Member] | Heartland [Member] | Real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Outstanding balance	229	534
Loans Purchased With Evidence of Credit Deterioration [Member] | Heartland [Member] | Consumer [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Outstanding balance		2
Loans Purchased With Evidence of Credit Deterioration [Member] | Summit [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Outstanding balance	4,523	6,213
Loans Purchased With Evidence of Credit Deterioration [Member] | Summit [Member] | Commercial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Outstanding balance	3,653	5,245
Loans Purchased With Evidence of Credit Deterioration [Member] | Summit [Member] | Real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Outstanding balance	870	967
Loans Purchased With Evidence of Credit Deterioration [Member] | Peoples Bancorp Inc [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Outstanding balance	441	856
Loans Purchased With Evidence of Credit Deterioration [Member] | Peoples Bancorp Inc [Member] | Commercial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Outstanding balance	315	692
Loans Purchased With Evidence of Credit Deterioration [Member] | Peoples Bancorp Inc [Member] | Real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Outstanding balance	126	165
Loans Purchased With Evidence of Credit Deterioration [Member] | Kosciusko Financial Inc [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Outstanding balance	1,241	2,109
Loans Purchased With Evidence of Credit Deterioration [Member] | Kosciusko Financial Inc [Member] | Commercial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Outstanding balance	838	1,652
Loans Purchased With Evidence of Credit Deterioration [Member] | Kosciusko Financial Inc [Member] | Real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Outstanding balance	403	457
Loans Purchased With Evidence of Credit Deterioration [Member] | LaPorte Bancorp Inc [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Outstanding balance	2,071	4,355
Loans Purchased With Evidence of Credit Deterioration [Member] | LaPorte Bancorp Inc [Member] | Commercial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Outstanding balance	1,034	3,200
Loans Purchased With Evidence of Credit Deterioration [Member] | LaPorte Bancorp Inc [Member] | Real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Outstanding balance	1,004	1,114
Loans Purchased With Evidence of Credit Deterioration [Member] | LaPorte Bancorp Inc [Member] | Consumer [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Outstanding balance	33	$ 41
Loans Purchased With Evidence of Credit Deterioration [Member] | Lafayette Community Bancorp [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Outstanding balance	4,271
Loans Purchased With Evidence of Credit Deterioration [Member] | Lafayette Community Bancorp [Member] | Commercial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Outstanding balance	4,271
Loans Purchased With Evidence of Credit Deterioration [Member] | Wolverine Bancorp Inc [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Outstanding balance	16,697
Loans Purchased With Evidence of Credit Deterioration [Member] | Wolverine Bancorp Inc [Member] | Commercial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Outstanding balance	$ 16,697

Accounting for Certain Loans 81

Accounting for Certain Loans Acquired in a Transfer - Amounts of Loans (Parenthetical) (Detail) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for loan losses	$ 16,394	$ 14,837	$ 14,534	$ 16,501
Loans Purchased With Evidence of Credit Deterioration [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for loan losses	$ 0	$ 0

Accounting for Certain Loans 82

Accounting for Certain Loans Acquired in a Transfer - Accretable Yield or Income Expected to be Collected (Detail) - Loans Purchased With Evidence of Credit Deterioration [Member] - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Accounts, Notes, Loans and Financing Receivable [Line Items]
Balance at January 1	$ 3,457	$ 2,058
Additions	3,200	2,270
Accretion	(1,176)	(660)
Reclassification from nonaccretable difference	0
Disposals	(316)	(211)
Balance at December 31	5,165	3,457
Heartland [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Balance at January 1	557	795
Additions	0
Accretion	(99)	(164)
Reclassification from nonaccretable difference	0
Disposals	(6)	(74)
Balance at December 31	452	557
Summit [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Balance at January 1	502	708
Additions	0
Accretion	(353)	(171)
Reclassification from nonaccretable difference	0
Disposals	(2)	(35)
Balance at December 31	147	502
Peoples Bancorp Inc [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Balance at January 1	389	555
Additions	0
Accretion	(388)	(106)
Reclassification from nonaccretable difference	0
Disposals	(1)	(60)
Balance at December 31	0	389
Kosciusko Financial Inc [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Balance at January 1	530
Additions	0	634
Accretion	(101)	(72)
Reclassification from nonaccretable difference	0
Disposals	(43)	(32)
Balance at December 31	386	530
LaPorte Bancorp Inc [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Balance at January 1	1,479
Additions	0	1,636
Accretion	(235)	(147)
Reclassification from nonaccretable difference	0
Disposals	(264)	(10)
Balance at December 31	980	1,479
Lafayette Community Bancorp [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Balance at January 1	0
Additions	933
Accretion	0
Reclassification from nonaccretable difference	0
Disposals	0
Balance at December 31	933	0
Wolverine Bancorp Inc [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Balance at January 1	0
Additions	2,267
Accretion	0
Reclassification from nonaccretable difference	0
Disposals	0
Balance at December 31	$ 2,267	$ 0

Accounting for Certain Loans 83

Accounting for Certain Loans Acquired in a Transfer - Additional Information (Detail) - USD ($)	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Business Acquisition [Line Items]
Total provision charged to operating expense	$ 1,100,000	$ 710,000	$ 330,000	$ 330,000	$ 623,000	$ 455,000	$ 232,000	$ 532,000	$ 2,470,000	$ 1,842,000	$ 3,162,000
Loans Purchased With Evidence of Credit Deterioration [Member]
Business Acquisition [Line Items]
Total provision charged to operating expense									0	71,000
Allowances for loan losses									$ 71,000	$ 0

Allowance for Loan Losses - Add

Allowance for Loan Losses - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2017
Minimum [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Actual loss history experienced by the Company	1 year
Maximum [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Actual loss history experienced by the Company	5 years
Allowance for loan losses charge down family first and junior lien mortgages past due period	180 days
Allowance for loan losses charge down unsecured open end loans past due period	90 days
Allowance for loan losses charge down other secured loans past due period	90 days

Allowance for Loan Losses - All

Allowance for Loan Losses - Allowance for Loan Losses (Detail) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Financing Receivable, Allowance for Credit Losses [Line Items]
Balance at beginning of the period				$ 14,837				$ 14,534	$ 14,837	$ 14,534	$ 16,501
Total loans charged-off									2,253	2,660	6,099
Total loan recoveries									1,340	1,121	970
Net loans charged-off									913	1,539	5,129
Total provision charged to operating expense	$ 1,100	$ 710	$ 330	$ 330	$ 623	$ 455	$ 232	$ 532	2,470	1,842	3,162
Balance at the end of the period	$ 16,394				$ 14,837				16,394	14,837	14,534
Commercial [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans charged-off									377	758	3,437
Total loan recoveries									268	210	192
Total provision charged to operating expense									2,164	(68)	2,531
Commercial [Member] | Owner Occupied Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans charged-off									68	181	2,208
Total loan recoveries									9	31	104
Commercial [Member] | Non Owner Occupied Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans charged-off									20	471	556
Total loan recoveries									32	55	1
Commercial [Member] | Residential Development [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loan recoveries									8	8
Commercial [Member] | Development & Spec Land Loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans charged-off									1
Total loan recoveries											35
Commercial [Member] | Commercial and Industrial [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans charged-off									288	106	673
Total loan recoveries									219	116	52
Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans charged-off									89	213	288
Total loan recoveries									44	97	69
Total provision charged to operating expense									(81)	(23)	62
Real Estate [Member] | Residential Mortgage [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans charged-off									89	213	288
Total loan recoveries									44	97	69
Consumer [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans charged-off									1,787	1,689	2,374
Total loan recoveries									1,028	814	709
Total provision charged to operating expense									387	1,933	569
Consumer [Member] | Direct Installment [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans charged-off									389	329	367
Total loan recoveries									531	81	106
Consumer [Member] | Indirect Installment [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans charged-off									1,193	1,051	1,081
Total loan recoveries									497	529	489
Consumer [Member] | Home Equity Loan [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans charged-off									$ 205	309	926
Total loan recoveries										$ 204	$ 114

Allowance for Loan Losses - A86

Allowance for Loan Losses - Allowance for Loan Losses and Recorded Investment in Loans by Portfolio Segment (Detail) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Financing Receivable, Allowance for Credit Losses [Line Items]
Total ending allowance balance	$ 16,394	$ 14,837	$ 14,534	$ 16,501
Total ending loans balance	7,187	2,250	$ 7,019
Loans Purchased With Evidence of Credit Deterioration [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total ending allowance balance	0	0
Allowance for Loan Losses [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance For Loan Losses, Individually evaluated for impairment	184	4
Allowance For Loan Losses, Collectively evaluated for impairment	16,210	14,833
Total ending allowance balance	16,394	14,837
Allowance for Loan Losses [Member] | Loans Purchased With Evidence of Credit Deterioration [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance For Loan Losses, Loans acquired with deteriorated credit quality	0
Commercial [Member] | Allowance for Loan Losses [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance For Loan Losses, Individually evaluated for impairment	184	4
Allowance For Loan Losses, Collectively evaluated for impairment	8,450	6,575
Total ending allowance balance	8,634	6,579
Commercial [Member] | Allowance for Loan Losses [Member] | Loans Purchased With Evidence of Credit Deterioration [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance For Loan Losses, Loans acquired with deteriorated credit quality	0
Real Estate [Member] | Allowance for Loan Losses [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance For Loan Losses, Individually evaluated for impairment	0
Allowance For Loan Losses, Collectively evaluated for impairment	2,188	2,090
Total ending allowance balance	2,188	2,090
Real Estate [Member] | Allowance for Loan Losses [Member] | Loans Purchased With Evidence of Credit Deterioration [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance For Loan Losses, Loans acquired with deteriorated credit quality	0
Consumer [Member] | Allowance for Loan Losses [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance For Loan Losses, Individually evaluated for impairment	0
Allowance For Loan Losses, Collectively evaluated for impairment	4,542	4,914
Total ending allowance balance	4,542	4,914
Consumer [Member] | Allowance for Loan Losses [Member] | Loans Purchased With Evidence of Credit Deterioration [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance For Loan Losses, Loans acquired with deteriorated credit quality	0
Loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Loans: Individually evaluated for impairment	7,187	2,250
Loans: Collectively evaluated for impairment	2,834,034	2,140,481
Total ending loans balance	2,841,221	2,142,731
Loans [Member] | Loans Purchased With Evidence of Credit Deterioration [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Loans acquired with deteriorated credit quality	0
Loans [Member] | Commercial [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Loans: Individually evaluated for impairment	7,187	2,250
Loans: Collectively evaluated for impairment	1,615,927	1,071,199
Total ending loans balance	1,623,114	1,073,449
Loans [Member] | Commercial [Member] | Loans Purchased With Evidence of Credit Deterioration [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Loans acquired with deteriorated credit quality	0
Loans [Member] | Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Loans: Individually evaluated for impairment	0
Loans: Collectively evaluated for impairment	608,575	533,399
Total ending loans balance	608,575	533,399
Loans [Member] | Real Estate [Member] | Loans Purchased With Evidence of Credit Deterioration [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Loans acquired with deteriorated credit quality	0
Loans [Member] | Consumer [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Loans: Individually evaluated for impairment	0
Loans: Collectively evaluated for impairment	514,544	399,676
Total ending loans balance	514,544	399,676
Loans [Member] | Consumer [Member] | Loans Purchased With Evidence of Credit Deterioration [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Loans acquired with deteriorated credit quality	0
Mortgage Warehousing [Member] | Allowance for Loan Losses [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance For Loan Losses, Individually evaluated for impairment	0
Allowance For Loan Losses, Collectively evaluated for impairment	1,030	1,254
Total ending allowance balance	1,030	1,254
Mortgage Warehousing [Member] | Allowance for Loan Losses [Member] | Loans Purchased With Evidence of Credit Deterioration [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance For Loan Losses, Loans acquired with deteriorated credit quality	0
Mortgage Warehousing [Member] | Loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Loans: Individually evaluated for impairment	0
Loans: Collectively evaluated for impairment	94,988	136,207
Total ending loans balance	94,988	$ 136,207
Mortgage Warehousing [Member] | Loans [Member] | Loans Purchased With Evidence of Credit Deterioration [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Loans acquired with deteriorated credit quality	$ 0

Non-performing Assets and Imp87

Non-performing Assets and Impaired Loans - Non-accrual, Loans Past Due Over 90 Days Still on Accrual, and Troubled Debt Restructured ("TDRs") by Class of Loans (Detail) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non-accrual	$ 13,276	$ 7,936
Loans Past Due Over 90 Days Still Accruing	167	241
Non-Performing TDRs	1,013	1,014
Performing TDRs	1,958	1,492
Total Non-Performing Loans	16,414	10,683
Commercial [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non-accrual	6,689	2,249
Loans Past Due Over 90 Days Still Accruing		183
Non-Performing TDRs	451
Performing TDRs	1
Total Non-Performing Loans	7,141	2,432
Commercial [Member] | Owner Occupied Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non-accrual	4,742	1,532
Loans Past Due Over 90 Days Still Accruing		183
Non-Performing TDRs	11
Performing TDRs	1
Total Non-Performing Loans	4,754	1,715
Commercial [Member] | Non Owner Occupied Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non-accrual	115	440
Non-Performing TDRs	440
Total Non-Performing Loans	555	440
Commercial [Member] | Development & Spec Land Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non-accrual	176	118
Total Non-Performing Loans	176	118
Commercial [Member] | Commercial and Industrial [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non-accrual	1,656	159
Total Non-Performing Loans	1,656	159
Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non-accrual	3,693	2,959
Non-Performing TDRs	351	809
Performing TDRs	1,672	1,254
Total Non-Performing Loans	5,716	5,022
Real Estate [Member] | Residential Mortgage [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non-accrual	3,693	2,959
Non-Performing TDRs	351	576
Performing TDRs	1,450	1,254
Total Non-Performing Loans	5,494	4,789
Real Estate [Member] | Residential Construction [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non-Performing TDRs		233
Performing TDRs	222
Total Non-Performing Loans	222	233
Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non-accrual	2,894	2,728
Loans Past Due Over 90 Days Still Accruing	167	58
Non-Performing TDRs	211	205
Performing TDRs	285	238
Total Non-Performing Loans	3,557	3,229
Consumer [Member] | Direct Installment [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non-accrual	373	512
Total Non-Performing Loans	373	512
Consumer [Member] | Indirect Installment [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non-accrual	1,041	659
Loans Past Due Over 90 Days Still Accruing	167	49
Total Non-Performing Loans	1,208	708
Consumer [Member] | Home Equity Loan [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non-accrual	1,480	1,557
Loans Past Due Over 90 Days Still Accruing		9
Non-Performing TDRs	211	205
Performing TDRs	285	238
Total Non-Performing Loans	$ 1,976	$ 2,009

Non-performing Assets and Imp88

Non-performing Assets and Impaired Loans - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2017USD ($)ConsecutivePaymentContract	Dec. 31, 2016USD ($)
Financing Receivable, Modifications [Line Items]
Non-accrual loans	$ 13,276,000	$ 7,936,000
Non-performing TDRs	$ 1,000,000
Loan delinquency period	90 days
Minimum period required for satisfactory performance to return loan from non-accrual to accrual status	6 months
Restructured loan reported in TDRs	$ 3,000,000
Restructured loan returned to accruing status number of Consecutive Payments of loan | ConsecutivePayment	6
Specific reserves allocated to troubled debt restructuring	$ 50,000
Number TDRs returned to accrual status | Contract	2
Performing Financing Receivable [Member]
Financing Receivable, Modifications [Line Items]
Restructured loan reported in TDRs	$ 2,000,000
Principal Forgiveness [Member]
Financing Receivable, Modifications [Line Items]
Restructured loan reported in TDRs	0
Loans Purchased With Evidence of Credit Deterioration [Member]
Financing Receivable, Modifications [Line Items]
Non-accrual loans	3,900,000
Non-performing TDRs	$ 467,000
Minimum [Member]
Financing Receivable, Modifications [Line Items]
Loan delinquency period	90 days
Delay or shortfall in payments of loan	30 days
Loans with an aggregate credit exposure	$ 1,000,000
Loans classified as TDR after a period	90 days
Minimum [Member] | Good Pass [Member]
Financing Receivable, Modifications [Line Items]
Number of consecutive years of profit Unaudited Financial Information for Good Pass Rating	5 years
Number of years of Satisfactory Relationship with bank for Good Pass Rating	5 years
Number of consecutive years of profit for Good Pass Rating	3 years
Minimum [Member] | Satisfactory Pass [Member]
Financing Receivable, Modifications [Line Items]
Minimum number of years of Satisfactory Repayment required for Satisfactory Pass Rating	2 years
Maximum [Member]
Financing Receivable, Modifications [Line Items]
Loans with an aggregate credit exposure	$ 3,500,000
Loans classified as TDR after a period	120 days

Non-performing Assets and Imp89

Non-performing Assets and Impaired Loans - Commercial Loans Individually Evaluated for Impairment by Class of Loans (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Financing Receivable, Impaired [Line Items]
Unpaid Principal Balance total	$ 7,141	$ 2,250	$ 7,005
Total ending loans balance	7,187	2,250	7,019
Allowance For Loan Loss Allocated	184	4	202
Average Balance in Impaired Loans total	3,774	2,905	7,110
Cash/Accrual Interest Income Recognized, Total	86	95	58
Commercial [Member]
Financing Receivable, Impaired [Line Items]
Unpaid Principal Balance With no recorded allowance	6,210	2,219	6,428
Recorded Investment With no recorded allowance	6,256	2,218	6,442
Allowance For Loan Loss Allocated With no recorded allowance	0	0	0
Average Balance in Impaired Loans With no recorded allowance	3,696	2,900	6,699
Cash/Accrual Interest Income Recognized, With no recorded allowance	40	93	37
Unpaid Principal Balance With an allowance recorded	931	31	577
Recorded Investment With an allowance recorded	931	32	577
Allowance For Loan Loss Allocated	184	4	202
Average Balance in Impaired Loans With an allowance recorded	78	5	411
Cash/Accrual Interest Income Recognized, With an allowance recorded	46	2	21
Commercial [Member] | Owner Occupied Real Estate [Member]
Financing Receivable, Impaired [Line Items]
Unpaid Principal Balance With no recorded allowance	3,824	1,533	1,340
Recorded Investment With no recorded allowance	3,849	1,533	1,339
Allowance For Loan Loss Allocated With no recorded allowance	0	0	0
Average Balance in Impaired Loans With no recorded allowance	1,673	1,619	1,001
Cash/Accrual Interest Income Recognized, With no recorded allowance	11	58	22
Unpaid Principal Balance With an allowance recorded	931		410
Recorded Investment With an allowance recorded	931		410
Allowance For Loan Loss Allocated	184		105
Average Balance in Impaired Loans With an allowance recorded	78		243
Cash/Accrual Interest Income Recognized, With an allowance recorded	46		8
Commercial [Member] | Non Owner Occupied Real Estate [Member]
Financing Receivable, Impaired [Line Items]
Unpaid Principal Balance With no recorded allowance	554	440	4,938
Recorded Investment With no recorded allowance	570	440	4,953
Allowance For Loan Loss Allocated With no recorded allowance	0	0	0
Average Balance in Impaired Loans With no recorded allowance	345	871	5,417
Cash/Accrual Interest Income Recognized, With no recorded allowance		18	8
Unpaid Principal Balance With an allowance recorded			70
Recorded Investment With an allowance recorded			70
Allowance For Loan Loss Allocated			32
Average Balance in Impaired Loans With an allowance recorded			6
Cash/Accrual Interest Income Recognized, With an allowance recorded			13
Commercial [Member] | Residential Development [Member]
Financing Receivable, Impaired [Line Items]
Allowance For Loan Loss Allocated With no recorded allowance	0	0	0
Commercial [Member] | Development & Spec Land Loans [Member]
Financing Receivable, Impaired [Line Items]
Unpaid Principal Balance With no recorded allowance	176	118	71
Recorded Investment With no recorded allowance	174	118	71
Allowance For Loan Loss Allocated With no recorded allowance	0	0	0
Average Balance in Impaired Loans With no recorded allowance	233	61	6
Cash/Accrual Interest Income Recognized, With no recorded allowance	4	16	3
Commercial [Member] | Commercial and Industrial [Member]
Financing Receivable, Impaired [Line Items]
Unpaid Principal Balance With no recorded allowance	1,656	128	79
Recorded Investment With no recorded allowance	1,663	127	79
Allowance For Loan Loss Allocated With no recorded allowance	0	0	0
Average Balance in Impaired Loans With no recorded allowance	1,445	349	275
Cash/Accrual Interest Income Recognized, With no recorded allowance	$ 25	1	4
Unpaid Principal Balance With an allowance recorded		31	97
Recorded Investment With an allowance recorded		32	97
Allowance For Loan Loss Allocated		4	65
Average Balance in Impaired Loans With an allowance recorded		5	$ 162
Cash/Accrual Interest Income Recognized, With an allowance recorded		$ 2

Non-performing Assets and Imp90

Non-performing Assets and Impaired Loans - Payment Status by Class of Loan (Detail) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	$ 9,496	$ 6,556
Loans Not Past Due	2,816,206	2,123,813
Total	$ 2,825,702	$ 2,130,369
Total Past Due, Percentage of Total Loans	0.34%	0.31%
Loans Not Past Due, Percentage of Total Loans	99.66%	99.69%
Commercial [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	$ 4,749	$ 2,591
Loans Not Past Due	1,607,460	1,063,608
Total	1,612,209	1,066,199
Commercial [Member] | Owner Occupied Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	3,563	1,251
Loans Not Past Due	544,033	336,297
Total	547,596	337,548
Commercial [Member] | Non Owner Occupied Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	634	357
Loans Not Past Due	663,647	461,540
Total	664,281	461,897
Commercial [Member] | Residential Development [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans Not Past Due	16,431	5,006
Total	16,431	5,006
Commercial [Member] | Development & Spec Land Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	31	1
Loans Not Past Due	48,643	31,227
Total	48,674	31,228
Commercial [Member] | Commercial and Industrial [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	521	982
Loans Not Past Due	334,706	229,538
Total	335,227	230,520
Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	1,360	1,009
Loans Not Past Due	697,533	663,562
Total	698,893	664,571
Real Estate [Member] | Residential Mortgage [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	1,297	1,009
Loans Not Past Due	587,061	507,224
Total	588,358	508,233
Real Estate [Member] | Residential Construction [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	63
Loans Not Past Due	15,964	20,611
Total	16,027	20,611
Real Estate [Member] | Mortgage Warehousing [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans Not Past Due	94,508	135,727
Total	94,508	135,727
Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	3,387	2,956
Loans Not Past Due	511,213	396,643
Total	514,600	399,599
Consumer [Member] | Direct Installment [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	88	143
Loans Not Past Due	89,529	71,007
Total	89,617	71,150
Consumer [Member] | Direct Installment Purchased [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans Not Past Due	82	119
Total	82	119
Consumer [Member] | Indirect Installment [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	2,270	1,625
Loans Not Past Due	225,053	151,579
Total	227,323	153,204
Consumer [Member] | Home Equity Loan [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	1,029	1,188
Loans Not Past Due	196,549	173,938
Total	197,578	175,126
30 - 59 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	$ 6,426	$ 5,684
Total Past Due, Percentage of Total Loans	0.23%	0.27%
30 - 59 Days Past Due [Member] | Commercial [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	$ 2,676	$ 2,408
30 - 59 Days Past Due [Member] | Commercial [Member] | Owner Occupied Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	1,613	1,068
30 - 59 Days Past Due [Member] | Commercial [Member] | Non Owner Occupied Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	512	357
30 - 59 Days Past Due [Member] | Commercial [Member] | Development & Spec Land Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	31	1
30 - 59 Days Past Due [Member] | Commercial [Member] | Commercial and Industrial [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	520	982
30 - 59 Days Past Due [Member] | Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	1,311	886
30 - 59 Days Past Due [Member] | Real Estate [Member] | Residential Mortgage [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	1,248	886
30 - 59 Days Past Due [Member] | Real Estate [Member] | Residential Construction [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	63
30 - 59 Days Past Due [Member] | Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	2,439	2,390
30 - 59 Days Past Due [Member] | Consumer [Member] | Direct Installment [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	78	139
30 - 59 Days Past Due [Member] | Consumer [Member] | Indirect Installment [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	1,859	1,339
30 - 59 Days Past Due [Member] | Consumer [Member] | Home Equity Loan [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	502	912
60 - 89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	$ 2,903	$ 631
Total Past Due, Percentage of Total Loans	0.10%	0.03%
60 - 89 Days Past Due [Member] | Commercial [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	$ 2,073
60 - 89 Days Past Due [Member] | Commercial [Member] | Owner Occupied Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	1,950
60 - 89 Days Past Due [Member] | Commercial [Member] | Non Owner Occupied Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	122
60 - 89 Days Past Due [Member] | Commercial [Member] | Commercial and Industrial [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	1
60 - 89 Days Past Due [Member] | Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	49	$ 123
60 - 89 Days Past Due [Member] | Real Estate [Member] | Residential Mortgage [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	49	123
60 - 89 Days Past Due [Member] | Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	781	508
60 - 89 Days Past Due [Member] | Consumer [Member] | Direct Installment [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	10	4
60 - 89 Days Past Due [Member] | Consumer [Member] | Indirect Installment [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	244	237
60 - 89 Days Past Due [Member] | Consumer [Member] | Home Equity Loan [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	527	267
Greater than 90 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	$ 167	$ 241
Total Past Due, Percentage of Total Loans	0.01%	0.01%
Greater than 90 Days Past Due [Member] | Commercial [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due		$ 183
Greater than 90 Days Past Due [Member] | Commercial [Member] | Owner Occupied Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due		183
Greater than 90 Days Past Due [Member] | Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	$ 167	58
Greater than 90 Days Past Due [Member] | Consumer [Member] | Indirect Installment [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	$ 167	49
Greater than 90 Days Past Due [Member] | Consumer [Member] | Home Equity Loan [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due		$ 9

Non-performing Assets and Imp91

Non-performing Assets and Impaired Loans - Loans by Credit Grades (Detail) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Financing Receivable, Recorded Investment [Line Items]
Total	$ 2,825,702	$ 2,130,369
Commercial [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	1,612,209	1,066,199
Commercial [Member] | Owner Occupied Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	547,596	337,548
Commercial [Member] | Non Owner Occupied Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	664,281	461,897
Commercial [Member] | Residential Development [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	16,431	5,006
Commercial [Member] | Development & Spec Land Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	48,674	31,228
Commercial [Member] | Commercial and Industrial [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	335,227	230,520
Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	698,893	664,571
Real Estate [Member] | Residential Mortgage [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	588,358	508,233
Real Estate [Member] | Residential Construction [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	16,027	20,611
Real Estate [Member] | Mortgage Warehousing [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	94,508	135,727
Consumer [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	514,600	399,599
Consumer [Member] | Direct Installment [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	89,617	71,150
Consumer [Member] | Direct Installment Purchased [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	82	119
Consumer [Member] | Indirect Installment [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	227,323	153,204
Consumer [Member] | Home Equity Loan [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	197,578	175,126
Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	$ 2,758,720	$ 2,090,978
Percentage of total loans	97.63%	98.15%
Pass [Member] | Commercial [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	$ 1,554,500	$ 1,035,059
Pass [Member] | Commercial [Member] | Owner Occupied Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	520,907	322,924
Pass [Member] | Commercial [Member] | Non Owner Occupied Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	655,410	455,648
Pass [Member] | Commercial [Member] | Residential Development [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	16,431	5,006
Pass [Member] | Commercial [Member] | Development & Spec Land Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	47,562	31,057
Pass [Member] | Commercial [Member] | Commercial and Industrial [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	314,190	220,424
Pass [Member] | Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	693,177	659,549
Pass [Member] | Real Estate [Member] | Residential Mortgage [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	582,864	503,444
Pass [Member] | Real Estate [Member] | Residential Construction [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	15,805	20,378
Pass [Member] | Real Estate [Member] | Mortgage Warehousing [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	94,508	135,727
Pass [Member] | Consumer [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	511,043	396,370
Pass [Member] | Consumer [Member] | Direct Installment [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	89,244	70,638
Pass [Member] | Consumer [Member] | Direct Installment Purchased [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	82	119
Pass [Member] | Consumer [Member] | Indirect Installment [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	226,115	152,496
Pass [Member] | Consumer [Member] | Home Equity Loan [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	195,602	173,117
Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	$ 20,820	$ 9,029
Percentage of total loans	0.74%	0.42%
Special Mention [Member] | Commercial [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	$ 20,820	$ 9,029
Special Mention [Member] | Commercial [Member] | Owner Occupied Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	8,622	4,960
Special Mention [Member] | Commercial [Member] | Non Owner Occupied Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	3,864	341
Special Mention [Member] | Commercial [Member] | Development & Spec Land Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	886
Special Mention [Member] | Commercial [Member] | Commercial and Industrial [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	7,448	3,728
Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	$ 46,162	$ 30,362
Percentage of total loans	1.63%	1.43%
Substandard [Member] | Commercial [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	$ 36,889	$ 22,111
Substandard [Member] | Commercial [Member] | Owner Occupied Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	18,067	9,664
Substandard [Member] | Commercial [Member] | Non Owner Occupied Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	5,007	5,908
Substandard [Member] | Commercial [Member] | Development & Spec Land Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	226	171
Substandard [Member] | Commercial [Member] | Commercial and Industrial [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	13,589	6,368
Substandard [Member] | Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	5,716	5,022
Substandard [Member] | Real Estate [Member] | Residential Mortgage [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	5,494	4,789
Substandard [Member] | Real Estate [Member] | Residential Construction [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	222	233
Substandard [Member] | Consumer [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	3,557	3,229
Substandard [Member] | Consumer [Member] | Direct Installment [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	373	512
Substandard [Member] | Consumer [Member] | Indirect Installment [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	1,208	708
Substandard [Member] | Consumer [Member] | Home Equity Loan [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	$ 1,976	$ 2,009
Doubtful [Member]
Financing Receivable, Recorded Investment [Line Items]
Percentage of total loans	0.00%	0.00%

Premises and Equipment - Summar

Premises and Equipment - Summary of Premises and Equipment (Detail) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Property, Plant and Equipment [Line Items]
Total cost	$ 112,368	$ 99,604
Accumulated depreciation	(36,839)	(33,247)
Net premise and equipment	75,529	66,357
Land [Member]
Property, Plant and Equipment [Line Items]
Total cost	21,633	20,032
Buildings and Improvements [Member]
Property, Plant and Equipment [Line Items]
Total cost	68,447	59,607
Furniture and Equipment [Member]
Property, Plant and Equipment [Line Items]
Total cost	$ 22,288	$ 19,965

Loan Servicing - Additional Inf

Loan Servicing - Additional Information (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Jan. 01, 2015
Receivables [Abstract]
Unpaid principal balances of loans serviced for others totaled	$ 1,310,000	$ 1,301,000
Aggregate fair value of capitalized mortgage servicing rights	12,800	12,100	$ 10,800	$ 7,600
Mortgage servicing rights, net	11,602	11,174	8,874
Bank recorded additional impairment	$ 80	$ 110	$ 59

Loan Servicing - Originated Mor

Loan Servicing - Originated Mortgage Servicing Rights (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Payments for (Proceeds from) Mortgage Servicing Rights [Abstract]
Balances, January 1	$ 11,681	$ 9,271	$ 7,980
Servicing rights capitalized	2,109	3,426	2,974
Amortization of servicing rights	(1,601)	(1,016)	(1,683)
Balances, December 31	12,189	11,681	9,271
Balances, January 1	(507)	(397)	(338)
Additions	(85)	(236)	(130)
Reductions	5	126	71
Balances, December 31	(587)	(507)	(397)
Mortgage servicing rights, net	$ 11,602	$ 11,174	$ 8,874

Goodwill and Intangible Asset95

Goodwill and Intangible Assets - Additional Information (Detail) - USD ($)	Oct. 17, 2017	Sep. 01, 2017	Nov. 07, 2016	Jul. 18, 2016	Jun. 01, 2016	Jul. 01, 2015	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Intangible Assets [Line Items]
Goodwill acquired							$ 42,939,000	$ 27,341,000
Goodwill impairment loss							0	0
Amortization expense for intangible assets totaled							1,500,000	$ 1,200,000	$ 988,000
Peoples Bancorp Inc [Member]
Intangible Assets [Line Items]
Goodwill acquired						$ 21,400,000
Core deposit intangible amortization period									10 years
Central National Bank & Trust [Member]
Intangible Assets [Line Items]
Goodwill acquired			$ 609,000
Core deposit intangible amortization period								10 years
LaPorte Bancorp Inc [Member]
Intangible Assets [Line Items]
Goodwill acquired				$ 21,000,000
Core deposit intangible amortization period								10 years
Goodwill measurement period adjustment							$ 704,000
Kosciusko Financial Inc [Member]
Intangible Assets [Line Items]
Goodwill acquired					$ 6,400,000
Core deposit intangible amortization period							10 years
Wolverine Bancorp Inc [Member]
Intangible Assets [Line Items]
Goodwill acquired	$ 26,800,000
Core deposit intangible amortization period							10 years
Lafayette Community Bancorp [Member]
Intangible Assets [Line Items]
Goodwill acquired		$ 15,400,000
Core deposit intangible amortization period							10 years
Core Deposits [Member] | Minimum [Member]
Intangible Assets [Line Items]
Core deposit intangible amortization period							7 years
Core Deposits [Member] | Maximum [Member]
Intangible Assets [Line Items]
Core deposit intangible amortization period							10 years

Goodwill and Intangible Asset96

Goodwill and Intangible Assets - Changes in Carrying Amount of Goodwill (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Goodwill and Intangible Assets Disclosure [Abstract]
Balance, January 1	$ 76,941	$ 49,600
Goodwill acquired	42,939	27,341
Balance, December 31	$ 119,880	$ 76,941

Goodwill and Intangible Asset97

Goodwill and Intangible Assets - Amortizable Intangible Assets (Detail) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Finite-Lived Intangible Assets [Line Items]
Amortizable intangible assets Core deposit intangible, Gross Carrying Amount	$ 12,400
Core Deposits [Member]
Finite-Lived Intangible Assets [Line Items]
Amortizable intangible assets Core deposit intangible, Gross Carrying Amount	20,711	$ 16,151
Amortizable intangible assets Core deposit intangible, Accumulated Amortization	$ (8,309)	$ (6,785)

Goodwill and Intangible Asset98

Goodwill and Intangible Assets - Estimated Amortization (Detail) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Finite-Lived Intangible Assets, Net, Amortization Expense, Fiscal Year Maturity [Abstract]
2,018	$ 2,012
2,019	1,787
2,020	1,481
2,021	1,394
2,022	1,375
Thereafter	4,353
Estimated amortization	$ 12,402	$ 9,366

Deposits - Deposits (Detail)

Deposits - Deposits (Detail) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Deposits [Line Items]
Noninterest-bearing demand deposits	$ 601,805	$ 496,248
Interest-bearing demand deposits	909,638	850,641
Money market (variable rate)	378,108	290,896
Savings deposits	424,500	357,582
Other certificates and time deposits	436,367	370,482
Total deposits	2,881,003	2,471,210
Certificates of Deposit of $250,000 or More [Member]
Deposits [Line Items]
Certificates of deposit	$ 130,585	$ 105,361

Deposits - Certificates and Oth

Deposits - Certificates and Other Time Deposits for Both Retail and Brokered (Detail) $ in Thousands	Dec. 31, 2017USD ($)
Time Deposits By Maturity [Line Items]
2,018	$ 277,498
2,019	164,585
2,020	63,896
2,021	19,514
2,022	18,658
Thereafter	22,801
Certificates and other time deposits	566,952
Retail [Member]
Time Deposits By Maturity [Line Items]
2,018	258,488
2,019	152,027
2,020	56,838
2,021	16,128
2,022	16,758
Thereafter	22,222
Certificates and other time deposits	522,461
Brokered [Member]
Time Deposits By Maturity [Line Items]
2,018	19,010
2,019	12,558
2,020	7,058
2,021	3,386
2,022	1,900
Thereafter	579
Certificates and other time deposits	$ 44,491

Borrowings - Borrowings (Detail

Borrowings - Borrowings (Detail) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Debt Disclosure [Abstract]
Federal Home Loan Bank advances, variable and fixed rates ranging from 0.93% to 7.53%, due at various dates through November 15, 2024	$ 336,308	$ 124,034
Securities sold under agreements to repurchase	61,097	57,144
Federal Reserve Bank discount window	11,000
Federal funds purchased	143,252	66,811
Notes payable, variable rate of 2.75%, due at various dates through July 13, 2019	12,500	19,500
Total borrowings	$ 564,157	$ 267,489

Borrowings - Borrowings (Parent

Borrowings - Borrowings (Parenthetical) (Detail)	12 Months Ended
	Dec. 31, 2017
Borrowings Under Repurchase Agreements [Line Items]
Notes payable, variable rate	2.75%
Notes payable, due date	Jul. 13, 2019
Maximum [Member]
Borrowings Under Repurchase Agreements [Line Items]
Federal Home Loan Bank advances, variable and fixed rates	7.53%
Minimum [Member]
Borrowings Under Repurchase Agreements [Line Items]
Federal Home Loan Bank advances, variable and fixed rates	0.93%

Borrowings - Additional Informa

Borrowings - Additional Information (Detail) $ in Millions	Dec. 31, 2017USD ($)
Debt Disclosure [Abstract]
Federal Home Loan Bank advances are secured by first and second mortgage loans and mortgage warehouse loans	$ 503.8
Available credit lines with various money center banks	$ 127.2

Borrowings - Contractual Maturi

Borrowings - Contractual Maturities (Detail) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Debt Disclosure [Abstract]
2,018	$ 430,078
2,019	69,252
2,020	37,472
2,021	5,042
2,022	12,154
Thereafter	10,159
Total borrowings	$ 564,157	$ 267,489

Repurchase Agreements - Summary

Repurchase Agreements - Summary of Repurchase Agreements Accounted as Secured Borrowings (Detail) $ in Thousands	Dec. 31, 2017USD ($)
Assets Sold under Agreements to Repurchase [Line Items]
Repurchase Agreements	$ 61,097
Securities pledged for Repurchase Agreements, Total	73,998
Federal Agency Collateralized Mortgage Obligations [Member]
Assets Sold under Agreements to Repurchase [Line Items]
Securities pledged for Repurchase Agreements, Total	38,421
Federal Agency Mortgage-backed Pools [Member]
Assets Sold under Agreements to Repurchase [Line Items]
Securities pledged for Repurchase Agreements, Total	35,577
Remaining Contractual Maturity of the Agreements, Overnight and Continuous [Member]
Assets Sold under Agreements to Repurchase [Line Items]
Repurchase Agreements	61,097
Securities pledged for Repurchase Agreements, Total	73,998
Remaining Contractual Maturity of the Agreements, Overnight and Continuous [Member] | Federal Agency Collateralized Mortgage Obligations [Member]
Assets Sold under Agreements to Repurchase [Line Items]
Securities pledged for Repurchase Agreements, Total	38,421
Remaining Contractual Maturity of the Agreements, Overnight and Continuous [Member] | Federal Agency Mortgage-backed Pools [Member]
Assets Sold under Agreements to Repurchase [Line Items]
Securities pledged for Repurchase Agreements, Total	$ 35,577

Repurchase Agreements - Additio

Repurchase Agreements - Additional Information (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Disclosure of Repurchase Agreements [Abstract]
Maximum amount of outstanding agreements	$ 63.1	$ 157.7
Daily average amount of outstanding agreements	$ 55.2	$ 134.2

Subordinated Debentures - Addit

Subordinated Debentures - Additional Information (Detail) - USD ($)	1 Months Ended					12 Months Ended
	Dec. 31, 2006	Oct. 31, 2004	Jun. 30, 2004	Mar. 30, 2004	Jun. 30, 2003	Dec. 31, 2017	Dec. 31, 2016
Subordinate Debenture [Line Items]
Junior subordinated debentures and the securities variable rate						2.75%
LIBOR period						3 months
Junior subordinated debentures maturity date						Jul. 13, 2019
Carrying value of securities, net of remaining purchase discount						$ 37,653,000	$ 37,456,000
Horizon Statutory Trust Two [Member]
Subordinate Debenture [Line Items]
Trust Preferred Capital Securities Sold		$ 10,300,000
Securities bearing interest rate						90-day LIBOR plus 1.95%
Junior subordinated debentures and the securities variable rate		1.95%
LIBOR period						90 days
Interest rate on junior subordinated debentures and securities						3.64%
Junior subordinated debentures maturity date						Oct. 21, 2034
Cost of issuance of the securities		$ 17,500
First call date of the securities						Oct. 31, 2009
Horizon Bancorp Capital Trust Three [Member]
Subordinate Debenture [Line Items]
Trust Preferred Capital Securities Sold	$ 12,400,000
Securities bearing interest rate						90-day LIBOR plus 1.65%
Junior subordinated debentures and the securities variable rate	1.65%
LIBOR period						90 days
Interest rate on junior subordinated debentures and securities						3.34%
Junior subordinated debentures maturity date						Jan. 30, 2037
Cost of issuance of the securities	$ 12,647
Alliance Financial Statutory Trust One [Member]
Subordinate Debenture [Line Items]
Trust Preferred Capital Securities Sold			$ 5,200,000
Securities bearing interest rate						90-day LIBOR plus 2.65%
Junior subordinated debentures and the securities variable rate			2.65%
LIBOR period						90 days
Interest rate on junior subordinated debentures and securities						4.34%
Junior subordinated debentures maturity date						Jun. 1, 2034
Am Tru Statutory Trust One [Member]
Subordinate Debenture [Line Items]
Trust Preferred Capital Securities Sold				$ 3,500,000
Securities bearing interest rate						90-day LIBOR plus 2.85%
Junior subordinated debentures and the securities variable rate				2.85%
LIBOR period						90 days
Interest rate on junior subordinated debentures and securities						4.54%
Junior subordinated debentures maturity date						Mar. 1, 2034
Carrying value of securities, net of remaining purchase discount						$ 3,300,000
Heartland Statutory Trust Two [Member]
Subordinate Debenture [Line Items]
Trust Preferred Capital Securities Sold	$ 3,000,000
Securities bearing interest rate						90-day LIBOR plus 1.67%
Junior subordinated debentures and the securities variable rate	1.67%
LIBOR period						90 days
Interest rate on junior subordinated debentures and securities						3.36%
Junior subordinated debentures maturity date						Dec. 1, 2036
Carrying value of securities, net of remaining purchase discount						$ 1,800,000
City Savings Trust [Member]
Subordinate Debenture [Line Items]
Trust Preferred Capital Securities Sold					$ 5,000,000
Securities bearing interest rate						90-day LIBOR plus 3.10%
Junior subordinated debentures and the securities variable rate					3.10%
LIBOR period						90 days
Interest rate on junior subordinated debentures and securities						4.79%
Junior subordinated debentures maturity date						Jun. 1, 2033
Carrying value of securities, net of remaining purchase discount						$ 4,400,000

Employee Stock Ownership Plan -

Employee Stock Ownership Plan - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Eligible compensation for ESOP	$ 265,000
Cash contributions and expense recorded for the ESOP	$ 600,000	$ 550,000	$ 450,000
Employee stock ownership plan outstanding shares	963,628
Percentage of outstanding shares	3.80%

Employee Thrift and Defined 109

Employee Thrift and Defined Benefit Plan - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Employee Thrift Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Bank's expense related to the thrift plan	$ 942,000	$ 785,000	$ 848,000
Thrift Plan owns outstanding shares	497,948
Percentage of outstanding shares owns with thrift plan	1.90%
Pentegra Defined Benefit Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Bank's expense related to the thrift plan	$ 0	$ 0
Pentegra Plan date	Aug. 1, 2007
Employer identification number	135,645,888
Plan number	333
Withdrawal liability	$ 3,400,000

Income Tax - Reconciliation of

Income Tax - Reconciliation of Income Taxes (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Currently payable
Federal	$ 12,079	$ 7,467	$ 5,511
Deferred
Federal	331	1,334	1,721
Revaluation of deferred tax assets	2,426
Total income tax expense	14,836	8,801	7,232
Reconciliation of federal statutory to actual tax expense
Federal statutory income tax at 35%	16,783	11,450	9,724
Tax exempt interest	(2,699)	(1,882)	(1,708)
Tax exempt income	(638)	(575)	(488)
Stock compensation	(546)
Revaluation of deferred tax assets	2,426
Other tax exempt income	(456)	(608)	(199)
Nondeductible and other	(34)	416	(97)
Total income tax expense	$ 14,836	$ 8,801	$ 7,232

Income Tax - Reconciliation 111

Income Tax - Reconciliation of Income Taxes (Parenthetical) (Detail)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Tax Disclosure [Abstract]
Federal statutory income tax rate	35.00%	35.00%	35.00%

Income Tax - Reconciliation 112

Income Tax - Reconciliation of Deferred Tax Assets & Liabilities (Detail) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Assets
Allowance for loan losses	$ 3,396	$ 5,581
Net operating loss (from acquisitions)	1,658	2,368
Director and employee benefits	2,276	3,124
Unrealized loss on AFS securities and fair value hedge	1,147	937
Accrued Pension	852	1,323
Fair value adjustment on acquisitions	1,087	2,340
Other	1,083	1,593
Total assets	11,499	17,266
Liabilities
Depreciation	(1,680)	(1,916)
State tax	(210)	(341)
Federal Home Loan Bank stock dividends	(339)	(474)
Difference in basis of intangible assets	(2,831)	(4,654)
Other	(125)	(431)
Total liabilities	(5,185)	(7,816)
Valuation allowance	(1,613)	(2,018)
Net deferred tax asset	$ 4,701	$ 7,432

Income Tax - Additional Informa

Income Tax - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Taxes [Line Items]
U.S. federal corporate tax rate		35.00%	35.00%	35.00%
Previously acquired institutions amount of allocated income to bad debt deductions		$ 12,800,000
Unrecorded deferred income tax liability		$ 2,700,000
Bad debt reserve, description		Retained earnings of the Bank include approximately $12.8 million for which no deferred income tax liability has been recognized. This amount represents an allocation of previously acquired institutions income to bad debt deductions as of December 31, 1987 for tax purposes only. Reductions of amounts so allocated for purposes other than tax bad debt losses including redemption of bank stock or excess dividends, or loss of “bank” status would create income for tax purposes only, which would be subject to the then-current corporate income tax rate.
Scenario, Forecast [Member]
Income Taxes [Line Items]
U.S. federal corporate tax rate	21.00%
State Tax Jurisdiction [Member]
Income Taxes [Line Items]
Operating loss carry forwards		$ 25,200,000
Federal Jurisdiction [Member]
Income Taxes [Line Items]
Operating loss carry forwards		$ 74,000
Minimum [Member] | State Tax Jurisdiction [Member]
Income Taxes [Line Items]
Operating loss carry forward expiration year		2,024
Minimum [Member] | Federal Jurisdiction [Member]
Income Taxes [Line Items]
Operating loss carry forward expiration year		2,032

Accumulated Other Comprehens114

Accumulated Other Comprehensive Loss - Components of Accumulated Other Comprehensive Loss (Detail) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Accumulated Other Comprehensive Income (Loss) [Line Items]
Tax effect	$ 1,914	$ 3,039
Total accumulated other comprehensive loss	(3,551)	(5,644)
Unrealized Gain (Loss) on Securities Available for Sale [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive income (loss), before tax	(3,937)	(6,007)
Unamortized Gain on Securities Held to Maturity, Previously Transferred from AFS [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive income (loss), before tax	200	456
Unrealized Loss on Derivative Instruments [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive income (loss), before tax	$ (1,728)	$ (3,132)

Commitments, Off Balance Sheets

Commitments, Off Balance Sheets Risk and Contingencies - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Commitments and Contingencies Disclosure [Abstract]
Commitments to make loans	$ 802,900,000	$ 808,300,000
Commitments under outstanding standby letters of credit	3,400,000	$ 1,000,000
Anticipated losses from unused commitments	$ 0

Regulatory Capital - Summary of

Regulatory Capital - Summary of Regulatory Capital Requirement (Detail) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Total capital (to risk-weighted assets), Actual, Amount	$ 384,800	$ 316,576
Total capital (to risk-weighted assets), Actual, Ratio	12.91%	13.87%
Total capital (to risk-weighted assets), For capital adequacy purposes, Amount	$ 238,543	$ 182,596
Total capital (to risk-weighted assets), For capital adequacy purposes, Ratio	8.00%	8.00%
Total capital (to risk-weighted assets), Required for capital1 adequacy purposes with capital buffer, Amount	$ 275,816	$ 196,976
Total capital (to risk-weighted assets), Required for capital1 adequacy purposes with capital buffer, Ratio	9.25%	8.63%
Tier 1 capital (to average assets), Actual, Amount	$ 368,355	$ 301,739
Tier 1 capital (to average assets), Actual, Ratio	12.35%	13.22%
Tier 1 capital (to average assets), For capital adequacy purposes, Amount	$ 178,907	$ 136,947
Tier 1 capital (to average assets), For capital adequacy purpose, Ratio	6.00%	6.00%
Tier 1 capital (to average assets), Required for capital1 adequacy purposes with capital buffer, Amount	$ 216,180	$ 151,326
Tier 1 capital (to average assets), Required for capital1 adequacy purposes with capital buffer, Ratio	7.25%	6.63%
Common equity tier 1 capital, Actual Amount	$ 329,892	$ 263,313
Common equity tier 1 capital, Actual Ratio	11.06%	11.50%
Common equity tier 1 capital,For capital adequacy purposes, Amount	$ 134,181	$ 103,036
Common equity tier 1 capital, For capital adequacy purpose, Ratio	4.50%	4.50%
Common equity tier 1 capital (to risk-weighted assets), Required for capital1 adequacy purposes with capital buffer, Amount	$ 171,454	$ 117,460
Common equity tier 1 capital (to risk-weighted assets), Required for capital1 adequacy purposes with capital buffer, Ratio	5.75%	5.13%
Tier 1 capital (to average assets), Actual, Amount	$ 368,355	$ 301,739
Tier 1 capital (to average assets), Actual, Ratio	9.92%	10.44%
Tier 1 capital (to average assets), For capital adequacy purposes, Amount	$ 148,503	$ 115,609
Tier 1 capital (to average assets), For capital adequacy purpose, Ratio	4.00%	4.00%
Tier 1 capital (to average assets), Required for capital1 adequacy purposes with capital buffer, Amount	$ 148,503	$ 115,609
Tier 1 capital (to average assets), Required for capital1 adequacy purposes with capital buffer, Ratio	4.00%	4.00%
Bank [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Total capital (to risk-weighted assets), Actual, Amount	$ 382,788	$ 319,013
Total capital (to risk-weighted assets), Actual, Ratio	12.85%	13.98%
Total capital (to risk-weighted assets), For capital adequacy purposes, Amount	$ 238,386	$ 182,541
Total capital (to risk-weighted assets), For capital adequacy purposes, Ratio	8.00%	8.00%
Total capital (to risk-weighted assets), Required for capital1 adequacy purposes with capital buffer, Amount	$ 275,634	$ 196,916
Total capital (to risk-weighted assets), Required for capital1 adequacy purposes with capital buffer, Ratio	9.25%	8.63%
Total capital (to risk-weighted assets), For well capitalized purpose, Amount	$ 297,982	$ 228,176
Total capital (to risk-weighted assets), For well capitalized purpose, Ratio	10.00%	10.00%
Tier 1 capital (to average assets), Actual, Amount	$ 366,343	$ 304,176
Tier 1 capital (to average assets), Actual, Ratio	12.29%	13.33%
Tier 1 capital (to average assets), For capital adequacy purposes, Amount	$ 178,790	$ 136,905
Tier 1 capital (to average assets), For capital adequacy purpose, Ratio	6.00%	6.00%
Tier 1 capital (to average assets), Required for capital1 adequacy purposes with capital buffer, Amount	$ 216,038	$ 151,280
Tier 1 capital (to average assets), Required for capital1 adequacy purposes with capital buffer, Ratio	7.25%	6.63%
Tier 1 capital (to average assets), For well capitalized purpose, Amount	$ 238,386	$ 182,540
Tier 1 capital (to average assets), For well capitalized purposes, Ratio	8.00%	8.00%
Common equity tier 1 capital, Actual Amount	$ 366,343	$ 304,176
Common equity tier 1 capital, Actual Ratio	12.29%	13.33%
Common equity tier 1 capital,For capital adequacy purposes, Amount	$ 134,092	$ 102,679
Common equity tier 1 capital, For capital adequacy purpose, Ratio	4.50%	4.50%
Common equity tier 1 capital (to risk-weighted assets), Required for capital1 adequacy purposes with capital buffer, Amount	$ 171,340	$ 117,054
Common equity tier 1 capital (to risk-weighted assets), Required for capital1 adequacy purposes with capital buffer, Ratio	5.75%	5.13%
Common equity tier 1 capital, For well capitalized purpose, Amount	$ 193,689	$ 148,314
Common equity tier 1 capital, For well capitalized purposes, Ratio	6.50%	6.50%
Tier 1 capital (to average assets), Actual, Amount	$ 366,343	$ 304,176
Tier 1 capital (to average assets), Actual, Ratio	9.89%	9.93%
Tier 1 capital (to average assets), For capital adequacy purposes, Amount	$ 148,116	$ 122,521
Tier 1 capital (to average assets), For capital adequacy purpose, Ratio	4.00%	4.00%
Tier 1 capital (to average assets), Required for capital1 adequacy purposes with capital buffer, Amount	$ 148,116	$ 122,521
Tier 1 capital (to average assets), Required for capital1 adequacy purposes with capital buffer, Ratio	4.00%	4.00%
Tier 1 capital (to average assets), For well capitalized purpose, Amount	$ 185,145	$ 153,151
Tier 1 capital (to average assets), For well capitalized purposes, Ratio	5.00%	5.00%

Regulatory Capital - Additional

Regulatory Capital - Additional Information (Detail)	Dec. 31, 2019	Dec. 31, 2017	Dec. 31, 2015
Schedule Of Regulatory Assets And Liabilities [Line Items]
Capital conservation buffer		1.25%	0.00%
Scenario, Forecast [Member]
Schedule Of Regulatory Assets And Liabilities [Line Items]
Capital conservation buffer	2.50%

Share-Based Compensation - Addi

Share-Based Compensation - Additional Information (Detail)	Nov. 14, 2016	Dec. 31, 2017USD ($)$ / sharesshares	Dec. 31, 2016USD ($)$ / shares	Dec. 31, 2015USD ($)$ / shares
Stock Based Compensation [Line Items]
Stock split ratio	1.5
Share-based compensation, performance awards, performance goals description		The performance shares that are awarded become earned and vested based on the achievement of certain performance goals during a performance period as established by the Committee at the time of each grant. The performance goals are based on a comparison of the Company’s average performance over the performance period for the return on common equity, compounded annual growth rate of total assets, and return on average assets, all as relative to the average performance for publicly traded banks with total assets between $1 billion and $5 billion on the SNL Bank Index. Holders of performance share awards receive pass-through dividends but do not have any voting rights before the performance shares are earned and vested.
Total assets		$ 3,964,303,000	$ 3,141,156,000
Tax benefit associated with compensation expense		114,000	113,000	$ 101,000
Total compensation cost		325,000	324,000	288,000
Total compensation cost		1,700,000	608,000	643,000
Cash received from option exercise		1,600,000	214,000	403,000
Actual tax benefit realized for the tax deductions		522,000	$ 158,000	$ 151,000
Unrecognized compensation cost		$ 911,000
Weighted-average period cost over which cost is expected to be recognized		1 year 6 months
Option Activity Under the 2013 Plan [Member]
Stock Based Compensation [Line Items]
Maximum common shares issued under the plan | shares		1,037,550
Number of shares available incentive stock options | shares		150,000
Non-option awards granted | shares		600,000
Weighted average grant-date fair value of options granted | $ / shares		$ 7.25	$ 3.89	$ 4.09
Option Activity Under the 2003 Plan [Member]
Stock Based Compensation [Line Items]
Maximum common shares issued under the plan | shares		506,250
Number of shares available incentive stock options | shares		506,250
Non-option awards granted | shares		253,125
Additional common shares available for issuance | shares		590,625
Grants vest at the end of		4 years
Option Activity Under the 2003 Plan [Member] | Minimum [Member]
Stock Based Compensation [Line Items]
Grants vest at the end of		3 years
Option Activity Under the 2003 Plan [Member] | Maximum [Member]
Stock Based Compensation [Line Items]
Grants vest at the end of		5 years
Performance Based Share Awards [Member] | Minimum [Member]
Stock Based Compensation [Line Items]
Total assets		$ 1,000,000,000
Performance Based Share Awards [Member] | Maximum [Member]
Stock Based Compensation [Line Items]
Total assets		5,000,000,000
Restricted and Performance Shares [Member]
Stock Based Compensation [Line Items]
Tax benefit associated with compensation expense		47,000	$ 99,000	$ 124,000
Total compensation cost		$ 135,000	$ 284,000	$ 355,000

Share-Based Compensation - Summ

Share-Based Compensation - Summary of Option Activity (Detail) - Option Activity Under the 2003 Plan [Member] $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2017USD ($)$ / sharesshares
Schedule Of Stock Option Activity [Line Items]
Option outstanding, Shares, Beginning balance | shares	36,635
Option granted, Shares | shares	0
Option Exercised, Shares | shares	(9,185)
Option forfeited, Shares | shares	0
Option outstanding, Shares, Ending balance | shares	27,450
Option Exercisable, Shares, Ending balance | shares	27,450
Option outstanding, Weighted Average Exercise Price, Beginning balance | $ / shares	$ 7.25
Option Granted, Weighted Average Exercise Price | $ / shares	0
Option Exercised, Weighted Average Exercise Price | $ / shares	6.86
Option Forfeited, Weighted Average Exercise Price | $ / shares	0
Option Outstanding, Weighted Average Exercise Price, Ending balance | $ / shares	7.37
Option Exercisable, Weighted Average Exercise Price, Ending balance | $ / shares	$ 7.37
Option Outstanding, Weighted Average Remaining Contractual Term	2 years 8 months 23 days
Option Exercisable, Weighted Average Remaining Contractual Term	2 years 8 months 23 days
Option outstanding, Aggregate Intrinsic Value | $	$ 560,691
Option Exercisable, Aggregate Intrinsic Value | $	$ 560,691

Share-Based Compensation - Fair

Share-Based Compensation - Fair Value of Options Granted (Detail)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions and Methodology [Abstract]
Dividend yields	1.75%	2.34%	2.35%
Volatility factors of expected market price of common stock	28.52%	28.60%	28.97%
Risk-free interest rates	2.42%	1.83%	2.10%
Expected life of options	8 years	8 years	8 years

Share-Based Compensation - S121

Share-Based Compensation - Summary of Option Activity Under 2013 Plan (Detail) - Option Activity Under the 2013 Plan [Member] $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2017USD ($)$ / sharesshares
Schedule Of Stock Option Activity [Line Items]
Option outstanding, Shares, Beginning balance | shares	286,586
Option granted, Shares | shares	43,502
Option Exercised, Shares | shares	(108,434)
Option forfeited, Shares | shares	(5,871)
Option outstanding, Shares, Ending balance | shares	215,783
Option Exercisable, Shares, Ending balance | shares	88,036
Option outstanding, Weighted Average Exercise Price, Beginning balance | $ / shares	$ 15.08
Option Granted, Weighted Average Exercise Price | $ / shares	25.14
Option Exercised, Weighted Average Exercise Price | $ / shares	14.77
Option Forfeited, Weighted Average Exercise Price | $ / shares	15.64
Option Outstanding, Weighted Average Exercise Price, Ending balance | $ / shares	17.25
Option Exercisable, Weighted Average Exercise Price, Ending balance | $ / shares	$ 14.77
Option Outstanding, Weighted Average Remaining Contractual Term	7 years 8 months 9 days
Option Exercisable, Weighted Average Remaining Contractual Term	6 years 7 months 13 days
Option outstanding, Aggregate Intrinsic Value | $	$ 2,276,823
Option Exercisable, Aggregate Intrinsic Value | $	$ 1,147,538

Share-Based Compensation - S122

Share-Based Compensation - Summary of Status of Non-vested, Restricted and Performance Shares (Detail) - Restricted and Performance Shares [Member]	12 Months Ended
	Dec. 31, 2017$ / sharesshares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Non-vested beginning of year, Shares | shares	70,959
Vested, Shares | shares	(6,754)
Granted, Shares | shares	41,786
Forfeited, Shares | shares	(9,461)
Non-vested, end of year, Shares | shares	96,530
Non-vested beginning of year, Weighted Average Grant Date Fair Value | $ / shares	$ 15.59
Vested, Weighted Average Grant Date Fair Value | $ / shares	14.80
Granted, Weighted Average Grant Date Fair Value | $ / shares	25.49
Forfeited, Weighted Average Grant Date Fair Value | $ / shares	15.05
Non-vested end of year, Weighted Average Grant Date Fair Value | $ / shares	$ 19.98

Derivative Financial Instrum123

Derivative Financial Instruments - Additional Information (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Derivative [Line Items]
LIBOR period	3 months
Weighted average fixed rate	5.81%
Recorded period of effectiveness of cash flow hedges on net income	12 months
Recorded period of effectiveness of fair value hedges on net income	12 months
Recorded period of effectiveness of fair value of derivatives on net income	12 months
LaPorte Bancorp Inc [Member]
Derivative [Line Items]
LIBOR period	1 month
Weighted average fixed rate	2.31%
Cash Flow Hedging [Member]
Derivative [Line Items]
Notional amount of interest	$ 30.5	$ 30.5
Cash Flow Hedging [Member] | LaPorte Bancorp Inc [Member]
Derivative [Line Items]
Notional amount of interest	30
Derivative in Fair Value Hedging Relationship [Member]
Derivative [Line Items]
Notional amount of interest	$ 154.6	$ 122.4

Derivative Financial Instrum124

Derivative Financial Instruments - Fair Value of Derivative Financial Instruments (Detail) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Derivatives, Fair Value [Line Items]
Total Asset Derivatives	$ 954	$ 608
Total Liability Derivatives	2,542	3,160
Derivatives Designated as Hedging Instruments [Member]
Derivatives, Fair Value [Line Items]
Total Asset Derivatives	811	6
Total Liability Derivatives	2,539	3,138
Derivatives Designated as Hedging Instruments [Member] | Interest Rate Contracts One [Member] | Other Liabilities [Member]
Derivatives, Fair Value [Line Items]
Total Liability Derivatives	811	6
Derivatives Designated as Hedging Instruments [Member] | Interest Rate Contracts Two [Member] | Other Liabilities [Member]
Derivatives, Fair Value [Line Items]
Total Liability Derivatives	1,728	3,132
Derivatives Designated as Hedging Instruments [Member] | Interest Rate Contracts Two [Member] | Other Assets [Member]
Derivatives, Fair Value [Line Items]
Total Asset Derivatives	811	6
Derivatives Not Designated as Hedging Instruments [Member]
Derivatives, Fair Value [Line Items]
Total Asset Derivatives	143	602
Total Liability Derivatives	3	22
Derivatives Not Designated as Hedging Instruments [Member] | Mortgage Loan Contracts [Member] | Other Liabilities [Member]
Derivatives, Fair Value [Line Items]
Total Liability Derivatives	3	22
Derivatives Not Designated as Hedging Instruments [Member] | Mortgage Loan Contracts [Member] | Other Assets [Member]
Derivatives, Fair Value [Line Items]
Total Asset Derivatives	$ 143	$ 602

Derivative Financial Instrum125

Derivative Financial Instruments - Effect of Derivative Instruments on Condensed Consolidated Statements of Income Derivative in Cash Flow Hedging Relationship (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Cash Flow Hedging [Member] | Interest Rate Contracts One [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Comprehensive Income on Derivative (Effective Portion)	$ 913	$ 6	$ 127

Derivative Financial Instrum126

Derivative Financial Instruments - Effect of Derivative Instruments on Consolidated Statements of Income Derivative in Fair Value Hedging Relationship (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Interest Income - Loans [Member] | Derivative in Fair Value Hedging Relationship [Member] | Interest Rate Contracts One [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain (Loss) Recognized on Derivative	$ (817)	$ (1,776)	$ 574
Interest Income - Loans [Member] | Derivative in Fair Value Hedging Relationship [Member] | Interest Rate Contracts Two [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain (Loss) Recognized on Derivative	817	1,776	(574)
Derivatives Not Designated as Hedging Instruments [Member] | Other income - Gain on Sale of Loans [Member] | Mortgage Loan Contracts [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain (Loss) Recognized on Derivative	$ (439)	$ (62)	$ 195

Disclosures about Fair Value127

Disclosures about Fair Value of Assets and Liabilities - Fair Value Measurements of Assets and Liabilities Recognized on a Recurring Basis (Detail) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total available-for-sale securities, Fair Value	$ 509,665	$ 439,831
U.S. Treasury and Federal Agencies [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total available-for-sale securities, Fair Value	19,052	7,989
State and Municipal [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total available-for-sale securities, Fair Value	149,564	116,592
Federal Agency Collateralized Mortgage Obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total available-for-sale securities, Fair Value	130,365	137,195
Federal Agency Mortgage-backed Pools [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total available-for-sale securities, Fair Value	208,657	176,726
Corporate Notes [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total available-for-sale securities, Fair Value	385	$ 1,329
Private Labeled Mortgage-backed Pools [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total available-for-sale securities, Fair Value	1,642
Recurring Basis [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total available-for-sale securities, Fair Value	509,665		$ 439,831
Recurring Basis [Member] | U.S. Treasury and Federal Agencies [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total available-for-sale securities, Fair Value	19,052		7,989
Recurring Basis [Member] | State and Municipal [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total available-for-sale securities, Fair Value	149,564		116,592
Recurring Basis [Member] | Federal Agency Collateralized Mortgage Obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total available-for-sale securities, Fair Value	130,365		137,195
Recurring Basis [Member] | Federal Agency Mortgage-backed Pools [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total available-for-sale securities, Fair Value	208,657		176,726
Recurring Basis [Member] | Corporate Notes [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total available-for-sale securities, Fair Value	385		1,329
Recurring Basis [Member] | Private Labeled Mortgage-backed Pools [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total available-for-sale securities, Fair Value	1,642
Recurring Basis [Member] | Hedged Loans [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivatives, fair value	154,575		122,345
Recurring Basis [Member] | Forward Sale Commitments [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivatives, fair value	143		602
Recurring Basis [Member] | Interest Rate Swap [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivatives, fair value	(917)		(3,138)
Recurring Basis [Member] | Commitments To Originate Loans [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivatives, fair value	(3)		(22)
Recurring Basis [Member] | Significant Other Observable Inputs (Level 2) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total available-for-sale securities, Fair Value	509,665		439,831
Recurring Basis [Member] | Significant Other Observable Inputs (Level 2) [Member] | U.S. Treasury and Federal Agencies [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total available-for-sale securities, Fair Value	19,052		7,989
Recurring Basis [Member] | Significant Other Observable Inputs (Level 2) [Member] | State and Municipal [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total available-for-sale securities, Fair Value	149,564		116,592
Recurring Basis [Member] | Significant Other Observable Inputs (Level 2) [Member] | Federal Agency Collateralized Mortgage Obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total available-for-sale securities, Fair Value	130,365		137,195
Recurring Basis [Member] | Significant Other Observable Inputs (Level 2) [Member] | Federal Agency Mortgage-backed Pools [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total available-for-sale securities, Fair Value	208,657		176,726
Recurring Basis [Member] | Significant Other Observable Inputs (Level 2) [Member] | Corporate Notes [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total available-for-sale securities, Fair Value	385		1,329
Recurring Basis [Member] | Significant Other Observable Inputs (Level 2) [Member] | Private Labeled Mortgage-backed Pools [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total available-for-sale securities, Fair Value	1,642
Recurring Basis [Member] | Significant Other Observable Inputs (Level 2) [Member] | Hedged Loans [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivatives, fair value	154,575		122,345
Recurring Basis [Member] | Significant Other Observable Inputs (Level 2) [Member] | Forward Sale Commitments [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivatives, fair value	143		602
Recurring Basis [Member] | Significant Other Observable Inputs (Level 2) [Member] | Interest Rate Swap [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivatives, fair value	(917)		(3,138)
Recurring Basis [Member] | Significant Other Observable Inputs (Level 2) [Member] | Commitments To Originate Loans [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivatives, fair value	$ (3)		$ (22)

Disclosures about Fair Value128

Disclosures about Fair Value of Assets and Liabilities - Realized Gains and Losses included in Net Income for Periods in Consolidated Statements of Income (Detail) - Non Interest Income Total Gains and Losses [Member] - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Included in net income	$ (439)	$ (62)	$ 195
Hedged Loans [Member]
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Included in net income	(817)	(1,776)	574
Interest Rate Swap [Member]
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Included in net income	817	1,776	(574)
Derivative Loan Commitments [Member]
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Included in net income	$ (439)	$ (62)	$ 195

Disclosures about Fair Value129

Disclosures about Fair Value of Assets and Liabilities - Other Assets Measured at Fair Value on Nonrecurring Basis (Detail) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Fair Value Of Assets And Liabilities Measured On Non Recurring Basis [Line Items]
Impaired loans	$ 11,602
Significant Unobservable Inputs (Level 3) [Member]
Fair Value Of Assets And Liabilities Measured On Non Recurring Basis [Line Items]
Impaired loans	11,602
Significant Unobservable Inputs (Level 3) [Member] | Impaired Loans [Member]
Fair Value Of Assets And Liabilities Measured On Non Recurring Basis [Line Items]
Impaired loans	6,957	$ 2,246
Significant Unobservable Inputs (Level 3) [Member] | Mortgage Servicing Rights [Member]
Fair Value Of Assets And Liabilities Measured On Non Recurring Basis [Line Items]
Impaired loans	11,602	11,174
Fair Value, Measurements, Nonrecurring [Member] | Impaired Loans [Member]
Fair Value Of Assets And Liabilities Measured On Non Recurring Basis [Line Items]
Impaired loans	6,957	2,246
Fair Value, Measurements, Nonrecurring [Member] | Mortgage Servicing Rights [Member]
Fair Value Of Assets And Liabilities Measured On Non Recurring Basis [Line Items]
Impaired loans		11,174
Fair Value, Measurements, Nonrecurring [Member] | Significant Unobservable Inputs (Level 3) [Member] | Impaired Loans [Member]
Fair Value Of Assets And Liabilities Measured On Non Recurring Basis [Line Items]
Impaired loans	$ 6,957	2,246
Fair Value, Measurements, Nonrecurring [Member] | Significant Unobservable Inputs (Level 3) [Member] | Mortgage Servicing Rights [Member]
Fair Value Of Assets And Liabilities Measured On Non Recurring Basis [Line Items]
Impaired loans		$ 11,174

Disclosures about Fair Value130

Disclosures about Fair Value of Assets and Liabilities - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Fair Value Disclosures [Abstract]
Reduced in carrying amount of mortgage servicing rights	$ 587,000	$ 507,000

Disclosures about Fair Value131

Disclosures about Fair Value of Assets and Liabilities - Qualitative Information about Unobservable Inputs Used in Recurring and Nonrecurring Level 3 Fair Value Measurements, Other than Goodwill (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Fair Value	$ 11,602
Discount rate	10.00%
Significant Unobservable Inputs (Level 3) [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Fair Value	$ 11,602
Significant Unobservable Inputs (Level 3) [Member] | Impaired Loans [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Fair Value	$ 6,957	$ 2,246
Valuation Technique	Collateral based measurement
Impaired loans	Discount to reflect current market conditions and ultimate collectability
Significant Unobservable Inputs (Level 3) [Member] | Mortgage Servicing Rights [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Fair Value	$ 11,602	$ 11,174
Valuation Technique	Discounted cashflows
Impaired loans	Discount rate, Constant prepayment rate, Probability of default
Minimum [Member] | Significant Unobservable Inputs (Level 3) [Member] | Impaired Loans [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Discount to reflect current market conditions and ultimate collectability	0.00%	10.00%
Minimum [Member] | Significant Unobservable Inputs (Level 3) [Member] | Mortgage Servicing Rights [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Discount rate	9.60%	10.00%
Constant prepayment rate	9.20%	4.00%
Probability of default	0.00%	1.00%
Maximum [Member] | Significant Unobservable Inputs (Level 3) [Member] | Impaired Loans [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Discount to reflect current market conditions and ultimate collectability	46.80%	16.00%
Maximum [Member] | Significant Unobservable Inputs (Level 3) [Member] | Mortgage Servicing Rights [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Discount rate	10.80%	16.00%
Constant prepayment rate	27.70%	7.00%
Probability of default	1.50%	10.00%
Weighted Average [Member] | Significant Unobservable Inputs (Level 3) [Member] | Impaired Loans [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Discount to reflect current market conditions and ultimate collectability	2.60%	13.00%
Weighted Average [Member] | Significant Unobservable Inputs (Level 3) [Member] | Mortgage Servicing Rights [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Discount rate	9.70%	13.00%
Constant prepayment rate	10.50%	4.60%
Probability of default	0.20%	4.50%

Fair Value of Financial Inst132

Fair Value of Financial Instruments - Summary of Estimated Fair Values of Financial Instruments (Detail) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Assets
Cash and due from banks	$ 76,441	$ 70,832
Investment securities, held to maturity	200,448	193,194
Loans held for sale	3,094	8,087
Loans excluding loan level hedges, net	2,824,827	2,127,894
Stock in FHLB and FRB	18,105	23,932
Interest receivable	16,244	12,713
Liabilities
Non-interest bearing deposits	601,805	496,248
Interest-bearing deposits	2,279,198	1,974,962
Borrowings	564,157	267,489
Subordinated debentures	37,653	37,456
Interest payable	886	472
Carrying Amount [Member]
Assets
Cash and due from banks	76,441	70,832
Investment securities, held to maturity	200,448	193,194
Loans held for sale	3,094	8,087
Loans excluding loan level hedges, net	2,661,026	1,998,804
Stock in FHLB	18,105
Stock in FHLB and FRB		23,932
Interest receivable	16,244	12,713
Liabilities
Non-interest bearing deposits	601,805	496,248
Interest-bearing deposits	2,279,198	1,974,962
Borrowings	564,157	267,489
Subordinated debentures	37,653	37,456
Interest payable	886	472
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Assets
Cash and due from banks	76,441	70,832
Liabilities
Non-interest bearing deposits	601,805	496,248
Significant Other Observable Inputs (Level 2) [Member]
Assets
Investment securities, held to maturity	201,085	194,086
Stock in FHLB	18,105
Stock in FHLB and FRB		23,932
Interest receivable	16,244	12,713
Liabilities
Interest-bearing deposits	2,156,487	1,839,167
Borrowings	560,057	261,141
Subordinated debentures	35,994	36,371
Interest payable	886	472
Significant Unobservable Inputs (Level 3) [Member]
Assets
Loans held for sale	3,094	8,087
Loans excluding loan level hedges, net	$ 2,585,879	$ 1,965,928

Condensed Financial Informat133

Condensed Financial Information (Parent Company Only) - Condensed Balance Sheets (Detail) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Assets
Total cash and cash equivalents	$ 76,441	$ 70,832	$ 48,650	$ 43,476
Other assets	40,963	44,620
Total assets	3,964,303	3,141,156
Liabilities
Borrowings	564,157	267,489
Subordinated debentures	37,653	37,456
Other liabilities	23,526	23,674
Stockholders' Equity	457,078	340,855	266,832	194,414
Total liabilities and stockholders' equity	3,964,303	3,141,156
Parent Company [Member]
Assets
Total cash and cash equivalents	13,361	15,736	$ 26,507	$ 19,195
Investment in Subsidiaries	497,623	386,389
Other assets	1,318	2,504
Total assets	512,302	404,629
Liabilities
Borrowings	12,500	19,500
Subordinated debentures	37,653	37,456
Other liabilities	5,071	6,818
Stockholders' Equity	457,078	340,855
Total liabilities and stockholders' equity	$ 512,302	$ 404,629

Condensed Financial Informat134

Condensed Financial Information (Parent Company Only) - Condensed Statements of Income (Detail) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Operating Income (Expense)
Other income									$ 1,773	$ 1,039	$ 1,103
Interest expense	$ (5,319)	$ (4,191)	$ (3,607)	$ (3,266)	$ (8,450)	$ (4,552)	$ (3,781)	$ (3,754)	(16,383)	(20,537)	(13,854)
Employee benefit expense									(51,375)	(44,013)	(37,712)
Income Before Income Tax									47,953	32,713	27,781
Income Tax Benefit									(14,836)	(8,801)	(7,232)
Net income	7,650	8,171	9,072	8,224	5,603	6,602	6,326	5,381	33,117	23,912	20,549
Preferred stock dividend										(42)	(125)
Net Income Available to Common Shareholders	$ 7,650	$ 8,171	$ 9,072	$ 8,224	$ 5,603	$ 6,602	$ 6,326	$ 5,339	33,117	23,870	20,424
Parent Company [Member]
Operating Income (Expense)
Dividend income from Bank									27,000	20,000	30,470
Investment income										33	15
Other income									540	42	24
Interest expense									(2,791)	(2,376)	(2,009)
Employee benefit expense									(1,094)	(1,158)	(1,093)
Other expense									(326)	1,279	910
Income Before Undistributed Income of Subsidiaries									23,329	17,820	28,317
Undistributed Income of Subsidiaries									8,804	5,938	(8,168)
Income Before Income Tax									32,133	23,758	20,149
Income Tax Benefit									984	154	400
Net income									33,117	23,912	20,549
Preferred stock dividend										(42)	(125)
Net Income Available to Common Shareholders									$ 33,117	$ 23,870	$ 20,424

Condensed Financial Informat135

Condensed Financial Information (Parent Company Only) - Condensed Statements of Comprehensive Income (Detail) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Condensed Comprehensive Income [Line Items]
Net income	$ 7,650	$ 8,171	$ 9,072	$ 8,224	$ 5,603	$ 6,602	$ 6,326	$ 5,381	$ 33,117	$ 23,912	$ 20,549
Other Comprehensive Income (Loss)
Change in fair value of derivative instruments, net of taxes									913	6	127
Other Comprehensive Income (Loss), Net of Tax									2,093	(4,921)	(2,244)
Comprehensive Income									35,210	18,991	18,305
Parent Company [Member]
Condensed Comprehensive Income [Line Items]
Net income									33,117	23,912	20,549
Other Comprehensive Income (Loss)
Change in fair value of derivative instruments, net of taxes									913	6	127
Unrealized appreciation for the period on held-to-maturity securities, net of taxes									(166)	(424)	(357)
Unrealized appreciation (depreciation) on available-for-sale securities, net of taxes									1,371	(3,310)	(1,891)
Less: reclassification adjustment for realized gains included in net income, net of taxes									(25)	(1,193)	(123)
Other Comprehensive Income (Loss), Net of Tax									2,093	(4,921)	(2,244)
Comprehensive Income									$ 35,210	$ 18,991	$ 18,305

Condensed Financial Informat136

Condensed Financial Information (Parent Company Only) - Condensed Statements of Cash Flows (Detail) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Operating Activities
Net income	$ 7,650	$ 8,171	$ 9,072	$ 8,224	$ 5,603	$ 6,602	$ 6,326	$ 5,381	$ 33,117	$ 23,912	$ 20,549
Items not requiring (providing) cash
Change in Share based compensation									325	324	288
Other assets									6,173	489	8,569
Other liabilities									(5,776)	(8,381)	(472)
Net cash provided by operating activities									49,064	25,548	35,230
Investing Activities
Net cash used in investing activities									(279,874)	226,390	(124,188)
Financing Activities
Redemption of preferred stock										(12,500)
Net change in borrowings									259,895	(255,994)	49,421
Dividends paid on preferred shares										(42)	(125)
Dividends paid on common shares									(11,720)	(8,382)	(6,216)
Exercise of stock options									1,600	214	403
Net cash provided by (used in) financing activities									236,419	(229,756)	94,132
Net Change in Cash and Cash Equivalents									5,609	22,182	5,174
Cash and Cash Equivalents, Beginning of Period				70,832				48,650	70,832	48,650	43,476
Cash and Cash Equivalents, End of Period	76,441				70,832				76,441	70,832	48,650
Peoples Bancorp Inc [Member]
Investing Activities
Acquisition of businesses											182,413
Kosciusko Financial Inc [Member]
Investing Activities
Acquisition of businesses										30,437
LaPorte Bancorp Inc [Member]
Investing Activities
Acquisition of businesses										116,521
Central National Bank & Trust [Member]
Investing Activities
Acquisition of businesses										22,549
Lafayette Community Bancorp [Member]
Investing Activities
Acquisition of businesses									20,425
Wolverine Bancorp Inc [Member]
Investing Activities
Acquisition of businesses									12,788
Parent Company [Member]
Operating Activities
Net income									33,117	23,912	20,549
Items not requiring (providing) cash
Equity in undistributed net income of subsidiaries									(8,804)	(5,938)	8,168
Change in Share based compensation									325	284	288
Amortization of unearned compensation									135	324	355
Other assets									388	888	(634)
Other liabilities									(1,675)	(244)	(13)
Net cash provided by operating activities									23,486	19,226	28,713
Investing Activities
Net cash used in investing activities									(8,942)	(29,145)	(19,365)
Financing Activities
Redemption of preferred stock										(12,500)
Net change in borrowings									(6,803)	19,500
Dividends paid on preferred shares										(42)	(125)
Dividends paid on common shares									(11,720)	(8,382)	(6,216)
Exercise of stock options									1,604	572	4,305
Net cash provided by (used in) financing activities									(16,919)	(852)	(2,036)
Net Change in Cash and Cash Equivalents									(2,375)	(10,771)	7,312
Cash and Cash Equivalents, Beginning of Period				$ 15,736				$ 26,507	15,736	26,507	19,195
Cash and Cash Equivalents, End of Period	$ 13,361				$ 15,736				13,361	15,736	26,507
Parent Company [Member] | Peoples Bancorp Inc [Member]
Investing Activities
Acquisition of businesses											$ (19,365)
Parent Company [Member] | Kosciusko Financial Inc [Member]
Investing Activities
Acquisition of businesses										(6,741)
Parent Company [Member] | LaPorte Bancorp Inc [Member]
Investing Activities
Acquisition of businesses										(17,108)
Parent Company [Member] | Central National Bank & Trust [Member]
Investing Activities
Acquisition of businesses										$ (5,296)
Parent Company [Member] | Lafayette Community Bancorp [Member]
Investing Activities
Acquisition of businesses									(1,254)
Parent Company [Member] | Wolverine Bancorp Inc [Member]
Investing Activities
Acquisition of businesses									$ (7,688)

Quarterly Results of Operati137

Quarterly Results of Operations (Unaudited) - Summary of Quarterly Consolidated Results of Operations (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017		Dec. 31, 2016		Dec. 31, 2015
Quarterly Financial Information Disclosure [Abstract]
Interest income	$ 36,774	$ 32,070	$ 30,805	$ 28,834	$ 29,390	$ 28,962	$ 24,650	$ 23,528	$ 128,483		$ 106,529		$ 88,588
Interest expense	5,319	4,191	3,607	3,266	8,450	4,552	3,781	3,754	16,383		20,537		13,854
Net interest income	31,455	27,879	27,198	25,568	20,940	24,410	20,869	19,774	112,100		85,992		74,734
Provision for loan losses	1,100	710	330	330	623	455	232	532	2,470		1,842		3,162
Gain on sale of securities		6	(3)	35	961		767	108	38		1,836		189
Net income	7,650	8,171	9,072	8,224	5,603	6,602	6,326	5,381	33,117		23,912		20,549
Net Income Available to Common Shareholders	$ 7,650	$ 8,171	$ 9,072	$ 8,224	$ 5,603	$ 6,602	$ 6,326	$ 5,339	$ 33,117		$ 23,870		$ 20,424
Earnings per share:
Basic	$ 0.30	$ 0.36	$ 0.41	$ 0.37	$ 0.25	$ 0.31	$ 0.35	$ 0.30	$ 1.44	[1]	$ 1.19	[1]	$ 1.30	[1]
Diluted	$ 0.30	$ 0.36	$ 0.41	$ 0.37	$ 0.25	$ 0.30	$ 0.34	$ 0.30	$ 1.43	[1]	$ 1.19	[1]	$ 1.26	[1]
Average shares outstanding:
Basic	25,140,800	22,580,160	22,176,465	22,175,526	22,155,549	21,538,752	18,268,880	17,924,124	23,035,824		19,987,728		15,765,444
Diluted	25,262,010	22,715,273	22,322,390	22,326,071	22,283,722	21,651,953	18,364,167	18,012,726	23,173,626		20,082,410		16,197,312
[1]	Adjusted for 3:2 stock split on November 14, 2016