Heartland Financial USA (HTLF) 10-Q 8 May 18 2018 Q1 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	3 Months Ended
	Mar. 31, 2018	May 07, 2018
Document and Entity Information [Abstract]
Entity Registrant Name	HEARTLAND FINANCIAL USA INC
Entity Central Index Key	920,112
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Document Type	10-Q
Document Period End Date	Mar. 31, 2018
Document Fiscal Year Focus	2,018
Document Fiscal Period Focus	Q1
Amendment Flag	false
Entity Common Stock, Shares Outstanding		31,068,676

CONSOLIDATED BALANCE SHEETS

CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
ASSETS
Cash and due from banks	$ 143,071	$ 168,723
Interest bearing deposits with the Federal Reserve Bank and other banks and other short-term investments	123,275	27,280
Cash and cash equivalents	266,346	196,003
Time deposits in other financial institutions	6,297	9,820
Securities:
Available for sale, at fair value (cost of $2,080,514 at March 31, 2018, and $2,248,181 at December 31, 2017)	2,027,665	2,216,753
Held to maturity, at cost (fair value of $258,638 at March 31, 2018, and $265,494 at December 31, 2017)	249,766	253,550
Other investments, at cost	22,982	22,563
Loans held for sale	24,376	44,560
Loans receivable:
Held to maturity	6,746,015	6,391,464
Allowance for loan and lease losses	(58,656)	(55,686)
Loans receivable, net	6,687,359	6,335,778
Premises, furniture and equipment, net	171,385	172,324
Premises, furniture and equipment held for sale	1,477	1,977
Other real estate, net	11,801	10,777
Goodwill	270,305	236,615
Core deposit intangibles and customer relationship intangibles, net	41,063	35,203
Servicing rights, net	25,471	25,857
Cash surrender value on life insurance	143,444	142,818
Other assets	106,126	106,141
TOTAL ASSETS	10,055,863	9,810,739
Deposits:
Demand	3,094,457	2,983,128
Savings	4,536,106	4,240,328
Time	910,977	923,453
Total deposits	8,541,540	8,146,909
Short-term borrowings	131,240	324,691
Other borrowings	276,118	285,011
Accrued expenses and other liabilities	55,460	62,671
TOTAL LIABILITIES	9,004,358	8,819,282
STOCKHOLDERS' EQUITY:
Common stock (par value $1 per share; 40,000,000 shares authorized at both March 31, 2018, and December 31, 2017; issued 31,068,239 shares at March 31, 2018, and 29,953,356 shares at December 31, 2017)	31,068	29,953
Capital surplus	557,990	503,709
Retained earnings	500,959	481,331
Accumulated other comprehensive loss	(39,450)	(24,474)
Treasury stock at cost (0 shares at both March 31, 2018, and December 31, 2017)	0	0
TOTAL STOCKHOLDERS' EQUITY	1,051,505	991,457
TOTAL LIABILITIES AND EQUITY	10,055,863	9,810,739
Preferred Stock
STOCKHOLDERS' EQUITY:
Preferred stock	0	0
Series A Junior Participating Preferred Stock
STOCKHOLDERS' EQUITY:
Preferred stock	0	0
Series C Senior Non-Cumulative Perpetual Preferred Stock
STOCKHOLDERS' EQUITY:
Preferred stock	0	0
Series D Senior Non-Cumulative Perpetual Preferred Stock
STOCKHOLDERS' EQUITY:
Preferred stock	$ 938	$ 938

CONSOLIDATED BALANCE SHEETS (Pa

CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Cost of available for sale securities	$ 2,080,514	$ 2,248,181
Fair value of held to maturity securities	$ 258,638	$ 265,494
Common stock, par value (in dollars per share)	$ 1	$ 1
Common stock, shares authorized (in shares)	40,000,000	30,000,000
Common stock, shares issued (in shares)	31,068,239	29,953,356
Treasury stock (in shares)	0	0
Preferred Stock
Preferred stock, par value (in dollars per share)	$ 1	$ 1
Preferred stock, shares authorized (in shares)	17,604	17,604
Preferred stock, shares issued (in shares)	0	0
Preferred stock, shares outstanding (in shares)	0	0
Series A Junior Participating Preferred Stock
Preferred stock, par value (in dollars per share)	$ 1	$ 1
Preferred stock, shares authorized (in shares)	16,000	16,000
Preferred stock, shares issued (in shares)	0	0
Preferred stock, shares outstanding (in shares)	0	0
Series C Senior Non-Cumulative Perpetual Preferred Stock
Preferred stock, par value (in dollars per share)	$ 1	$ 1
Preferred stock, shares authorized (in shares)	81,698	81,698
Preferred stock, shares issued (in shares)	0	0
Preferred stock, shares outstanding (in shares)	0	0
Series D Senior Non-Cumulative Perpetual Preferred Stock
Preferred stock, par value (in dollars per share)	$ 1	$ 1
Preferred stock, shares authorized (in shares)	3,000	3,000
Preferred stock, shares issued (in shares)	745	745
Preferred stock, shares outstanding (in shares)	745	745

CONSOLIDATED STATEMENTS OF INCO

CONSOLIDATED STATEMENTS OF INCOME (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
INTEREST INCOME:
Interest and fees on loans	$ 85,651	$ 66,898
Interest on securities:
Taxable	11,577	8,253
Nontaxable	3,579	5,191
Interest on federal funds sold	0	0
Interest on interest bearing deposits in other financial institutions	407	209
TOTAL INTEREST INCOME	101,214	80,551
INTEREST EXPENSE:
Interest on deposits	5,766	3,730
Interest on short-term borrowings	268	137
Interest on other borrowings	3,596	3,656
TOTAL INTEREST EXPENSE	9,630	7,523
NET INTEREST INCOME	91,584	73,028
Provision for loan losses	4,263	3,641
NET INTEREST INCOME AFTER PROVISION FOR LOAN LOSSES	87,321	69,387
NONINTEREST INCOME:
Service charges and fees	10,079	9,457
Loan servicing income	1,754	1,724
Trust fees	4,680	3,631
Brokerage and insurance commissions	907	1,036
Securities gains, net	1,441	2,482
Unrealized loss on equity securities, net	(28)	0
Net gains on sale of loans held for sale	4,051	6,147
Valuation allowance on commercial servicing rights	(2)	5
Income on bank owned life insurance	614	617
Other noninterest income	1,220	794
TOTAL NONINTEREST INCOME	24,716	25,893
NONINTEREST EXPENSES:
Salaries and employee benefits	48,710	41,767
Occupancy	6,043	5,073
Furniture and equipment	2,749	2,501
Professional fees	8,459	8,309
FDIC insurance assessments	989	807
Advertising	1,940	2,424
Core deposit intangibles and customer relationship intangibles amortization	1,863	1,171
Other real estate and loan collection expenses	732	828
(Gain)/loss on sales/valuations of assets, net	(197)	412
Restructuring expenses	2,564	0
Other noninterest expenses	9,794	8,448
TOTAL NONINTEREST EXPENSES	83,646	71,740
INCOME BEFORE INCOME TAXES	28,391	23,540
Income taxes	5,123	5,530
NET INCOME	23,268	18,010
Preferred dividends	(13)	(19)
Interest expense on convertible preferred debt	0	5
NET INCOME AVAILABLE TO COMMON STOCKHOLDERS	$ 23,255	$ 17,996
EARNINGS PER COMMON SHARE - BASIC (in dollars per share)	$ 0.76	$ 0.68
EARNINGS PER COMMON SHARE - DILUTED (in dollars per share)	0.76	0.68
CASH DIVIDENDS DECLARED PER COMMON SHARE (in dollars per share)	$ 0.13	$ 0.11

CONSOLIDATED STATEMENTS OF INC5

CONSOLIDATED STATEMENTS OF INCOME (Unaudited) (Parenthetical) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Interest expense related to derivatives reclassified from accumulated other comprehensive income	$ 3,596	$ 3,656
Net security gains reclassified from accumulated other comprehensive income	1,441	2,482
Income tax expense reclassified from accumulated other comprehensive income	5,123	5,530
Reclassification out of Accumulated Other Comprehensive Income | Accumulated Net Gain (Loss) from Derivatives
Interest expense related to derivatives reclassified from accumulated other comprehensive income	197	397
Reclassification out of Accumulated Other Comprehensive Income | Accumulated Net Unrealized Investment Gain (Loss)
Net security gains reclassified from accumulated other comprehensive income	1,441	2,482
Reclassification out of Accumulated Other Comprehensive Income | Accumulated Other Comprehensive Income (Loss)
Income tax expense reclassified from accumulated other comprehensive income	$ 261	$ 778

CONSOLIDATED STATEMENTS OF COMP

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Statement of Comprehensive Income [Abstract]
Net income	$ 23,268	$ 18,010
Securities:
Net change in unrealized gain (loss) on securities	(19,834)	5,379
Reclassification adjustment for net gains realized in net income	(1,441)	(2,482)
Income taxes	5,391	(1,111)
Other comprehensive income (loss) on securities	(15,884)	1,786
Derivatives used in cash flow hedging relationships:
Net change in unrealized gain on derivatives	1,699	136
Reclassification adjustment for net losses on derivatives realized in net income	197	397
Income taxes	(708)	(215)
Other comprehensive income on cash flow hedges	1,188	318
Other comprehensive income (loss)	(14,696)	2,104
TOTAL COMPREHENSIVE INCOME	$ 8,572	$ 20,114

CONSOLIDATED STATEMENTS OF CASH

CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	$ 23,268	$ 18,010
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	6,802	7,023
Provision for loan losses	4,263	3,641
Net amortization of premium on securities	5,823	7,226
Securities gains, net	(1,441)	(2,482)
Unrealized loss on equity securities, net	28	0
Stock based compensation	1,858	1,782
Loans originated for sale	(112,433)	(164,324)
Proceeds on sales of loans held for sale	135,506	180,404
Net gains on sale of loans held for sale	(2,889)	(3,828)
Decrease in accrued interest receivable	3,239	93
Decrease in prepaid expenses	194	84
Increase in accrued interest payable	1,029	825
Capitalization of servicing rights	(1,183)	(2,226)
Valuation allowance on commercial servicing rights	2	(5)
(Gain)/loss on sales/valuations of assets, net	(197)	412
Net excess tax benefit from stock based compensation	611	888
Other, net	(5,441)	(13,767)
NET CASH PROVIDED BY OPERATING ACTIVITIES	59,039	33,756
CASH FLOWS FROM INVESTING ACTIVITIES:
Proceeds from the sale of securities available for sale	392,246	221,637
Proceeds from the redemption of time deposits in other financial institutions	8,767	5,867
Proceeds from the maturity of and principal paydowns on securities available for sale	49,603	47,515
Proceeds from the maturity of and principal paydowns on securities held to maturity	3,570	2,823
Proceeds from the maturity of and principal paydowns on time deposits in other financial institutions	4,368	3,185
Proceeds from the maturity of and principal paydowns on other investments	677	1,521
Purchase of securities available for sale	(244,289)	(312,769)
Purchase of other investments	(644)	(968)
Net (increase) decrease in loans	(32,314)	80,916
Capital expenditures	(2,356)	(3,588)
Net cash and cash equivalents received in acquisitions	5,543	33,698
Proceeds from the sale of equipment	615	3
Proceeds on sale of OREO and other repossessed assets	668	585
NET CASH PROVIDED BY INVESTING ACTIVITIES	186,454	80,425
CASH FLOWS FROM FINANCING ACTIVITIES:
Net increase in demand deposits	5,834	22,799
Net increase in savings deposits	100,608	88,767
Net decrease in time deposit accounts	(69,143)	(50,612)
Proceeds on short-term revolving credit line	15,000	0
Net decrease in short-term borrowings	(168,451)	(131,068)
Proceeds from short term FHLB advances	220,000	60,939
Repayments of short term FHLB advances	(260,000)	(81,305)
Repayments of other borrowings	(14,995)	(6,432)
Purchase of treasury stock	(97)	(160)
Proceeds from issuance of common stock	14	218
Dividends paid	(3,920)	(2,900)
NET CASH USED BY FINANCING ACTIVITIES	(175,150)	(99,754)
Net increase in cash and cash equivalents	70,343	14,427
Cash and cash equivalents at beginning of year	196,003	158,724
CASH AND CASH EQUIVALENTS AT END OF PERIOD	266,346	173,151
Supplemental disclosures:
Cash paid for income/franchise taxes	2	5
Cash paid for interest	8,601	6,698
Loans transferred to OREO	939	2,680
Purchases of securities available for sale, accrued, not settled	0	3,654
Conversion of convertible debt to common stock	0	167
Conversion of Series D preferred stock to common stock	0	419
Stock consideration granted for acquisitions	$ 53,621	$ 22,589

CONSOLIDATED STATEMENTS OF CHAN

CONSOLIDATED STATEMENTS OF CHANGES IN EQUITY (Unaudited) - USD ($) $ in Thousands	Total	Preferred Stock	Preferred StockSeries D Preferred Stock	Common Stock	Capital Surplus	Retained Earnings	Accumulated Other Comprehensive Income (Loss)	Treasury Stock
Balance at beginning of period at Dec. 31, 2016	$ 740,916	$ 1,357		$ 26,120	$ 328,376	$ 416,109	$ (31,046)	$ 0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Comprehensive income	20,114					18,010	2,104
Cash dividends declared:
Preferred	(19)					(19)
Common	(2,881)					(2,881)
Conversion of Series D preferred stock	(419)		$ (419)
Purchase of shares of common stock	(160)							(160)
Issuance of shares of common stock	21,979			554	21,265			160
Stock based compensation	1,782				1,782
Balance at end of period at Mar. 31, 2017	781,312	938		26,674	351,423	431,219	(28,942)	0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Reclassification of unrealized net gain on equity securities	0					(280)	(280)
Balance at beginning of period at Dec. 31, 2017	991,457	938		29,953	503,709	481,331	(24,474)	0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Comprehensive income	8,572					23,268	(14,696)
Cash dividends declared:
Preferred	(13)					(13)
Common	(3,907)					(3,907)
Purchase of shares of common stock	(97)							(97)
Issuance of shares of common stock	53,635			1,115	52,423			97
Stock based compensation	1,858				1,858
Balance at end of period at Mar. 31, 2018	$ 1,051,505	$ 938		$ 31,068	$ 557,990	$ 500,959	$ (39,450)	$ 0

CONSOLIDATED STATEMENTS OF CHA9

CONSOLIDATED STATEMENTS OF CHANGES IN EQUITY (Unaudited) (Parenthetical) - $ / shares	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Cash dividends per share common stock (in dollars per share)	$ 0.13	$ 0.11
Shares of common stock purchased (in shares)	1,761	3,338
Shares of common stock issued (in shares)	1,116,644	557,530
Series D Preferred Stock
Cash dividends per share preferred stock (in dollars per share)	$ 17.50	$ 17.50

Basis of Presentation

Basis of Presentation	3 Months Ended
	Mar. 31, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Presentation	BASIS OF PRESENTATION The interim unaudited consolidated financial statements contained herein should be read in conjunction with the audited consolidated financial statements and accompanying notes to the consolidated financial statements for the fiscal year ended December 31, 2017 , included in the Form 10-K of Heartland Financial USA, Inc. ("Heartland") filed with the Securities and Exchange Commission ("SEC") on February 28, 2018 . Foot note disclosures to the interim unaudited consolidated financial statements which would substantially duplicate the disclosure contained in the footnotes to the audited consolidated financial statements have been omitted. The financial information of Heartland included herein has been prepared in accordance with U.S. generally accepted accounting principles for interim financial reporting and has been prepared pursuant to the rules and regulations for reporting on Form 10-Q and Rule 10-01 of Regulation S-X. Such information reflects all adjustments (consisting of normal recurring adjustments), that are, in the opinion of management, necessary for a fair presentation of the financial position and results of operations for the periods presented. The results of the interim period ended March 31, 2018 , are not necessarily indicative of the results expected for the year ending December 31, 2018 . In the Annual Report on Form 10-K for the year ended December 31, 2017, Heartland reported the results of operations through two business segments: Community and Other Banking and Mortgage Banking. Effective January 1, 2018, the recently restructured mortgage banking segment is no longer a reportable segment due to the significant reduction in infrastructure and the reporting structure of the mortgage sales staff, who currently report directly to the bank president in each market. Accordingly, Heartland is no longer reporting results of operations by segment. Earnings Per Share Basic earnings per share is determined using net income available to common stockholders and weighted average common shares outstanding. Diluted earnings per share is computed by dividing net income available to common stockholders by the weighted average common shares and assumed incremental common shares issued. Amounts used in the determination of basic and diluted earnings per share for the three -month periods ended March 31, 2018 , and 2017 , are shown in the table below: Three Months Ended (Dollars and number of shares in thousands, except per share data) 2018 2017 Net income $ 23,268 $ 18,010 Preferred dividends (13 ) (19 ) Interest expense on convertible preferred debt — 5 Net income available to common stockholders $ 23,255 $ 17,996 Weighted average common shares outstanding for basic earnings per share 30,442 26,335 Assumed incremental common shares issued upon non-vested restricted stock units 203 293 Weighted average common shares for diluted earnings per share 30,645 26,628 Earnings per common share — basic $ 0.76 $ 0.68 Earnings per common share — diluted $ 0.76 $ 0.68 Number of antidilutive common stock equivalents excluded from diluted earnings per share computation — — Stock-Based Compensation Heartland may grant, through its Nominating and Compensation Committee (the "Compensation Committee"), non-qualified and incentive stock options, stock appreciation rights, stock awards, restricted stock, restricted stock units and cash incentive awards, under its 2012 Long-Term Incentive Plan (the "Plan"). The Plan was originally approved by stockholders in May 2012 and was amended effective March 8, 2016, to increase the number of shares of common stock authorized for issuance and make certain other changes to the Plan. As of March 31, 2018 , 459,893 shares of common stock were available for issuance under future awards that may be granted under the Plan to employees and directors of, and service providers to, Heartland or its subsidiaries. Financial Accounting Standards Board ("FASB") Accounting Standards Codification ("ASC") Topic 718, "Compensation-Stock Compensation" requires the measurement of the cost of employee services received in exchange for an award of equity instruments based upon the fair value of the award on the grant date. The cost of the award is based upon its fair value estimated on the date of grant and recognized in the consolidated statements of income over the vesting period of the award. The fair market value of restricted stock and restricted stock units is based on the fair value of the underlying shares of common stock on the date of grant. The fair value of stock options is estimated on the date of grant using the Black-Scholes model. Forfeitures are accounted for as they occur. The amount of tax benefit related to the exercise, vesting and forfeiture of equity-based awards reflected as a tax benefit in Heartland's income tax expense was $611,000 and $ 888,000 during the three months ended March 31, 2018 and 2017, respectively. Restricted Stock Units The Plan permits the Compensation Committee to grant restricted stock units ("RSUs"). In the first quarter of 2018, the Compensation Committee granted time-based RSUs with respect to 52,153 shares of common stock, and in the first quarter of 2017, the Compensation Committee granted time-based RSUs with respect to 55,665 shares of common stock to selected officers and employees. The time-based RSUs represent the right, without payment, to receive shares of Heartland common stock on a specified date in the future. The time-based RSUs granted in 2018 vest over three years in equal installments on March 6 of each of the three years following the year of the grant, while the 2017 time-based RSUs vest in equal installments on January 19 of each of the three years following the year of the grant. The time-based RSUs may also vest upon death or disability, upon a change in control or upon a "qualified retirement" (as defined in the RSU agreement). The retiree is required to sign a non-solicitation agreement as a condition to vesting. In addition to the time-based RSUs referenced in the preceding paragraph, the Compensation Committee granted one -year performance-based RSUs with respect to 18,988 shares of common stock in the first quarter of 2018, and 27,570 shares of common stock in the first quarter of 2017. These performance-based RSUs are earned based on satisfaction of performance targets for the fiscal years ended December 31, 2018, and December 31, 2017, respectively, and then fully vest on a specified date in the third calendar year following the year of the initial grant. The Compensation Committee also granted three -year performance-based RSUs with respect to 16,108 shares and 9,032 shares of common stock in the first quarter of 2018 and 2017, respectively. These performance-based RSUs will be earned based on satisfaction of performance targets for the three -year performance period ended December 31, 2020, and December 31, 2019, respectively. These performance-based RSUs or a portion thereof may vest in 2021 and 2020, respectively, after measurement of performance in relation to the performance targets. The one -year and three -year performance-based RSUs vest to the extent that they are earned upon death or disability or upon a "qualified retirement." Upon a change in control, performance-based RSUs shall become vested at 100% of target if the RSU obligations are not assumed by the successor company. If the successor company does assume the RSU obligations, the 2017 and 2018 performance-based RSUs will vest at 100% of target upon a "Termination of Service" within the period beginning six months prior to a change in control and ending twenty-four months after a change in control. All of Heartland's RSUs will be settled in common stock upon vesting and are not entitled to dividends until vested. The Compensation Committee may grant RSUs under the Plan to directors as part of their compensation, to new management level employees at commencement of employment, and to other employees and service providers as incentives. During the three months ended March 31, 2018 , and March 31, 2017 , no time-based RSUs were granted to directors and new employees. A summary of the RSUs outstanding as of March 31, 2018 and 2017 , and changes during the three months ended March 31, 2018 and 2017 , follows: 2018 2017 Shares Weighted-Average Grant Date Fair Value Shares Weighted-Average Grant Date Fair Value Outstanding at January 1 301,578 $ 34.74 346,817 $ 27.61 Granted 87,249 55.25 92,267 47.50 Vested (107,553 ) 30.79 (103,897 ) 24.74 Forfeited (19,113 ) 43.62 (7,765 ) 31.03 Outstanding at March 31 262,161 $ 42.60 327,422 $ 34.04 Total compensation costs recorded for RSUs were $1.9 million and $1.7 million for the three -month periods ended March 31, 2018 and 2017 . As of March 31, 2018 , there were $6.1 million of total unrecognized compensation costs related to the Plan for RSUs that are expected to be recognized through 2021. Options Although the Plan provides authority to the Compensation Committee to grant stock options, no options were granted during the first three months of 2018 and 2017 . Prior to 2009, options were typically granted annually with an expiration date ten years after the date of grant. Vesting was generally over a five -year service period with equal portions of a grant becoming exercisable at three years, four years, and five years after the date of grant. A summary of the stock options outstanding as of March 31, 2018 and 2017 , and changes during the three months ended March 31, 2018 and 2017 , follows: 2018 2017 Shares Weighted-Average Exercise Price Shares Weighted-Average Exercise Price Outstanding at January 1 6,500 $ 18.60 26,400 $ 18.60 Granted — — — — Exercised (6,500 ) 18.60 (5,500 ) 18.60 Forfeited — — — — Outstanding at March 31 — $ — 20,900 $ 18.60 Options exercisable at March 31 — $ — 20,900 $ 18.60 The intrinsic value for the total of all options exercised during the three months ended March 31, 2018 , was $231,000 . Cash received from options exercised was $ 121,000 for the three months ended March 31, 2018 , and $102,000 for the three months ended March 31, 2017 . No compensation costs were recorded for options during the three month periods ended March 31, 2018 and 2017 . There are no unrecorded compensation costs related to options at March 31, 2018 . No stock options vested during the three -month periods ended March 31, 2018 and 2017 . Subsequent Events - Heartland has evaluated subsequent events that may require recognition or disclosure through the filing date of this Quarterly Report on Form 10-Q with the SEC. Effect of New Financial Accounting Standards In May 2014, the FASB issued Accounting Standards Update ("ASU") 2014-09, " Revenue from Contracts with Customers." The amendment clarifies the principles for recognizing revenue and develops a common revenue standard. The amendment outlines a single comprehensive model for entities to use in accounting for revenue arising from contracts with customers and supersedes most current revenue recognition guidance, including industry-specific guidance. The core principle of the revenue model is that "an entity recognizes revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services." In applying the revenue model to contracts within its scope, an entity should apply the following steps: (i) identify the contract(s) with a customer, (ii) identify the performance obligations in the contract, (iii) determine the transaction price, (iv) allocate the transaction price to the performance obligations in the contract, and (v) recognize revenue when (or as) the entity satisfies a performance obligation. The new guidance does not apply to certain contracts within the scope of other ASC Topics, such as lease contracts, insurance contracts, financing arrangements, financial instruments, guarantees other than product or service warranties and nonmonetary exchanges between entities in the same line of business to facilitate sales to customers. Heartland evaluates noninterest income contracts affected by the new guidance by analyzing contracts and current accounting practices to determine if a change is appropriate. The amendment is largely consistent with existing guidance and current practices; however Heartland had to change the recognition of certain recurring revenue streams within trust and investment management fees. Heartland adopted the accounting standard effective January 1, 2018, as required, using a modified retrospective approach. However, the adoption of these amendments did not have a significant effect on Heartland's results of operations, financial position and liquidity other than expanded disclosure requirements. See Note 9, "Revenue," for further details regarding Heartland's revenue. In January 2016, the FASB issued guidance ASU 2016-01, " Recognition and Measurement of Financial Assets and Financial Liabilitie s." The amendments in ASU 2016-01 to Subtopic 825-10, Financial Instruments, contain the following elements: (1) require equity investments to be measured at fair value with changes in fair value recognized in net income; (2) simplify the impairment assessment of equity investments without readily determinable fair values by requiring a qualitative assessment to identify impairment; (3) eliminates the requirement for public entities to disclose the methods 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; (4) requires public business entities to use the exit price notion when measuring the fair value of financial instruments for disclosure purposes; (5) requires an entity 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 when the entity has elected to measure the liability at fair value in accordance with the fair value option for financial instruments; (6) requires separate presentation of financial assets and financial liabilities by measurement category and form of financial asset on the balance sheet or accompanying notes to the financial statements; and (7) clarifies that the entity should evaluate the need for a valuation allowance on a deferred tax asset related to available for sale securities in combination with the entity's other deferred tax assets. The amendments are effective for fiscal years beginning after December 15, 2017, and for interim periods within those fiscal years. Except for the early application of the amendment noted in item (5) above, early adoption of the amendments in this update is not permitted. Entities are required to and Heartland applied the amendment by means of a cumulative-effect adjustment as of the beginning of the fiscal year of adoption, with the exception of the amendment related to equity securities without readily determinable fair values, which are to be applied prospectively to equity investments that exist as of the adoption date. Heartland adopted the accounting standard on January 1, 2018, as required, and the adoption of these amendments did not have a material impact on its results of operations, financial position and liquidity. Heartland reclassified $280,000 from accumulated other comprehensive income to retained earnings on January 1, 2018, related to the fair value of its equity investments. In February 2016, the FASB issued ASU 2016-02, " Leases (Topic 842). " Topic 842 requires a lessee to recognize leases on-balance sheet and disclose key information about leasing arrangements. The new standard establishes a right-of-use model (ROU) that requires a lessee to recognize a ROU asset and lease liability on the balance sheet for all leases with a term longer than 12 months. Leases will be classified as financing or operating, with classification affecting the pattern and classification of expense recognition in the income statement. The amendment is effective for fiscal years beginning after December 15, 2018, including interim periods within those fiscal years, and will be applied on a modified retrospective basis. Heartland leases certain properties and equipment under operating leases that will result in recognition of lease assets and lease liabilities on the consolidated balance sheets under the ASU; however the majority of Heartland's properties and equipment are owned, not leased. The modified retrospective approach includes a number of optional practical expedients that entities may elect to apply. These practical expedients relate to the identification and classification of leases that commenced before the effective date, initial direct costs for leases that commenced before the effective date, and the ability to use hindsight in evaluating lessee options to extend or terminate a lease or to purchase the underlying asset. Early adoption is permitted. In January 2018, the FASB issued an amendment to provide entities with the optional practical expedient to not evaluate existing or expired land easements that were previously not accounted for as leases under Topic 840. Heartland intends to adopt the accounting standard in 2019, as required, and does not expect the adoption of this standard to have a significant impact on its results of operations, financial position and liquidity. Heartland has signed an agreement with a cloud-based lease software provider, and implementation of the software started in the first quarter of 2018. In June 2016, the FASB issued ASU 2016-13, " Financial Instruments - Credit Losses (Topic 326) ." The amendments in this ASU require a financial asset (or a group of financial assets) measured at amortized cost basis to be presented at the net amount expected to be collected. The allowance for credit losses is a valuation account that is deducted from the amortized cost basis of the financial asset(s) to present the net carrying value at the amount expected to be collected on the financial asset. The amendments in this ASU indicate that an entity should not use the length of time a security has been in an unrealized loss position to avoid recording a credit loss. In addition, in determining whether a credit loss exists, the amendments in this ASU also remove the requirements to consider the historical and implied volatility of the fair value of a security and recoveries or declines in fair value after the balance sheet date. The amendment is effective for fiscal years beginning after December 15, 2019, including interim periods within those fiscal years. An entity may adopt the amendments earlier as of the fiscal years beginning after December 15, 2018, including interim periods within those fiscal years. Heartland intends to adopt the accounting standard in 2020, as required, and is currently evaluating the potential impact of this guidance on its results of operations, financial position and liquidity. Upon adoption of ASU 2016-13, a cumulative-effect adjustment to retained earnings will be recorded as of the beginning of the first reporting period in which the guidance is effective. Heartland has formed an internal committee to assess and implement the standard, and Heartland has entered into an agreement with a third party vendor to evaluate potential methodologies and data. In August 2016, the FASB issued ASU 2016-15, " Statement of Cash Flows (Topic 230) - Classification of Certain Cash Receipts and Cash Payments. " The amendments in this update address eight specific cash flow issues with the objective of reducing the existing diversity in practice. The amendment is effective for fiscal years beginning after December 15, 2017, including interim periods within those fiscal years. Early adoption is permitted, including adoption in an interim period. If an entity early adopts the amendments in an interim period, any adjustments should be reflected as of the beginning of the fiscal year that includes the interim period. An entity that elects early adoption must adopt all of the amendments in the same period. The amendments in this update should be applied using a retrospective transition method to each period presented. Heartland adopted this ASU on January 1, 2018, as required, and the adoption of these amendments did not have a material impact on Heartland's results of operations, financial position and liquidity. In October 2016, the FASB issued ASU 2016-16, "Income Taxes (Topic 740) - Intra-Entity Transfer of Assets Other Than Inventory." The amendment requires an entity to recognize income tax consequences on an intra-entity transfer of an asset other than inventory at the time the transaction occurs. The amendment is effective for fiscal years beginning after December 15, 2017, including interim periods within those fiscal years. The amendments must be applied and Heartland applied these amendments using a modified retrospective basis. Heartland adopted this ASU on January 1, 2018, as required, and the adoption of this amendment did not have a material impact on Heartland's results of operations, financial position and liquidity. In January 2017, the FASB issued ASU No. 2017-01, " Business Combinations (Topic 805): Clarifying the Definition of a Business ," which narrows the definition of a business and provides a framework that gives entities a basis for making reasonable judgments about whether a transaction involves an asset or a business. ASU 2017-01 is effective for public business entities in annual periods beginning after December 15, 2017, including interim periods therein. Heartland adopted ASU 2017-01 on January 1, 2018, as required, and the adoption did not have a material impact on Heartland's results of operations, financial position, and liquidity. In January 2017, the FASB issued ASU 2017-04, "Intangibles - Goodwill and Other (Topic 350)." This amendment is to simplify the subsequent measurement of goodwill by eliminating step two from the goodwill impairment test. Instead, an entity will perform only step one of its quantitative goodwill impairment test by comparing the fair value of a reporting unit with its carrying amount, and then recognizing the impairment charge for the amount by which the carrying amount exceeds the reporting unit's fair value; however, the loss recognized cannot exceed the total amount of goodwill allocated to that reporting unit. An entity will still have the option to perform a qualitative assessment for a reporting unit to determine if the quantitative step one impairment test is necessary. This amendment is effective for annual or interim goodwill impairment tests in fiscal years beginning after December 15, 2019, and should be applied prospectively. Early adoption is permitted, including in an interim period for impairment tests performed after January 1, 2017. Heartland intends to adopt this ASU in the third quarter of 2020, consistent with the annual impairment test as of September 30, 2020, and is currently evaluating the potential impact of this guidance on its results of operations, financial position and liquidity. In March 2017, the FASB issued ASU 2017-08, "Receivables - Nonrefundable Fee and Other Costs (Subtopic 310-20)." These amendments shorten the amortization period for certain callable debt securities held at a premium. Specifically, the amendments require the premium to be amortized to the earliest call date. The amendments do not require an accounting change for securities held at a discount. Discounts continue to be amortized to maturity. These amendments are effective for public business entities for fiscal years and interim periods within those fiscal years, beginning after December 15, 2018. Early adoption is permitted, including adoption in an interim period. If any entity early adopts the amendments in an interim period, any adjustments must be reflected as of the beginning of the fiscal year that includes the interim period. The amendments must be applied and Heartland intends to apply these amendments on a modified retrospective basis, with a cumulative-effect adjustment directly to retained earnings as of the beginning of the period of adoption. Heartland intends to adopt this ASU in 2019, as required, and is currently evaluating the potential impact on its results of operations, financial position and liquidity. In May 2017, the FASB issued ASU 2017-09, " Compensation - Stock Compensation (Topic 718) ." The amendments provide guidance about which changes to the terms or conditions of a share-based payment award require an entity to apply modification accounting in Topic 718. An entity should account for the effects of a modification unless all the following are met: (1) the fair value (or calculated value or intrinsic value, if such an alternative measurement method is used) of the modified award is the same as the fair value (or calculated value or intrinsic value, if such an alternative measurement method is used) of the original award immediately before the original award is modified. If the modification does not affect any of the inputs to the valuation technique that the entity uses to value the award, the entity is not required to estimate the value immediately before and after the modification; (2) the vesting conditions of the modified award are the same as the vesting conditions of the original award immediately before the original award is modified; and (3) the classification of the modified award as an equity instrument or a liability instrument is the same as the classification of the original award immediately before the original award is modified. The amendments are effective for annual periods and interim periods within those annual periods, beginning after December 15, 2017. Early adoption is permitted, including adoption in any interim periods for public business entities for reporting periods for which financial statements have not yet been issued. The amendments should be applied and Heartland applied these amendments prospectively to an award modified on or after the adoption date. Heartland adopted this ASU on January 1, 2018, as required, the adoption did not have a material impact to its results of operations, financial position and liquidity because Heartland has not typically modified share-based payment awards after the original award has been granted. In August 2017, the FASB issued ASU 2017-12, " Derivatives and Hedging: Targeted Improvements to Accounting for Hedging Activities ." The purpose of this updated guidance is to better align a company’s financial reporting for hedging activities with the economic objectives of those activities. ASU 2017-12 is effective for public business entities for fiscal years beginning after December 15, 2018, with early adoption, including adoption in an interim period, permitted. ASU 2017-12 requires a modified retrospective transition method in which Heartland will recognize the cumulative effect of the change on the opening balance of each affected component of equity in the consolidated balance sheet as of the date of adoption. Heartland intends to adopt this ASU in 2019, as required, and does not believe there will be a material impact to its results of operations, financial position and liquidity. In February 2018, the FASB issued ASU 2018-02, " Income Statement-Reporting Comprehensive Income (Topic 220). " This ASU allows for the option to reclassify from accumulated other comprehensive income ("AOCI") to retained earnings for stranded tax effects resulting from the newly enacted federal corporate income tax rate in the Tax Cuts and Jobs Act of 2017, which was enacted on December 22, 2017. The legislation included a reduction to the corporate income tax rate from 35 percent to 21 percent effective January 1, 2018. The amount of the reclassification would be the difference between the historical corporate income tax rate and the newly enacted 21 percent corporate income tax rate. The amendments in this ASU are effective for fiscal years beginning after December 15, 2018, including interim periods within those fiscal years. Early adoption is permitted for public businesses for reporting periods for which financial statements have not yet been issued. Heartland adopted the guidance as of December 31, 2017. The adoption of this ASU was accounted for as a cumulative-effect adjustment to the balance sheet resulting in a $4.5 million increase to retained earnings and a corresponding decrease to AOCI on December 31, 2017.

Acquisitions

Acquisitions	3 Months Ended
	Mar. 31, 2018
Business Combinations [Abstract]
Acquisitions	ACQUISITIONS First Bank Lubbock Bancshares, Inc. On December 12, 2017, Heartland entered into a definitive merger agreement with First Bank Lubbock Bancshares, Inc., parent company of FirstBank & Trust Company, headquartered in Lubbock, Texas. Under the terms of the definitive merger agreement, Heartland will acquire First Bank Lubbock Bancshares, Inc. in a transaction valued at approximately $185.6 million as of the announcement date, subject to certain adjustments. Shareholders of First Bank Lubbock Bancshares, Inc. will receive a combination of Heartland common stock and cash. As of March 31, 2018, FirstBank & Trust Company had total assets of $971.5 million , including $704.9 million of gross loans held to maturity, and deposits of $869.3 million . Upon closing of the transaction, FirstBank & Trust Company will become a wholly-owned subsidiary of Heartland and will continue to operate under its current name and management team as Heartland's eleventh state-chartered bank. Heartland has received approval by the bank regulatory authorities related to this acquisition. The transaction is expected to close in the second quarter of 2018. Signature Bancshares, Inc. On February 23, 2018, Heartland completed the acquisition of Signature Bancshares, Inc., parent company of Signature Bank, headquartered in Minnetonka, Minnesota. Under the terms of the definitive merger agreement, Heartland acquired Signature Bancshares, Inc. in a transaction valued at approximately $61.4 million , of which $7.8 million was cash, and the remainder was settled by delivery of 1,000,843 shares of Heartland common stock. Simultaneous with the close, Signature Bank merged into Heartland's wholly-owned Minnesota Bank & Trust subsidiary, and the combined entity operates under the Minnesota Bank & Trust brand name. The transaction included, at fair value, total assets of $427.1 million , including $324.5 million of gross loans held to maturity, and deposits of $357.3 million . The transaction was a tax-free reorganization with respect to the stock consideration received by the stockholders of Signature Bancshares, Inc. Citywide Banks of Colorado, Inc. On July 7, 2017, Heartland acquired Citywide Banks of Colorado, Inc., parent company of Citywide Banks, headquartered in Aurora, Colorado. The transaction consideration was approximately $211.2 million , of which $58.6 million was cash, and the remainder was settled by delivery of 3,216,161 shares of Heartland common stock. Simultaneous with the close, Citywide Banks merged into Heartland's Centennial Bank and Trust subsidiary, and the combined entity operates as Citywide Banks. The transaction included, at fair value, total assets of $1.49 billion , including $985.4 million of net loans outstanding, and $1.21 billion of deposits on the acquisition date. Included in this transaction was one bank building with a fair value of $1.4 million that Heartland intends to sell and is classified as premises, furniture and equipment held for sale on the consolidated balance sheets. The transaction was a tax-free reorganization with respect to the stock consideration received by the stockholders of Citywide Banks of Colorado, Inc. Founders Bancorp On February 28, 2017, Heartland acquired Founders Bancorp, parent company of Founders Community Bank, based in San Luis Obispo, California. The purchase price was approximately $31.0 million , which was paid by delivery of 455,877 shares of Heartland common stock and cash of $8.4 million . The transaction included, at fair value, total assets of $213.9 million , loans of $96.4 million , and deposits of $181.5 million on the acquisition date. The transaction also included one bank building with a fair value of $576,000 that Heartland sold during the second quarter of 2017. Simultaneous with the closing of the transaction, Founders Community Bank merged into Heartland's Premier Valley Bank subsidiary. The transaction was a tax-free reorganization with respect to the stock consideration received by the stockholders of Founders Bancorp.

Securities

Securities	3 Months Ended
	Mar. 31, 2018
Investments, Debt and Equity Securities [Abstract]
Securities	SECURITIES The amortized cost, gross unrealized gains and losses, and estimated fair values of securities available for sale as of March 31, 2018 , and December 31, 2017 , are summarized in the table below, in thousands: Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Estimated Fair Value March 31, 2018 U.S. government corporations and agencies $ 11,254 $ 3 $ (69 ) $ 11,188 Mortgage and asset-backed securities 1,691,092 3,968 (47,456 ) 1,647,604 Obligations of states and political subdivisions 361,475 1,132 (10,427 ) 352,180 Total debt securities 2,063,821 5,103 (57,952 ) 2,010,972 Equity securities 16,693 — — 16,693 Total $ 2,080,514 $ 5,103 $ (57,952 ) $ 2,027,665 December 31, 2017 U.S. government corporations and agencies $ 5,358 $ 8 $ (38 ) $ 5,328 Mortgage and asset-backed securities 1,785,467 5,856 (37,587 ) 1,753,736 Obligations of states and political subdivisions 441,060 4,669 (4,714 ) 441,015 Total debt securities 2,231,885 10,533 (42,339 ) 2,200,079 Equity securities 16,296 378 — 16,674 Total $ 2,248,181 $ 10,911 $ (42,339 ) $ 2,216,753 The amortized cost, gross unrealized gains and losses and estimated fair values of held to maturity securities as of March 31, 2018 , and December 31, 2017 , are summarized in the table below, in thousands: Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Estimated Fair Value March 31, 2018 Obligations of states and political subdivisions $ 249,766 $ 9,699 $ (827 ) $ 258,638 Total $ 249,766 $ 9,699 $ (827 ) $ 258,638 December 31, 2017 Obligations of states and political subdivisions $ 253,550 $ 12,460 $ (516 ) $ 265,494 Total $ 253,550 $ 12,460 $ (516 ) $ 265,494 At March 31, 2018 , approximately 77% of Heartland's mortgage and asset-backed securities were issued by government-sponsored enterprises. The amortized cost and estimated fair value of debt securities available for sale at March 31, 2018 , by contractual maturity, are as follows, in thousands. Expected maturities will differ from contractual maturities because issuers may have the right to call or prepay obligations with or without penalties. March 31, 2018 Amortized Cost Estimated Fair Value Due in 1 year or less $ 5,397 $ 5,392 Due in 1 to 5 years 56,369 56,209 Due in 5 to 10 years 116,517 112,484 Due after 10 years 194,446 189,283 Total debt securities 372,729 363,368 Mortgage and asset-backed securities 1,691,092 1,647,604 Equity securities 16,693 16,693 Total investment securities $ 2,080,514 $ 2,027,665 The amortized cost and estimated fair value of debt securities held to maturity at March 31, 2018 , by contractual maturity, are as follows, in thousands. Expected maturities will differ from contractual maturities because issuers may have the right to call or prepay obligations with or without penalties. March 31, 2018 Amortized Cost Estimated Fair Value Due in 1 year or less $ 2,486 $ 2,523 Due in 1 to 5 years 27,627 28,231 Due in 5 to 10 years 104,170 106,538 Due after 10 years 115,483 121,346 Total investment securities $ 249,766 $ 258,638 As of March 31, 2018 , and December 31, 2017 , securities with a fair value of $594.3 million and $670.3 million , respectively, were pledged to secure public and trust deposits, short-term borrowings and for other purposes as required or permitted by law. Gross gains and losses realized related to the sales of securities available for sale for the three -month periods ended March 31, 2018 and 2017 , are summarized as follows, in thousands: Three Months Ended 2018 2017 Proceeds from sales $ 392,246 $ 221,637 Gross security gains 3,013 3,830 Gross security losses 1,572 1,339 The following tables summarize, in thousands, the amount of unrealized losses, defined as the amount by which cost or amortized cost exceeds fair value, and the related fair value of investments with unrealized losses in Heartland's securities portfolio as of March 31, 2018 , and December 31, 2017 . The investments were segregated into two categories: those that have been in a continuous unrealized loss position for less than 12 months and those that have been in a continuous unrealized loss position for 12 months or more. The reference point for determining how long an investment was in an unrealized loss position w as March 31, 2017 , and December 31, 2016 , respectively. Securities for which Heartland has taken credit-related other-than-temporary impairment ("OTTI") write-downs are categorized as being "less than 12 months" or "12 months or longer" in a continuous loss position based on the point in time that the fair value declined to below the cost basis and not the period of time since the credit-related OTTI write-down. Securities available for sale Less than 12 months 12 months or longer Total Fair Value Unrealized Losses Fair Value Unrealized Losses Fair Value Unrealized Losses March 31, 2018 U.S. government corporations and agencies $ 10,685 $ (69 ) $ — $ — $ 10,685 $ (69 ) Mortgage and asset-backed securities 923,293 (18,459 ) 379,672 (28,997 ) 1,302,965 (47,456 ) Obligations of states and political subdivisions 177,100 (3,456 ) 131,574 (6,971 ) 308,674 (10,427 ) Total debt securities 1,111,078 (21,984 ) 511,246 (35,968 ) 1,622,324 (57,952 ) Total temporarily impaired securities $ 1,111,078 $ (21,984 ) $ 511,246 $ (35,968 ) $ 1,622,324 $ (57,952 ) December 31, 2017 U.S. government corporations and agencies $ 4,819 $ (38 ) $ — $ — $ 4,819 $ (38 ) Mortgage and asset-backed securities 851,070 (11,533 ) 399,978 (26,054 ) 1,251,048 (37,587 ) Obligations of states and political subdivisions 93,040 (667 ) 159,180 (4,047 ) 252,220 (4,714 ) Total debt securities 948,929 (12,238 ) 559,158 (30,101 ) 1,508,087 (42,339 ) Total temporarily impaired securities $ 948,929 $ (12,238 ) $ 559,158 $ (30,101 ) $ 1,508,087 $ (42,339 ) Securities held to maturity Less than 12 months 12 months or longer Total Fair Value Unrealized Losses Fair Value Unrealized Losses Fair Value Unrealized Losses March 31, 2018 Obligations of states and political subdivisions $ 30,496 $ (272 ) $ 7,907 $ (555 ) $ 38,403 $ (827 ) Total temporarily impaired securities $ 30,496 $ (272 ) $ 7,907 $ (555 ) $ 38,403 $ (827 ) December 31, 2017 Obligations of states and political subdivisions $ 8,512 $ (49 ) $ 8,989 $ (467 ) $ 17,501 $ (516 ) Total temporarily impaired securities $ 8,512 $ (49 ) $ 8,989 $ (467 ) $ 17,501 $ (516 ) Heartland reviews the investment securities portfolio on a quarterly basis to monitor its exposure to OTTI. A determination as to whether a security's decline in fair value is other-than-temporary takes into consideration numerous factors and the relative significance of any single factor can vary by security. Some factors Heartland may consider in the OTTI analysis include the length of time the security has been in an unrealized loss position, changes in security ratings, financial condition of the issuer, as well as security and industry specific economic conditions. In addition, with regard to debt securities, Heartland may also evaluate payment structure, whether there are defaulted payments or expected defaults, prepayment speeds and the value of any underlying collateral. For certain debt securities in unrealized loss positions, Heartland prepares cash flow analyses to compare the present value of cash flows expected to be collected from the security with the amortized cost basis of the security. The remaining unrealized losses on Heartland's mortgage and asset-backed securities are the result of changes in market interest rates or widening of market spreads subsequent to the initial purchase of the securities. The losses are not related to concerns regarding the underlying credit of the issuers or the underlying collateral. It is expected that the securities will not be settled at a price less than the amortized cost of the investment. Because the decline in fair value is attributable to changes in interest rates or widening market spreads and not credit quality, and because Heartland has the intent and ability to hold these investments until a market price recovery or to maturity and does not believe it will be required to sell the securities before maturity, these investments are not considered other-than-temporarily impaired. The remaining unrealized losses on Heartland's obligations of states and political subdivisions are the result of changes in market interest rates or widening of market spreads subsequent to the initial purchase of the securities. Management monitors the published credit ratings of these securities and the stability of the underlying municipalities. Because the decline in fair value is attributable to changes in interest rates or widening market spreads due to insurance company downgrades and not underlying credit quality, and because Heartland has the intent and ability to hold these investments until a market price recovery or to maturity and does not believe it will be required to sell the securities before maturity, these investments are not considered other-than-temporarily impaired. There were no gross realized gains or losses on the sale of available for sale or held to maturity securities with OTTI write-downs for the three-month periods ended March 31, 2018, and March 31, 2017, respectively. Included in other securities at March 31, 2018 , and December 31, 2017 , were shares of stock in the Federal Home Loan Banks (the "FHLBs") of Des Moines, Chicago, Dallas, San Francisco and Topeka at an amortized cost of $14.3 million and $ 14.0 million , respectively. The Heartland banks are required by federal law to maintain FHLB stock as members of the various FHLBs. These equity securities are "restricted" in that they can only be sold back to the respective institutions from which they were acquired or another member institution at par. Therefore, the FHLB stock is less liquid than other marketable equity securities, and the fair value approximates amortized cost. Heartland considers its FHLB stock as a long-term investment that provides access to competitive products and liquidity. Heartland evaluates impairment in these investments based on the ultimate recoverability of the par value and, at March 31, 2018 , did not consider the investments to be other than temporarily impaired.

Loans

Loans	3 Months Ended
	Mar. 31, 2018
Receivables [Abstract]
Loans	LOANS Loans as of March 31, 2018 , and December 31, 2017 , were as follows, in thousands: March 31, 2018 December 31, 2017 Loans receivable held to maturity: Commercial $ 1,806,683 $ 1,646,606 Commercial real estate 3,323,094 3,163,269 Agricultural and agricultural real estate 518,386 511,588 Residential real estate 624,725 624,279 Consumer 474,929 447,484 Gross loans receivable held to maturity 6,747,817 6,393,226 Unearned discount (1,620 ) (556 ) Deferred loan fees (182 ) (1,206 ) Total net loans receivable held to maturity 6,746,015 6,391,464 Allowance for loan losses (58,656 ) (55,686 ) Loans receivable, net $ 6,687,359 $ 6,335,778 Heartland has certain lending policies and procedures in place that are designed to provide for an acceptable level of credit risk. The board of directors reviews and approves these policies and procedures on a regular basis. A reporting system supplements the review process by providing management and the board with frequent reports related to loan production, loan quality, concentrations of credit, loan delinquencies and nonperforming loans and potential problem loans. Diversification in the loan portfolio is also a means of managing risk associated with fluctuations in economic conditions. Heartland originates commercial and commercial real estate loans for a wide variety of business purposes, including lines of credit for capital and operating purposes and term loans for real estate and equipment purchases. Agricultural loans provide financing for capital improvements and farm operations, as well as livestock and machinery purchases. Residential mortgage loans are originated for the construction, purchase or refinancing of single family residential properties. Consumer loans include loans for motor vehicles, home improvement, home equity and personal lines of credit. Heartland's consumer finance subsidiaries, Citizens Finance Co. and Citizens Finance of Illinois Co., typically lend to borrowers with past credit problems or limited credit histories, which comprises approximately 15% of Heartland's total consumer loan portfolio. Under Heartland’s credit practices, a loan is impaired when, based on current information and events, it is probable that Heartland will be unable to collect all amounts due according to the contractual terms of the loan agreement. Loan impairment is measured based on the present value of expected future cash flows discounted at the loan’s effective interest rate, except where more practical, impairment is measured at the observable market price of the loan or the fair value of the collateral if the loan is collateral dependent. The following table shows the balance in the allowance for loan losses at March 31, 2018 , and December 31, 2017 , and the related loan balances, disaggregated on the basis of impairment methodology, in thousands. Loans evaluated under ASC 310-10-35 include loans on nonaccrual status and troubled debt restructurings, which are individually evaluated for impairment, and other impaired loans deemed to have similar risk characteristics. All other loans are collectively evaluated for impairment under ASC 450-20. Heartland has made no significant changes to the accounting for the allowance for loan losses during 2018. Allowance For Loan Losses Gross Loans Receivable Held to Maturity Ending Balance Under ASC 310-10-35 Ending Balance Under ASC 450-20 Total Ending Balance Evaluated for Impairment Under ASC 310-10-35 Ending Balance Evaluated for Impairment Under ASC 450-20 Total March 31, 2018 Commercial $ 2,425 $ 16,970 $ 19,395 $ 9,005 $ 1,797,678 $ 1,806,683 Commercial real estate 736 22,733 23,469 22,920 3,300,174 3,323,094 Agricultural and agricultural real estate 787 3,929 4,716 16,896 501,490 518,386 Residential real estate 386 1,755 2,141 28,324 596,401 624,725 Consumer 1,137 7,798 8,935 6,427 468,502 474,929 Total $ 5,471 $ 53,185 $ 58,656 $ 83,572 $ 6,664,245 $ 6,747,817 December 31, 2017 Commercial $ 1,613 $ 16,485 $ 18,098 $ 7,415 $ 1,639,191 $ 1,646,606 Commercial real estate 766 21,184 21,950 23,705 3,139,564 3,163,269 Agricultural and agricultural real estate 546 3,712 4,258 13,304 498,284 511,588 Residential real estate 430 1,794 2,224 27,141 597,138 624,279 Consumer 1,400 7,756 9,156 6,903 440,581 447,484 Total $ 4,755 $ 50,931 $ 55,686 $ 78,468 $ 6,314,758 $ 6,393,226 The following table presents nonaccrual loans, accruing loans past due 90 days or more and performing troubled debt restructured loans at March 31, 2018 , and December 31, 2017 , in thousands: March 31, 2018 December 31, 2017 Nonaccrual loans $ 60,644 $ 58,272 Nonaccrual troubled debt restructured loans 4,162 4,309 Total nonaccrual loans $ 64,806 $ 62,581 Accruing loans past due 90 days or more $ 22 $ 830 Performing troubled debt restructured loans $ 3,206 $ 6,617 The following tables provide information on troubled debt restructured loans that were modified during the three -month periods ended March 31, 2018 , and March 31, 2017 , dollars in thousands: Three Months Ended 2018 2017 Number of Loans Pre- Modification Recorded Investment Post- Modification Recorded Investment Number of Loans Pre- Modification Recorded Investment Post- Modification Recorded Investment Commercial — $ — $ — — $ — $ — Commercial real estate — — — — — — Total commercial and commercial real estate — — — — — — Agricultural and agricultural real estate — — — — — — Residential real estate 5 877 752 3 348 348 Consumer — — — — — — Total 5 $ 877 $ 752 3 $ 348 $ 348 The pre-modification and post-modification recorded investment represents amounts as of the date of loan modification. The change related to the pre-modification investment and post-modification investment amounts on Heartland's residential real estate trouble debt restructured loans is due to $142,000 of principal deferment collected from government guarantees and $17,000 of capitalized interest and escrow. At March 31, 2018 , there were no commitments to extend credit to any of the borrowers with an existing troubled debt restructured loan. The following table shows troubled debt restructured loans for which there was a payment default during the three month periods ended March 31, 2018 , and March 31, 2017 , that had been modified during the twelve-month period prior to default, in thousands: With Payment Defaults During the Following Periods Three Months Ended 2018 2017 Number of Loans Recorded Investment Number of Loans Recorded Investment Commercial — $ — — $ — Commercial real estate — — — — Total commercial and commercial real estate — — — — Agricultural and agricultural real estate — — — — Residential real estate 3 519 — — Consumer — — — — Total 3 $ 519 — $ — Heartland's internal rating system is a series of grades reflecting management's risk assessment, based on its analysis of the borrower's financial condition. The "pass" category consists of all loans that are not in the "nonpass" category, categorized into a range of loan grades that reflect increasing, though still acceptable, risk. Movement of risk through the various grade levels in the pass category is monitored for early identification of credit deterioration. The "nonpass" category consists of special mention, substandard, doubtful and loss loans. The "special mention" rating is attached to loans where the borrower exhibits negative trends in financial circumstances due to borrower specific or systemic conditions that, if left uncorrected, threaten the borrower's capacity to meet its debt obligations. The borrower is believed to have sufficient financial flexibility to react to and resolve its negative financial situation. These credits are closely monitored for improvement or deterioration. The "substandard" rating is assigned to loans that are inadequately protected by the current net worth and paying capacity of the borrower and that may be further at risk due to deterioration in the value of collateral pledged. Well-defined weaknesses jeopardize liquidation of the debt. These loans are still considered collectible; however, a distinct possibility exists that Heartland will sustain some loss if deficiencies are not corrected. Substandard loans may exhibit some or all of the following weaknesses: deteriorating financial trends, lack of earnings, inadequate debt service capacity, excessive debt and/or lack of liquidity. The "doubtful" rating is assigned to loans where identified weaknesses in the borrowers' ability to repay the loan make collection or liquidation in full, on the basis of existing facts, conditions and values, highly questionable and improbable. These borrowers are usually in default, lack liquidity and capital, as well as resources necessary to remain as an operating entity. Specific pending events, such as capital injections, liquidations or perfection of liens on additional collateral, may strengthen the credit, thus deferring the rating of the loan as "loss" until the exact status of the loan can be determined. The loss rating is assigned to loans considered uncollectible. Heartland had no loans classified as loss or doubtful as of March 31, 2018. Loans are placed on "nonaccrual" when management does not expect to collect payments of principal and interest in full or when principal or interest has been in default for a period of 90 days or more, unless the loan is both well secured and in the process of collection. The following table presents loans by credit quality indicator at March 31, 2018 , and December 31, 2017 , in thousands: Pass Nonpass Total March 31, 2018 Commercial $ 1,677,338 $ 129,345 $ 1,806,683 Commercial real estate 3,146,622 176,472 3,323,094 Total commercial and commercial real estate 4,823,960 305,817 5,129,777 Agricultural and agricultural real estate 442,484 75,902 518,386 Residential real estate 585,886 38,839 624,725 Consumer 461,786 13,143 474,929 Total gross loans receivable held to maturity $ 6,314,116 $ 433,701 $ 6,747,817 December 31, 2017 Commercial $ 1,552,783 $ 93,823 $ 1,646,606 Commercial real estate 2,985,501 177,768 3,163,269 Total commercial and commercial real estate 4,538,284 271,591 4,809,875 Agricultural and agricultural real estate 451,539 60,049 511,588 Residential real estate 586,623 37,656 624,279 Consumer 432,936 14,548 447,484 Total gross loans receivable held to maturity $ 6,009,382 $ 383,844 $ 6,393,226 The nonpass category in the table above is comprised of approximately 55% special mention loans and 45% substandard loans as of March 31, 2018 . The percent of nonpass loans on nonaccrual status as of March 31, 2018 , was 15% . As of December 31, 2017 , the nonpass category in the table above was comprised of approximately 52% special mention loans and 48% substandard loans. The percent of nonpass loans on nonaccrual status as of December 31, 2017 , was 16% . Loans delinquent 30 to 89 days as a percent of total loans were 0.21% at March 31, 2018 , compared to 0 .27% at December 31, 2017 . Changes in credit risk are monitored on a regular basis and changes in risk ratings are made when identified. All impaired loans are reviewed at least annually. As of March 31, 2018 , Heartland had $ 2.8 million of loans secured by residential real estate property that were in the process of foreclosure. The following table sets forth information regarding Heartland's accruing and nonaccrual loans at March 31, 2018 , and December 31, 2017 , in thousands: Accruing Loans 30-59 Days Past Due 60-89 Days 90 Days or More Past Due Total Past Due Current Nonaccrual Total Loans March 31, 2018 Commercial $ 2,906 $ 1,883 $ — $ 4,789 $ 1,793,565 $ 8,329 $ 1,806,683 Commercial real estate 403 740 — 1,143 3,305,043 16,908 3,323,094 Total commercial and commercial real estate 3,309 2,623 — 5,932 5,098,608 25,237 5,129,777 Agricultural and agricultural real estate 1,147 69 22 1,238 500,320 16,828 518,386 Residential real estate 2,891 66 — 2,957 602,927 18,841 624,725 Consumer 2,618 1,477 — 4,095 466,934 3,900 474,929 Total gross loans receivable held to maturity $ 9,965 $ 4,235 $ 22 $ 14,222 $ 6,668,789 $ 64,806 $ 6,747,817 December 31, 2017 Commercial $ 1,246 $ 259 $ 100 $ 1,605 $ 1,637,773 $ 7,228 $ 1,646,606 Commercial real estate 4,769 2,326 — 7,095 3,139,576 16,598 3,163,269 Total commercial and commercial real estate 6,015 2,585 100 8,700 4,777,349 23,826 4,809,875 Agricultural and agricultural real estate 604 134 — 738 497,546 13,304 511,588 Residential real estate 2,022 270 — 2,292 601,120 20,867 624,279 Consumer 4,734 943 730 6,407 436,493 4,584 447,484 Total gross loans receivable held to maturity $ 13,375 $ 3,932 $ 830 $ 18,137 $ 6,312,508 $ 62,581 $ 6,393,226 The majority of Heartland's impaired loans are on nonaccrual or have had their terms restructured in a troubled debt restructuring. The following tables present, by category of loan, impaired loans, the unpaid contractual loan balances at March 31, 2018 , and December 31, 2017 ; the outstanding loan balances recorded on the consolidated balance sheets at March 31, 2018 , and December 31, 2017 ; any related allowance recorded for those loans as of March 31, 2018 , and December 31, 2017 ; the average outstanding loan balances recorded on the consolidated balance sheets during the three -months ended March 31, 2018 , and year ended December 31, 2017 ; and the interest income recognized on the impaired loans during the three -month period ended March 31, 2018 , and year ended December 31, 2017 , in thousands: Unpaid Contractual Balance Loan Balance Related Allowance Recorded Year- to- Date Avg. Loan Balance Year- to- Date Interest Income Recognized March 31, 2018 Impaired loans with a related allowance: Commercial $ 2,816 $ 2,816 $ 2,425 $ 2,472 $ — Commercial real estate 11,180 9,324 736 9,520 8 Total commercial and commercial real estate 13,996 12,140 3,161 11,992 8 Agricultural and agricultural real estate 1,536 1,536 787 1,537 — Residential real estate 1,693 1,693 386 1,608 3 Consumer 2,859 2,859 1,137 3,069 9 Total impaired loans with a related allowance $ 20,084 $ 18,228 $ 5,471 $ 18,206 $ 20 Impaired loans without a related allowance: Commercial $ 7,308 $ 6,189 $ — $ 5,449 $ 49 Commercial real estate 14,202 13,596 — 13,879 97 Total commercial and commercial real estate 21,510 19,785 — 19,328 146 Agricultural and agricultural real estate 17,388 15,360 — 12,954 1 Residential real estate 26,635 26,631 — 26,878 109 Consumer 3,757 3,568 — 3,912 22 Total impaired loans without a related allowance $ 69,290 $ 65,344 $ — $ 63,072 $ 278 Total impaired loans held to maturity: Commercial $ 10,124 $ 9,005 $ 2,425 $ 7,921 $ 49 Commercial real estate 25,382 22,920 736 23,399 105 Total commercial and commercial real estate 35,506 31,925 3,161 31,320 154 Agricultural and agricultural real estate 18,924 16,896 787 14,491 1 Residential real estate 28,328 28,324 386 28,486 112 Consumer 6,616 6,427 1,137 6,981 31 Total impaired loans held to maturity $ 89,374 $ 83,572 $ 5,471 $ 81,278 $ 298 Unpaid Contractual Balance Loan Balance Related Allowance Recorded Year-to- Date Avg. Loan Balance Year-to- Date Interest Income Recognized December 31, 2017 Impaired loans with a related allowance: Commercial $ 2,292 $ 2,292 $ 1,613 $ 3,607 $ 39 Commercial real estate 11,925 10,068 766 11,479 34 Total commercial and commercial real estate 14,217 12,360 2,379 15,086 73 Agricultural and agricultural real estate 1,539 1,539 546 3,437 — Residential real estate 1,568 1,568 430 2,056 15 Consumer 2,634 2,634 1,400 2,370 41 Total impaired loans with a related allowance $ 19,958 $ 18,101 $ 4,755 $ 22,949 $ 129 Impaired loans without a related allowance: Commercial $ 6,243 $ 5,123 $ — $ 2,586 $ 165 Commercial real estate 14,243 13,637 — 20,148 514 Total commercial and commercial real estate 20,486 18,760 — 22,734 679 Agricultural and agricultural real estate 13,793 11,765 — 9,654 — Residential real estate 25,573 25,573 — 26,024 277 Consumer 4,269 4,269 — 3,884 73 Total impaired loans without a related allowance $ 64,121 $ 60,367 $ — $ 62,296 $ 1,029 Total impaired loans held to maturity: Commercial $ 8,535 $ 7,415 $ 1,613 $ 6,193 $ 204 Commercial real estate 26,168 23,705 766 31,627 548 Total commercial and commercial real estate 34,703 31,120 2,379 37,820 752 Agricultural and agricultural real estate 15,332 13,304 546 13,091 — Residential real estate 27,141 27,141 430 28,080 292 Consumer 6,903 6,903 1,400 6,254 114 Total impaired loans held to maturity $ 84,079 $ 78,468 $ 4,755 $ 85,245 $ 1,158 On February 23, 2018, Heartland acquired Signature Bancshares, Inc., parent company of Signature Bank, based in Minnetonka, Minnesota. As of February 23, 2018, Signature Bancshares, Inc. had gross loans of $ 335.1 million and the estimated fair value of the loans acquired was $ 324.5 million . Included in loans acquired from Signature Bank is a lease portfolio with a fair value of $16.0 million . The lease portfolio is include with the commercial loan category for disclosure purposes. On July 7, 2017, Heartland acquired Citywide Banks of Colorado, Inc., parent company of Citywide Banks, based in Denver, Colorado. As of July 7, 2017, Citywide Banks had gross loans of $1.00 billion , and the estimated fair value of the loans acquired was $985.4 million . On February 28, 2017, Heartland acquired Founders Bancorp, parent company of Founders Community Bank, based in San Luis Obispo, California. As of February 28, 2017, Founders Community Bank had gross loans of $98.9 million , and the estimated fair value of the loans acquired was $96.4 million . Heartland uses the acquisition method of accounting for purchased loans in accordance with ASC 805, " Business Combinations." Purchased loans acquired in a business combination are recorded at estimated fair value on their purchase date, but the purchaser cannot carry over the related allowance for loan losses. Purchased loans are accounted for under ASC 310-30, " Loans and Debt Securities with Deteriorated Credit Quality," when the loans have evidence of credit deterioration since origination, and when at the date of the acquisition, it is probable that Heartland will not collect all contractually required principal and interest payments. Evidence of credit quality deterioration at the purchase date includes statistics such as past due and nonaccrual status. Generally, acquired loans that meet Heartland’s definition for nonaccrual status fall within the scope of ASC 310-30. The difference between contractually required payments at acquisition and the cash flows expected to be collected at acquisition is referred to as the nonaccretable difference, which is included in the carrying value of the loans. Subsequent decreases to the expected cash flows of the loan will generally result in a provision for loan losses. Subsequent increases in cash flows result in a reversal of the provision for loan losses to the extent of prior charges, or a reclassification of the difference from nonaccretable to accretable with a positive impact on future interest income. Further, any excess of cash flows expected at acquisition over the estimated fair value is referred to as the accretable yield and is recognized into interest income over the remaining life of the loan when there is a reasonable expectation about the amount and timing of such cash flows. At March 31, 2018 , and December 31, 2017 , the carrying amount of loans acquired since 2015 consist of purchased impaired and nonimpaired loans as summarized in the following table, in thousands: March 31, 2018 December 31, 2017 Impaired Non Impaired Total Loans Impaired Non Impaired Total Loans Commercial $ 3,142 $ 262,107 $ 265,249 $ 952 $ 187,375 $ 188,327 Commercial real estate 2,474 1,078,724 1,081,198 2,572 1,052,469 1,055,041 Agricultural and agricultural real estate — 26 26 — 1,242 1,242 Residential real estate 199 181,020 181,219 214 173,909 174,123 Consumer loans — 78,613 78,613 — 51,292 51,292 Total loans $ 5,815 $ 1,600,490 $ 1,606,305 $ 3,738 $ 1,466,287 $ 1,470,025 Changes in accretable yield on acquired loans with evidence of credit deterioration at the date of acquisition for the three -month periods ended March 31, 2018 , and March 31, 2017 , were as follows, in thousands: Three Months Ended 2018 2017 Balance at beginning of period $ 57 $ 182 Original yield premium, net, at date of acquisition (56 ) — Accretion (199 ) (173 ) Reclassification from nonaccretable difference (1) 198 127 Balance at period end $ — $ 136 (1) Represents increases in estimated cash flows expected to be received, primarily due to lower estimated credit losses. For loans acquired since January 2015, on the acquisition dates the preliminary estimate of the contractually required payments receivable for all loans with evidence of credit deterioration since origination was $26.0 million , and the estimated fair value of these loans was $15.0 million . At March 31, 2018 , a majority of these loans were valued based upon the liquidation value of the underlying collateral, because the expected cash flows are primarily based on the liquidation of such collateral, and the timing and amount of the cash flows could not be reasonably estimated. At March 31, 2018 , there was no allowance recorded and $139,000 of allowance recorded at December 31, 2017, related to these ASC 310-30 loans. Provision expense of $0 and $1,000 was recorded for the three-month periods ended March 31, 2018 , and 2017 , respectively. For loans acquired since January 2015, the preliminary estimate on the acquisition dates of the contractually required payments receivable for all nonimpaired loans acquired was $2.99 billion , and the estimated fair value of the loans was $2.91 billion .

Allowance for Loan Losses

Allowance for Loan Losses	3 Months Ended
	Mar. 31, 2018
Loans and Leases Receivable Disclosure [Abstract]
Allowance for Loan Losses	ALLOWANCE FOR LOAN LOSSES Changes in the allowance for loan losses for the three -month periods ended March 31, 2018 , and March 31, 2017 , were as follows, in thousands: Commercial Commercial Real Estate Agricultural Residential Real Estate Consumer Total Balance at December 31, 2017 $ 18,098 $ 21,950 $ 4,258 $ 2,224 $ 9,156 $ 55,686 Charge-offs (794 ) (125 ) — (16 ) (1,289 ) (2,224 ) Recoveries 104 448 14 75 290 931 Provision 1,987 1,196 444 (142 ) 778 4,263 Balance at March 31, 2018 $ 19,395 $ 23,469 $ 4,716 $ 2,141 $ 8,935 $ 58,656 Commercial Commercial Real Estate Agricultural Residential Real Estate Consumer Total Balance at December 31, 2016 $ 14,765 $ 24,319 $ 4,210 $ 2,263 $ 8,767 $ 54,324 Charge-offs (230 ) (608 ) (871 ) (265 ) (1,744 ) (3,718 ) Recoveries 234 212 1 2 303 752 Provision 1,411 (126 ) 643 183 1,530 3,641 Balance at March 31, 2017 $ 16,180 $ 23,797 $ 3,983 $ 2,183 $ 8,856 $ 54,999 Management allocates the allowance for loan losses by pools of risk within each loan portfolio. The allocation of the allowance for loan losses by loan portfolio is made for analytical purposes and is not necessarily indicative of the trend of future loan losses in any particular category. The total allowance for loan losses is available to absorb losses from any segment of the loan portfolio.

Goodwill, Core Deposit Premium

Goodwill, Core Deposit Premium and Other Intangible Assets	3 Months Ended
	Mar. 31, 2018
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill, Core Deposit Premium and Other Intangible Assets	GOODWILL, CORE DEPOSIT PREMIUM AND OTHER INTANGIBLE ASSETS Heartland had goodwill of $ 270.3 million at March 31, 2018 , and $236.6 million at December 31, 2017 . Heartland conducts its annual internal assessment of the goodwill both at the consolidated level and at its subsidiaries as of September 30. There was no goodwill impairment as of the most recent assessment. Heartland recorded $33.7 million of goodwill and $7.7 million of core deposit intangibles in connection with the acquisition of Signature Bancshares, Inc., parent company of Signature Bank, headquartered in Minnetonka, Minnesota on February 23, 2018. Heartland recorded $95.2 million of goodwill and $16.0 million of core deposit intangibles in connection with the acquisition of Citywide Banks of Colorado, Inc., parent company of Citywide Banks, headquartered in Aurora, Colorado on July 7, 2017. Heartland recorded $13.8 million of goodwill and $2.5 million of core deposit intangibles in connection with the acquisition of Founders Bancorp, parent company of Founders Community Bank, based in San Luis Obispo, California on February 28, 2017. The core deposit intangibles recorded with the Signature Bancshares, Inc., Citywide Banks of Colorado, Inc., and Founders Bancorp acquisitions are not deductible for tax purposes and are expected to be amortized over a period of 10 years on an accelerated basis. Goodwill related to the Signature Bancshares, Inc., Citywide Banks of Colorado, Inc., and Founders Bancorp acquisitions resulted from expected operational synergies, increased market presence, cross-selling opportunities, and expanded business lines and is not deductible for tax purposes. Heartland's intangible assets consist of core deposit intangibles, mortgage servicing rights, customer relationship intangibles, and commercial servicing rights. The gross carrying amount of these intangible assets and the associated accumulated amortization at March 31, 2018 , and December 31, 2017 , are presented in the table below, in thousands: March 31, 2018 December 31, 2017 Gross Carrying Amount Accumulated Amortization Net Carrying Amount Gross Carrying Amount Accumulated Amortization Net Carrying Amount Amortizing intangible assets: Core deposit intangibles $ 69,731 $ 28,939 $ 40,792 $ 62,008 $ 27,086 $ 34,922 Customer relationship intangibles 1,177 906 271 1,177 896 281 Mortgage servicing rights 42,249 19,084 23,165 42,139 18,891 23,248 Commercial servicing rights 6,740 4,434 2,306 6,719 4,110 2,609 Total $ 119,897 $ 53,363 $ 66,534 $ 112,043 $ 50,983 $ 61,060 The following table shows the estimated future amortization expense for amortizable intangible assets, in thousands: Core Deposit Intangibles Customer Relationship Intangibles Mortgage Servicing Rights Commercial Servicing Rights Total Nine months ending December 31, 2018 $ 5,957 $ 29 $ 6,776 $ 471 $ 13,233 Year ending December 31, 2019 7,092 38 4,097 522 11,749 2020 6,220 37 3,512 411 10,180 2021 5,323 36 2,927 354 8,640 2022 4,175 34 2,341 290 6,840 2023 3,691 33 1,756 163 5,643 Thereafter 8,334 64 1,756 95 10,249 Total $ 40,792 $ 271 $ 23,165 $ 2,306 $ 66,534 Projections of amortization expense for mortgage servicing rights are based on existing asset balances and the existing interest rate environment as of March 31, 2018 . Heartland's actual experience may be significantly different depending upon changes in mortgage interest rates and market conditions. Mortgage loans serviced for others were approximately $3.54 billion and $ 3.56 billion as of March 31, 2018 , and December 31, 2017 , respectively. Custodial escrow balances maintained in connection with the mortgage loan servicing portfolio were approximately $23.2 million and $17.3 million as of March 31, 2018 , and December 31, 2017 , respectively. The fair value of Heartland's mortgage servicing rights was estimated at $40.4 million at March 31, 2018 , and $37.1 million at December 31, 2017 . Heartland's mortgage servicing rights portfolio is comprised of loans serviced for the Federal National Mortgage Association ("FNMA") and the Federal Home Loan Mortgage Corporation ("FHLMC"). Prior to the third quarter of 2017, Heartland also serviced loans for the Government National Mortgage Association ("GNMA"). The servicing rights portfolio is separated into 15 - and 30 -year tranches, and the servicing rights portfolio is an asset of one of Heartland's subsidiaries. During the third quarter of 2017, Heartland entered into an agreement to sell substantially all of its GNMA servicing portfolio, which contained loans with an unpaid principal balance of approximately $773.9 million . The transaction qualified as a sale, and $6.9 million of mortgage servicing rights were de-recognized on the consolidated balance sheet as of December 31, 2017 . The fair value of mortgage servicing rights is calculated based upon a discounted cash flow analysis. Cash flow assumptions, including prepayment speeds, servicing costs and escrow earnings are considered in the calculation. The average constant prepayment rate was 8.23% and 9.73% for the March 31, 2018 , and December 31, 2017 , valuations, respectively. The discount rate was 9.04% and 9.06% for the March 31, 2018 , and December 31, 2017 , valuations, respectively. The average capitalization rate for the first three months of 2018 ranged from 96 to 125 basis points compared to the range of 91 to 150 basis points for 2017 . Fees collected for the servicing of mortgage loans for others were $ 2.2 million and $ 3.2 million for the three months ended March 31, 2018 , and March 31, 2017 . The following table summarizes, in thousands, the changes in capitalized mortgage servicing rights for the three months ended March 31, 2018 , and March 31, 2017 : 2018 2017 Balance at January 1, $ 23,248 $ 32,088 Originations 1,162 2,132 Amortization (1,245 ) (2,261 ) Balance at period end $ 23,165 $ 31,959 Fair value of mortgage servicing rights $ 40,434 $ 47,564 Mortgage servicing rights, net to servicing portfolio 0.66 % 0.74 % Heartland's commercial servicing portfolio is comprised of loans guaranteed by the Small Business Administration and United States Department of Agriculture that have been sold with servicing retained by Heartland, which totaled $125.5 million at March 31, 2018 and $139.9 million at December 31, 2017. The commercial servicing rights portfolio is separated into two tranches at the respective Heartland subsidiary, loans with a term of less than 20 years and loans with a term of more than 20 years . Fees collected for the servicing of commercial loans for others were $420,000 and $415,000 for the three months ended March 31, 2018 , and March 31, 2017 , respectively. The fair value of each commercial servicing rights portfolio is calculated based upon a discounted cash flow analysis. Cash flow assumptions, including prepayment speeds and servicing costs, are considered in the calculation. The range of average constant prepayment rates for the valuations was 8.27% to 9.89% as of March 31, 2018 , compared to 7.27% to 8.88% as of December 31, 2017 . The discount rate range was 13.09% to 16.71% for the March 31, 2018 , valuations compared to 13.04% to 15.49% for the December 31, 2017 , valuations. The capitalization rate for 2018 ranged from 310 to 445 basis points compared to 310 to 445 basis points for 2017 . The total fair value of Heartland's commercial servicing rights was estimated at $2.8 million as of March 31, 2018 , and $ 3.2 million as of December 31, 2017. The following table summarizes, in thousands, the changes in capitalized commercial servicing rights for the three months ended March 31, 2018 , and March 31, 2017 : 2018 2017 Balance at January 1, $ 2,609 $ 3,690 Originations 21 93 Amortization (322 ) (306 ) Valuation allowance on commercial servicing rights (2 ) 5 Balance at period end $ 2,306 $ 3,482 Fair value of commercial servicing rights $ 2,781 $ 4,040 Commercial servicing rights, net to servicing portfolio 1.84 % 2.17 % Mortgage and commercial servicing rights are initially recorded at fair value in net gains on sale of loans held for sale when they are acquired through loan sales. Fair value is based on market prices for comparable servicing contracts, when available, or based on a valuation model that calculates the present value of estimated future net servicing income. Mortgage and commercial servicing rights are subsequently measured using the amortization method, which requires the asset to be amortized into noninterest income in proportion to, and over the period of, the estimated future net servicing income of the underlying loans. Servicing rights are evaluated for impairment at each Heartland subsidiary based upon the fair value of the assets as compared to the carrying amount. Impairment is recognized through a valuation allowance for specific tranches to the extent that fair value is less than carrying amount at each Heartland subsidiary. At March 31, 2018 , no valuation allowance was required on commercial servicing rights with a term less than 20 years and a $14,000 valuation allowance was required on commercial servicing rights with a term greater than 20 years. At December 31, 2017 , no valuation allowance was required on commercial servicing rights with a term less than 20 years and a $12,000 valuation allowance was required on commercial servicing rights with a term greater than 20 years. The following table summarizes, in thousands, the book value, the fair value of each tranche of the commercial servicing rights and any recorded valuation allowance at each respective subsidiary at March 31, 2018 , and December 31, 2017 : March 31, 2018 Book Value- Less than 20 Years Fair Value- Less than 20 Years Impairment- Less than 20 Years Book Value- More than 20 Years Fair Value- More than 20 Years Impairment- More than 20 Years Citywide Banks $ 6 $ 10 $ — $ 33 $ 36 $ — Premier Valley Bank 72 104 — 286 272 14 Wisconsin Bank & Trust 368 534 — 1,554 1,825 — Total $ 446 $ 648 $ — $ 1,873 $ 2,133 $ 14 December 31, 2017 Citywide Banks $ 8 $ 11 $ — $ 34 $ 37 $ — Premier Valley Bank 83 110 — 303 291 12 Wisconsin Bank & Trust 446 619 — 1,747 2,153 — Total $ 537 $ 740 $ — $ 2,084 $ 2,481 $ 12

Derivative Financial Instrument

Derivative Financial Instruments	3 Months Ended
	Mar. 31, 2018
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivative Financial Instruments	DERIVATIVE FINANCIAL INSTRUMENTS Heartland uses derivative financial instruments as part of its interest rate risk management strategy. As part of the strategy, Heartland considers the use of interest rate swaps, caps, floors, collars, and certain interest rate lock commitments and forward sales of securities related to mortgage banking activities. Heartland's current strategy includes the use of interest rate swaps, interest rate lock commitments and forward sales of mortgage securities. In addition, Heartland is facilitating back-to-back loan swaps to assist customers in managing interest rate risk. Heartland's objectives are to add stability to its net interest margin and to manage its exposure to movements in interest rates. The contract or notional amount of a derivative is used to determine, along with the other terms of the derivative, the amounts to be exchanged between the counterparties. Heartland is exposed to credit risk in the event of nonperformance by counterparties to financial instruments. Heartland minimizes this risk by entering into derivative contracts with counterparties that meet Heartland’s credit standards, and the contracts contain collateral provisions protecting the at-risk party. Heartland has not experienced any losses from nonperformance by these counterparties. Heartland monitors counterparty risk in accordance with the provisions of ASC 815. In addition, interest rate-related derivative instruments generally contain language outlining collateral pledging requirements for each counterparty. Collateral must be posted when the market value exceeds certain threshold limits which are determined by credit ratings of each counterparty. Heartland was required to pledge no cash as collateral at March 31, 2018 , and $1.2 million at December 31, 2017 . At March 31, 2018 , $860,000 of collateral was required to be pledged by Heartland's counterparties, compared to no collateral at December 31, 2017 . Heartland's derivative and hedging instruments are recorded at fair value on the consolidated balance sheets. See Note 8, “Fair Value,” for additional fair value information and disclosures. Cash Flow Hedges Heartland has variable rate funding which creates exposure to variability in interest payments due to changes in interest rates. To manage the interest rate risk related to the variability of interest payments, Heartland has entered into various interest rate swap agreements. Amounts reported in accumulated other comprehensive income related to derivatives will be reclassified to interest expense as interest payments are received or made on Heartland's variable-rate liabilities. For the three months ended March 31, 2018 , the change in net unrealized losses on cash flow hedges reflects changes in the fair value of the swaps and reclassification from accumulated other comprehensive income to interest expense totaling $197,000 . For the next twelve months, Heartland estimates that cash payments and reclassification from accumulated other comprehensive income to interest expense will total $789,000 . Heartland entered into five forward starting interest rate swap transactions to effectively convert Heartland Financial Statutory Trust IV, V, and VII, which total $ 65.0 million , as well as Morrill Statutory Trust I and II, which total $ 20.0 million , from variable rate subordinated debentures to fixed rate debt. For accounting purposes, these five swap transactions are designated as cash flow hedges of the changes in LIBOR, the benchmark interest rate being hedged, associated with the interest payments made on $85.0 million of Heartland's subordinated debentures that reset quarterly on a specified reset date. At inception, Heartland asserted that the underlying principal balance would remain outstanding throughout the hedge transaction, making it probable that sufficient LIBOR-based interest payments would exist through the maturity date of the swaps. The table below identifies the balance sheet category and fair values of Heartland's derivative instruments designated as cash flow hedges at March 31, 2018 , and December 31, 2017 , in thousands: Notional Amount Fair Value Balance Sheet Category Receive Rate Weighted Average Pay Rate Maturity March 31, 2018 Interest rate swap $ 25,000 $ 239 Other assets 2.178 % 2.255 % 03/17/2021 Interest rate swap 20,000 (380 ) Other liabilities 1.704 3.355 01/07/2020 Interest rate swap 10,000 69 Other assets 2.286 1.674 03/26/2019 Interest rate swap 10,000 68 Other assets 2.178 1.658 03/18/2019 Interest rate swap 32,667 1,010 Other assets 4.240 3.674 05/10/2021 Interest rate swap 20,000 316 Other assets 2.125 2.390 06/15/2024 Interest rate swap 20,000 339 Other assets 2.006 2.352 03/01/2024 December 31, 2017 Interest rate swap $ 25,000 $ (106 ) Other liabilities 1.600 % 2.255 % 03/17/2021 Interest rate swap 20,000 (621 ) Other liabilities 1.350 3.355 01/07/2020 Interest rate swap 10,000 30 Other assets 1.329 1.674 03/26/2019 Interest rate swap 10,000 29 Other assets 1.600 1.658 03/18/2019 Interest rate swap 33,667 759 Other assets 3.932 3.674 05/10/2021 Interest rate swap (1) 20,000 (177 ) Other liabilities 1.588 2.390 06/15/2024 Interest rate swap (2) 20,000 (149 ) Other Liabilities 1.481 2.352 03/01/2024 The table below identifies the gains and losses recognized on Heartland's derivative instruments designated as cash flow hedges for the three -month periods ended March 31, 2018 , and March 31, 2017 , in thousands: Effective Portion Ineffective Portion Recognized in OCI Reclassified from AOCI into Income Recognized in Income on Derivatives Amount of Gain (Loss) Category Amount of Gain (Loss) Category Amount of Gain (Loss) Three Months Ended March 31, 2018 Interest rate swaps $ 1,896 Interest expense $ (197 ) Other income $ — Three Months Ended March 31, 2017 Interest rate swaps $ 533 Interest expense $ (397 ) Other income $ — Fair Value Hedges Heartland uses interest rate swaps to convert certain long term fixed rate loans to floating rates to hedge interest rate risk exposure. Heartland uses hedge accounting in accordance with ASC 815, with the unrealized gains and losses, representing the change in fair value of the derivative and the change in fair value of the risk being hedged on the related loan, being recorded in the consolidated statements of income. The ineffective portions of the unrealized gains or losses, if any, are recorded in interest income and interest expense in the consolidated statements of income. Heartland uses statistical regression to assess hedge effectiveness, both at the inception of the hedge as well as on a continual basis. The regression analysis involves regressing the periodic change in the fair value of the hedging instrument against the periodic changes in the fair value of the asset being hedged due to changes in the hedge risk. Heartland was required to pledge $3.2 million and $3.9 million of cash as collateral for these fair value hedges at March 31, 2018 , and December 31, 2017, respectively. The table below identifies the notional amount, fair value and balance sheet category of Heartland's fair value hedges at March 31, 2018 , and December 31, 2017 , in thousands: Notional Amount Fair Value Balance Sheet Category March 31, 2018 Fair value hedges $ 35,436 $ (105 ) Other liabilities December 31, 2017 Fair value hedges $ 35,635 $ (999 ) Other liabilities The table below identifies the gains and losses recognized on Heartland's fair value hedges for the three month periods ended March 31, 2018 , and March 31, 2017 , in thousands: Amount of Gain (Loss) Income Statement Category Three Months Ended March 31, 2018 Fair value hedges $ 894 Interest income Three Months Ended March 31, 2017 Fair value hedges $ 194 Interest income Embedded Derivatives Heartland has fixed rate loans with embedded derivatives. The loans contain terms that affect the cash flows or value of the loan similar to a derivative instrument, and therefore are considered to contain an embedded derivative. The embedded derivatives are bifurcated from the loans because the terms of the derivative instrument are not clearly and closely related to the loans. The embedded derivatives are recorded at fair value on the consolidated balance sheets as a part of other assets, and changes in the fair value are a component of noninterest income. The table below identifies the notional amount, fair value and balance sheet category of Heartland's embedded derivatives at March 31, 2018 , and December 31, 2017 , in thousands: Notional Amount Fair Value Balance Sheet Category March 31, 2018 Embedded derivatives $ 13,907 $ 461 Other assets December 31, 2017 Embedded derivatives $ 14,045 $ 738 Other assets The table below identifies the gains and losses recognized on Heartland's embedded derivatives for the three month periods ended March 31, 2018 , and March 31, 2017 , in thousands: Amount of Gain (Loss) Income Statement Category Three Months Ended March 31, 2018 Embedded derivatives $ 277 Other noninterest income Three Months Ended March 31, 2017 Embedded derivatives $ 117 Other noninterest income In conjunction with the CIC Bancshares, Inc. transaction on February 5, 2016, Heartland assumed convertible subordinated debt. The subordinated debt has a face value of $2.0 million , and the embedded conversion option allows the holder to convert the debt to Heartland common equity in any increment and at the discretion of the holder. The conversion option is bifurcated from the debt because the terms of the conversion option are not clearly and closely related to the terms of the debt. On February 5, 2016, the total number of shares to be issued upon conversion was 73,394 . At March 31, 2018, and December 31, 2017, the remaining shares to be issued upon conversion totaled zero . During 2017, all of the remaining convertible subordinated debt was converted to common stock, resulting in the issuance of 20,481 shares of common stock. The embedded conversion option was reported at fair value on the consolidated balance sheets using the Black-Scholes model. The following table identifies, in thousands, the notional amount, fair value, balance sheet category and income statement category for the change in fair value of the embedded conversion option as of March 31, 2018 , and December 31, 2017 : Notional Amount Fair Value Balance Sheet Category March 31, 2018 Embedded conversion option $ — $ — Other liabilities December 31, 2017 Embedded conversion option $ — $ — Other liabilities The table below identifies the gains and losses recognized on Heartland's embedded conversion options for the three -month periods ended March 31, 2018 , and March 31, 2017 , in thousands: Amount of Gain (Loss) Income Statement Category Three Months Ended March 31, 2018 Embedded conversion option $ — Other noninterest income Three Months Ended March 31, 2017 Embedded conversion option $ 97 Other noninterest income Back-to-Back Loan Swaps Heartland has interest rate swap loan relationships with customers to meet their financing needs. Upon entering into these loan swaps, Heartland enters into offsetting positions with counterparties in order to minimize interest rate risk. These back-to-back loan swaps qualify as free standing financial derivatives with the fair values reported in other assets and other liabilities on the consolidated balance sheets. Heartland was required to post $495,000 and $1.6 million as of March 31, 2018 , and December 31, 2017 , respectively, as collateral related to these back-to-back swaps. Heartland's counterparties were required to pledge $1.6 million at March 31, 2018 , and $190,000 at December 31, 2017 . Any gains and losses on these back-to-back swaps are recorded in noninterest income on the consolidated statements of income, and for the three months ended March 31, 2018 and March 31, 2017 , no gain or loss was recognized. The table below identifies the balance sheet category and fair values of Heartland's derivative instruments designated as loan swaps at March 31, 2018 , and December 31, 2017 , in thousands: Notional Amount Fair Value Balance Sheet Category Weighted Average Receive Rate Weighted Average Pay Rate March 31, 2018 Customer interest rate swaps $ 162,882 $ 3,763 Other assets 4.82 % 4.73 % Customer interest rate swaps 162,882 (3,763 ) Other liabilities 4.73 4.82 December 31, 2017 Customer interest rate swaps $ 126,766 $ 2,377 Other assets 4.70 % 4.03 % Customer interest rate swaps 126,766 (2,377 ) Other liabilities 4.03 4.70 Other Free Standing Derivatives Heartland has entered into interest rate lock commitments to originate residential mortgage loans held for sale and forward commitments to sell residential mortgage loans and mortgage backed securities that are considered derivative instruments. Heartland enters into forward commitments for the future delivery of residential mortgage loans when interest rate lock commitments are entered into in order to economically hedge the effect of future changes in interest rates on the commitments to fund the loans as well as on residential mortgage loans available for sale. The fair value of these commitments is recorded on the consolidated balance sheets, with the changes in fair value recorded in the consolidated statements of income as a component of gains on sale of loans held for sale. These derivative contracts are designated as free standing derivative contracts and are not designated against specific assets and liabilities on the consolidated balance sheets or forecasted transactions and therefore do not qualify for hedge accounting treatment. Heartland was required to pledge collateral of $203,000 at March 31, 2018 , and $20,000 at December 31, 2017 . Heartland's counterparties were required to pledge $0 and $29,000 at March 31, 2018 , and December 31, 2017 , respectively, as collateral for these forward commitments. Heartland acquired undesignated interest rate swaps in 2015. These swaps were entered into primarily for the benefit of customers seeking to manage their interest rate risk and are not designated against specific assets or liabilities on the consolidated balance sheet or forecasted transactions and therefore do not qualify for hedge accounting in accordance with ASC 815. These swaps are carried at fair value on the consolidated balance sheets as a component of other liabilities, with changes in the fair value recorded as a component of other noninterest income. The table below identifies the balance sheet category and fair values of Heartland's other free standing derivative instruments not designated as hedging instruments at March 31, 2018 , and December 31, 2017 , in thousands: Balance Sheet Category Notional Amount Fair Value March 31, 2018 Interest rate lock commitments (mortgage) Other assets $ 65,591 $ 1,959 Forward commitments Other assets 55,118 283 Forward commitments Other liabilities 91,625 (320 ) Undesignated interest rate swaps Other liabilities 13,907 (461 ) December 31, 2017 Interest rate lock commitments (mortgage) Other assets $ 53,588 $ 1,738 Forward commitments Other assets 37,286 80 Forward commitments Other liabilities 118,632 (232 ) Undesignated interest rate swaps Other liabilities 14,045 (738 ) The table below identifies the income statement category of the gains and losses recognized in income on Heartland's other free standing derivative instruments not designated as hedging instruments for the three -month periods ended March 31, 2018 , and March 31, 2017 , in thousands: Income Statement Category Gain (Loss) Recognized Three Months Ended March 31, 2018 Interest rate lock commitments (mortgage) Net gains on sale of loans held for sale $ 17 Forward commitments Net gains on sale of loans held for sale 115 Undesignated interest rate swaps Other noninterest income 277 Three Months Ended March 31, 2017 Interest rate lock commitments (mortgage) Net gains on sale of loans held for sale $ 1,062 Forward commitments Net gains on sale of loans held for sale (2,739 ) Undesignated interest rate swaps Other noninterest income 117

Fair Value

Fair Value	3 Months Ended
	Mar. 31, 2018
Fair Value Disclosures [Abstract]
Fair Value	FAIR VALUE Heartland utilizes fair value measurements to record fair value adjustments to certain assets and liabilities and to determine fair value disclosures. Securities available for sale, trading securities and derivatives are recorded in the consolidated balance sheets at fair value on a recurring basis. Additionally, from time to time, Heartland may be required to record at fair value other assets on a nonrecurring basis such as loans held for sale, loans held to maturity and certain other assets including, but not limited to, mortgage servicing rights, commercial servicing rights and other real estate owned. These nonrecurring fair value adjustments typically involve application of the lower of cost or fair value accounting or write-downs of individual assets. Fair Value Hierarchy Under ASC 820, assets and liabilities are grouped at fair value in three levels, based on the markets in which the assets and liabilities are traded and the reliability of the assumptions used to determine fair value. These levels are: Level 1 — Valuation is based upon quoted prices for identical instruments in active markets. Level 2 — Valuation is based upon quoted prices for similar instruments in active markets, or similar instruments in markets that are not active, and model-based valuation techniques for all significant assumptions are observable in the market. Level 3 — Valuation is generated from model-based techniques that use at least one significant assumption not observable in the market. These unobservable assumptions reflect estimates of assumptions that market participants would use in pricing the asset or liability. Valuation techniques include use of option pricing models, discounted cash flow models and similar techniques. The following is a description of valuation methodologies used for assets and liabilities recorded at fair value on a recurring or non-recurring basis. Assets Securities Available for Sale and Held to Maturity Securities available for sale are recorded at fair value on a recurring basis. Securities held to maturity are generally recorded at cost and are recorded at fair value only to the extent a decline in fair value is determined to be other-than-temporary. Fair value measurement is based upon quoted prices, if available. If quoted prices are not available, fair values are measured using independent pricing models or other model-based valuation techniques such as the present value of future cash flows, adjusted for the security's credit rating, prepayment assumptions and other factors such as credit loss assumptions. Level 1 securities include those traded on an active exchange, such as the New York Stock Exchange, as well as U.S. Treasury securities. Level 2 securities include U.S. government and agency securities, mortgage and asset-backed securities and private collateralized mortgage obligations, municipal bonds and corporate debt securities. On a quarterly basis, a secondary independent pricing service is used for the securities portfolio to validate the pricing from Heartland's primary pricing service. Loans Held for Sale Loans held for sale are carried at the lower of cost or fair value on an aggregate basis. The fair value of loans held for sale is based on what secondary markets are currently offering for portfolios with similar characteristics. As such, Heartland classifies loans held for sale subjected to nonrecurring fair value adjustments as Level 2. Loans Held to Maturity Heartland does not record loans held to maturity at fair value on a recurring basis. However, from time to time, a loan is considered impaired and an allowance for loan losses is established. Loans for which it is probable that payment of interest and principal will not be made in accordance with the contractual terms of the loan agreement are considered impaired. Once a loan is identified as individually impaired, management measures impairment in accordance with ASC 310. The fair value of impaired loans is measured using one of the following impairment methods: 1) the present value of expected future cash flows discounted at the loan's effective interest rate or 2) the observable market price of the loan or 3) the fair value of the collateral if the loan is collateral dependent. In accordance with ASC 820, impaired loans measured at fair value are classified as nonrecurring Level 3 in the fair value hierarchy. Premises, Furniture and Equipment Held for Sale Heartland values premises, furniture and equipment held for sale based on third-party appraisals less estimated disposal costs. Heartland considers third party appraisals, as well as independent fair value assessments from Realtors or persons involved in selling bank premises, furniture and equipment, in determining the fair value of particular properties. Accordingly, the valuation of premises, furniture and equipment held for sale is subject to significant external and internal judgment. Heartland periodically reviews premises, furniture and equipment held for sale to determine if the fair value of the property, less disposal costs, has declined below its recorded book value and records any adjustments accordingly. Premises, furniture and equipment held for sale are classified as nonrecurring Level 3 in the fair value hierarchy. Mortgage Servicing Rights Mortgage servicing rights assets represent the value associated with servicing residential real estate loans that have been sold to outside investors with servicing retained. Heartland uses the amortization method (i.e., the lower of amortized cost or estimated fair value measured on a nonrecurring basis), not fair value measurement accounting, to determine the carrying value of its mortgage servicing rights. The fair value for servicing assets is determined through discounted cash flow analysis and utilizes discount rates, prepayment speeds and delinquency rate assumptions as inputs. All of the assumptions in the discounted cash flow analysis require a significant degree of management estimation and judgment. Mortgage servicing rights are subject to impairment testing. The carrying values of these rights are reviewed quarterly for impairment based upon the calculation of fair value as performed by an outside third party. For purposes of measuring impairment, the rights are stratified into certain risk characteristics including note type and note term. If the valuation model reflects a fair value less than the carrying value, mortgage servicing rights are adjusted to fair value through a valuation allowance. Heartland classifies mortgage servicing rights as nonrecurring with Level 3 measurement inputs. Commercial Servicing Rights Commercial servicing rights assets represent the value associated with servicing commercial loans guaranteed by the Small Business Administration and the United States Department of Agriculture that have been sold with servicing retained by Heartland. Heartland uses the amortization method (i.e., the lower of amortized cost or estimated fair value measured on a nonrecurring basis), not fair value measurement accounting, to determine the carrying value of its commercial servicing rights. The fair value for servicing assets is determined through market prices for comparable servicing contracts, when available, or through a valuation model that calculates the present value of estimated future net servicing income. Inputs utilized include discount rates, prepayment speeds and delinquency rate assumptions as inputs. All of these assumptions require a significant degree of management estimation and judgment. Commercial servicing rights are subject to impairment testing, and the carrying values of these rights are reviewed quarterly for impairment based upon the calculation of fair value as performed by an outside third party. If the valuation model reflects a fair value less than the carrying value, commercial servicing rights are adjusted to fair value through a valuation allowance. Heartland classifies commercial servicing rights as nonrecurring with Level 3 measurement inputs. Derivative Financial Instruments Heartland's current interest rate risk strategy includes interest rate swaps. The valuation of these instruments is determined using widely accepted valuation techniques including discounted cash flow analysis on the expected cash flows of each derivative. This analysis reflects the contractual terms of the derivatives, including the period to maturity, and uses observable market-based inputs, including interest rate curves and implied volatilities. To comply with the provisions of ASC 820, Heartland incorporates credit valuation adjustments to appropriately reflect both its own nonperformance risk and the respective counterparty's nonperformance risk in the fair value measurements. In adjusting the fair value of its derivative contracts for the effect of nonperformance risk, Heartland has considered the impact of netting any applicable credit enhancements, such as collateral postings, thresholds, mutual puts, and guarantees. Although Heartland has determined that the majority of the inputs used to value its derivatives fall within Level 2 of the fair value hierarchy, the credit valuation adjustments associated with its derivatives utilize Level 3 inputs, such as estimates of current credit spreads to evaluate the likelihood of default by itself and its counterparties. However, as of March 31, 2018 , and December 31, 2017 , Heartland has assessed the significance of the impact of the credit valuation adjustments on the overall valuation of its derivative positions and has determined that the credit valuation adjustments are not significant to the overall valuation of its derivatives. As a result, Heartland has determined that its derivative valuations in their entirety are classified in Level 2 of the fair value hierarchy. Interest rate lock commitments Heartland uses an internal valuation model that relies on internally developed inputs to estimate the fair value of its interest rate lock commitments which is based on unobservable inputs that reflect management's assumptions and specific information about each borrower. Interest rate lock commitments are classified in Level 3 of the fair value hierarchy. Forward commitments The fair value of forward commitments are estimated using an internal valuation model, which includes current trade pricing for similar financial instruments in active markets that Heartland has the ability to access and are classified in Level 2 of the fair value hierarchy. Other Real Estate Owned Other real estate owned ("OREO") represents property acquired through foreclosures and settlements of loans. Property acquired is carried at the fair value of the property at the time of acquisition (representing the property's cost basis), plus any acquisition costs, or the estimated fair value of the property, less disposal costs. Heartland considers third party appraisals, as well as independent fair value assessments from realtors or persons involved in selling OREO, in determining the fair value of particular properties. Accordingly, the valuation of OREO is subject to significant external and internal judgment. Heartland periodically reviews OREO to determine if the fair value of the property, less disposal costs, has declined below its recorded book value and records any adjustments accordingly. OREO is classified as nonrecurring Level 3 of the fair value hierarchy. The table below presents Heartland's assets and liabilities that are measured at fair value on a recurring basis as of March 31, 2018 , and December 31, 2017 , in thousands, aggregated by the level in the fair value hierarchy within which those measurements fall: Total Fair Value Level 1 Level 2 Level 3 March 31, 2018 Assets Securities available for sale U.S. government corporations and agencies $ 11,188 $ 9,421 $ 1,767 $ — Mortgage and asset-backed securities 1,647,604 — 1,647,604 — Obligations of states and political subdivisions 352,180 — 352,180 — Corporate debt securities — — — — Equity securities 16,693 — 16,693 — Derivative financial instruments (1) 6,265 — 6,265 — Interest rate lock commitments 1,959 — — 1,959 Forward commitments 283 — 283 — Total assets at fair value $ 2,036,172 $ 9,421 $ 2,024,792 $ 1,959 Liabilities Derivative financial instruments (2) $ 4,709 $ — $ 4,709 $ — Forward commitments 320 — 320 — Total liabilities at fair value $ 5,029 $ — $ 5,029 $ — December 31, 2017 Assets Securities available for sale U.S. government corporations and agencies $ 5,328 $ 3,484 $ 1,844 $ — Mortgage and asset-backed securities 1,753,736 — 1,753,736 — Obligations of states and political subdivisions 441,015 — 441,015 — Equity securities 16,674 — 16,674 — Derivative financial instruments (1) 3,933 — 3,933 — Interest rate lock commitments 1,738 — — 1,738 Forward commitments 80 — 80 — Total assets at fair value $ 2,222,504 $ 3,484 $ 2,217,282 $ 1,738 Liabilities Derivative financial instruments (2) $ 5,167 $ — $ 5,167 $ — Forward commitments 232 — 232 — Total liabilities at fair value $ 5,399 $ — $ 5,399 $ — (1) Includes cash flow hedges, embedded derivatives and back-to-back loan swaps (2) Includes cash flow hedges, fair value hedges, back-to-back loan swaps, embedded conversion options and free standing derivative instruments The tables below present Heartland's assets that are measured at fair value on a nonrecurring basis, in thousands: Fair Value Measurements at March 31, 2018 Total Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Year-to- Date (Gains) Losses Collateral dependent impaired loans: Commercial $ 2,923 $ — $ — $ 2,923 $ — Commercial real estate 8,316 — — 8,316 — Agricultural and agricultural real estate 8,041 — — 8,041 — Residential real estate 1,421 — — 1,421 4 Consumer 1,721 — — 1,721 — Total collateral dependent impaired loans $ 22,422 $ — $ — $ 22,422 $ 4 Loans held for sale $ 24,376 $ — $ 24,376 $ — $ 288 Other real estate owned $ 11,801 $ — $ — $ 11,801 $ 16 Premises, furniture and equipment held for sale $ 1,477 $ — $ — $ 1,477 $ (115 ) Commercial servicing rights $ 272 $ — $ — $ 272 $ 2 Fair Value Measurements at December 31, 2017 Total Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Year-to- Collateral dependent impaired loans: Commercial $ 3,212 $ — $ — $ 3,212 $ 1,119 Commercial real estate 9,480 — — 9,480 322 Agricultural and agricultural real estate 8,406 — — 8,406 2,028 Residential real estate 1,137 — — 1,137 — Consumer 1,234 — — 1,234 — Total collateral dependent impaired loans $ 23,469 $ — $ — — $ 23,469 $ 3,469 Loans held for sale $ 44,560 $ — $ 44,560 $ — $ 190 Other real estate owned $ 10,777 $ — $ — $ 10,777 $ 737 Premises, furniture and equipment held for sale $ 1,977 $ — $ — $ 1,977 $ 192 Commercial servicing rights $ 291 $ — $ — $ 291 $ (21 ) The following tables present additional quantitative information about assets measured at fair value and for which Heartland has utilized Level 3 inputs to determine fair value, in thousands: Fair Value at 3/31/2018 Valuation Technique Unobservable Input Range (Weighted Average) Interest rate lock commitments $ 1,959 Discounted cash flows Closing ratio 0-99% (89%) (1) Premises, furniture and equipment held for sale 1,477 Modified appraised value Third party appraisal (2) Appraisal discount 0-10% (4) Commercial servicing rights 272 Discounted cash flows Third party valuation (3) Other real estate owned 11,801 Modified appraised value Third party appraisal (2) Appraisal discount 0-10% Collateral dependent impaired loans: Commercial 2,923 Modified appraised value Third party appraisal (2) Appraisal discount 0-10% (4) Commercial real estate 8,316 Modified appraised value Third party appraisal (2) Appraisal discount 0-10% (4) Agricultural and agricultural real estate 8,041 Modified appraised value Third party appraisal (2) Appraisal discount 0-10% (4) Residential real estate 1,421 Modified appraised value Third party appraisal (2) Appraisal discount 0-12% (4) Consumer 1,721 Modified appraised value Third party valuation (2) Valuation discount 0-14% (4) (1) The significant unobservable input used in the fair value measurement is the closing ratio, which represents the percentage of loans currently in a lock position which management estimates will ultimately close. The closing ratio calculation takes into consideration historical data and loan-level data. (2) Third party appraisals are obtained and updated at least annually to establish the value of the underlying asset, but the disclosure of the unobservable inputs used by the appraisers would not be meaningful because the range will vary widely from appraisal to appraisal. (3) The significant unobservable input used in the fair value measurement are the value indices, which are weighted-average spreads to LIBOR based on maturity groups. (4) Discounts applied to the appraised values primarily include estimated sales costs, but also consider the age of the appraisal, changes in local market conditions and changes in the current condition of the collateral. Fair Value at 12/31/2017 Valuation Technique Unobservable Input Range (Weighted Average) Interest rate lock commitments $ 1,738 Discounted cash flows Closing ratio 0-99% (89%) (1) Premises, furniture and equipment held for sale 1,977 Modified appraised value Third party appraisal (2) 0-10% (4) Commercial servicing rights 291 Discounted cash flows Third party valuation (3) Other real estate owned 10,777 Modified appraised value Third party appraisal (2) Appraisal discount 0-10% Collateral dependent impaired loans: Commercial 3,212 Modified appraised value Third party appraisal (2) Appraisal discount 0-15% (4) Commercial real estate 9,480 Modified appraised value Third party appraisal (2) Appraisal discount 0-12% (4) Agricultural and agricultural real estate 8,406 Modified appraised value Third party appraisal (2) Appraisal discount 0-10% (4) Residential real estate 1,137 Modified appraised value Third party appraisal (2) Appraisal discount 0-12% (4) Consumer 1,234 Modified appraised value Third party valuation (2) Valuation discount 0-12% (4) (1) The significant unobservable input used in the fair value measurement is the closing ratio, which represents the percentage of loans currently in a lock position which management estimates will ultimately close. The closing ratio calculation takes into consideration historical data and loan-level data. (2) Third party appraisals are obtained and updated at least annually to establish the value of the underlying asset, but the disclosure of the unobservable inputs used by the appraisers would not be meaningful because the range will vary widely from appraisal to appraisal. (3) The significant unobservable input used in the fair value measurement are the value indices, which are weighted-average spreads to LIBOR based on maturity groups. (4) Discounts applied to the appraised values primarily include estimated sales costs, but also consider the age of the appraisal, changes in local market conditions and changes in the current condition of the collateral. The changes in fair value of the interest rate lock commitments, which are Level 3 financial instruments measured on a recurring basis, are summarized in the following table, in thousands: For the Three Months Ended For the Year Ended December 31, 2017 Balance at January 1, $ 1,738 $ 2,790 Total gains (losses) included in earnings 17 (1,479 ) Issuances 492 1,875 Settlements (288 ) (1,448 ) Balance at period end $ 1,959 $ 1,738 Gains included in gains (losses) on sale of loans held for sale attributable to interest rate lock commitments held at March 31, 2018 , and December 31, 2017 , were $2.0 million and $1.7 million , respectively. The tables below summarize the estimated fair value of Heartland's financial instruments as defined by ASC 825 as of March 31, 2018 , and December 31, 2017 , in thousands. The carrying amounts in the following tables are recorded in the consolidated balance sheets under the indicated captions. In accordance with ASC 825, the assets and liabilities that are not financial instruments are not included in the disclosure, such as the value of the commercial and mortgage servicing rights, premises, furniture and equipment, premises, furniture and equipment held for sale, OREO, goodwill, and other intangibles and other liabilities. Heartland does not believe that the estimated information presented herein is representative of the earnings power or value of Heartland. The following analysis, which is inherently limited in depicting fair value, also does not consider any value associated with either existing customer relationships or the ability of Heartland to create value through loan origination, deposit gathering or fee generating activities. Many of the estimates presented herein are based upon the use of highly subjective information and assumptions and, accordingly, the results may not be precise. Management believes that fair value estimates may not be comparable between financial institutions due to the wide range of permitted valuation techniques and numerous estimates which must be made. Furthermore, because the disclosed fair value amounts were estimated as of the balance sheet date, the amounts actually realized or paid upon maturity or settlement of the various financial instruments could be significantly different. Fair Value Measurements at March 31, 2018 Carrying Amount Estimated Fair Value Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Financial assets: Cash and cash equivalents $ 266,346 $ 266,346 $ 266,346 $ — $ — Time deposits in other financial institutions 6,297 6,297 6,297 — — Securities: Available for sale 2,027,665 2,027,665 9,421 2,018,244 — Held to maturity 249,766 258,638 — 258,638 — Other investments 22,982 22,982 — 22,982 — Loans held for sale 24,376 24,376 — 24,376 — Loans, net: Commercial 1,786,838 1,766,760 — 1,763,837 2,923 Commercial real estate 3,298,798 3,280,785 — 3,272,469 8,316 Agricultural and agricultural real estate 514,471 508,582 — 500,541 8,041 Residential real estate 621,295 614,234 — 612,813 1,421 Consumer 465,957 464,793 — 463,072 1,721 Total Loans, net 6,687,359 6,635,154 — 6,612,732 22,422 Cash surrender value on life insurance 143,444 143,444 — 143,444 — Derivative financial instruments (1) 6,265 6,265 — 6,265 — Interest rate lock commitments 1,959 1,959 — — 1,959 Forward commitments 283 283 — 283 — Financial liabilities: Deposits Demand deposits 3,094,457 3,094,457 — 3,094,457 — Savings deposits 4,536,106 4,536,106 — 4,536,106 — Time deposits 910,977 910,977 — 910,977 — Short term borrowings 131,240 131,240 — 131,240 — Other borrowings 276,118 276,193 — 276,193 — Derivative financial instruments (2) 4,709 4,709 — 4,709 — Forward commitments 320 320 — 320 — (1) Includes cash flow hedges, embedded derivatives and back-to-back loan swaps (2) Includes cash flow hedges, fair value hedges, back-to-back loan swaps, embedded conversion options and free standing derivative instruments Fair Value Measurements at December 31, 2017 Carrying Amount Estimated Fair Value Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Financial assets: Cash and cash equivalents $ 196,003 $ 196,003 $ 196,003 $ — $ — Time deposits in other financial institutions 9,820 9,820 9,820 — — Securities: Available for sale 2,216,753 2,216,753 3,484 2,213,269 — Held to maturity 253,550 265,494 — 265,494 — Other investments 22,563 22,563 — 22,563 — Loans held for sale 44,560 44,560 — 44,560 — Loans, net: Commercial 1,628,043 1,617,956 — 1,614,744 3,212 Commercial real estate 3,140,427 3,132,542 — 3,123,062 9,480 Agricultural and agricultural real estate 508,075 508,987 — 500,581 8,406 Residential real estate 620,939 614,667 — 613,530 1,137 Consumer 438,294 440,820 — 439,586 1,234 Total Loans, net 6,335,778 6,314,972 — 6,291,503 23,469 Cash surrender value on life insurance 142,818 142,818 — 142,818 — Derivative financial instruments (1) 3,933 3,933 — 3,933 — Interest rate lock commitments 1,738 1,738 — — 1,738 Forward commitments 80 80 — 80 — Financial liabilities: Deposits Demand deposits 2,983,128 2,983,128 — 2,983,128 — Savings deposits 4,240,328 4,240,328 — 4,240,328 — Time deposits 923,453 923,453 — 923,453 — Short term borrowings 324,691 324,691 — 324,691 — Other borrowings 285,011 285,609 — 285,609 — Derivative financial instruments (2) 5,167 5,167 — 5,167 — Forward commitments 232 232 — 232 — (1) Includes cash flow hedges, embedded derivatives and back-to-back loan swaps (2) Includes cash flow hedges, fair value hedges, back-to-back loan swaps, embedded conversion options and free standing derivative instruments Cash and Cash Equivalents — The carrying amount is a reasonable estimate of fair value due to the short-term nature of these instruments. Time Deposits in Other Financial Institutions — The carrying amount is a reasonable estimate of fair value due to the short-term nature of these instruments. Securities — For securities either held to maturity, available for sale or trading, fair value equals quoted market price if available. If a quoted market price is not available, fair value is estimated using quoted market prices for similar securities. For Level 3 securities, Heartland utilizes independent pricing provided by third party vendors or brokers. Other Investments — Fair value measurement of other investments, which consists primarily of FHLB stock, are based on their redeemable value, which is at cost due to the restrictions placed on their transferability. The market for these securities is restricted to the issuer of the stock and subject to impairment evaluation. Loans — Beginning in the first quarter of 2018, the fair value of loans were determined using an exit price methodology as prescribed by ASU 2016-01, which was effective on January 1, 2018. The exit price estimation of fair value is based on the present value of the expected cash flows. The projected cash flows are based on the contractual terms of the loans, adjusted for prepayments and a discount rate based on the relative risk of the cash flows. Other considerations include the loan type, remaining life of the loan and credit risk. In comparison, loan fair values as of December 31, 2017, were estimated based on an entrance price methodology, which discounts future cash flows using the current rates at which a similar loan would be made to borrowers with similar credit ratings and for the same remaining maturities. The fair value of non-impaired loans as of March 31, 2018, and December 31, 2017, are not comparable. The fair value of impaired loans is measured using the fair value of the underlying collateral. The fair value of loans held for sale is estimated using quoted market prices. Interest Rate Lock Commitments — The fair value of interest rate lock commitments is estimated using an internal valuation model, which includes grouping the interest rate lock commitments by interest rate and terms, applying an estimated closing ratio based on historical experience, and then multiplying by quoted investor prices determined to be reasonably applicable to the loan commitment groups based on interest rate, terms, and rate lock expiration dates of the loan commitment group. Forward Commitments — The fair value of these instruments is estimated using an internal valuation model, which includes current trade pricing for similar financial instruments. Derivative Financial Instruments — The fair value of all derivatives is estimated based on the amount that Heartland would pay or would be paid to terminate the contract or agreement, using current rates and prices, and, when appropriate, the current creditworthiness of the counter-party. Deposits — The fair value of demand deposits, savings accounts and certain money market deposits is the amount payable on demand at the reporting date. The fair value of fixed maturity certificates of deposit is estimated using the rates currently offered for deposits of similar remaining maturities. If the fair value of the fixed maturity certificates of deposit is calculated at less than the carrying amount, the carrying value of these deposits is reported as the fair value. Short-term and Other Borrowings — Rates currently available to Heartland for debt with similar terms and remaining maturities are used to estimate fair value of existing debt. Commitments to Extend Credit, Unused Lines of Credit and Standby Letters of Credit — Based upon management's analysis of the off balance sheet financial instruments, there are no significant unrealized gains or losses associated with these financial instruments based upon review of the fees currently charged to enter into similar agreements, taking into account the remaining terms of the agreements and the present creditworthiness of the counterparties.

Revenue

Revenue	3 Months Ended
	Mar. 31, 2018
Revenue from Contract with Customer [Abstract]
Revenue	REVENUE On January 1, 2018, Heartland adopted ASU 2014-09, "Revenue from Contracts with Customers" (Topic 606), and all subsequent ASUs that modified Topic 606. As stated in Note 1, the implementation of the new standard did not have a material impact on the measurement or recognition of revenue; as such, a cumulative effect adjustment to opening retained earnings was not deemed necessary. Results for reporting periods beginning after January 1, 2018 are presented under Topic 606, while prior period amounts were not adjusted and continue to be reported in accordance with Topic 605. Topic 606 does not apply to revenue associated with financial instruments, including revenue from loans and securities. In addition, certain noninterest income streams such as fees associated with loan servicing income, bank owned life insurance, derivatives and certain credit card fees are also not in scope of the new guidance. Topic 606 is applicable to noninterest revenue streams such as service charges and fees, trust fees, and brokerage and insurance commissions. However, the recognition of these revenue streams did not change significantly upon adoption of Topic 606. Substantially all of Heartland's revenue is generated from contracts with customers. Noninterest revenue streams in-scope of Topic 606 are discussed below. Service Charges and Fees Service charges and fees consist of revenue generated from deposit account related service charges and fees, overdraft fees, customer service fees, credit card fee income, debit card income and other service charges and fees. Service charges on deposit accounts consist of account analysis fees (i.e., net fees earned on analyzed business and public checking accounts), monthly service fees, check orders and other deposit account related fees. Heartland's performance obligation for account analysis fees and monthly service fees is generally satisfied, and the related revenue recognized, over the period in which the service is provided. Check orders and other deposit account related fees, including overdraft fees, are largely transactional based, and therefore, the performance obligation is satisfied, and related revenue recognized, at a point in time. Payment for service charges on deposit accounts is primarily received immediately or in the following month through a direct charge to customers’ accounts. Customer service fees and other service charges include revenue from processing wire transfers, bill pay service, cashier’s checks, and other services. Heartland's performance obligation for fees, exchange, and other service charges are largely satisfied, and related revenue recognized, when the services are rendered or upon completion. Payment is typically received immediately or in the following month. Credit card fee income and debit card income are comprised of interchange fees, ATM fees, and merchant services income. Credit card fee income and debit card income are earned whenever the banks' debit and credit cards are processed through card payment networks such as Visa. ATM fees are primarily generated when a bank cardholder uses an ATM that is not owned by one of Heartland's banks or a non-bank cardholder uses Heartland-owned ATM. Merchant services income mainly represents fees charged to merchants to process their debit and credit card transactions, in addition to account management fees. Trust Fees Trust fees are primarily comprised of fees earned from the management and administration of trusts and other customer assets. Heartland's performance obligation is generally satisfied over time and the resulting fees are recognized monthly, based upon the average daily market value or month-end market value of the assets under management and the applicable fee rate. Payment is generally received a few days before or after month end through a direct charge to customers’ accounts. Heartland does not earn performance-based incentives. Optional services such as real estate sales and tax return preparation services are also available to existing trust and asset management customers. Heartland's performance obligation for these transactional-based services is generally satisfied, and related revenue recognized, at a point in time (i.e., as incurred). Payment is received shortly after services are rendered. Brokerage and Insurance Commissions Brokerage commission primarily consist of commissions related to broker-dealer contracts. The contracts are between the customer and the broker-dealer, and Heartland satisfies its performance obligation and earns commission when the transactions are completed. The recognition of revenue is based on a defined fee schedule and does not require significant judgment. Payment is received shortly after services are rendered. Insurance commissions are related to commissions received directly from the insurance carrier. Heartland acts as an insurance agent between the customer and the insurance carrier. Heartland's performance obligations and associated fee and commission income are defined with each insurance product with the insurance company. When insurance payments are received from customers, a portion of the payment is recognized as commission revenue. The following presents noninterest income, segregated by revenue streams in-scope and out-of-scope of Topic 606, for the three months ended March 31, 2018, and 2017, in thousands: Three Months Ended March 31, 2018 2017 In-scope of Topic 606 Service charges and fees Service charges and fees on deposit accounts $ 2,618 $ 2,160 Overdraft fees 2,208 2,193 Customer service fees 77 49 Credit card fee income 2,190 2,033 Debit card income 2,985 3,021 Other service charges 1 1 Total service charges and fees 10,079 9,457 Trust fees 4,680 3,631 Brokerage and insurance commissions 907 1,036 Total noninterest income in-scope of Topic 606 15,666 14,124 Out-of-scope of Topic 606 Loan servicing income 1,754 1,724 Securities gains, net 1,441 2,482 Unrealized loss on equity securities, net (28 ) — Net gains on sale of loans held for sale 4,051 6,147 Valuation adjustment on commercial servicing rights (2 ) 5 Income on bank owned life insurance 614 617 Other noninterest income 1,220 794 Total noninterest income out-of-scope of Topic 606 9,050 11,769 Total noninterest income $ 24,716 $ 25,893 Contract Balances A contract asset balance occurs when an entity performs a service for a customer before the customer pays consideration (resulting in a contract receivable) or before payment is due (resulting in a contract asset). A contract liability balance is an entity’s obligation to transfer a service to a customer for which the entity has already received payment (or payment is due) from the customer. Heartland's noninterest revenue streams are largely based on transactional activity, or standard month-end revenue accruals such as asset management fees based on month-end market values. Consideration is often received immediately or shortly after Heartland satisfies its performance obligation and revenue is recognized. Heartland does not typically enter into long-term revenue contracts with customers, and therefore, does not experience significant contract balances. As of March 31, 2018, and December 31, 2017, Heartland did not have any significant contract balances. Contract Acquisition Costs In connection with the adoption of Topic 606, an entity is required to capitalize, and subsequently amortize into expense, certain incremental costs of obtaining a contract with a customer if these costs are expected to be recovered. The incremental costs of obtaining a contract are those costs that an entity incurs to obtain a contract with a customer that it would not have incurred if the contract had not been obtained (for example, sales commission). Heartland utilizes the practical expedient which allows entities to immediately expense contract acquisition costs when the asset that would have resulted from capitalizing these costs would have been amortized in one year or less. Upon adoption of Topic 606, Heartland did not capitalize any contract acquisition costs.

Basis of Presentation (Policies

Basis of Presentation (Policies)	3 Months Ended
	Mar. 31, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Presentation	The interim unaudited consolidated financial statements contained herein should be read in conjunction with the audited consolidated financial statements and accompanying notes to the consolidated financial statements for the fiscal year ended December 31, 2017 , included in the Form 10-K of Heartland Financial USA, Inc. ("Heartland") filed with the Securities and Exchange Commission ("SEC") on February 28, 2018 . Foot note disclosures to the interim unaudited consolidated financial statements which would substantially duplicate the disclosure contained in the footnotes to the audited consolidated financial statements have been omitted. The financial information of Heartland included herein has been prepared in accordance with U.S. generally accepted accounting principles for interim financial reporting and has been prepared pursuant to the rules and regulations for reporting on Form 10-Q and Rule 10-01 of Regulation S-X. Such information reflects all adjustments (consisting of normal recurring adjustments), that are, in the opinion of management, necessary for a fair presentation of the financial position and results of operations for the periods presented. The results of the interim period ended March 31, 2018 , are not necessarily indicative of the results expected for the year ending December 31, 2018 .
Earnings Per Share	Basic earnings per share is determined using net income available to common stockholders and weighted average common shares outstanding. Diluted earnings per share is computed by dividing net income available to common stockholders by the weighted average common shares and assumed incremental common shares issued.
Stock-Based Compensation	Heartland may grant, through its Nominating and Compensation Committee (the "Compensation Committee"), non-qualified and incentive stock options, stock appreciation rights, stock awards, restricted stock, restricted stock units and cash incentive awards, under its 2012 Long-Term Incentive Plan (the "Plan"). The Plan was originally approved by stockholders in May 2012 and was amended effective March 8, 2016, to increase the number of shares of common stock authorized for issuance and make certain other changes to the Plan. As of March 31, 2018 , 459,893 shares of common stock were available for issuance under future awards that may be granted under the Plan to employees and directors of, and service providers to, Heartland or its subsidiaries. Financial Accounting Standards Board ("FASB") Accounting Standards Codification ("ASC") Topic 718, "Compensation-Stock Compensation" requires the measurement of the cost of employee services received in exchange for an award of equity instruments based upon the fair value of the award on the grant date. The cost of the award is based upon its fair value estimated on the date of grant and recognized in the consolidated statements of income over the vesting period of the award. The fair market value of restricted stock and restricted stock units is based on the fair value of the underlying shares of common stock on the date of grant. The fair value of stock options is estimated on the date of grant using the Black-Scholes model. Forfeitures are accounted for as they occur. The amount of tax benefit related to the exercise, vesting and forfeiture of equity-based awards reflected as a tax benefit in Heartland's income tax expense was $611,000 and $ 888,000 during the three months ended March 31, 2018 and 2017, respectively. Restricted Stock Units The Plan permits the Compensation Committee to grant restricted stock units ("RSUs"). In the first quarter of 2018, the Compensation Committee granted time-based RSUs with respect to 52,153 shares of common stock, and in the first quarter of 2017, the Compensation Committee granted time-based RSUs with respect to 55,665 shares of common stock to selected officers and employees. The time-based RSUs represent the right, without payment, to receive shares of Heartland common stock on a specified date in the future. The time-based RSUs granted in 2018 vest over three years in equal installments on March 6 of each of the three years following the year of the grant, while the 2017 time-based RSUs vest in equal installments on January 19 of each of the three years following the year of the grant. The time-based RSUs may also vest upon death or disability, upon a change in control or upon a "qualified retirement" (as defined in the RSU agreement). The retiree is required to sign a non-solicitation agreement as a condition to vesting. In addition to the time-based RSUs referenced in the preceding paragraph, the Compensation Committee granted one -year performance-based RSUs with respect to 18,988 shares of common stock in the first quarter of 2018, and 27,570 shares of common stock in the first quarter of 2017. These performance-based RSUs are earned based on satisfaction of performance targets for the fiscal years ended December 31, 2018, and December 31, 2017, respectively, and then fully vest on a specified date in the third calendar year following the year of the initial grant. The Compensation Committee also granted three -year performance-based RSUs with respect to 16,108 shares and 9,032 shares of common stock in the first quarter of 2018 and 2017, respectively. These performance-based RSUs will be earned based on satisfaction of performance targets for the three -year performance period ended December 31, 2020, and December 31, 2019, respectively. These performance-based RSUs or a portion thereof may vest in 2021 and 2020, respectively, after measurement of performance in relation to the performance targets. The one -year and three -year performance-based RSUs vest to the extent that they are earned upon death or disability or upon a "qualified retirement." Upon a change in control, performance-based RSUs shall become vested at 100% of target if the RSU obligations are not assumed by the successor company. If the successor company does assume the RSU obligations, the 2017 and 2018 performance-based RSUs will vest at 100% of target upon a "Termination of Service" within the period beginning six months prior to a change in control and ending twenty-four months after a change in control. All of Heartland's RSUs will be settled in common stock upon vesting and are not entitled to dividends until vested. The Compensation Committee may grant RSUs under the Plan to directors as part of their compensation, to new management level employees at commencement of employment, and to other employees and service providers as incentives.
Subsequent Events	Heartland has evaluated subsequent events that may require recognition or disclosure through the filing date of this Quarterly Report on Form 10-Q with the SEC.
Effect of New Financial Accounting Standards	In May 2014, the FASB issued Accounting Standards Update ("ASU") 2014-09, " Revenue from Contracts with Customers." The amendment clarifies the principles for recognizing revenue and develops a common revenue standard. The amendment outlines a single comprehensive model for entities to use in accounting for revenue arising from contracts with customers and supersedes most current revenue recognition guidance, including industry-specific guidance. The core principle of the revenue model is that "an entity recognizes revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services." In applying the revenue model to contracts within its scope, an entity should apply the following steps: (i) identify the contract(s) with a customer, (ii) identify the performance obligations in the contract, (iii) determine the transaction price, (iv) allocate the transaction price to the performance obligations in the contract, and (v) recognize revenue when (or as) the entity satisfies a performance obligation. The new guidance does not apply to certain contracts within the scope of other ASC Topics, such as lease contracts, insurance contracts, financing arrangements, financial instruments, guarantees other than product or service warranties and nonmonetary exchanges between entities in the same line of business to facilitate sales to customers. Heartland evaluates noninterest income contracts affected by the new guidance by analyzing contracts and current accounting practices to determine if a change is appropriate. The amendment is largely consistent with existing guidance and current practices; however Heartland had to change the recognition of certain recurring revenue streams within trust and investment management fees. Heartland adopted the accounting standard effective January 1, 2018, as required, using a modified retrospective approach. However, the adoption of these amendments did not have a significant effect on Heartland's results of operations, financial position and liquidity other than expanded disclosure requirements. See Note 9, "Revenue," for further details regarding Heartland's revenue. In January 2016, the FASB issued guidance ASU 2016-01, " Recognition and Measurement of Financial Assets and Financial Liabilitie s." The amendments in ASU 2016-01 to Subtopic 825-10, Financial Instruments, contain the following elements: (1) require equity investments to be measured at fair value with changes in fair value recognized in net income; (2) simplify the impairment assessment of equity investments without readily determinable fair values by requiring a qualitative assessment to identify impairment; (3) eliminates the requirement for public entities to disclose the methods 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; (4) requires public business entities to use the exit price notion when measuring the fair value of financial instruments for disclosure purposes; (5) requires an entity 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 when the entity has elected to measure the liability at fair value in accordance with the fair value option for financial instruments; (6) requires separate presentation of financial assets and financial liabilities by measurement category and form of financial asset on the balance sheet or accompanying notes to the financial statements; and (7) clarifies that the entity should evaluate the need for a valuation allowance on a deferred tax asset related to available for sale securities in combination with the entity's other deferred tax assets. The amendments are effective for fiscal years beginning after December 15, 2017, and for interim periods within those fiscal years. Except for the early application of the amendment noted in item (5) above, early adoption of the amendments in this update is not permitted. Entities are required to and Heartland applied the amendment by means of a cumulative-effect adjustment as of the beginning of the fiscal year of adoption, with the exception of the amendment related to equity securities without readily determinable fair values, which are to be applied prospectively to equity investments that exist as of the adoption date. Heartland adopted the accounting standard on January 1, 2018, as required, and the adoption of these amendments did not have a material impact on its results of operations, financial position and liquidity. Heartland reclassified $280,000 from accumulated other comprehensive income to retained earnings on January 1, 2018, related to the fair value of its equity investments. In February 2016, the FASB issued ASU 2016-02, " Leases (Topic 842). " Topic 842 requires a lessee to recognize leases on-balance sheet and disclose key information about leasing arrangements. The new standard establishes a right-of-use model (ROU) that requires a lessee to recognize a ROU asset and lease liability on the balance sheet for all leases with a term longer than 12 months. Leases will be classified as financing or operating, with classification affecting the pattern and classification of expense recognition in the income statement. The amendment is effective for fiscal years beginning after December 15, 2018, including interim periods within those fiscal years, and will be applied on a modified retrospective basis. Heartland leases certain properties and equipment under operating leases that will result in recognition of lease assets and lease liabilities on the consolidated balance sheets under the ASU; however the majority of Heartland's properties and equipment are owned, not leased. The modified retrospective approach includes a number of optional practical expedients that entities may elect to apply. These practical expedients relate to the identification and classification of leases that commenced before the effective date, initial direct costs for leases that commenced before the effective date, and the ability to use hindsight in evaluating lessee options to extend or terminate a lease or to purchase the underlying asset. Early adoption is permitted. In January 2018, the FASB issued an amendment to provide entities with the optional practical expedient to not evaluate existing or expired land easements that were previously not accounted for as leases under Topic 840. Heartland intends to adopt the accounting standard in 2019, as required, and does not expect the adoption of this standard to have a significant impact on its results of operations, financial position and liquidity. Heartland has signed an agreement with a cloud-based lease software provider, and implementation of the software started in the first quarter of 2018. In June 2016, the FASB issued ASU 2016-13, " Financial Instruments - Credit Losses (Topic 326) ." The amendments in this ASU require a financial asset (or a group of financial assets) measured at amortized cost basis to be presented at the net amount expected to be collected. The allowance for credit losses is a valuation account that is deducted from the amortized cost basis of the financial asset(s) to present the net carrying value at the amount expected to be collected on the financial asset. The amendments in this ASU indicate that an entity should not use the length of time a security has been in an unrealized loss position to avoid recording a credit loss. In addition, in determining whether a credit loss exists, the amendments in this ASU also remove the requirements to consider the historical and implied volatility of the fair value of a security and recoveries or declines in fair value after the balance sheet date. The amendment is effective for fiscal years beginning after December 15, 2019, including interim periods within those fiscal years. An entity may adopt the amendments earlier as of the fiscal years beginning after December 15, 2018, including interim periods within those fiscal years. Heartland intends to adopt the accounting standard in 2020, as required, and is currently evaluating the potential impact of this guidance on its results of operations, financial position and liquidity. Upon adoption of ASU 2016-13, a cumulative-effect adjustment to retained earnings will be recorded as of the beginning of the first reporting period in which the guidance is effective. Heartland has formed an internal committee to assess and implement the standard, and Heartland has entered into an agreement with a third party vendor to evaluate potential methodologies and data. In August 2016, the FASB issued ASU 2016-15, " Statement of Cash Flows (Topic 230) - Classification of Certain Cash Receipts and Cash Payments. " The amendments in this update address eight specific cash flow issues with the objective of reducing the existing diversity in practice. The amendment is effective for fiscal years beginning after December 15, 2017, including interim periods within those fiscal years. Early adoption is permitted, including adoption in an interim period. If an entity early adopts the amendments in an interim period, any adjustments should be reflected as of the beginning of the fiscal year that includes the interim period. An entity that elects early adoption must adopt all of the amendments in the same period. The amendments in this update should be applied using a retrospective transition method to each period presented. Heartland adopted this ASU on January 1, 2018, as required, and the adoption of these amendments did not have a material impact on Heartland's results of operations, financial position and liquidity. In October 2016, the FASB issued ASU 2016-16, "Income Taxes (Topic 740) - Intra-Entity Transfer of Assets Other Than Inventory." The amendment requires an entity to recognize income tax consequences on an intra-entity transfer of an asset other than inventory at the time the transaction occurs. The amendment is effective for fiscal years beginning after December 15, 2017, including interim periods within those fiscal years. The amendments must be applied and Heartland applied these amendments using a modified retrospective basis. Heartland adopted this ASU on January 1, 2018, as required, and the adoption of this amendment did not have a material impact on Heartland's results of operations, financial position and liquidity. In January 2017, the FASB issued ASU No. 2017-01, " Business Combinations (Topic 805): Clarifying the Definition of a Business ," which narrows the definition of a business and provides a framework that gives entities a basis for making reasonable judgments about whether a transaction involves an asset or a business. ASU 2017-01 is effective for public business entities in annual periods beginning after December 15, 2017, including interim periods therein. Heartland adopted ASU 2017-01 on January 1, 2018, as required, and the adoption did not have a material impact on Heartland's results of operations, financial position, and liquidity. In January 2017, the FASB issued ASU 2017-04, "Intangibles - Goodwill and Other (Topic 350)." This amendment is to simplify the subsequent measurement of goodwill by eliminating step two from the goodwill impairment test. Instead, an entity will perform only step one of its quantitative goodwill impairment test by comparing the fair value of a reporting unit with its carrying amount, and then recognizing the impairment charge for the amount by which the carrying amount exceeds the reporting unit's fair value; however, the loss recognized cannot exceed the total amount of goodwill allocated to that reporting unit. An entity will still have the option to perform a qualitative assessment for a reporting unit to determine if the quantitative step one impairment test is necessary. This amendment is effective for annual or interim goodwill impairment tests in fiscal years beginning after December 15, 2019, and should be applied prospectively. Early adoption is permitted, including in an interim period for impairment tests performed after January 1, 2017. Heartland intends to adopt this ASU in the third quarter of 2020, consistent with the annual impairment test as of September 30, 2020, and is currently evaluating the potential impact of this guidance on its results of operations, financial position and liquidity. In March 2017, the FASB issued ASU 2017-08, "Receivables - Nonrefundable Fee and Other Costs (Subtopic 310-20)." These amendments shorten the amortization period for certain callable debt securities held at a premium. Specifically, the amendments require the premium to be amortized to the earliest call date. The amendments do not require an accounting change for securities held at a discount. Discounts continue to be amortized to maturity. These amendments are effective for public business entities for fiscal years and interim periods within those fiscal years, beginning after December 15, 2018. Early adoption is permitted, including adoption in an interim period. If any entity early adopts the amendments in an interim period, any adjustments must be reflected as of the beginning of the fiscal year that includes the interim period. The amendments must be applied and Heartland intends to apply these amendments on a modified retrospective basis, with a cumulative-effect adjustment directly to retained earnings as of the beginning of the period of adoption. Heartland intends to adopt this ASU in 2019, as required, and is currently evaluating the potential impact on its results of operations, financial position and liquidity. In May 2017, the FASB issued ASU 2017-09, " Compensation - Stock Compensation (Topic 718) ." The amendments provide guidance about which changes to the terms or conditions of a share-based payment award require an entity to apply modification accounting in Topic 718. An entity should account for the effects of a modification unless all the following are met: (1) the fair value (or calculated value or intrinsic value, if such an alternative measurement method is used) of the modified award is the same as the fair value (or calculated value or intrinsic value, if such an alternative measurement method is used) of the original award immediately before the original award is modified. If the modification does not affect any of the inputs to the valuation technique that the entity uses to value the award, the entity is not required to estimate the value immediately before and after the modification; (2) the vesting conditions of the modified award are the same as the vesting conditions of the original award immediately before the original award is modified; and (3) the classification of the modified award as an equity instrument or a liability instrument is the same as the classification of the original award immediately before the original award is modified. The amendments are effective for annual periods and interim periods within those annual periods, beginning after December 15, 2017. Early adoption is permitted, including adoption in any interim periods for public business entities for reporting periods for which financial statements have not yet been issued. The amendments should be applied and Heartland applied these amendments prospectively to an award modified on or after the adoption date. Heartland adopted this ASU on January 1, 2018, as required, the adoption did not have a material impact to its results of operations, financial position and liquidity because Heartland has not typically modified share-based payment awards after the original award has been granted. In August 2017, the FASB issued ASU 2017-12, " Derivatives and Hedging: Targeted Improvements to Accounting for Hedging Activities ." The purpose of this updated guidance is to better align a company’s financial reporting for hedging activities with the economic objectives of those activities. ASU 2017-12 is effective for public business entities for fiscal years beginning after December 15, 2018, with early adoption, including adoption in an interim period, permitted. ASU 2017-12 requires a modified retrospective transition method in which Heartland will recognize the cumulative effect of the change on the opening balance of each affected component of equity in the consolidated balance sheet as of the date of adoption. Heartland intends to adopt this ASU in 2019, as required, and does not believe there will be a material impact to its results of operations, financial position and liquidity. In February 2018, the FASB issued ASU 2018-02, " Income Statement-Reporting Comprehensive Income (Topic 220). " This ASU allows for the option to reclassify from accumulated other comprehensive income ("AOCI") to retained earnings for stranded tax effects resulting from the newly enacted federal corporate income tax rate in the Tax Cuts and Jobs Act of 2017, which was enacted on December 22, 2017. The legislation included a reduction to the corporate income tax rate from 35 percent to 21 percent effective January 1, 2018. The amount of the reclassification would be the difference between the historical corporate income tax rate and the newly enacted 21 percent corporate income tax rate. The amendments in this ASU are effective for fiscal years beginning after December 15, 2018, including interim periods within those fiscal years. Early adoption is permitted for public businesses for reporting periods for which financial statements have not yet been issued. Heartland adopted the guidance as of December 31, 2017. The adoption of this ASU was accounted for as a cumulative-effect adjustment to the balance sheet resulting in a $4.5 million increase to retained earnings and a corresponding decrease to AOCI on December 31, 2017.
Fair Value Hierarchy	Under ASC 820, assets and liabilities are grouped at fair value in three levels, based on the markets in which the assets and liabilities are traded and the reliability of the assumptions used to determine fair value. These levels are: Level 1 — Valuation is based upon quoted prices for identical instruments in active markets. Level 2 — Valuation is based upon quoted prices for similar instruments in active markets, or similar instruments in markets that are not active, and model-based valuation techniques for all significant assumptions are observable in the market. Level 3 — Valuation is generated from model-based techniques that use at least one significant assumption not observable in the market. These unobservable assumptions reflect estimates of assumptions that market participants would use in pricing the asset or liability. Valuation techniques include use of option pricing models, discounted cash flow models and similar techniques. The following is a description of valuation methodologies used for assets and liabilities recorded at fair value on a recurring or non-recurring basis. Assets Securities Available for Sale and Held to Maturity Securities available for sale are recorded at fair value on a recurring basis. Securities held to maturity are generally recorded at cost and are recorded at fair value only to the extent a decline in fair value is determined to be other-than-temporary. Fair value measurement is based upon quoted prices, if available. If quoted prices are not available, fair values are measured using independent pricing models or other model-based valuation techniques such as the present value of future cash flows, adjusted for the security's credit rating, prepayment assumptions and other factors such as credit loss assumptions. Level 1 securities include those traded on an active exchange, such as the New York Stock Exchange, as well as U.S. Treasury securities. Level 2 securities include U.S. government and agency securities, mortgage and asset-backed securities and private collateralized mortgage obligations, municipal bonds and corporate debt securities. On a quarterly basis, a secondary independent pricing service is used for the securities portfolio to validate the pricing from Heartland's primary pricing service. Loans Held for Sale Loans held for sale are carried at the lower of cost or fair value on an aggregate basis. The fair value of loans held for sale is based on what secondary markets are currently offering for portfolios with similar characteristics. As such, Heartland classifies loans held for sale subjected to nonrecurring fair value adjustments as Level 2. Loans Held to Maturity Heartland does not record loans held to maturity at fair value on a recurring basis. However, from time to time, a loan is considered impaired and an allowance for loan losses is established. Loans for which it is probable that payment of interest and principal will not be made in accordance with the contractual terms of the loan agreement are considered impaired. Once a loan is identified as individually impaired, management measures impairment in accordance with ASC 310. The fair value of impaired loans is measured using one of the following impairment methods: 1) the present value of expected future cash flows discounted at the loan's effective interest rate or 2) the observable market price of the loan or 3) the fair value of the collateral if the loan is collateral dependent. In accordance with ASC 820, impaired loans measured at fair value are classified as nonrecurring Level 3 in the fair value hierarchy. Premises, Furniture and Equipment Held for Sale Heartland values premises, furniture and equipment held for sale based on third-party appraisals less estimated disposal costs. Heartland considers third party appraisals, as well as independent fair value assessments from Realtors or persons involved in selling bank premises, furniture and equipment, in determining the fair value of particular properties. Accordingly, the valuation of premises, furniture and equipment held for sale is subject to significant external and internal judgment. Heartland periodically reviews premises, furniture and equipment held for sale to determine if the fair value of the property, less disposal costs, has declined below its recorded book value and records any adjustments accordingly. Premises, furniture and equipment held for sale are classified as nonrecurring Level 3 in the fair value hierarchy. Mortgage Servicing Rights Mortgage servicing rights assets represent the value associated with servicing residential real estate loans that have been sold to outside investors with servicing retained. Heartland uses the amortization method (i.e., the lower of amortized cost or estimated fair value measured on a nonrecurring basis), not fair value measurement accounting, to determine the carrying value of its mortgage servicing rights. The fair value for servicing assets is determined through discounted cash flow analysis and utilizes discount rates, prepayment speeds and delinquency rate assumptions as inputs. All of the assumptions in the discounted cash flow analysis require a significant degree of management estimation and judgment. Mortgage servicing rights are subject to impairment testing. The carrying values of these rights are reviewed quarterly for impairment based upon the calculation of fair value as performed by an outside third party. For purposes of measuring impairment, the rights are stratified into certain risk characteristics including note type and note term. If the valuation model reflects a fair value less than the carrying value, mortgage servicing rights are adjusted to fair value through a valuation allowance. Heartland classifies mortgage servicing rights as nonrecurring with Level 3 measurement inputs. Commercial Servicing Rights Commercial servicing rights assets represent the value associated with servicing commercial loans guaranteed by the Small Business Administration and the United States Department of Agriculture that have been sold with servicing retained by Heartland. Heartland uses the amortization method (i.e., the lower of amortized cost or estimated fair value measured on a nonrecurring basis), not fair value measurement accounting, to determine the carrying value of its commercial servicing rights. The fair value for servicing assets is determined through market prices for comparable servicing contracts, when available, or through a valuation model that calculates the present value of estimated future net servicing income. Inputs utilized include discount rates, prepayment speeds and delinquency rate assumptions as inputs. All of these assumptions require a significant degree of management estimation and judgment. Commercial servicing rights are subject to impairment testing, and the carrying values of these rights are reviewed quarterly for impairment based upon the calculation of fair value as performed by an outside third party. If the valuation model reflects a fair value less than the carrying value, commercial servicing rights are adjusted to fair value through a valuation allowance. Heartland classifies commercial servicing rights as nonrecurring with Level 3 measurement inputs. Derivative Financial Instruments Heartland's current interest rate risk strategy includes interest rate swaps. The valuation of these instruments is determined using widely accepted valuation techniques including discounted cash flow analysis on the expected cash flows of each derivative. This analysis reflects the contractual terms of the derivatives, including the period to maturity, and uses observable market-based inputs, including interest rate curves and implied volatilities. To comply with the provisions of ASC 820, Heartland incorporates credit valuation adjustments to appropriately reflect both its own nonperformance risk and the respective counterparty's nonperformance risk in the fair value measurements. In adjusting the fair value of its derivative contracts for the effect of nonperformance risk, Heartland has considered the impact of netting any applicable credit enhancements, such as collateral postings, thresholds, mutual puts, and guarantees. Although Heartland has determined that the majority of the inputs used to value its derivatives fall within Level 2 of the fair value hierarchy, the credit valuation adjustments associated with its derivatives utilize Level 3 inputs, such as estimates of current credit spreads to evaluate the likelihood of default by itself and its counterparties. However, as of March 31, 2018 , and December 31, 2017 , Heartland has assessed the significance of the impact of the credit valuation adjustments on the overall valuation of its derivative positions and has determined that the credit valuation adjustments are not significant to the overall valuation of its derivatives. As a result, Heartland has determined that its derivative valuations in their entirety are classified in Level 2 of the fair value hierarchy. Interest rate lock commitments Heartland uses an internal valuation model that relies on internally developed inputs to estimate the fair value of its interest rate lock commitments which is based on unobservable inputs that reflect management's assumptions and specific information about each borrower. Interest rate lock commitments are classified in Level 3 of the fair value hierarchy. Forward commitments The fair value of forward commitments are estimated using an internal valuation model, which includes current trade pricing for similar financial instruments in active markets that Heartland has the ability to access and are classified in Level 2 of the fair value hierarchy. Other Real Estate Owned Other real estate owned ("OREO") represents property acquired through foreclosures and settlements of loans. Property acquired is carried at the fair value of the property at the time of acquisition (representing the property's cost basis), plus any acquisition costs, or the estimated fair value of the property, less disposal costs. Heartland considers third party appraisals, as well as independent fair value assessments from realtors or persons involved in selling OREO, in determining the fair value of particular properties. Accordingly, the valuation of OREO is subject to significant external and internal judgment. Heartland periodically reviews OREO to determine if the fair value of the property, less disposal costs, has declined below its recorded book value and records any adjustments accordingly. OREO is classified as nonrecurring Level 3 of the fair value hierarchy.
Revenue Recognition	On January 1, 2018, Heartland adopted ASU 2014-09, "Revenue from Contracts with Customers" (Topic 606), and all subsequent ASUs that modified Topic 606. As stated in Note 1, the implementation of the new standard did not have a material impact on the measurement or recognition of revenue; as such, a cumulative effect adjustment to opening retained earnings was not deemed necessary. Results for reporting periods beginning after January 1, 2018 are presented under Topic 606, while prior period amounts were not adjusted and continue to be reported in accordance with Topic 605. Topic 606 does not apply to revenue associated with financial instruments, including revenue from loans and securities. In addition, certain noninterest income streams such as fees associated with loan servicing income, bank owned life insurance, derivatives and certain credit card fees are also not in scope of the new guidance. Topic 606 is applicable to noninterest revenue streams such as service charges and fees, trust fees, and brokerage and insurance commissions. However, the recognition of these revenue streams did not change significantly upon adoption of Topic 606. Substantially all of Heartland's revenue is generated from contracts with customers. Noninterest revenue streams in-scope of Topic 606 are discussed below. Service Charges and Fees Service charges and fees consist of revenue generated from deposit account related service charges and fees, overdraft fees, customer service fees, credit card fee income, debit card income and other service charges and fees. Service charges on deposit accounts consist of account analysis fees (i.e., net fees earned on analyzed business and public checking accounts), monthly service fees, check orders and other deposit account related fees. Heartland's performance obligation for account analysis fees and monthly service fees is generally satisfied, and the related revenue recognized, over the period in which the service is provided. Check orders and other deposit account related fees, including overdraft fees, are largely transactional based, and therefore, the performance obligation is satisfied, and related revenue recognized, at a point in time. Payment for service charges on deposit accounts is primarily received immediately or in the following month through a direct charge to customers’ accounts. Customer service fees and other service charges include revenue from processing wire transfers, bill pay service, cashier’s checks, and other services. Heartland's performance obligation for fees, exchange, and other service charges are largely satisfied, and related revenue recognized, when the services are rendered or upon completion. Payment is typically received immediately or in the following month. Credit card fee income and debit card income are comprised of interchange fees, ATM fees, and merchant services income. Credit card fee income and debit card income are earned whenever the banks' debit and credit cards are processed through card payment networks such as Visa. ATM fees are primarily generated when a bank cardholder uses an ATM that is not owned by one of Heartland's banks or a non-bank cardholder uses Heartland-owned ATM. Merchant services income mainly represents fees charged to merchants to process their debit and credit card transactions, in addition to account management fees. Trust Fees Trust fees are primarily comprised of fees earned from the management and administration of trusts and other customer assets. Heartland's performance obligation is generally satisfied over time and the resulting fees are recognized monthly, based upon the average daily market value or month-end market value of the assets under management and the applicable fee rate. Payment is generally received a few days before or after month end through a direct charge to customers’ accounts. Heartland does not earn performance-based incentives. Optional services such as real estate sales and tax return preparation services are also available to existing trust and asset management customers. Heartland's performance obligation for these transactional-based services is generally satisfied, and related revenue recognized, at a point in time (i.e., as incurred). Payment is received shortly after services are rendered. Brokerage and Insurance Commissions Brokerage commission primarily consist of commissions related to broker-dealer contracts. The contracts are between the customer and the broker-dealer, and Heartland satisfies its performance obligation and earns commission when the transactions are completed. The recognition of revenue is based on a defined fee schedule and does not require significant judgment. Payment is received shortly after services are rendered. Insurance commissions are related to commissions received directly from the insurance carrier. Heartland acts as an insurance agent between the customer and the insurance carrier. Heartland's performance obligations and associated fee and commission income are defined with each insurance product with the insurance company. When insurance payments are received from customers, a portion of the payment is recognized as commission revenue. Contract Balances A contract asset balance occurs when an entity performs a service for a customer before the customer pays consideration (resulting in a contract receivable) or before payment is due (resulting in a contract asset). A contract liability balance is an entity’s obligation to transfer a service to a customer for which the entity has already received payment (or payment is due) from the customer. Heartland's noninterest revenue streams are largely based on transactional activity, or standard month-end revenue accruals such as asset management fees based on month-end market values. Consideration is often received immediately or shortly after Heartland satisfies its performance obligation and revenue is recognized. Heartland does not typically enter into long-term revenue contracts with customers, and therefore, does not experience significant contract balances. As of March 31, 2018, and December 31, 2017, Heartland did not have any significant contract balances. Contract Acquisition Costs In connection with the adoption of Topic 606, an entity is required to capitalize, and subsequently amortize into expense, certain incremental costs of obtaining a contract with a customer if these costs are expected to be recovered. The incremental costs of obtaining a contract are those costs that an entity incurs to obtain a contract with a customer that it would not have incurred if the contract had not been obtained (for example, sales commission). Heartland utilizes the practical expedient which allows entities to immediately expense contract acquisition costs when the asset that would have resulted from capitalizing these costs would have been amortized in one year or less. Upon adoption of Topic 606, Heartland did not capitalize any contract acquisition costs.

Basis of Presentation (Tables)

Basis of Presentation (Tables)	3 Months Ended
	Mar. 31, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Schedule of Earnings Per Share, Basic and Diluted	Amounts used in the determination of basic and diluted earnings per share for the three -month periods ended March 31, 2018 , and 2017 , are shown in the table below: Three Months Ended (Dollars and number of shares in thousands, except per share data) 2018 2017 Net income $ 23,268 $ 18,010 Preferred dividends (13 ) (19 ) Interest expense on convertible preferred debt — 5 Net income available to common stockholders $ 23,255 $ 17,996 Weighted average common shares outstanding for basic earnings per share 30,442 26,335 Assumed incremental common shares issued upon non-vested restricted stock units 203 293 Weighted average common shares for diluted earnings per share 30,645 26,628 Earnings per common share — basic $ 0.76 $ 0.68 Earnings per common share — diluted $ 0.76 $ 0.68 Number of antidilutive common stock equivalents excluded from diluted earnings per share computation — —
Summary of Status of RSUs	A summary of the RSUs outstanding as of March 31, 2018 and 2017 , and changes during the three months ended March 31, 2018 and 2017 , follows: 2018 2017 Shares Weighted-Average Grant Date Fair Value Shares Weighted-Average Grant Date Fair Value Outstanding at January 1 301,578 $ 34.74 346,817 $ 27.61 Granted 87,249 55.25 92,267 47.50 Vested (107,553 ) 30.79 (103,897 ) 24.74 Forfeited (19,113 ) 43.62 (7,765 ) 31.03 Outstanding at March 31 262,161 $ 42.60 327,422 $ 34.04
Summary of Status of Stock Options	A summary of the stock options outstanding as of March 31, 2018 and 2017 , and changes during the three months ended March 31, 2018 and 2017 , follows: 2018 2017 Shares Weighted-Average Exercise Price Shares Weighted-Average Exercise Price Outstanding at January 1 6,500 $ 18.60 26,400 $ 18.60 Granted — — — — Exercised (6,500 ) 18.60 (5,500 ) 18.60 Forfeited — — — — Outstanding at March 31 — $ — 20,900 $ 18.60 Options exercisable at March 31 — $ — 20,900 $ 18.60

Securities (Tables)

Securities (Tables)	3 Months Ended
	Mar. 31, 2018
Investments, Debt and Equity Securities [Abstract]
Schedule of Available for Sale Securities	The amortized cost, gross unrealized gains and losses, and estimated fair values of securities available for sale as of March 31, 2018 , and December 31, 2017 , are summarized in the table below, in thousands: Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Estimated Fair Value March 31, 2018 U.S. government corporations and agencies $ 11,254 $ 3 $ (69 ) $ 11,188 Mortgage and asset-backed securities 1,691,092 3,968 (47,456 ) 1,647,604 Obligations of states and political subdivisions 361,475 1,132 (10,427 ) 352,180 Total debt securities 2,063,821 5,103 (57,952 ) 2,010,972 Equity securities 16,693 — — 16,693 Total $ 2,080,514 $ 5,103 $ (57,952 ) $ 2,027,665 December 31, 2017 U.S. government corporations and agencies $ 5,358 $ 8 $ (38 ) $ 5,328 Mortgage and asset-backed securities 1,785,467 5,856 (37,587 ) 1,753,736 Obligations of states and political subdivisions 441,060 4,669 (4,714 ) 441,015 Total debt securities 2,231,885 10,533 (42,339 ) 2,200,079 Equity securities 16,296 378 — 16,674 Total $ 2,248,181 $ 10,911 $ (42,339 ) $ 2,216,753
Schedule of Held to Maturity Securities	The amortized cost, gross unrealized gains and losses and estimated fair values of held to maturity securities as of March 31, 2018 , and December 31, 2017 , are summarized in the table below, in thousands: Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Estimated Fair Value March 31, 2018 Obligations of states and political subdivisions $ 249,766 $ 9,699 $ (827 ) $ 258,638 Total $ 249,766 $ 9,699 $ (827 ) $ 258,638 December 31, 2017 Obligations of states and political subdivisions $ 253,550 $ 12,460 $ (516 ) $ 265,494 Total $ 253,550 $ 12,460 $ (516 ) $ 265,494
Investments Classified by Contractual Maturity Date	The amortized cost and estimated fair value of debt securities available for sale at March 31, 2018 , by contractual maturity, are as follows, in thousands. Expected maturities will differ from contractual maturities because issuers may have the right to call or prepay obligations with or without penalties. March 31, 2018 Amortized Cost Estimated Fair Value Due in 1 year or less $ 5,397 $ 5,392 Due in 1 to 5 years 56,369 56,209 Due in 5 to 10 years 116,517 112,484 Due after 10 years 194,446 189,283 Total debt securities 372,729 363,368 Mortgage and asset-backed securities 1,691,092 1,647,604 Equity securities 16,693 16,693 Total investment securities $ 2,080,514 $ 2,027,665 The amortized cost and estimated fair value of debt securities held to maturity at March 31, 2018 , by contractual maturity, are as follows, in thousands. Expected maturities will differ from contractual maturities because issuers may have the right to call or prepay obligations with or without penalties. March 31, 2018 Amortized Cost Estimated Fair Value Due in 1 year or less $ 2,486 $ 2,523 Due in 1 to 5 years 27,627 28,231 Due in 5 to 10 years 104,170 106,538 Due after 10 years 115,483 121,346 Total investment securities $ 249,766 $ 258,638
Schedule of Realized Gross Gains (Losses)	Gross gains and losses realized related to the sales of securities available for sale for the three -month periods ended March 31, 2018 and 2017 , are summarized as follows, in thousands: Three Months Ended 2018 2017 Proceeds from sales $ 392,246 $ 221,637 Gross security gains 3,013 3,830 Gross security losses 1,572 1,339
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	The following tables summarize, in thousands, the amount of unrealized losses, defined as the amount by which cost or amortized cost exceeds fair value, and the related fair value of investments with unrealized losses in Heartland's securities portfolio as of March 31, 2018 , and December 31, 2017 . The investments were segregated into two categories: those that have been in a continuous unrealized loss position for less than 12 months and those that have been in a continuous unrealized loss position for 12 months or more. The reference point for determining how long an investment was in an unrealized loss position w as March 31, 2017 , and December 31, 2016 , respectively. Securities for which Heartland has taken credit-related other-than-temporary impairment ("OTTI") write-downs are categorized as being "less than 12 months" or "12 months or longer" in a continuous loss position based on the point in time that the fair value declined to below the cost basis and not the period of time since the credit-related OTTI write-down. Securities available for sale Less than 12 months 12 months or longer Total Fair Value Unrealized Losses Fair Value Unrealized Losses Fair Value Unrealized Losses March 31, 2018 U.S. government corporations and agencies $ 10,685 $ (69 ) $ — $ — $ 10,685 $ (69 ) Mortgage and asset-backed securities 923,293 (18,459 ) 379,672 (28,997 ) 1,302,965 (47,456 ) Obligations of states and political subdivisions 177,100 (3,456 ) 131,574 (6,971 ) 308,674 (10,427 ) Total debt securities 1,111,078 (21,984 ) 511,246 (35,968 ) 1,622,324 (57,952 ) Total temporarily impaired securities $ 1,111,078 $ (21,984 ) $ 511,246 $ (35,968 ) $ 1,622,324 $ (57,952 ) December 31, 2017 U.S. government corporations and agencies $ 4,819 $ (38 ) $ — $ — $ 4,819 $ (38 ) Mortgage and asset-backed securities 851,070 (11,533 ) 399,978 (26,054 ) 1,251,048 (37,587 ) Obligations of states and political subdivisions 93,040 (667 ) 159,180 (4,047 ) 252,220 (4,714 ) Total debt securities 948,929 (12,238 ) 559,158 (30,101 ) 1,508,087 (42,339 ) Total temporarily impaired securities $ 948,929 $ (12,238 ) $ 559,158 $ (30,101 ) $ 1,508,087 $ (42,339 )
Held-to-maturity Securities, Continuous Unrealized Loss Position, Fair Value	Securities held to maturity Less than 12 months 12 months or longer Total Fair Value Unrealized Losses Fair Value Unrealized Losses Fair Value Unrealized Losses March 31, 2018 Obligations of states and political subdivisions $ 30,496 $ (272 ) $ 7,907 $ (555 ) $ 38,403 $ (827 ) Total temporarily impaired securities $ 30,496 $ (272 ) $ 7,907 $ (555 ) $ 38,403 $ (827 ) December 31, 2017 Obligations of states and political subdivisions $ 8,512 $ (49 ) $ 8,989 $ (467 ) $ 17,501 $ (516 ) Total temporarily impaired securities $ 8,512 $ (49 ) $ 8,989 $ (467 ) $ 17,501 $ (516 )

Loans (Tables)

Loans (Tables)	3 Months Ended
	Mar. 31, 2018
Receivables [Abstract]
Schedule of Loans	Loans as of March 31, 2018 , and December 31, 2017 , were as follows, in thousands: March 31, 2018 December 31, 2017 Loans receivable held to maturity: Commercial $ 1,806,683 $ 1,646,606 Commercial real estate 3,323,094 3,163,269 Agricultural and agricultural real estate 518,386 511,588 Residential real estate 624,725 624,279 Consumer 474,929 447,484 Gross loans receivable held to maturity 6,747,817 6,393,226 Unearned discount (1,620 ) (556 ) Deferred loan fees (182 ) (1,206 ) Total net loans receivable held to maturity 6,746,015 6,391,464 Allowance for loan losses (58,656 ) (55,686 ) Loans receivable, net $ 6,687,359 $ 6,335,778
Allowance for Loan and Lease Losses, Based on Impairment Methodology	The following table shows the balance in the allowance for loan losses at March 31, 2018 , and December 31, 2017 , and the related loan balances, disaggregated on the basis of impairment methodology, in thousands. Loans evaluated under ASC 310-10-35 include loans on nonaccrual status and troubled debt restructurings, which are individually evaluated for impairment, and other impaired loans deemed to have similar risk characteristics. All other loans are collectively evaluated for impairment under ASC 450-20. Heartland has made no significant changes to the accounting for the allowance for loan losses during 2018. Allowance For Loan Losses Gross Loans Receivable Held to Maturity Ending Balance Under ASC 310-10-35 Ending Balance Under ASC 450-20 Total Ending Balance Evaluated for Impairment Under ASC 310-10-35 Ending Balance Evaluated for Impairment Under ASC 450-20 Total March 31, 2018 Commercial $ 2,425 $ 16,970 $ 19,395 $ 9,005 $ 1,797,678 $ 1,806,683 Commercial real estate 736 22,733 23,469 22,920 3,300,174 3,323,094 Agricultural and agricultural real estate 787 3,929 4,716 16,896 501,490 518,386 Residential real estate 386 1,755 2,141 28,324 596,401 624,725 Consumer 1,137 7,798 8,935 6,427 468,502 474,929 Total $ 5,471 $ 53,185 $ 58,656 $ 83,572 $ 6,664,245 $ 6,747,817 December 31, 2017 Commercial $ 1,613 $ 16,485 $ 18,098 $ 7,415 $ 1,639,191 $ 1,646,606 Commercial real estate 766 21,184 21,950 23,705 3,139,564 3,163,269 Agricultural and agricultural real estate 546 3,712 4,258 13,304 498,284 511,588 Residential real estate 430 1,794 2,224 27,141 597,138 624,279 Consumer 1,400 7,756 9,156 6,903 440,581 447,484 Total $ 4,755 $ 50,931 $ 55,686 $ 78,468 $ 6,314,758 $ 6,393,226
Schedule of Financing Receivables, Non Accrual Status	The following table presents nonaccrual loans, accruing loans past due 90 days or more and performing troubled debt restructured loans at March 31, 2018 , and December 31, 2017 , in thousands: March 31, 2018 December 31, 2017 Nonaccrual loans $ 60,644 $ 58,272 Nonaccrual troubled debt restructured loans 4,162 4,309 Total nonaccrual loans $ 64,806 $ 62,581 Accruing loans past due 90 days or more $ 22 $ 830 Performing troubled debt restructured loans $ 3,206 $ 6,617
Troubled Debt Restructuring on Loans Modified	The following tables provide information on troubled debt restructured loans that were modified during the three -month periods ended March 31, 2018 , and March 31, 2017 , dollars in thousands: Three Months Ended 2018 2017 Number of Loans Pre- Modification Recorded Investment Post- Modification Recorded Investment Number of Loans Pre- Modification Recorded Investment Post- Modification Recorded Investment Commercial — $ — $ — — $ — $ — Commercial real estate — — — — — — Total commercial and commercial real estate — — — — — — Agricultural and agricultural real estate — — — — — — Residential real estate 5 877 752 3 348 348 Consumer — — — — — — Total 5 $ 877 $ 752 3 $ 348 $ 348 The following table shows troubled debt restructured loans for which there was a payment default during the three month periods ended March 31, 2018 , and March 31, 2017 , that had been modified during the twelve-month period prior to default, in thousands: With Payment Defaults During the Following Periods Three Months Ended 2018 2017 Number of Loans Recorded Investment Number of Loans Recorded Investment Commercial — $ — — $ — Commercial real estate — — — — Total commercial and commercial real estate — — — — Agricultural and agricultural real estate — — — — Residential real estate 3 519 — — Consumer — — — — Total 3 $ 519 — $ —
Financing Receivable Credit Quality Indicators	The following table presents loans by credit quality indicator at March 31, 2018 , and December 31, 2017 , in thousands: Pass Nonpass Total March 31, 2018 Commercial $ 1,677,338 $ 129,345 $ 1,806,683 Commercial real estate 3,146,622 176,472 3,323,094 Total commercial and commercial real estate 4,823,960 305,817 5,129,777 Agricultural and agricultural real estate 442,484 75,902 518,386 Residential real estate 585,886 38,839 624,725 Consumer 461,786 13,143 474,929 Total gross loans receivable held to maturity $ 6,314,116 $ 433,701 $ 6,747,817 December 31, 2017 Commercial $ 1,552,783 $ 93,823 $ 1,646,606 Commercial real estate 2,985,501 177,768 3,163,269 Total commercial and commercial real estate 4,538,284 271,591 4,809,875 Agricultural and agricultural real estate 451,539 60,049 511,588 Residential real estate 586,623 37,656 624,279 Consumer 432,936 14,548 447,484 Total gross loans receivable held to maturity $ 6,009,382 $ 383,844 $ 6,393,226
Past Due Financing Receivables	The following table sets forth information regarding Heartland's accruing and nonaccrual loans at March 31, 2018 , and December 31, 2017 , in thousands: Accruing Loans 30-59 Days Past Due 60-89 Days 90 Days or More Past Due Total Past Due Current Nonaccrual Total Loans March 31, 2018 Commercial $ 2,906 $ 1,883 $ — $ 4,789 $ 1,793,565 $ 8,329 $ 1,806,683 Commercial real estate 403 740 — 1,143 3,305,043 16,908 3,323,094 Total commercial and commercial real estate 3,309 2,623 — 5,932 5,098,608 25,237 5,129,777 Agricultural and agricultural real estate 1,147 69 22 1,238 500,320 16,828 518,386 Residential real estate 2,891 66 — 2,957 602,927 18,841 624,725 Consumer 2,618 1,477 — 4,095 466,934 3,900 474,929 Total gross loans receivable held to maturity $ 9,965 $ 4,235 $ 22 $ 14,222 $ 6,668,789 $ 64,806 $ 6,747,817 December 31, 2017 Commercial $ 1,246 $ 259 $ 100 $ 1,605 $ 1,637,773 $ 7,228 $ 1,646,606 Commercial real estate 4,769 2,326 — 7,095 3,139,576 16,598 3,163,269 Total commercial and commercial real estate 6,015 2,585 100 8,700 4,777,349 23,826 4,809,875 Agricultural and agricultural real estate 604 134 — 738 497,546 13,304 511,588 Residential real estate 2,022 270 — 2,292 601,120 20,867 624,279 Consumer 4,734 943 730 6,407 436,493 4,584 447,484 Total gross loans receivable held to maturity $ 13,375 $ 3,932 $ 830 $ 18,137 $ 6,312,508 $ 62,581 $ 6,393,226
Summary of Impaired Loans	At March 31, 2018 , and December 31, 2017 , the carrying amount of loans acquired since 2015 consist of purchased impaired and nonimpaired loans as summarized in the following table, in thousands: March 31, 2018 December 31, 2017 Impaired Non Impaired Total Loans Impaired Non Impaired Total Loans Commercial $ 3,142 $ 262,107 $ 265,249 $ 952 $ 187,375 $ 188,327 Commercial real estate 2,474 1,078,724 1,081,198 2,572 1,052,469 1,055,041 Agricultural and agricultural real estate — 26 26 — 1,242 1,242 Residential real estate 199 181,020 181,219 214 173,909 174,123 Consumer loans — 78,613 78,613 — 51,292 51,292 Total loans $ 5,815 $ 1,600,490 $ 1,606,305 $ 3,738 $ 1,466,287 $ 1,470,025 The following tables present, by category of loan, impaired loans, the unpaid contractual loan balances at March 31, 2018 , and December 31, 2017 ; the outstanding loan balances recorded on the consolidated balance sheets at March 31, 2018 , and December 31, 2017 ; any related allowance recorded for those loans as of March 31, 2018 , and December 31, 2017 ; the average outstanding loan balances recorded on the consolidated balance sheets during the three -months ended March 31, 2018 , and year ended December 31, 2017 ; and the interest income recognized on the impaired loans during the three -month period ended March 31, 2018 , and year ended December 31, 2017 , in thousands: Unpaid Contractual Balance Loan Balance Related Allowance Recorded Year- to- Date Avg. Loan Balance Year- to- Date Interest Income Recognized March 31, 2018 Impaired loans with a related allowance: Commercial $ 2,816 $ 2,816 $ 2,425 $ 2,472 $ — Commercial real estate 11,180 9,324 736 9,520 8 Total commercial and commercial real estate 13,996 12,140 3,161 11,992 8 Agricultural and agricultural real estate 1,536 1,536 787 1,537 — Residential real estate 1,693 1,693 386 1,608 3 Consumer 2,859 2,859 1,137 3,069 9 Total impaired loans with a related allowance $ 20,084 $ 18,228 $ 5,471 $ 18,206 $ 20 Impaired loans without a related allowance: Commercial $ 7,308 $ 6,189 $ — $ 5,449 $ 49 Commercial real estate 14,202 13,596 — 13,879 97 Total commercial and commercial real estate 21,510 19,785 — 19,328 146 Agricultural and agricultural real estate 17,388 15,360 — 12,954 1 Residential real estate 26,635 26,631 — 26,878 109 Consumer 3,757 3,568 — 3,912 22 Total impaired loans without a related allowance $ 69,290 $ 65,344 $ — $ 63,072 $ 278 Total impaired loans held to maturity: Commercial $ 10,124 $ 9,005 $ 2,425 $ 7,921 $ 49 Commercial real estate 25,382 22,920 736 23,399 105 Total commercial and commercial real estate 35,506 31,925 3,161 31,320 154 Agricultural and agricultural real estate 18,924 16,896 787 14,491 1 Residential real estate 28,328 28,324 386 28,486 112 Consumer 6,616 6,427 1,137 6,981 31 Total impaired loans held to maturity $ 89,374 $ 83,572 $ 5,471 $ 81,278 $ 298 Unpaid Contractual Balance Loan Balance Related Allowance Recorded Year-to- Date Avg. Loan Balance Year-to- Date Interest Income Recognized December 31, 2017 Impaired loans with a related allowance: Commercial $ 2,292 $ 2,292 $ 1,613 $ 3,607 $ 39 Commercial real estate 11,925 10,068 766 11,479 34 Total commercial and commercial real estate 14,217 12,360 2,379 15,086 73 Agricultural and agricultural real estate 1,539 1,539 546 3,437 — Residential real estate 1,568 1,568 430 2,056 15 Consumer 2,634 2,634 1,400 2,370 41 Total impaired loans with a related allowance $ 19,958 $ 18,101 $ 4,755 $ 22,949 $ 129 Impaired loans without a related allowance: Commercial $ 6,243 $ 5,123 $ — $ 2,586 $ 165 Commercial real estate 14,243 13,637 — 20,148 514 Total commercial and commercial real estate 20,486 18,760 — 22,734 679 Agricultural and agricultural real estate 13,793 11,765 — 9,654 — Residential real estate 25,573 25,573 — 26,024 277 Consumer 4,269 4,269 — 3,884 73 Total impaired loans without a related allowance $ 64,121 $ 60,367 $ — $ 62,296 $ 1,029 Total impaired loans held to maturity: Commercial $ 8,535 $ 7,415 $ 1,613 $ 6,193 $ 204 Commercial real estate 26,168 23,705 766 31,627 548 Total commercial and commercial real estate 34,703 31,120 2,379 37,820 752 Agricultural and agricultural real estate 15,332 13,304 546 13,091 — Residential real estate 27,141 27,141 430 28,080 292 Consumer 6,903 6,903 1,400 6,254 114 Total impaired loans held to maturity $ 84,079 $ 78,468 $ 4,755 $ 85,245 $ 1,158
Changes in Accretable Yield on Acquired Loans	Changes in accretable yield on acquired loans with evidence of credit deterioration at the date of acquisition for the three -month periods ended March 31, 2018 , and March 31, 2017 , were as follows, in thousands: Three Months Ended 2018 2017 Balance at beginning of period $ 57 $ 182 Original yield premium, net, at date of acquisition (56 ) — Accretion (199 ) (173 ) Reclassification from nonaccretable difference (1) 198 127 Balance at period end $ — $ 136 (1) Represents increases in estimated cash flows expected to be received, primarily due to lower estimated credit losses.

Allowance for Loan Losses (Tabl

Allowance for Loan Losses (Tables)	3 Months Ended
	Mar. 31, 2018
Loans and Leases Receivable Disclosure [Abstract]
Changes in the Allowance for Loan and Leases Losses	Changes in the allowance for loan losses for the three -month periods ended March 31, 2018 , and March 31, 2017 , were as follows, in thousands: Commercial Commercial Real Estate Agricultural Residential Real Estate Consumer Total Balance at December 31, 2017 $ 18,098 $ 21,950 $ 4,258 $ 2,224 $ 9,156 $ 55,686 Charge-offs (794 ) (125 ) — (16 ) (1,289 ) (2,224 ) Recoveries 104 448 14 75 290 931 Provision 1,987 1,196 444 (142 ) 778 4,263 Balance at March 31, 2018 $ 19,395 $ 23,469 $ 4,716 $ 2,141 $ 8,935 $ 58,656 Commercial Commercial Real Estate Agricultural Residential Real Estate Consumer Total Balance at December 31, 2016 $ 14,765 $ 24,319 $ 4,210 $ 2,263 $ 8,767 $ 54,324 Charge-offs (230 ) (608 ) (871 ) (265 ) (1,744 ) (3,718 ) Recoveries 234 212 1 2 303 752 Provision 1,411 (126 ) 643 183 1,530 3,641 Balance at March 31, 2017 $ 16,180 $ 23,797 $ 3,983 $ 2,183 $ 8,856 $ 54,999

Goodwill, Core Deposit Premiu24

Goodwill, Core Deposit Premium and Other Intangible Assets (Tables)	3 Months Ended
	Mar. 31, 2018
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of Gross Carrying Amount and Accumulated Amortization of Other Intangible Assets	The gross carrying amount of these intangible assets and the associated accumulated amortization at March 31, 2018 , and December 31, 2017 , are presented in the table below, in thousands: March 31, 2018 December 31, 2017 Gross Carrying Amount Accumulated Amortization Net Carrying Amount Gross Carrying Amount Accumulated Amortization Net Carrying Amount Amortizing intangible assets: Core deposit intangibles $ 69,731 $ 28,939 $ 40,792 $ 62,008 $ 27,086 $ 34,922 Customer relationship intangibles 1,177 906 271 1,177 896 281 Mortgage servicing rights 42,249 19,084 23,165 42,139 18,891 23,248 Commercial servicing rights 6,740 4,434 2,306 6,719 4,110 2,609 Total $ 119,897 $ 53,363 $ 66,534 $ 112,043 $ 50,983 $ 61,060
Schedule of Estimated Future Amortization Expense of Amortizable Intangible Assets	The following table shows the estimated future amortization expense for amortizable intangible assets, in thousands: Core Deposit Intangibles Customer Relationship Intangibles Mortgage Servicing Rights Commercial Servicing Rights Total Nine months ending December 31, 2018 $ 5,957 $ 29 $ 6,776 $ 471 $ 13,233 Year ending December 31, 2019 7,092 38 4,097 522 11,749 2020 6,220 37 3,512 411 10,180 2021 5,323 36 2,927 354 8,640 2022 4,175 34 2,341 290 6,840 2023 3,691 33 1,756 163 5,643 Thereafter 8,334 64 1,756 95 10,249 Total $ 40,792 $ 271 $ 23,165 $ 2,306 $ 66,534
Summary of Changes in Servicing Rights	The following table summarizes, in thousands, the changes in capitalized mortgage servicing rights for the three months ended March 31, 2018 , and March 31, 2017 : 2018 2017 Balance at January 1, $ 23,248 $ 32,088 Originations 1,162 2,132 Amortization (1,245 ) (2,261 ) Balance at period end $ 23,165 $ 31,959 Fair value of mortgage servicing rights $ 40,434 $ 47,564 Mortgage servicing rights, net to servicing portfolio 0.66 % 0.74 % The following table summarizes, in thousands, the changes in capitalized commercial servicing rights for the three months ended March 31, 2018 , and March 31, 2017 : 2018 2017 Balance at January 1, $ 2,609 $ 3,690 Originations 21 93 Amortization (322 ) (306 ) Valuation allowance on commercial servicing rights (2 ) 5 Balance at period end $ 2,306 $ 3,482 Fair value of commercial servicing rights $ 2,781 $ 4,040 Commercial servicing rights, net to servicing portfolio 1.84 % 2.17 %
Schedule of Servicing Asset at Fair Value and Amortized Cost	The following table summarizes, in thousands, the book value, the fair value of each tranche of the commercial servicing rights and any recorded valuation allowance at each respective subsidiary at March 31, 2018 , and December 31, 2017 : March 31, 2018 Book Value- Less than 20 Years Fair Value- Less than 20 Years Impairment- Less than 20 Years Book Value- More than 20 Years Fair Value- More than 20 Years Impairment- More than 20 Years Citywide Banks $ 6 $ 10 $ — $ 33 $ 36 $ — Premier Valley Bank 72 104 — 286 272 14 Wisconsin Bank & Trust 368 534 — 1,554 1,825 — Total $ 446 $ 648 $ — $ 1,873 $ 2,133 $ 14 December 31, 2017 Citywide Banks $ 8 $ 11 $ — $ 34 $ 37 $ — Premier Valley Bank 83 110 — 303 291 12 Wisconsin Bank & Trust 446 619 — 1,747 2,153 — Total $ 537 $ 740 $ — $ 2,084 $ 2,481 $ 12

Derivative Financial Instrume25

Derivative Financial Instruments (Tables)	3 Months Ended
	Mar. 31, 2018
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Balance Sheet Category and Fair Values of Derivative Instruments	The table below identifies the notional amount, fair value and balance sheet category of Heartland's fair value hedges at March 31, 2018 , and December 31, 2017 , in thousands: Notional Amount Fair Value Balance Sheet Category March 31, 2018 Fair value hedges $ 35,436 $ (105 ) Other liabilities December 31, 2017 Fair value hedges $ 35,635 $ (999 ) Other liabilities The table below identifies the balance sheet category and fair values of Heartland's derivative instruments designated as cash flow hedges at March 31, 2018 , and December 31, 2017 , in thousands: Notional Amount Fair Value Balance Sheet Category Receive Rate Weighted Average Pay Rate Maturity March 31, 2018 Interest rate swap $ 25,000 $ 239 Other assets 2.178 % 2.255 % 03/17/2021 Interest rate swap 20,000 (380 ) Other liabilities 1.704 3.355 01/07/2020 Interest rate swap 10,000 69 Other assets 2.286 1.674 03/26/2019 Interest rate swap 10,000 68 Other assets 2.178 1.658 03/18/2019 Interest rate swap 32,667 1,010 Other assets 4.240 3.674 05/10/2021 Interest rate swap 20,000 316 Other assets 2.125 2.390 06/15/2024 Interest rate swap 20,000 339 Other assets 2.006 2.352 03/01/2024 December 31, 2017 Interest rate swap $ 25,000 $ (106 ) Other liabilities 1.600 % 2.255 % 03/17/2021 Interest rate swap 20,000 (621 ) Other liabilities 1.350 3.355 01/07/2020 Interest rate swap 10,000 30 Other assets 1.329 1.674 03/26/2019 Interest rate swap 10,000 29 Other assets 1.600 1.658 03/18/2019 Interest rate swap 33,667 759 Other assets 3.932 3.674 05/10/2021 Interest rate swap (1) 20,000 (177 ) Other liabilities 1.588 2.390 06/15/2024 Interest rate swap (2) 20,000 (149 ) Other Liabilities 1.481 2.352 03/01/2024 The table below identifies the balance sheet category and fair values of Heartland's derivative instruments designated as loan swaps at March 31, 2018 , and December 31, 2017 , in thousands: Notional Amount Fair Value Balance Sheet Category Weighted Average Receive Rate Weighted Average Pay Rate March 31, 2018 Customer interest rate swaps $ 162,882 $ 3,763 Other assets 4.82 % 4.73 % Customer interest rate swaps 162,882 (3,763 ) Other liabilities 4.73 4.82 December 31, 2017 Customer interest rate swaps $ 126,766 $ 2,377 Other assets 4.70 % 4.03 % Customer interest rate swaps 126,766 (2,377 ) Other liabilities 4.03 4.70
Gains (Losses) on Derivative Instruments	The table below identifies the gains and losses recognized on Heartland's fair value hedges for the three month periods ended March 31, 2018 , and March 31, 2017 , in thousands: Amount of Gain (Loss) Income Statement Category Three Months Ended March 31, 2018 Fair value hedges $ 894 Interest income Three Months Ended March 31, 2017 Fair value hedges $ 194 Interest income The table below identifies the gains and losses recognized on Heartland's derivative instruments designated as cash flow hedges for the three -month periods ended March 31, 2018 , and March 31, 2017 , in thousands: Effective Portion Ineffective Portion Recognized in OCI Reclassified from AOCI into Income Recognized in Income on Derivatives Amount of Gain (Loss) Category Amount of Gain (Loss) Category Amount of Gain (Loss) Three Months Ended March 31, 2018 Interest rate swaps $ 1,896 Interest expense $ (197 ) Other income $ — Three Months Ended March 31, 2017 Interest rate swaps $ 533 Interest expense $ (397 ) Other income $ —
Balance Sheet Category and Fair Values of Embedded Derivatives	The table below identifies the notional amount, fair value and balance sheet category of Heartland's embedded derivatives at March 31, 2018 , and December 31, 2017 , in thousands: Notional Amount Fair Value Balance Sheet Category March 31, 2018 Embedded derivatives $ 13,907 $ 461 Other assets December 31, 2017 Embedded derivatives $ 14,045 $ 738 Other assets The table below identifies the gains and losses recognized on Heartland's embedded derivatives for the three month periods ended March 31, 2018 , and March 31, 2017 , in thousands: Amount of Gain (Loss) Income Statement Category Three Months Ended March 31, 2018 Embedded derivatives $ 277 Other noninterest income Three Months Ended March 31, 2017 Embedded derivatives $ 117 Other noninterest income The following table identifies, in thousands, the notional amount, fair value, balance sheet category and income statement category for the change in fair value of the embedded conversion option as of March 31, 2018 , and December 31, 2017 : Notional Amount Fair Value Balance Sheet Category March 31, 2018 Embedded conversion option $ — $ — Other liabilities December 31, 2017 Embedded conversion option $ — $ — Other liabilities The table below identifies the gains and losses recognized on Heartland's embedded conversion options for the three -month periods ended March 31, 2018 , and March 31, 2017 , in thousands: Amount of Gain (Loss) Income Statement Category Three Months Ended March 31, 2018 Embedded conversion option $ — Other noninterest income Three Months Ended March 31, 2017 Embedded conversion option $ 97 Other noninterest income
Schedule of Other Derivatives Not Designated as Hedging Instruments, Balance Sheet and Income Category	The table below identifies the balance sheet category and fair values of Heartland's other free standing derivative instruments not designated as hedging instruments at March 31, 2018 , and December 31, 2017 , in thousands: Balance Sheet Category Notional Amount Fair Value March 31, 2018 Interest rate lock commitments (mortgage) Other assets $ 65,591 $ 1,959 Forward commitments Other assets 55,118 283 Forward commitments Other liabilities 91,625 (320 ) Undesignated interest rate swaps Other liabilities 13,907 (461 ) December 31, 2017 Interest rate lock commitments (mortgage) Other assets $ 53,588 $ 1,738 Forward commitments Other assets 37,286 80 Forward commitments Other liabilities 118,632 (232 ) Undesignated interest rate swaps Other liabilities 14,045 (738 ) The table below identifies the income statement category of the gains and losses recognized in income on Heartland's other free standing derivative instruments not designated as hedging instruments for the three -month periods ended March 31, 2018 , and March 31, 2017 , in thousands: Income Statement Category Gain (Loss) Recognized Three Months Ended March 31, 2018 Interest rate lock commitments (mortgage) Net gains on sale of loans held for sale $ 17 Forward commitments Net gains on sale of loans held for sale 115 Undesignated interest rate swaps Other noninterest income 277 Three Months Ended March 31, 2017 Interest rate lock commitments (mortgage) Net gains on sale of loans held for sale $ 1,062 Forward commitments Net gains on sale of loans held for sale (2,739 ) Undesignated interest rate swaps Other noninterest income 117

Fair Value (Tables)

Fair Value (Tables)	3 Months Ended
	Mar. 31, 2018
Fair Value Disclosures [Abstract]
Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis	The table below presents Heartland's assets and liabilities that are measured at fair value on a recurring basis as of March 31, 2018 , and December 31, 2017 , in thousands, aggregated by the level in the fair value hierarchy within which those measurements fall: Total Fair Value Level 1 Level 2 Level 3 March 31, 2018 Assets Securities available for sale U.S. government corporations and agencies $ 11,188 $ 9,421 $ 1,767 $ — Mortgage and asset-backed securities 1,647,604 — 1,647,604 — Obligations of states and political subdivisions 352,180 — 352,180 — Corporate debt securities — — — — Equity securities 16,693 — 16,693 — Derivative financial instruments (1) 6,265 — 6,265 — Interest rate lock commitments 1,959 — — 1,959 Forward commitments 283 — 283 — Total assets at fair value $ 2,036,172 $ 9,421 $ 2,024,792 $ 1,959 Liabilities Derivative financial instruments (2) $ 4,709 $ — $ 4,709 $ — Forward commitments 320 — 320 — Total liabilities at fair value $ 5,029 $ — $ 5,029 $ — December 31, 2017 Assets Securities available for sale U.S. government corporations and agencies $ 5,328 $ 3,484 $ 1,844 $ — Mortgage and asset-backed securities 1,753,736 — 1,753,736 — Obligations of states and political subdivisions 441,015 — 441,015 — Equity securities 16,674 — 16,674 — Derivative financial instruments (1) 3,933 — 3,933 — Interest rate lock commitments 1,738 — — 1,738 Forward commitments 80 — 80 — Total assets at fair value $ 2,222,504 $ 3,484 $ 2,217,282 $ 1,738 Liabilities Derivative financial instruments (2) $ 5,167 $ — $ 5,167 $ — Forward commitments 232 — 232 — Total liabilities at fair value $ 5,399 $ — $ 5,399 $ — (1) Includes cash flow hedges, embedded derivatives and back-to-back loan swaps (2) Includes cash flow hedges, fair value hedges, back-to-back loan swaps, embedded conversion options and free standing derivative instruments
Fair Value Measurements, Nonrecurring	The tables below present Heartland's assets that are measured at fair value on a nonrecurring basis, in thousands: Fair Value Measurements at March 31, 2018 Total Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Year-to- Date (Gains) Losses Collateral dependent impaired loans: Commercial $ 2,923 $ — $ — $ 2,923 $ — Commercial real estate 8,316 — — 8,316 — Agricultural and agricultural real estate 8,041 — — 8,041 — Residential real estate 1,421 — — 1,421 4 Consumer 1,721 — — 1,721 — Total collateral dependent impaired loans $ 22,422 $ — $ — $ 22,422 $ 4 Loans held for sale $ 24,376 $ — $ 24,376 $ — $ 288 Other real estate owned $ 11,801 $ — $ — $ 11,801 $ 16 Premises, furniture and equipment held for sale $ 1,477 $ — $ — $ 1,477 $ (115 ) Commercial servicing rights $ 272 $ — $ — $ 272 $ 2 Fair Value Measurements at December 31, 2017 Total Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Year-to- Collateral dependent impaired loans: Commercial $ 3,212 $ — $ — $ 3,212 $ 1,119 Commercial real estate 9,480 — — 9,480 322 Agricultural and agricultural real estate 8,406 — — 8,406 2,028 Residential real estate 1,137 — — 1,137 — Consumer 1,234 — — 1,234 — Total collateral dependent impaired loans $ 23,469 $ — $ — — $ 23,469 $ 3,469 Loans held for sale $ 44,560 $ — $ 44,560 $ — $ 190 Other real estate owned $ 10,777 $ — $ — $ 10,777 $ 737 Premises, furniture and equipment held for sale $ 1,977 $ — $ — $ 1,977 $ 192 Commercial servicing rights $ 291 $ — $ — $ 291 $ (21 )
Fair Value Inputs, Assets, Quantitative Information	The following tables present additional quantitative information about assets measured at fair value and for which Heartland has utilized Level 3 inputs to determine fair value, in thousands: Fair Value at 3/31/2018 Valuation Technique Unobservable Input Range (Weighted Average) Interest rate lock commitments $ 1,959 Discounted cash flows Closing ratio 0-99% (89%) (1) Premises, furniture and equipment held for sale 1,477 Modified appraised value Third party appraisal (2) Appraisal discount 0-10% (4) Commercial servicing rights 272 Discounted cash flows Third party valuation (3) Other real estate owned 11,801 Modified appraised value Third party appraisal (2) Appraisal discount 0-10% Collateral dependent impaired loans: Commercial 2,923 Modified appraised value Third party appraisal (2) Appraisal discount 0-10% (4) Commercial real estate 8,316 Modified appraised value Third party appraisal (2) Appraisal discount 0-10% (4) Agricultural and agricultural real estate 8,041 Modified appraised value Third party appraisal (2) Appraisal discount 0-10% (4) Residential real estate 1,421 Modified appraised value Third party appraisal (2) Appraisal discount 0-12% (4) Consumer 1,721 Modified appraised value Third party valuation (2) Valuation discount 0-14% (4) (1) The significant unobservable input used in the fair value measurement is the closing ratio, which represents the percentage of loans currently in a lock position which management estimates will ultimately close. The closing ratio calculation takes into consideration historical data and loan-level data. (2) Third party appraisals are obtained and updated at least annually to establish the value of the underlying asset, but the disclosure of the unobservable inputs used by the appraisers would not be meaningful because the range will vary widely from appraisal to appraisal. (3) The significant unobservable input used in the fair value measurement are the value indices, which are weighted-average spreads to LIBOR based on maturity groups. (4) Discounts applied to the appraised values primarily include estimated sales costs, but also consider the age of the appraisal, changes in local market conditions and changes in the current condition of the collateral. Fair Value at 12/31/2017 Valuation Technique Unobservable Input Range (Weighted Average) Interest rate lock commitments $ 1,738 Discounted cash flows Closing ratio 0-99% (89%) (1) Premises, furniture and equipment held for sale 1,977 Modified appraised value Third party appraisal (2) 0-10% (4) Commercial servicing rights 291 Discounted cash flows Third party valuation (3) Other real estate owned 10,777 Modified appraised value Third party appraisal (2) Appraisal discount 0-10% Collateral dependent impaired loans: Commercial 3,212 Modified appraised value Third party appraisal (2) Appraisal discount 0-15% (4) Commercial real estate 9,480 Modified appraised value Third party appraisal (2) Appraisal discount 0-12% (4) Agricultural and agricultural real estate 8,406 Modified appraised value Third party appraisal (2) Appraisal discount 0-10% (4) Residential real estate 1,137 Modified appraised value Third party appraisal (2) Appraisal discount 0-12% (4) Consumer 1,234 Modified appraised value Third party valuation (2) Valuation discount 0-12% (4) (1) The significant unobservable input used in the fair value measurement is the closing ratio, which represents the percentage of loans currently in a lock position which management estimates will ultimately close. The closing ratio calculation takes into consideration historical data and loan-level data. (2) Third party appraisals are obtained and updated at least annually to establish the value of the underlying asset, but the disclosure of the unobservable inputs used by the appraisers would not be meaningful because the range will vary widely from appraisal to appraisal. (3) The significant unobservable input used in the fair value measurement are the value indices, which are weighted-average spreads to LIBOR based on maturity groups. (4) Discounts applied to the appraised values primarily include estimated sales costs, but also consider the age of the appraisal, changes in local market conditions and changes in the current condition of the collateral.
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation	The changes in fair value of the interest rate lock commitments, which are Level 3 financial instruments measured on a recurring basis, are summarized in the following table, in thousands: For the Three Months Ended For the Year Ended December 31, 2017 Balance at January 1, $ 1,738 $ 2,790 Total gains (losses) included in earnings 17 (1,479 ) Issuances 492 1,875 Settlements (288 ) (1,448 ) Balance at period end $ 1,959 $ 1,738
Fair Value, by Balance Sheet Grouping	The following analysis, which is inherently limited in depicting fair value, also does not consider any value associated with either existing customer relationships or the ability of Heartland to create value through loan origination, deposit gathering or fee generating activities. Many of the estimates presented herein are based upon the use of highly subjective information and assumptions and, accordingly, the results may not be precise. Management believes that fair value estimates may not be comparable between financial institutions due to the wide range of permitted valuation techniques and numerous estimates which must be made. Furthermore, because the disclosed fair value amounts were estimated as of the balance sheet date, the amounts actually realized or paid upon maturity or settlement of the various financial instruments could be significantly different. Fair Value Measurements at March 31, 2018 Carrying Amount Estimated Fair Value Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Financial assets: Cash and cash equivalents $ 266,346 $ 266,346 $ 266,346 $ — $ — Time deposits in other financial institutions 6,297 6,297 6,297 — — Securities: Available for sale 2,027,665 2,027,665 9,421 2,018,244 — Held to maturity 249,766 258,638 — 258,638 — Other investments 22,982 22,982 — 22,982 — Loans held for sale 24,376 24,376 — 24,376 — Loans, net: Commercial 1,786,838 1,766,760 — 1,763,837 2,923 Commercial real estate 3,298,798 3,280,785 — 3,272,469 8,316 Agricultural and agricultural real estate 514,471 508,582 — 500,541 8,041 Residential real estate 621,295 614,234 — 612,813 1,421 Consumer 465,957 464,793 — 463,072 1,721 Total Loans, net 6,687,359 6,635,154 — 6,612,732 22,422 Cash surrender value on life insurance 143,444 143,444 — 143,444 — Derivative financial instruments (1) 6,265 6,265 — 6,265 — Interest rate lock commitments 1,959 1,959 — — 1,959 Forward commitments 283 283 — 283 — Financial liabilities: Deposits Demand deposits 3,094,457 3,094,457 — 3,094,457 — Savings deposits 4,536,106 4,536,106 — 4,536,106 — Time deposits 910,977 910,977 — 910,977 — Short term borrowings 131,240 131,240 — 131,240 — Other borrowings 276,118 276,193 — 276,193 — Derivative financial instruments (2) 4,709 4,709 — 4,709 — Forward commitments 320 320 — 320 — (1) Includes cash flow hedges, embedded derivatives and back-to-back loan swaps (2) Includes cash flow hedges, fair value hedges, back-to-back loan swaps, embedded conversion options and free standing derivative instruments Fair Value Measurements at December 31, 2017 Carrying Amount Estimated Fair Value Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Financial assets: Cash and cash equivalents $ 196,003 $ 196,003 $ 196,003 $ — $ — Time deposits in other financial institutions 9,820 9,820 9,820 — — Securities: Available for sale 2,216,753 2,216,753 3,484 2,213,269 — Held to maturity 253,550 265,494 — 265,494 — Other investments 22,563 22,563 — 22,563 — Loans held for sale 44,560 44,560 — 44,560 — Loans, net: Commercial 1,628,043 1,617,956 — 1,614,744 3,212 Commercial real estate 3,140,427 3,132,542 — 3,123,062 9,480 Agricultural and agricultural real estate 508,075 508,987 — 500,581 8,406 Residential real estate 620,939 614,667 — 613,530 1,137 Consumer 438,294 440,820 — 439,586 1,234 Total Loans, net 6,335,778 6,314,972 — 6,291,503 23,469 Cash surrender value on life insurance 142,818 142,818 — 142,818 — Derivative financial instruments (1) 3,933 3,933 — 3,933 — Interest rate lock commitments 1,738 1,738 — — 1,738 Forward commitments 80 80 — 80 — Financial liabilities: Deposits Demand deposits 2,983,128 2,983,128 — 2,983,128 — Savings deposits 4,240,328 4,240,328 — 4,240,328 — Time deposits 923,453 923,453 — 923,453 — Short term borrowings 324,691 324,691 — 324,691 — Other borrowings 285,011 285,609 — 285,609 — Derivative financial instruments (2) 5,167 5,167 — 5,167 — Forward commitments 232 232 — 232 — (1) Includes cash flow hedges, embedded derivatives and back-to-back loan swaps (2) Includes cash flow hedges, fair value hedges, back-to-back loan swaps, embedded conversion options and free standing derivative instruments

Revenue (Tables)

Revenue (Tables)	3 Months Ended
	Mar. 31, 2018
Revenue from Contract with Customer [Abstract]
Schedule of noninterest income in-scope and out-of-scope of Topic 606	The following presents noninterest income, segregated by revenue streams in-scope and out-of-scope of Topic 606, for the three months ended March 31, 2018, and 2017, in thousands: Three Months Ended March 31, 2018 2017 In-scope of Topic 606 Service charges and fees Service charges and fees on deposit accounts $ 2,618 $ 2,160 Overdraft fees 2,208 2,193 Customer service fees 77 49 Credit card fee income 2,190 2,033 Debit card income 2,985 3,021 Other service charges 1 1 Total service charges and fees 10,079 9,457 Trust fees 4,680 3,631 Brokerage and insurance commissions 907 1,036 Total noninterest income in-scope of Topic 606 15,666 14,124 Out-of-scope of Topic 606 Loan servicing income 1,754 1,724 Securities gains, net 1,441 2,482 Unrealized loss on equity securities, net (28 ) — Net gains on sale of loans held for sale 4,051 6,147 Valuation adjustment on commercial servicing rights (2 ) 5 Income on bank owned life insurance 614 617 Other noninterest income 1,220 794 Total noninterest income out-of-scope of Topic 606 9,050 11,769 Total noninterest income $ 24,716 $ 25,893

Basis of Presentation (Narrativ

Basis of Presentation (Narrative) (Details)	12 Months Ended
	Dec. 31, 2017segment
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Number of business segments	2

Basis of Presentation (Earnings

Basis of Presentation (Earnings Per Share) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Earnings Per Share
Net income	$ 23,268	$ 18,010
Preferred dividends	(13)	(19)
Interest expense on convertible preferred debt	0	5
NET INCOME AVAILABLE TO COMMON STOCKHOLDERS	$ 23,255	$ 17,996
Weighted average common shares outstanding for basic earnings per share (in shares)	30,442	26,335
Assumed incremental common shares issued upon non-vested restricted stock units (in shares)	203	293
Weighted average common shares for diluted earnings per share (in shares)	30,645	26,628
Earnings per common share — basic (in dollars per share)	$ 0.76	$ 0.68
Earnings per common share — diluted (in dollars per share)	$ 0.76	$ 0.68
Number of antidilutive common stock equivalents excluded from diluted earnings per share computation (in shares)	0	0

Basis of Presentation (Stock-Ba

Basis of Presentation (Stock-Based Compensation) (Details) - USD ($)	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Tax benefit from equity based awards	$ 611,000	$ 888,000
Options granted (in shares)	0	0
Intrinsic value for the total of all options exercised	$ 231,000
Cash received from options exercised	$ 121,000	$ 102,000
Options vested during period (in shares)	0	0
2017 and 2018 RSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation, period before change in control	6 months
Prior to 2009
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Typical options expiration period after date of grant	10 years
Time-based RSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation, award vesting periods	3 years	3 years
Performance-Based RSUs | Period One
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation, award vesting periods	1 year
Performance-Based RSUs | Period Two
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation, award vesting periods	3 years
RSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation costs	$ 1,900,000	$ 1,700,000
Share-based unrecognized compensation costs	6,100,000
Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation costs	0	$ 0
Share-based unrecognized compensation costs	$ 0
Stock Options | Prior to 2009
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation, award vesting periods	5 years
Stock Options | Period One | Prior to 2009
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation, award vesting periods	3 years
Stock Options | Period Two | Prior to 2009
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation, award vesting periods	4 years
Stock Options | Period Three | Prior to 2009
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation, award vesting periods	5 years
Long-Term Incentive Plan 2012
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares for issuance under future awards (in shares)	459,893
Long-Term Incentive Plan 2012 | Time-based RSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Equity instruments other than options, granted (in shares)	52,153	55,665
Long-Term Incentive Plan 2012 | Performance-Based RSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation, vesting percentage after change in control	100.00%
Long-Term Incentive Plan 2012 | Performance-Based RSUs | 2017 and 2018 RSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation, vesting percentage after change in control	100.00%
Share-based compensation, vesting period after change in control	24 months
Long-Term Incentive Plan 2012 | Performance-Based RSUs | Period One
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Equity instruments other than options, granted (in shares)	18,988	27,570
Long-Term Incentive Plan 2012 | Performance-Based RSUs | Period Two
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Equity instruments other than options, granted (in shares)	16,108	9,032
Long-Term Incentive Plan 2012 | RSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Equity instruments other than options, granted (in shares)	0	0

Basis of Presentation (Summary

Basis of Presentation (Summary of RSUs Outstanding) (Details) - RSUs - $ / shares	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Shares
Outstanding at beginning of period (in shares)	301,578	346,817
Granted (in shares)	87,249	92,267
Vested (in shares)	(107,553)	(103,897)
Forfeited (in shares)	(19,113)	(7,765)
Outstanding at end of period (in shares)	262,161	327,422
Weighted-Average Grant Date Fair Value
Outstanding at beginning of period (in dollars per share)	$ 34.74	$ 27.61
Granted (in dollars per share)	55.25	47.50
Vested (in dollars per share)	30.79	24.74
Forfeited (in dollars per share)	43.62	31.03
Outstanding at end of period (in dollars per share)	$ 42.60	$ 34.04

Basis of Presentation (Summar32

Basis of Presentation (Summary of Stock Options Outstanding) (Details) - $ / shares	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Shares
Outstanding at beginning of period (in shares)	6,500	26,400
Granted (in shares)	0	0
Exercised (in shares)	(6,500)	(5,500)
Forfeited (in shares)	0	0
Outstanding at end of period (in shares)	0	20,900
Options exercisable at end of period (in shares)	0	20,900
Weighted-Average Exercise Price
Outstanding at beginning of period (in dollars per share)	$ 18.60	$ 18.60
Granted (in dollars per share)	0	0
Exercised (in dollars per share)	18.60	18.60
Forfeited (in dollars per share)	0	0
Outstanding at end of period (in dollars per share)	0	18.60
Options exercisable at end of period (in dollars per share)	$ 0	$ 18.60

Basis of Presentation (Effect o

Basis of Presentation (Effect of New Financial Accounting Standards) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Jan. 01, 2018
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Reclassification of unrealized net gain on equity securities	$ 0
Accumulated Other Comprehensive Income (Loss)
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Reclassification of unrealized net gain on equity securities	280
Accumulated Other Comprehensive Income (Loss) | ASU 2016-01
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Reclassification of unrealized net gain on equity securities		$ (280)
Accumulated Other Comprehensive Income (Loss) | ASU 2018-02
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative-effect adjustment	(4,500)
Retained Earnings
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Reclassification of unrealized net gain on equity securities	280
Retained Earnings | ASU 2016-01
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Reclassification of unrealized net gain on equity securities		$ 280
Retained Earnings | ASU 2018-02
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative-effect adjustment	$ 4,500

Acquisitions (Details)

Acquisitions (Details) $ in Thousands	Feb. 23, 2018USD ($)shares	Jul. 07, 2017USD ($)buildingshares	Feb. 28, 2017USD ($)buildingshares	Jun. 30, 2018USD ($)	Jun. 30, 2017USD ($)	Mar. 31, 2018USD ($)	Dec. 31, 2017USD ($)
Business Acquisition [Line Items]
Assets						$ 10,055,863	$ 9,810,739
Held to maturity						6,746,015	6,391,464
Deposits						8,541,540	$ 8,146,909
Signature Bancshares, Inc.
Business Acquisition [Line Items]
Purchase price	$ 61,400
Purchase price in cash	$ 7,800
Purchase price paid by delivery of shares of common stock (in shares) | shares	1,000,843
Citywide Banks
Business Acquisition [Line Items]
Purchase price		$ 211,200
Purchase price in cash		$ 58,600
Purchase price paid by delivery of shares of common stock (in shares) | shares		3,216,161
Assets		$ 1,490,000
Held to maturity		985,400
Deposits		$ 1,210,000
Number of bank buildings sold (building) | building		1
Fair value of buildings sold		$ 1,400
Founders Bancorp
Business Acquisition [Line Items]
Purchase price			$ 31,000
Purchase price in cash			$ 8,400
Purchase price paid by delivery of shares of common stock (in shares) | shares			455,877
Assets			$ 213,900
Deposits			$ 181,500
Number of bank buildings sold (building) | building			1
Fair value of buildings sold					$ 576
Loans			$ 96,400
First Bank Lubbock Bancshares, Inc.
Business Acquisition [Line Items]
Assets						971,500
Held to maturity						704,900
Deposits						$ 869,300
Signature Bancshares, Inc.
Business Acquisition [Line Items]
Assets	$ 427,100
Held to maturity	324,500
Deposits	$ 357,300
Scenario, Forecast [Member] | First Bank Lubbock Bancshares, Inc.
Business Acquisition [Line Items]
Purchase price				$ 185,600

Securities (Securities availabl

Securities (Securities available for sale) (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Schedule of Available-for-sale Securities [Line Items]
Equity Securities, FV-NI	$ 16,693
Marketable Securities, Amortized Cost Basis	2,080,514
Gross Unrealized Gains	5,103
Gross Unrealized Losses	(57,952)
Marketable Securities	2,027,665
Amortized Cost	2,080,514	$ 2,248,181
Gross Unrealized Gains		10,911
Gross Unrealized Losses		(42,339)
Securities available for sale	2,027,665	2,216,753
Total debt securities
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	2,063,821
Gross Unrealized Gains	5,103
Gross Unrealized Losses	(57,952)
Estimated Fair Value	2,010,972
Amortized Cost		2,231,885
Gross Unrealized Gains		10,533
Gross Unrealized Losses		(42,339)
Securities available for sale		2,200,079
U.S. government corporations and agencies
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	11,254
Gross Unrealized Gains	3
Gross Unrealized Losses	(69)
Estimated Fair Value	11,188
Amortized Cost		5,358
Gross Unrealized Gains		8
Gross Unrealized Losses		(38)
Securities available for sale		5,328
Mortgage and asset-backed securities
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	1,691,092
Gross Unrealized Gains	3,968
Gross Unrealized Losses	(47,456)
Estimated Fair Value	1,647,604
Amortized Cost		1,785,467
Gross Unrealized Gains		5,856
Gross Unrealized Losses		(37,587)
Securities available for sale		1,753,736
Obligations of states and political subdivisions
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	361,475
Gross Unrealized Gains	1,132
Gross Unrealized Losses	(10,427)
Estimated Fair Value	$ 352,180
Amortized Cost		441,060
Gross Unrealized Gains		4,669
Gross Unrealized Losses		(4,714)
Securities available for sale		441,015
Equity securities
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost		16,296
Gross Unrealized Gains		378
Gross Unrealized Losses		0
Securities available for sale		$ 16,674

Securities (Held to maturity se

Securities (Held to maturity securities) (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	$ 249,766	$ 253,550
Gross Unrealized Gains	9,699	12,460
Gross Unrealized Losses	(827)	(516)
Estimated Fair Value	258,638	265,494
Obligations of states and political subdivisions
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	249,766	253,550
Gross Unrealized Gains	9,699	12,460
Gross Unrealized Losses	(827)	(516)
Estimated Fair Value	$ 258,638	$ 265,494

Securities (Narrative) (Details

Securities (Narrative) (Details) - USD ($)	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Investment [Line Items]
Fair value of securities pledged	$ 594,300,000		$ 670,300,000
Gross realized gains on available-for-sale securities	0	$ 0
FHLB	$ 14,300,000		$ 14,000,000
Mortgage-backed Securities, Issued by US Government Sponsored Enterprises
Investment [Line Items]
Percentage of mortgage and asset-backed securities issued by government-sponsored enterprises	77.00%

Securities (Securities availa38

Securities (Securities available for sale (debt maturities)) (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Amortized Cost
Due in 1 year or less	$ 5,397
Due in 1 to 5 years	56,369
Due in 5 to 10 years	116,517
Due after 10 years	194,446
Total debt securities	372,729
Mortgage and asset-backed securities	1,691,092
Equity securities	16,693
Amortized Cost	2,080,514	$ 2,248,181
Estimated Fair Value
Due in 1 year or less	5,392
Due in 1 to 5 years	56,209
Due in 5 to 10 years	112,484
Due after 10 years	189,283
Total debt securities	363,368
Mortgage and asset-backed securities	1,647,604
Equity securities	16,693
Estimated Fair Value	$ 2,027,665	$ 2,216,753

Securities (Securities held to

Securities (Securities held to maturity (debt maturities)) (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Amortized Cost
Due in 1 year or less	$ 2,486
Due in 1 to 5 years	27,627
Due in 5 to 10 years	104,170
Due after 10 years	115,483
Amortized Cost	249,766	$ 253,550
Estimated Fair Value
Due in 1 year or less	2,523
Due in 1 to 5 years	28,231
Due in 5 to 10 years	106,538
Due after 10 years	121,346
Estimated Fair Value	$ 258,638	$ 265,494

Securities (Gross realized gain

Securities (Gross realized gain (loss)) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Investments, Debt and Equity Securities [Abstract]
Proceeds from sales	$ 392,246	$ 221,637
Gross security gains	3,013	3,830
Gross security losses	$ 1,572	$ 1,339

Securities (Available for sale

Securities (Available for sale securities losses) (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Fair Value
Less than 12 months	$ 1,111,078	$ 948,929
12 months or longer	511,246	559,158
Total	1,622,324	1,508,087
Unrealized Losses
Less than 12 months	(21,984)	(12,238)
12 months or longer	(35,968)	(30,101)
Total	(57,952)	(42,339)
Total debt securities
Fair Value
Less than 12 months	1,111,078	948,929
12 months or longer	511,246	559,158
Total	1,622,324	1,508,087
Unrealized Losses
Less than 12 months	(21,984)	(12,238)
12 months or longer	(35,968)	(30,101)
Total	(57,952)	(42,339)
U.S. government corporations and agencies
Fair Value
Less than 12 months	10,685	4,819
12 months or longer	0	0
Total	10,685	4,819
Unrealized Losses
Less than 12 months	(69)	(38)
12 months or longer	0	0
Total	(69)	(38)
Mortgage and asset-backed securities
Fair Value
Less than 12 months	923,293	851,070
12 months or longer	379,672	399,978
Total	1,302,965	1,251,048
Unrealized Losses
Less than 12 months	(18,459)	(11,533)
12 months or longer	(28,997)	(26,054)
Total	(47,456)	(37,587)
Obligations of states and political subdivisions
Fair Value
Less than 12 months	177,100	93,040
12 months or longer	131,574	159,180
Total	308,674	252,220
Unrealized Losses
Less than 12 months	(3,456)	(667)
12 months or longer	(6,971)	(4,047)
Total	$ (10,427)	$ (4,714)

Securities (Held to maturity 42

Securities (Held to maturity securities losses) (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Fair Value
Less than 12 months	$ 30,496	$ 8,512
12 months or longer	7,907	8,989
Total	38,403	17,501
Unrealized Losses
Less than 12 months	(272)	(49)
12 months or longer	(555)	(467)
Total	(827)	(516)
Obligations of states and political subdivisions
Fair Value
Less than 12 months	30,496	8,512
12 months or longer	7,907	8,989
Total	38,403	17,501
Unrealized Losses
Less than 12 months	(272)	(49)
12 months or longer	(555)	(467)
Total	$ (827)	$ (516)

Loans (Loans receivable) (Detai

Loans (Loans receivable) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Dec. 31, 2017
Loans and Leases [Line Items]
Gross loans receivable held to maturity	$ 6,747,817	$ 6,393,226
Unearned discount	(1,620)	(556)
Deferred loan fees	(182)	(1,206)
Total net loans receivable held to maturity	6,746,015	6,391,464
Allowance for loan and lease losses	(58,656)	(55,686)
Loans receivable, net	6,687,359	6,335,778
Commercial
Loans and Leases [Line Items]
Gross loans receivable held to maturity	5,129,777	4,809,875
Commercial | Commercial
Loans and Leases [Line Items]
Gross loans receivable held to maturity	1,806,683	1,646,606
Commercial | Commercial real estate
Loans and Leases [Line Items]
Gross loans receivable held to maturity	3,323,094	3,163,269
Agricultural and agricultural real estate
Loans and Leases [Line Items]
Gross loans receivable held to maturity	518,386	511,588
Residential real estate
Loans and Leases [Line Items]
Gross loans receivable held to maturity	624,725	624,279
Consumer
Loans and Leases [Line Items]
Gross loans receivable held to maturity	$ 474,929	$ 447,484
Consumer | Loans and Finance Receivables | Citizens Finance Co
Loans and Leases [Line Items]
Concentration risk, percentage	15.00%

Loans (Allowance for credit los

Loans (Allowance for credit losses on financing receivables) (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017	Mar. 31, 2017	Dec. 31, 2016
Financing Receivable, Allowance for Credit Losses [Line Items]
Ending Balance Under ASC 310-10-35	$ 5,471	$ 4,755
Ending Balance Under ASC 450-20	53,185	50,931
Total	58,656	55,686	$ 54,999	$ 54,324
Ending Balance Evaluated for Impairment Under ASC 310-10-35	83,572	78,468
Ending Balance Evaluated for Impairment Under ASC 450-20	6,664,245	6,314,758
Total	6,747,817	6,393,226
Commercial
Financing Receivable, Allowance for Credit Losses [Line Items]
Total	5,129,777	4,809,875
Commercial | Commercial
Financing Receivable, Allowance for Credit Losses [Line Items]
Ending Balance Under ASC 310-10-35	2,425	1,613
Ending Balance Under ASC 450-20	16,970	16,485
Total	19,395	18,098	16,180	14,765
Ending Balance Evaluated for Impairment Under ASC 310-10-35	9,005	7,415
Ending Balance Evaluated for Impairment Under ASC 450-20	1,797,678	1,639,191
Total	1,806,683	1,646,606
Commercial | Commercial real estate
Financing Receivable, Allowance for Credit Losses [Line Items]
Ending Balance Under ASC 310-10-35	736	766
Ending Balance Under ASC 450-20	22,733	21,184
Total	23,469	21,950	23,797	24,319
Ending Balance Evaluated for Impairment Under ASC 310-10-35	22,920	23,705
Ending Balance Evaluated for Impairment Under ASC 450-20	3,300,174	3,139,564
Total	3,323,094	3,163,269
Agricultural and agricultural real estate
Financing Receivable, Allowance for Credit Losses [Line Items]
Ending Balance Under ASC 310-10-35	787	546
Ending Balance Under ASC 450-20	3,929	3,712
Total	4,716	4,258	3,983	4,210
Ending Balance Evaluated for Impairment Under ASC 310-10-35	16,896	13,304
Ending Balance Evaluated for Impairment Under ASC 450-20	501,490	498,284
Total	518,386	511,588
Residential real estate
Financing Receivable, Allowance for Credit Losses [Line Items]
Ending Balance Under ASC 310-10-35	386	430
Ending Balance Under ASC 450-20	1,755	1,794
Total	2,141	2,224	2,183	2,263
Ending Balance Evaluated for Impairment Under ASC 310-10-35	28,324	27,141
Ending Balance Evaluated for Impairment Under ASC 450-20	596,401	597,138
Total	624,725	624,279
Consumer
Financing Receivable, Allowance for Credit Losses [Line Items]
Ending Balance Under ASC 310-10-35	1,137	1,400
Ending Balance Under ASC 450-20	7,798	7,756
Total	8,935	9,156	$ 8,856	$ 8,767
Ending Balance Evaluated for Impairment Under ASC 310-10-35	6,427	6,903
Ending Balance Evaluated for Impairment Under ASC 450-20	468,502	440,581
Total	$ 474,929	$ 447,484

Loans (Financing receivables, n

Loans (Financing receivables, non accrual status) (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Receivables [Abstract]
Nonaccrual loans	$ 60,644	$ 58,272
Nonaccrual troubled debt restructured loans	4,162	4,309
Total nonaccrual loans	64,806	62,581
Accruing loans past due 90 days or more	22	830
Performing troubled debt restructured loans	$ 3,206	$ 6,617

Loans (Troubled debt restructur

Loans (Troubled debt restructuring) (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2018USD ($)loan	Mar. 31, 2017USD ($)loan
Financing Receivable, Modifications [Line Items]
Number of Loans | loan	5	3
Pre- Modification Recorded Investment	$ 877	$ 348
Post- Modification Recorded Investment	$ 752	$ 348
With Payment Defaults During the Following Periods
Number of Loans | loan	3	0
Recorded Investment	$ 519	$ 0
Commercial
Financing Receivable, Modifications [Line Items]
Number of Loans | loan	0	0
Pre- Modification Recorded Investment	$ 0	$ 0
Post- Modification Recorded Investment	$ 0	$ 0
With Payment Defaults During the Following Periods
Number of Loans | loan	0	0
Recorded Investment	$ 0	$ 0
Commercial | Commercial
Financing Receivable, Modifications [Line Items]
Number of Loans | loan	0	0
Pre- Modification Recorded Investment	$ 0	$ 0
Post- Modification Recorded Investment	$ 0	$ 0
With Payment Defaults During the Following Periods
Number of Loans | loan	0	0
Recorded Investment	$ 0	$ 0
Commercial | Commercial real estate
Financing Receivable, Modifications [Line Items]
Number of Loans | loan	0	0
Pre- Modification Recorded Investment	$ 0	$ 0
Post- Modification Recorded Investment	$ 0	$ 0
With Payment Defaults During the Following Periods
Number of Loans | loan	0	0
Recorded Investment	$ 0	$ 0
Agricultural and agricultural real estate
Financing Receivable, Modifications [Line Items]
Number of Loans | loan	0	0
Pre- Modification Recorded Investment	$ 0	$ 0
Post- Modification Recorded Investment	$ 0	$ 0
With Payment Defaults During the Following Periods
Number of Loans | loan	0	0
Recorded Investment	$ 0	$ 0
Residential real estate
Financing Receivable, Modifications [Line Items]
Number of Loans | loan	5	3
Pre- Modification Recorded Investment	$ 877	$ 348
Post- Modification Recorded Investment	$ 752	$ 348
With Payment Defaults During the Following Periods
Number of Loans | loan	3	0
Recorded Investment	$ 519	$ 0
Consumer
Financing Receivable, Modifications [Line Items]
Number of Loans | loan	0	0
Pre- Modification Recorded Investment	$ 0	$ 0
Post- Modification Recorded Investment	$ 0	$ 0
With Payment Defaults During the Following Periods
Number of Loans | loan	0	0
Recorded Investment	$ 0	$ 0

Loans (Troubled debt) (Narrativ

Loans (Troubled debt) (Narrative) (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2018USD ($)loan
Financing Receivable, Recorded Investment [Line Items]
Principal deferment collected from government guarantees	$ 142
Capitalized interest and escrow	$ 17
Doubtful
Financing Receivable, Recorded Investment [Line Items]
Number of loan relationships | loan	0

Loans (Loans by credit quality

Loans (Loans by credit quality indicator) (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Financing Receivable, Recorded Investment [Line Items]
Total gross loans receivable held to maturity	$ 6,747,817	$ 6,393,226
Loans delinquent 30 to 89 days, percentage	0.21%	0.27%
Loans secured by residential real estate property in process of foreclosure	$ 2,800
Pass
Financing Receivable, Recorded Investment [Line Items]
Total gross loans receivable held to maturity	6,314,116	$ 6,009,382
Nonpass
Financing Receivable, Recorded Investment [Line Items]
Total gross loans receivable held to maturity	$ 433,701	$ 383,844
Percent of nonaccrual loans	15.00%	16.00%
Special Mention
Financing Receivable, Recorded Investment [Line Items]
Percent of loans	55.00%	52.00%
Substandard
Financing Receivable, Recorded Investment [Line Items]
Percent of loans	45.00%	48.00%
Commercial
Financing Receivable, Recorded Investment [Line Items]
Total gross loans receivable held to maturity	$ 5,129,777	$ 4,809,875
Commercial | Pass
Financing Receivable, Recorded Investment [Line Items]
Total gross loans receivable held to maturity	4,823,960	4,538,284
Commercial | Nonpass
Financing Receivable, Recorded Investment [Line Items]
Total gross loans receivable held to maturity	305,817	271,591
Commercial | Commercial
Financing Receivable, Recorded Investment [Line Items]
Total gross loans receivable held to maturity	1,806,683	1,646,606
Commercial | Commercial | Pass
Financing Receivable, Recorded Investment [Line Items]
Total gross loans receivable held to maturity	1,677,338	1,552,783
Commercial | Commercial | Nonpass
Financing Receivable, Recorded Investment [Line Items]
Total gross loans receivable held to maturity	129,345	93,823
Commercial | Commercial real estate
Financing Receivable, Recorded Investment [Line Items]
Total gross loans receivable held to maturity	3,323,094	3,163,269
Commercial | Commercial real estate | Pass
Financing Receivable, Recorded Investment [Line Items]
Total gross loans receivable held to maturity	3,146,622	2,985,501
Commercial | Commercial real estate | Nonpass
Financing Receivable, Recorded Investment [Line Items]
Total gross loans receivable held to maturity	176,472	177,768
Agricultural and agricultural real estate
Financing Receivable, Recorded Investment [Line Items]
Total gross loans receivable held to maturity	518,386	511,588
Agricultural and agricultural real estate | Pass
Financing Receivable, Recorded Investment [Line Items]
Total gross loans receivable held to maturity	442,484	451,539
Agricultural and agricultural real estate | Nonpass
Financing Receivable, Recorded Investment [Line Items]
Total gross loans receivable held to maturity	75,902	60,049
Residential real estate
Financing Receivable, Recorded Investment [Line Items]
Total gross loans receivable held to maturity	624,725	624,279
Residential real estate | Pass
Financing Receivable, Recorded Investment [Line Items]
Total gross loans receivable held to maturity	585,886	586,623
Residential real estate | Nonpass
Financing Receivable, Recorded Investment [Line Items]
Total gross loans receivable held to maturity	38,839	37,656
Consumer
Financing Receivable, Recorded Investment [Line Items]
Total gross loans receivable held to maturity	474,929	447,484
Consumer | Pass
Financing Receivable, Recorded Investment [Line Items]
Total gross loans receivable held to maturity	461,786	432,936
Consumer | Nonpass
Financing Receivable, Recorded Investment [Line Items]
Total gross loans receivable held to maturity	$ 13,143	$ 14,548

Loans (Past due financing recei

Loans (Past due financing receivables) (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Financing Receivable, Recorded Investment, Past Due [Line Items]
Accruing Loans and Leases, Past Due	$ 14,222	$ 18,137
Accruing Loans and Leases, Current	6,668,789	6,312,508
Nonaccrual	64,806	62,581
Total	6,747,817	6,393,226
30-59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Accruing Loans and Leases, Past Due	9,965	13,375
60-89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Accruing Loans and Leases, Past Due	4,235	3,932
90 Days or More Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Accruing Loans and Leases, Past Due	22	830
Commercial
Financing Receivable, Recorded Investment, Past Due [Line Items]
Accruing Loans and Leases, Past Due	5,932	8,700
Accruing Loans and Leases, Current	5,098,608	4,777,349
Nonaccrual	25,237	23,826
Total	5,129,777	4,809,875
Commercial | 30-59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Accruing Loans and Leases, Past Due	3,309	6,015
Commercial | 60-89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Accruing Loans and Leases, Past Due	2,623	2,585
Commercial | 90 Days or More Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Accruing Loans and Leases, Past Due	0	100
Commercial | Commercial
Financing Receivable, Recorded Investment, Past Due [Line Items]
Accruing Loans and Leases, Past Due	4,789	1,605
Accruing Loans and Leases, Current	1,793,565	1,637,773
Nonaccrual	8,329	7,228
Total	1,806,683	1,646,606
Commercial | Commercial | 30-59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Accruing Loans and Leases, Past Due	2,906	1,246
Commercial | Commercial | 60-89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Accruing Loans and Leases, Past Due	1,883	259
Commercial | Commercial | 90 Days or More Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Accruing Loans and Leases, Past Due	0	100
Commercial | Commercial real estate
Financing Receivable, Recorded Investment, Past Due [Line Items]
Accruing Loans and Leases, Past Due	1,143	7,095
Accruing Loans and Leases, Current	3,305,043	3,139,576
Nonaccrual	16,908	16,598
Total	3,323,094	3,163,269
Commercial | Commercial real estate | 30-59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Accruing Loans and Leases, Past Due	403	4,769
Commercial | Commercial real estate | 60-89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Accruing Loans and Leases, Past Due	740	2,326
Commercial | Commercial real estate | 90 Days or More Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Accruing Loans and Leases, Past Due	0	0
Agricultural and agricultural real estate
Financing Receivable, Recorded Investment, Past Due [Line Items]
Accruing Loans and Leases, Past Due	1,238	738
Accruing Loans and Leases, Current	500,320	497,546
Nonaccrual	16,828	13,304
Total	518,386	511,588
Agricultural and agricultural real estate | 30-59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Accruing Loans and Leases, Past Due	1,147	604
Agricultural and agricultural real estate | 60-89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Accruing Loans and Leases, Past Due	69	134
Agricultural and agricultural real estate | 90 Days or More Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Accruing Loans and Leases, Past Due	22	0
Residential real estate
Financing Receivable, Recorded Investment, Past Due [Line Items]
Accruing Loans and Leases, Past Due	2,957	2,292
Accruing Loans and Leases, Current	602,927	601,120
Nonaccrual	18,841	20,867
Total	624,725	624,279
Residential real estate | 30-59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Accruing Loans and Leases, Past Due	2,891	2,022
Residential real estate | 60-89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Accruing Loans and Leases, Past Due	66	270
Residential real estate | 90 Days or More Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Accruing Loans and Leases, Past Due	0	0
Consumer
Financing Receivable, Recorded Investment, Past Due [Line Items]
Accruing Loans and Leases, Past Due	4,095	6,407
Accruing Loans and Leases, Current	466,934	436,493
Nonaccrual	3,900	4,584
Total	474,929	447,484
Consumer | 30-59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Accruing Loans and Leases, Past Due	2,618	4,734
Consumer | 60-89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Accruing Loans and Leases, Past Due	1,477	943
Consumer | 90 Days or More Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Accruing Loans and Leases, Past Due	$ 0	$ 730

Loans (Impaired loans) (Details

Loans (Impaired loans) (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2018	Dec. 31, 2017
Unpaid Contractual Balance
Total impaired loans with a related allowance	$ 20,084	$ 19,958
Total impaired loans without a related allowance	69,290	64,121
Total impaired loans held to maturity	89,374	84,079
Loan Balance
Total impaired loans with a related allowance	18,228	18,101
Total impaired loans without a related allowance	65,344	60,367
Total impaired loans held to maturity	83,572	78,468
Related Allowance Recorded	5,471	4,755
Year- to- Date Avg. Loan Balance
Total impaired loans with a related allowance	18,206	22,949
Total impaired loans without a related allowance	63,072	62,296
Total impaired loans held to maturity	81,278	85,245
Year- to- Date Interest Income Recognized
Total impaired loans with a related allowance	20	129
Total impaired loans without a related allowance	278	1,029
Total impaired loans held to maturity	298	1,158
Commercial
Unpaid Contractual Balance
Total impaired loans with a related allowance	13,996	14,217
Total impaired loans without a related allowance	21,510	20,486
Total impaired loans held to maturity	35,506	34,703
Loan Balance
Total impaired loans with a related allowance	12,140	12,360
Total impaired loans without a related allowance	19,785	18,760
Total impaired loans held to maturity	31,925	31,120
Related Allowance Recorded	3,161	2,379
Year- to- Date Avg. Loan Balance
Total impaired loans with a related allowance	11,992	15,086
Total impaired loans without a related allowance	19,328	22,734
Total impaired loans held to maturity	31,320	37,820
Year- to- Date Interest Income Recognized
Total impaired loans with a related allowance	8	73
Total impaired loans without a related allowance	146	679
Total impaired loans held to maturity	154	752
Commercial | Commercial
Unpaid Contractual Balance
Total impaired loans with a related allowance	2,816	2,292
Total impaired loans without a related allowance	7,308	6,243
Total impaired loans held to maturity	10,124	8,535
Loan Balance
Total impaired loans with a related allowance	2,816	2,292
Total impaired loans without a related allowance	6,189	5,123
Total impaired loans held to maturity	9,005	7,415
Related Allowance Recorded	2,425	1,613
Year- to- Date Avg. Loan Balance
Total impaired loans with a related allowance	2,472	3,607
Total impaired loans without a related allowance	5,449	2,586
Total impaired loans held to maturity	7,921	6,193
Year- to- Date Interest Income Recognized
Total impaired loans with a related allowance	0	39
Total impaired loans without a related allowance	49	165
Total impaired loans held to maturity	49	204
Commercial | Commercial real estate
Unpaid Contractual Balance
Total impaired loans with a related allowance	11,180	11,925
Total impaired loans without a related allowance	14,202	14,243
Total impaired loans held to maturity	25,382	26,168
Loan Balance
Total impaired loans with a related allowance	9,324	10,068
Total impaired loans without a related allowance	13,596	13,637
Total impaired loans held to maturity	22,920	23,705
Related Allowance Recorded	736	766
Year- to- Date Avg. Loan Balance
Total impaired loans with a related allowance	9,520	11,479
Total impaired loans without a related allowance	13,879	20,148
Total impaired loans held to maturity	23,399	31,627
Year- to- Date Interest Income Recognized
Total impaired loans with a related allowance	8	34
Total impaired loans without a related allowance	97	514
Total impaired loans held to maturity	105	548
Agricultural and agricultural real estate
Unpaid Contractual Balance
Total impaired loans with a related allowance	1,536	1,539
Total impaired loans without a related allowance	17,388	13,793
Total impaired loans held to maturity	18,924	15,332
Loan Balance
Total impaired loans with a related allowance	1,536	1,539
Total impaired loans without a related allowance	15,360	11,765
Total impaired loans held to maturity	16,896	13,304
Related Allowance Recorded	787	546
Year- to- Date Avg. Loan Balance
Total impaired loans with a related allowance	1,537	3,437
Total impaired loans without a related allowance	12,954	9,654
Total impaired loans held to maturity	14,491	13,091
Year- to- Date Interest Income Recognized
Total impaired loans with a related allowance	0	0
Total impaired loans without a related allowance	1	0
Total impaired loans held to maturity	1	0
Residential real estate
Unpaid Contractual Balance
Total impaired loans with a related allowance	1,693	1,568
Total impaired loans without a related allowance	26,635	25,573
Total impaired loans held to maturity	28,328	27,141
Loan Balance
Total impaired loans with a related allowance	1,693	1,568
Total impaired loans without a related allowance	26,631	25,573
Total impaired loans held to maturity	28,324	27,141
Related Allowance Recorded	386	430
Year- to- Date Avg. Loan Balance
Total impaired loans with a related allowance	1,608	2,056
Total impaired loans without a related allowance	26,878	26,024
Total impaired loans held to maturity	28,486	28,080
Year- to- Date Interest Income Recognized
Total impaired loans with a related allowance	3	15
Total impaired loans without a related allowance	109	277
Total impaired loans held to maturity	112	292
Consumer
Unpaid Contractual Balance
Total impaired loans with a related allowance	2,859	2,634
Total impaired loans without a related allowance	3,757	4,269
Total impaired loans held to maturity	6,616	6,903
Loan Balance
Total impaired loans with a related allowance	2,859	2,634
Total impaired loans without a related allowance	3,568	4,269
Total impaired loans held to maturity	6,427	6,903
Related Allowance Recorded	1,137	1,400
Year- to- Date Avg. Loan Balance
Total impaired loans with a related allowance	3,069	2,370
Total impaired loans without a related allowance	3,912	3,884
Total impaired loans held to maturity	6,981	6,254
Year- to- Date Interest Income Recognized
Total impaired loans with a related allowance	9	41
Total impaired loans without a related allowance	22	73
Total impaired loans held to maturity	$ 31	$ 114

Loans (Carrying amount of loans

Loans (Carrying amount of loans acquired) (Narrative) (Details) - USD ($) $ in Millions	Feb. 23, 2018	Jul. 07, 2017	Feb. 28, 2017
Signature Bancshares, Inc.
Business Acquisition [Line Items]
Loans held to maturity	$ 324.5
Estimated fair value of loans acquired	335.1
Citywide Banks
Business Acquisition [Line Items]
Loans held to maturity		$ 985.4
Estimated fair value of loans acquired		$ 1,000
Founders Bancorp
Business Acquisition [Line Items]
Loans held to maturity			$ 96.4
Estimated fair value of loans acquired			$ 98.9
Commercial | Signature Bancshares, Inc.
Business Acquisition [Line Items]
Loans held to maturity	$ 16

Loans (Carrying amount of loa52

Loans (Carrying amount of loans acquired) (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2018	Dec. 31, 2017
Loans covered by loss share agreement (carrying amount) [Line Items]
Purchased loans	$ 1,606,305	$ 1,470,025
Commercial | Commercial
Loans covered by loss share agreement (carrying amount) [Line Items]
Purchased loans	265,249	188,327
Commercial | Commercial real estate
Loans covered by loss share agreement (carrying amount) [Line Items]
Purchased loans	1,081,198	1,055,041
Agricultural and agricultural real estate
Loans covered by loss share agreement (carrying amount) [Line Items]
Purchased loans	26	1,242
Residential real estate
Loans covered by loss share agreement (carrying amount) [Line Items]
Purchased loans	181,219	174,123
Consumer
Loans covered by loss share agreement (carrying amount) [Line Items]
Purchased loans	78,613	51,292
Impaired Purchased Loans
Loans covered by loss share agreement (carrying amount) [Line Items]
Purchased loans	5,815	3,738
Impaired Purchased Loans | Commercial | Commercial
Loans covered by loss share agreement (carrying amount) [Line Items]
Purchased loans	3,142	952
Impaired Purchased Loans | Commercial | Commercial real estate
Loans covered by loss share agreement (carrying amount) [Line Items]
Purchased loans	2,474	2,572
Impaired Purchased Loans | Agricultural and agricultural real estate
Loans covered by loss share agreement (carrying amount) [Line Items]
Purchased loans	0	0
Impaired Purchased Loans | Residential real estate
Loans covered by loss share agreement (carrying amount) [Line Items]
Purchased loans	199	214
Impaired Purchased Loans | Consumer
Loans covered by loss share agreement (carrying amount) [Line Items]
Purchased loans	0	0
Non Impaired Purchased Loans
Loans covered by loss share agreement (carrying amount) [Line Items]
Purchased loans	1,600,490	1,466,287
Non Impaired Purchased Loans | Commercial | Commercial
Loans covered by loss share agreement (carrying amount) [Line Items]
Purchased loans	262,107	187,375
Non Impaired Purchased Loans | Commercial | Commercial real estate
Loans covered by loss share agreement (carrying amount) [Line Items]
Purchased loans	1,078,724	1,052,469
Non Impaired Purchased Loans | Agricultural and agricultural real estate
Loans covered by loss share agreement (carrying amount) [Line Items]
Purchased loans	26	1,242
Non Impaired Purchased Loans | Residential real estate
Loans covered by loss share agreement (carrying amount) [Line Items]
Purchased loans	181,020	173,909
Non Impaired Purchased Loans | Consumer
Loans covered by loss share agreement (carrying amount) [Line Items]
Purchased loans	$ 78,613	$ 51,292

Loans (Change in accretable yie

Loans (Change in accretable yield on acquired loans) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Accretable Yield Movement Schedule [Roll Forward]
Balance at beginning of period	$ 57	$ 182
Original yield premium, net, at date of acquisition	(56)	0
Accretion	(199)	(173)
Reclassification from nonaccretable difference	198	127
Balance at end of period	$ 0	$ 136

Loans (Change in accretable y54

Loans (Change in accretable yield on acquired loans) (Narrative) (Details) - USD ($)	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for loan and lease losses	$ 58,656,000		$ 55,686,000
Provision for loan losses	4,263,000	$ 3,641,000
2015, 2016 and 2017 Acquisitions
Accounts, Notes, Loans and Financing Receivable [Line Items]
Contractually required payments of loans acquired	26,000,000
Estimated fair value of loans acquired	15,000,000
Allowance for loan and lease losses	0		$ 139,000
Provision for loan losses	0	$ 1,000
Non Impaired Purchased Loans | Two Thousand Fifteen Acquisitions [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Contractually required payments of loans acquired	2,990,000,000
Estimated fair value of loans acquired	$ 2,910,000,000

Allowance for Loan Losses (Deta

Allowance for Loan Losses (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Beginning Balance	$ 55,686	$ 54,324
Charge-offs	(2,224)	(3,718)
Recoveries	931	752
Provision	4,263	3,641
Ending Balance	58,656	54,999
Agricultural and agricultural real estate
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Beginning Balance	4,258	4,210
Charge-offs	0	(871)
Recoveries	14	1
Provision	444	643
Ending Balance	4,716	3,983
Residential real estate
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Beginning Balance	2,224	2,263
Charge-offs	(16)	(265)
Recoveries	75	2
Provision	(142)	183
Ending Balance	2,141	2,183
Consumer
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Beginning Balance	9,156	8,767
Charge-offs	(1,289)	(1,744)
Recoveries	290	303
Provision	778	1,530
Ending Balance	8,935	8,856
Commercial | Commercial
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Beginning Balance	18,098	14,765
Charge-offs	(794)	(230)
Recoveries	104	234
Provision	1,987	1,411
Ending Balance	19,395	16,180
Commercial real estate | Commercial
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Beginning Balance	21,950	24,319
Charge-offs	(125)	(608)
Recoveries	448	212
Provision	1,196	(126)
Ending Balance	$ 23,469	$ 23,797

Goodwill, Core Deposit Premiu56

Goodwill, Core Deposit Premium and Other Intangible Assets (Goodwill) (Narrative) (Details) - USD ($)	Sep. 30, 2017	Mar. 31, 2018	Feb. 23, 2018	Dec. 31, 2017	Jul. 07, 2017	Feb. 28, 2017
Goodwill [Line Items]
Goodwill		$ 270,305,000		$ 236,615,000
Goodwill impairment	$ 0
Core Deposits
Goodwill [Line Items]
Intangibles, amortization period		10 years
Signature Bancshares, Inc.
Goodwill [Line Items]
Goodwill			$ 33,700,000
Signature Bancshares, Inc. | Core Deposits
Goodwill [Line Items]
Intangibles recognized			$ 7,700,000
Citywide Banks
Goodwill [Line Items]
Goodwill					$ 95,200,000
Citywide Banks | Core Deposits
Goodwill [Line Items]
Intangibles recognized					$ 16,000,000
Founders Bancorp
Goodwill [Line Items]
Goodwill						$ 13,800,000
Founders Bancorp | Core Deposits
Goodwill [Line Items]
Intangibles recognized						$ 2,500,000

Goodwill, Core Deposit Premiu57

Goodwill, Core Deposit Premium and Other Intangible Assets (Carrying amount of intangible assets (incl accumulated amortization) (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 119,897	$ 112,043
Accumulated Amortization	53,363	50,983
Net Carrying Amount	66,534	61,060
Core deposit intangibles
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	69,731	62,008
Accumulated Amortization	28,939	27,086
Net Carrying Amount	40,792	34,922
Customer relationship intangibles
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	1,177	1,177
Accumulated Amortization	906	896
Net Carrying Amount	271	281
Mortgage servicing rights
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	42,249	42,139
Accumulated Amortization	19,084	18,891
Net Carrying Amount	23,165	23,248
Commercial servicing rights
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	6,740	6,719
Accumulated Amortization	4,434	4,110
Net Carrying Amount	$ 2,306	$ 2,609

Goodwill, Core Deposit Premiu58

Goodwill, Core Deposit Premium and Other Intangible Assets (Estimated future amortization expense for amortizable intangible assets) (Details) $ in Thousands	Mar. 31, 2018USD ($)
Future amortization expense for amortizable intangible assets [Line Items]
Nine months ending December 31, 2018	$ 13,233
Year ending December 31,
2,019	11,749
2,020	10,180
2,021	8,640
2,022	6,840
2,023	5,643
Thereafter	10,249
Total	66,534
Core deposit intangibles
Future amortization expense for amortizable intangible assets [Line Items]
Nine months ending December 31, 2018	5,957
Year ending December 31,
2,019	7,092
2,020	6,220
2,021	5,323
2,022	4,175
2,023	3,691
Thereafter	8,334
Total	40,792
Customer relationship intangibles
Future amortization expense for amortizable intangible assets [Line Items]
Nine months ending December 31, 2018	29
Year ending December 31,
2,019	38
2,020	37
2,021	36
2,022	34
2,023	33
Thereafter	64
Total	271
Mortgage servicing rights
Future amortization expense for amortizable intangible assets [Line Items]
Nine months ending December 31, 2018	6,776
Year ending December 31,
2,019	4,097
2,020	3,512
2,021	2,927
2,022	2,341
2,023	1,756
Thereafter	1,756
Total	23,165
Commercial servicing rights
Future amortization expense for amortizable intangible assets [Line Items]
Nine months ending December 31, 2018	471
Year ending December 31,
2,019	522
2,020	411
2,021	354
2,022	290
2,023	163
Thereafter	95
Total	$ 2,306

Goodwill, Core Deposit Premiu59

Goodwill, Core Deposit Premium and Other Intangible Assets (Mortgage and commercial loans servicing) (Narrative) (Details) - USD ($)	3 Months Ended			12 Months Ended
	Mar. 31, 2018	Sep. 30, 2017	Mar. 31, 2017	Dec. 31, 2017
Valuation servicing rights in tranches [Line Items]
Mortgage loans serviced for others	$ 3,540,000,000			$ 3,560,000,000
Custodial escrow balances maintained	23,200,000			17,300,000
Total net loans receivable held to maturity		$ 773,900,000
Amount derecognized	6,900,000
Loans serviced	25,471,000			25,857,000
Mortgage Servicing Rights
Valuation servicing rights in tranches [Line Items]
Servicing asset at amortized value	$ 40,434,000		$ 47,564,000	$ 37,100,000
Prepayment rate (percent)	8.23%			9.73%
Discount rate (percent)	9.04%			9.06%
Fees collected for servicing of mortgage loans	$ 2,200,000		$ 3,200,000
Mortgage Servicing Rights | Minimum
Valuation servicing rights in tranches [Line Items]
Average cap rate (percent)	0.96%		0.91%
Mortgage Servicing Rights | Maximum
Valuation servicing rights in tranches [Line Items]
Average cap rate (percent)	1.25%		1.50%
Mortgage Servicing Rights 15-year Tranche
Valuation servicing rights in tranches [Line Items]
Servicing asset, agreement term	15 years
Mortgage Servicing Rights 30-year Tranche
Valuation servicing rights in tranches [Line Items]
Servicing asset, agreement term	30 years
Commercial Servicing Rights
Valuation servicing rights in tranches [Line Items]
Servicing asset at amortized value	$ 2,781,000		$ 4,040,000	$ 3,200,000
Loans serviced	$ 125,500,000			$ 139,900,000
Commercial Servicing Rights | Minimum
Valuation servicing rights in tranches [Line Items]
Prepayment rate (percent)	8.27%			7.27%
Discount rate (percent)	13.09%			13.04%
Average cap rate (percent)	3.10%		3.10%
Commercial Servicing Rights | Maximum
Valuation servicing rights in tranches [Line Items]
Prepayment rate (percent)	9.89%			8.88%
Discount rate (percent)	16.71%			15.49%
Average cap rate (percent)	4.45%		4.45%
Commercial Servicing Rights Less Than 20 Years
Valuation servicing rights in tranches [Line Items]
Servicing asset at amortized value	$ 648,000			$ 740,000
Servicing asset, agreement term	20 years
Fees collected for servicing of mortgage loans	$ 420,000		$ 415,000
Valuation allowance	0			0
Commercial Servicing Rights More Than 20 Years
Valuation servicing rights in tranches [Line Items]
Servicing asset at amortized value	$ 2,133,000			2,481,000
Servicing asset, agreement term	20 years
Valuation allowance	$ 14,000			$ 12,000

Goodwill, Core Deposit Premiu60

Goodwill, Core Deposit Premium and Other Intangible Assets (Changes in capitalized mortgage and commercial servicing rights) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Servicing Asset at Fair Value, Amount [Roll Forward]
Valuation allowance on commercial servicing rights	$ (2)	$ 5
Mortgage Servicing Rights
Servicing Asset at Fair Value, Amount [Roll Forward]
Balance at beginning of period	23,248	32,088
Originations	1,162	2,132
Amortization	(1,245)	(2,261)
Balance at end of period	23,165	31,959
Fair value of mortgage servicing rights	$ 40,434	$ 47,564	$ 37,100
Mortgage servicing rights, net to servicing portfolio (percent)	0.66%	0.74%
Commercial servicing rights
Servicing Asset at Fair Value, Amount [Roll Forward]
Balance at beginning of period	$ 2,609	$ 3,690
Originations	21	93
Amortization	(322)	(306)
Valuation allowance on commercial servicing rights	(2)	5
Balance at end of period	2,306	3,482
Fair value of mortgage servicing rights	$ 2,781	$ 4,040	$ 3,200
Mortgage servicing rights, net to servicing portfolio (percent)	1.84%	2.17%

Goodwill, Core Deposit Premiu61

Goodwill, Core Deposit Premium and Other Intangible Assets (Book value, fair value of commercial serving rights and impairment) (Details) - USD ($)	3 Months Ended	12 Months Ended
	Mar. 31, 2018	Dec. 31, 2017
Less than 20 Years
Finite-Lived Intangible Assets [Line Items]
Book Value	$ 446,000	$ 537,000
Fair Value	648,000	740,000
Impairment	0	0
More than 20 Years
Finite-Lived Intangible Assets [Line Items]
Book Value	1,873,000	2,084,000
Fair Value	2,133,000	2,481,000
Impairment	14,000	12,000
Citywide Banks | Less than 20 Years
Finite-Lived Intangible Assets [Line Items]
Book Value	6,000	8,000
Fair Value	10,000	11,000
Impairment	0	0
Citywide Banks | More than 20 Years
Finite-Lived Intangible Assets [Line Items]
Book Value	33,000	34,000
Fair Value	36,000	37,000
Impairment	0	0
Premier Valley Bank | Less than 20 Years
Finite-Lived Intangible Assets [Line Items]
Book Value	72,000	83,000
Fair Value	104,000	110,000
Impairment	0	0
Premier Valley Bank | More than 20 Years
Finite-Lived Intangible Assets [Line Items]
Book Value	286,000	303,000
Fair Value	272,000	291,000
Impairment	14,000	12,000
Wisconsin Bank & Trust | Less than 20 Years
Finite-Lived Intangible Assets [Line Items]
Book Value	368,000	446,000
Fair Value	534,000	619,000
Impairment	0	0
Wisconsin Bank & Trust | More than 20 Years
Finite-Lived Intangible Assets [Line Items]
Book Value	1,554,000	1,747,000
Fair Value	1,825,000	2,153,000
Impairment	$ 0	$ 0

Derivative Financial Instrume62

Derivative Financial Instruments (Cash collateral on derivative financial instruments) (Narrative) (Details) - USD ($)	Mar. 31, 2018	Dec. 31, 2017
Derivative [Line Items]
Cash pledged as collateral	$ 0	$ 1,200,000
Counterparties
Derivative [Line Items]
Cash pledged as collateral	$ 860,000	$ 0

Derivative Financial Instrume63

Derivative Financial Instruments (Cash flow hedges) (Narrative) (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2018USD ($)transaction
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Change in net unrealized losses on cash flow hedges	$ 197
Estimated amount to be reclassified from accumulated other comprehensive income to interest expense within the next twelve months	$ 789
Interest Rate Swap | Cash Flow Hedges
Derivative [Line Items]
Number of swap transactions | transaction	5
Derivative, notional amount	$ 85,000
Interest Rate Swap | Cash Flow Hedges | Heartland Financial Statutory Trust IV, V and VII
Derivative [Line Items]
Derivative, notional amount	65,000
Interest Rate Swap | Cash Flow Hedges | Morrill Statutory Trust I and II
Derivative [Line Items]
Derivative, notional amount	$ 20,000

Derivative Financial Instrume64

Derivative Financial Instruments (Cash flow hedges) (Balance sheet category and fair values) (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Other assets | Interest Rate Swap due March 17, 2021
Derivatives, Fair Value [Line Items]
Notional Amount, Other Assets	$ 25,000
Fair Value, Other Assets	$ 239
Receive Rate	2.178%
Weighted Average Pay Rate	2.255%
Other assets | Interest Rate Swap due March 26, 2019
Derivatives, Fair Value [Line Items]
Notional Amount, Other Assets	$ 10,000	$ 10,000
Fair Value, Other Assets	$ 69	$ 30
Receive Rate	2.286%	1.329%
Weighted Average Pay Rate	1.674%	1.674%
Other assets | Interest Rate Swap due March 18, 2019
Derivatives, Fair Value [Line Items]
Notional Amount, Other Assets	$ 10,000	$ 10,000
Fair Value, Other Assets	$ 68	$ 29
Receive Rate	2.178%	1.60%
Weighted Average Pay Rate	1.658%	1.658%
Other assets | Interest Rate Swap due May 10, 2021
Derivatives, Fair Value [Line Items]
Notional Amount, Other Assets	$ 32,667	$ 33,667
Fair Value, Other Assets	$ 1,010	$ 759
Receive Rate	4.24%	3.932%
Weighted Average Pay Rate	3.674%	3.674%
Other assets | Interest Rate Swap due June 15, 2024
Derivatives, Fair Value [Line Items]
Notional Amount, Other Assets	$ 20,000
Fair Value, Other Assets	$ 316
Receive Rate	2.125%
Weighted Average Pay Rate	2.39%
Other assets | Interest Rate Swap due March 1, 2024
Derivatives, Fair Value [Line Items]
Notional Amount, Other Assets	$ 20,000
Fair Value, Other Assets	$ 339
Receive Rate	2.006%
Weighted Average Pay Rate	2.352%
Other liabilities | Interest Rate Swap due March 17, 2021
Derivatives, Fair Value [Line Items]
Notional Amount, Other Liabilities		$ 25,000
Fair Value, Other Liabilities		$ (106)
Receive Rate		1.60%
Weighted Average Pay Rate		2.255%
Other liabilities | Interest Rate Swap due January 7, 2020
Derivatives, Fair Value [Line Items]
Notional Amount, Other Liabilities	$ 20,000	$ 20,000
Fair Value, Other Liabilities	$ (380)	$ (621)
Receive Rate	1.704%	1.35%
Weighted Average Pay Rate	3.355%	3.355%
Other liabilities | Interest Rate Swap due June 15, 2024
Derivatives, Fair Value [Line Items]
Notional Amount, Other Liabilities		$ 20,000
Fair Value, Other Liabilities		$ (177)
Receive Rate		1.588%
Weighted Average Pay Rate		2.39%
Other liabilities | Interest Rate Swap due March 1, 2024
Derivatives, Fair Value [Line Items]
Notional Amount, Other Liabilities		$ 20,000
Fair Value, Other Liabilities		$ (149)
Receive Rate		1.481%
Weighted Average Pay Rate		2.352%

Derivative Financial Instrume65

Derivative Financial Instruments (Cash flow hedges) (Gains (losses) recognized) (Details) - Interest rate swaps - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Trading Activity, Gains and Losses, Net [Line Items]
Effective Portion, Recognized in OCI, Amount of Gain (Loss)	$ 1,896	$ 533
Interest expense
Trading Activity, Gains and Losses, Net [Line Items]
Effective Portion, Reclassified from AOCI into Income, Amount of Gain (Loss)	(197)	(397)
Other income
Trading Activity, Gains and Losses, Net [Line Items]
Ineffective Portion, Recognized in Income on Derivatives, Amount of Gain (Loss)	$ 0	$ 0

Derivative Financial Instrume66

Derivative Financial Instruments (Fair value hedges) (Narrative) (Details) - USD ($)	Mar. 31, 2018	Dec. 31, 2017
Derivative [Line Items]
Cash pledged as collateral	$ 0	$ 1,200,000
Fair Value Hedging | Interest Rate Swap
Derivative [Line Items]
Cash pledged as collateral	$ 3,200,000	$ 3,900,000

Derivative Financial Instrume67

Derivative Financial Instruments (Fair value hedges) (Balance sheet category and fair values) (Details) - Other liabilities - USD ($)	Mar. 31, 2018	Dec. 31, 2017	Feb. 05, 2016
Derivative [Line Items]
Notional Amount			$ 2,000,000
Fair value hedges
Derivative [Line Items]
Notional Amount	$ 35,436,000	$ 35,635,000
Fair Value	$ (105,000)	$ (999,000)

Derivative Financial Instrume68

Derivative Financial Instruments (Fair value hedges) (Gains (losses) recognized) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Fair value hedges | Interest income
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain (Loss)	$ 894	$ 194

Derivative Financial Instrume69

Derivative Financial Instruments (Embedded derivatives) (Balance sheet category and fair values) (Details) - Embedded derivatives - Other assets - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Derivative [Line Items]
Notional Amount	$ 13,907	$ 14,045
Fair Value	$ 461	$ 738

Derivative Financial Instrume70

Derivative Financial Instruments (Embedded derivatives) (Gain (losses) recognized) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Other noninterest income | Embedded derivatives
Derivative [Line Items]
Amount of Gain (Loss)	$ 277	$ 117

Derivative Financial Instrume71

Derivative Financial Instruments (Embedded derivatives) (Narrative) (Details)	Feb. 05, 2016USD ($)shares	Mar. 31, 2018shares	Dec. 31, 2017shares
Derivative [Line Items]
Number of shares to be issued upon conversion (in shares)	73,394	0	0
Number of shares issued upon conversion (in shares)			20,481
Other liabilities
Derivative [Line Items]
Derivative, notional amount | $	$ 2,000,000

Derivative Financial Instrume72

Derivative Financial Instruments (Embedded derivatives) (Embedded conversion options) (Balance sheet category and fair values) (Details) - Other liabilities - USD ($)	Mar. 31, 2018	Dec. 31, 2017	Feb. 05, 2016
Derivative [Line Items]
Notional Amount			$ 2,000,000
Embedded conversion option
Derivative [Line Items]
Notional Amount	$ 0	$ 0
Fair Value	$ 0	$ 0

Derivative Financial Instrume73

Derivative Financial Instruments (Embedded derivatives) (Embedded conversion options) (Gain (losses) recognized) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Other noninterest income | Embedded conversion option
Derivative [Line Items]
Amount of Gain (Loss)	$ 0	$ 97

Derivative Financial Instrume74

Derivative Financial Instruments (Back-to-back loan swaps) (Narrative) (Details) - USD ($)	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Derivative [Line Items]
Cash pledged as collateral	$ 0		$ 1,200,000
Counterparties
Derivative [Line Items]
Cash pledged as collateral	860,000		0
Back-to-Back Loan Swaps | Interest Rate Swap
Derivative [Line Items]
Cash pledged as collateral	495,000		1,600,000
Back-to-Back Loan Swaps | Interest Rate Swap | Interest income
Derivative [Line Items]
Gain (loss) recognized	0	$ 0
Back-to-Back Loan Swaps | Interest Rate Swap | Counterparties
Derivative [Line Items]
Cash pledged as collateral	$ 1,600,000		$ 190,000

Derivative Financial Instrume75

Derivative Financial Instruments (Back-to-back loan swaps) (Balance sheet category and fair values) (Details) - USD ($)	Mar. 31, 2018	Dec. 31, 2017	Feb. 05, 2016
Other liabilities
Derivative [Line Items]
Notional Amount			$ 2,000,000
Back-to-Back Loan Swaps | Other assets
Derivative [Line Items]
Notional Amount	$ 162,882,000	$ 126,766,000
Fair Value, Receive fixed-pay floating interest rate swap	3,763,000	2,377,000
Back-to-Back Loan Swaps | Other liabilities
Derivative [Line Items]
Notional Amount	162,882,000	126,766,000
Fair Value, Pay fixed-receive floating interest rate swap	$ (3,763,000)	$ (2,377,000)
Long | Back-to-Back Loan Swaps | Other assets
Derivative [Line Items]
Derivative, Average Variable Interest Rate	4.82%	4.70%
Long | Back-to-Back Loan Swaps | Other liabilities
Derivative [Line Items]
Derivative, Average Variable Interest Rate	4.73%	4.03%
Short | Back-to-Back Loan Swaps | Other assets
Derivative [Line Items]
Derivative, Average Variable Interest Rate	4.73%	4.03%
Short | Back-to-Back Loan Swaps | Other liabilities
Derivative [Line Items]
Derivative, Average Variable Interest Rate	4.82%	4.70%

Derivative Financial Instrume76

Derivative Financial Instruments (Other free standing derivatives) (Narrative) (Details) - USD ($)	Mar. 31, 2018	Dec. 31, 2017
Derivative [Line Items]
Cash pledged as collateral	$ 0	$ 1,200,000
Counterparties
Derivative [Line Items]
Cash pledged as collateral	860,000	0
Not Designated as Hedging Instrument
Derivative [Line Items]
Cash pledged as collateral	203,000	20,000
Not Designated as Hedging Instrument | Counterparties
Derivative [Line Items]
Cash pledged as collateral	$ 0	$ 29,000

Derivative Financial Instrume77

Derivative Financial Instruments (Other free standing derivatives) (Balance sheet category and fair values) (Details) - Not Designated as Hedging Instrument - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Other assets | Interest rate lock commitments (mortgage)
Derivatives, Fair Value [Line Items]
Notional Amount, Other Assets	$ 65,591	$ 53,588
Fair Value, Other Assets	1,959	1,738
Other assets | Forward commitments
Derivatives, Fair Value [Line Items]
Notional Amount, Other Assets	55,118	37,286
Fair Value, Other Assets	283	80
Other liabilities | Forward commitments
Derivatives, Fair Value [Line Items]
Notional Amount, Other Liabilities	91,625	118,632
Fair Value, Other Liabilities	(320)	(232)
Other liabilities | Undesignated interest rate swaps
Derivatives, Fair Value [Line Items]
Notional Amount, Other Liabilities	13,907	14,045
Fair Value, Other Liabilities	$ (461)	$ (738)

Derivative Financial Instrume78

Derivative Financial Instruments (Other free standing derivatives) (Gains (losses) recognized) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Net gains on sale of loans held for sale | Interest rate lock commitments (mortgage)
Trading Activity, Gains and Losses, Net [Line Items]
Gain (Loss) Recognized	$ 17	$ 1,062
Net gains on sale of loans held for sale | Forward commitments
Trading Activity, Gains and Losses, Net [Line Items]
Gain (Loss) Recognized	115	(2,739)
Other noninterest income | Undesignated interest rate swaps
Trading Activity, Gains and Losses, Net [Line Items]
Gain (Loss) Recognized	$ 277	$ 117

Fair Value (Fair value measurem

Fair Value (Fair value measurement recurring) (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Assets
Securities available for sale	$ 2,027,665	$ 2,216,753
Level 1
Assets
Securities available for sale	9,421	3,484
Derivative assets	0	0
Liabilities
Derivative liabilities	0	0
Level 2
Assets
Securities available for sale	2,018,244	2,213,269
Derivative assets	6,265	3,933
Liabilities
Derivative liabilities	4,709	5,167
Level 3
Assets
Securities available for sale	0	0
Derivative assets	0	0
Liabilities
Derivative liabilities	0	0
Interest rate lock commitments | Level 1
Assets
Derivative assets	0	0
Interest rate lock commitments | Level 2
Assets
Derivative assets	0	0
Interest rate lock commitments | Level 3
Assets
Derivative assets	1,959	1,738
Forward commitments | Level 1
Assets
Derivative assets	0	0
Liabilities
Derivative liabilities	0	0
Forward commitments | Level 2
Assets
Derivative assets	283	80
Liabilities
Derivative liabilities	320	232
Forward commitments | Level 3
Assets
Derivative assets	0	0
Liabilities
Derivative liabilities	0	0
U.S. government corporations and agencies
Assets
Securities available for sale		5,328
Mortgage and asset-backed securities
Assets
Securities available for sale		1,753,736
Obligations of states and political subdivisions
Assets
Securities available for sale		441,015
Equity securities
Assets
Securities available for sale		16,674
Recurring Basis
Assets
Total assets at fair value	2,036,172	2,222,504
Liabilities
Total liabilities at fair value	5,029	5,399
Recurring Basis | Level 1
Assets
Total assets at fair value	9,421	3,484
Liabilities
Total liabilities at fair value	0	0
Recurring Basis | Level 2
Assets
Total assets at fair value	2,024,792	2,217,282
Liabilities
Total liabilities at fair value	5,029	5,399
Recurring Basis | Level 3
Assets
Total assets at fair value	1,959	1,738
Liabilities
Total liabilities at fair value	0	0
Recurring Basis | Derivative Financial Instruments
Assets
Derivative assets	6,265	3,933
Liabilities
Derivative liabilities	4,709	5,167
Recurring Basis | Derivative Financial Instruments | Level 1
Assets
Derivative assets	0	0
Liabilities
Derivative liabilities	0	0
Recurring Basis | Derivative Financial Instruments | Level 2
Assets
Derivative assets	6,265	3,933
Liabilities
Derivative liabilities	4,709	5,167
Recurring Basis | Derivative Financial Instruments | Level 3
Assets
Derivative assets	0	0
Liabilities
Derivative liabilities	0	0
Recurring Basis | Interest rate lock commitments
Assets
Derivative assets	1,959	1,738
Recurring Basis | Interest rate lock commitments | Level 1
Assets
Derivative assets	0	0
Recurring Basis | Interest rate lock commitments | Level 2
Assets
Derivative assets	0	0
Recurring Basis | Interest rate lock commitments | Level 3
Assets
Derivative assets	1,959	1,738
Recurring Basis | Forward commitments
Assets
Derivative assets	283	80
Liabilities
Derivative liabilities	320	232
Recurring Basis | Forward commitments | Level 1
Assets
Derivative assets	0	0
Liabilities
Derivative liabilities	0	0
Recurring Basis | Forward commitments | Level 2
Assets
Derivative assets	283	80
Liabilities
Derivative liabilities	320	232
Recurring Basis | Forward commitments | Level 3
Assets
Derivative assets	0	0
Liabilities
Derivative liabilities	0	0
Recurring Basis | U.S. government corporations and agencies
Assets
Securities available for sale	11,188	5,328
Recurring Basis | U.S. government corporations and agencies | Level 1
Assets
Securities available for sale	9,421	3,484
Recurring Basis | U.S. government corporations and agencies | Level 2
Assets
Securities available for sale	1,767	1,844
Recurring Basis | U.S. government corporations and agencies | Level 3
Assets
Securities available for sale	0	0
Recurring Basis | Mortgage and asset-backed securities
Assets
Securities available for sale	1,647,604	1,753,736
Recurring Basis | Mortgage and asset-backed securities | Level 1
Assets
Securities available for sale	0	0
Recurring Basis | Mortgage and asset-backed securities | Level 2
Assets
Securities available for sale	1,647,604	1,753,736
Recurring Basis | Mortgage and asset-backed securities | Level 3
Assets
Securities available for sale	0	0
Recurring Basis | Obligations of states and political subdivisions
Assets
Securities available for sale	352,180	441,015
Recurring Basis | Obligations of states and political subdivisions | Level 1
Assets
Securities available for sale	0	0
Recurring Basis | Obligations of states and political subdivisions | Level 2
Assets
Securities available for sale	352,180	441,015
Recurring Basis | Obligations of states and political subdivisions | Level 3
Assets
Securities available for sale	0	0
Recurring Basis | Corporate debt securities
Assets
Securities available for sale	0
Recurring Basis | Corporate debt securities | Level 1
Assets
Securities available for sale	0
Recurring Basis | Corporate debt securities | Level 2
Assets
Securities available for sale	0
Recurring Basis | Corporate debt securities | Level 3
Assets
Securities available for sale	0
Recurring Basis | Equity securities
Assets
Securities available for sale	16,693	16,674
Recurring Basis | Equity securities | Level 1
Assets
Securities available for sale	0	0
Recurring Basis | Equity securities | Level 2
Assets
Securities available for sale	16,693	16,674
Recurring Basis | Equity securities | Level 3
Assets
Securities available for sale	$ 0	$ 0

Fair Value (Fair value measur80

Fair Value (Fair value measurement non-recurring) (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other real estate owned	$ 11,801	$ 10,777
Premises, furniture and equipment held for sale	1,477	1,977
Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans held for sale	0	0
Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans held for sale	24,376	44,560
Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans held for sale	0	0
Other real estate owned	11,801	10,777
Commercial servicing rights | Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Commercial servicing rights	272	291
Premises, furniture and equipment held for sale | Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Premises, furniture and equipment held for sale	1,477	1,977
Commercial | Commercial | Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Collateral dependent impaired loans	2,923	3,212
Commercial | Commercial real estate | Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Collateral dependent impaired loans	8,316	9,480
Agricultural and agricultural real estate | Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Collateral dependent impaired loans	8,041	8,406
Residential real estate | Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Collateral dependent impaired loans	1,421	1,137
Consumer | Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Collateral dependent impaired loans	1,721	1,234
Nonrecurring Basis
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Collateral dependent impaired loans	22,422	23,469
Loans held for sale	24,376	44,560
Other real estate owned	11,801	10,777
Nonrecurring Basis | Year-to- Date (Gains) Losses
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Collateral dependent impaired loans	4	3,469
Loans held for sale	288	190
Other real estate owned	16	737
Nonrecurring Basis | Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Collateral dependent impaired loans	0	0
Loans held for sale	0	0
Other real estate owned	0	0
Nonrecurring Basis | Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Collateral dependent impaired loans	0	0
Loans held for sale	24,376	44,560
Other real estate owned	0	0
Nonrecurring Basis | Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Collateral dependent impaired loans	22,422	23,469
Loans held for sale	0	0
Other real estate owned	11,801	10,777
Nonrecurring Basis | Commercial servicing rights
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Commercial servicing rights	272	291
Nonrecurring Basis | Commercial servicing rights | Year-to- Date (Gains) Losses
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Commercial servicing rights	2	(21)
Nonrecurring Basis | Commercial servicing rights | Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Commercial servicing rights	0	0
Nonrecurring Basis | Commercial servicing rights | Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Commercial servicing rights	0	0
Nonrecurring Basis | Commercial servicing rights | Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Commercial servicing rights	272	291
Nonrecurring Basis | Premises, furniture and equipment held for sale
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Premises, furniture and equipment held for sale	1,477	1,977
Nonrecurring Basis | Premises, furniture and equipment held for sale | Year-to- Date (Gains) Losses
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Premises, furniture and equipment held for sale	(115)	192
Nonrecurring Basis | Premises, furniture and equipment held for sale | Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Premises, furniture and equipment held for sale	0	0
Nonrecurring Basis | Premises, furniture and equipment held for sale | Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Premises, furniture and equipment held for sale	0	0
Nonrecurring Basis | Premises, furniture and equipment held for sale | Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Premises, furniture and equipment held for sale	1,477	1,977
Nonrecurring Basis | Commercial | Commercial
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Collateral dependent impaired loans	2,923	3,212
Nonrecurring Basis | Commercial | Commercial | Year-to- Date (Gains) Losses
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Collateral dependent impaired loans	0	1,119
Nonrecurring Basis | Commercial | Commercial | Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Collateral dependent impaired loans	0	0
Nonrecurring Basis | Commercial | Commercial | Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Collateral dependent impaired loans	0	0
Nonrecurring Basis | Commercial | Commercial | Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Collateral dependent impaired loans	2,923	3,212
Nonrecurring Basis | Commercial | Commercial real estate
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Collateral dependent impaired loans	8,316	9,480
Nonrecurring Basis | Commercial | Commercial real estate | Year-to- Date (Gains) Losses
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Collateral dependent impaired loans	0	322
Nonrecurring Basis | Commercial | Commercial real estate | Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Collateral dependent impaired loans	0	0
Nonrecurring Basis | Commercial | Commercial real estate | Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Collateral dependent impaired loans	0	0
Nonrecurring Basis | Commercial | Commercial real estate | Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Collateral dependent impaired loans	8,316	9,480
Nonrecurring Basis | Agricultural and agricultural real estate
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Collateral dependent impaired loans	8,041	8,406
Nonrecurring Basis | Agricultural and agricultural real estate | Year-to- Date (Gains) Losses
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Collateral dependent impaired loans	0	2,028
Nonrecurring Basis | Agricultural and agricultural real estate | Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Collateral dependent impaired loans	0	0
Nonrecurring Basis | Agricultural and agricultural real estate | Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Collateral dependent impaired loans	0	0
Nonrecurring Basis | Agricultural and agricultural real estate | Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Collateral dependent impaired loans	8,041	8,406
Nonrecurring Basis | Residential real estate
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Collateral dependent impaired loans	1,421	1,137
Nonrecurring Basis | Residential real estate | Year-to- Date (Gains) Losses
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Collateral dependent impaired loans	4	0
Nonrecurring Basis | Residential real estate | Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Collateral dependent impaired loans	0	0
Nonrecurring Basis | Residential real estate | Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Collateral dependent impaired loans	0	0
Nonrecurring Basis | Residential real estate | Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Collateral dependent impaired loans	1,421	1,137
Nonrecurring Basis | Consumer
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Collateral dependent impaired loans	1,721	1,234
Nonrecurring Basis | Consumer | Year-to- Date (Gains) Losses
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Collateral dependent impaired loans	0	0
Nonrecurring Basis | Consumer | Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Collateral dependent impaired loans	0	0
Nonrecurring Basis | Consumer | Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Collateral dependent impaired loans	0	0
Nonrecurring Basis | Consumer | Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Collateral dependent impaired loans	$ 1,721	$ 1,234

Fair Value (Quantitative Inform

Fair Value (Quantitative Information about Level 3 fair value measurements) (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2018	Dec. 31, 2017
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Securities available for sale	$ 2,027,665	$ 2,216,753
Premises, furniture and equipment held for sale	1,477	1,977
Other real estate owned	$ 11,801	$ 10,777
Commercial servicing rights | Minimum
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Pretax discount rate (percent)	13.09%	13.04%
Commercial servicing rights | Maximum
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Pretax discount rate (percent)	16.71%	15.49%
Level 3
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Securities available for sale	$ 0	$ 0
Derivative assets	0	0
Other real estate owned	$ 11,801	$ 10,777
Level 3 | Minimum
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Pretax discount rate (percent)	0.00%	0.00%
Level 3 | Maximum
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Pretax discount rate (percent)	10.00%	10.00%
Level 3 | Commercial | Commercial
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Collateral dependent impaired loans	$ 2,923	$ 3,212
Level 3 | Commercial | Commercial | Minimum
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Pretax discount rate (percent)	0.00%	0.00%
Level 3 | Commercial | Commercial | Maximum
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Pretax discount rate (percent)	10.00%	15.00%
Level 3 | Commercial | Commercial real estate
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Collateral dependent impaired loans	$ 8,316	$ 9,480
Level 3 | Commercial | Commercial real estate | Minimum
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Pretax discount rate (percent)	0.00%	0.00%
Level 3 | Commercial | Commercial real estate | Maximum
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Pretax discount rate (percent)	10.00%	12.00%
Level 3 | Agricultural and agricultural real estate
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Collateral dependent impaired loans	$ 8,041	$ 8,406
Level 3 | Agricultural and agricultural real estate | Minimum
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Pretax discount rate (percent)	0.00%	0.00%
Level 3 | Agricultural and agricultural real estate | Maximum
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Pretax discount rate (percent)	10.00%	10.00%
Level 3 | Residential real estate
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Collateral dependent impaired loans	$ 1,421	$ 1,137
Level 3 | Residential real estate | Minimum
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Pretax discount rate (percent)	0.00%	0.00%
Level 3 | Residential real estate | Maximum
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Pretax discount rate (percent)	12.00%	12.00%
Level 3 | Consumer
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Collateral dependent impaired loans	$ 1,721	$ 1,234
Level 3 | Consumer | Minimum
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Pretax discount rate (percent)	0.00%	0.00%
Level 3 | Consumer | Maximum
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Pretax discount rate (percent)	14.00%	12.00%
Level 3 | Commercial servicing rights
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Commercial servicing rights	$ 272	$ 291
Level 3 | Premises, furniture and equipment held for sale
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Premises, furniture and equipment held for sale	$ 1,477	$ 1,977
Level 3 | Premises, furniture and equipment held for sale | Minimum
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Pretax discount rate (percent)	0.00%	0.00%
Level 3 | Premises, furniture and equipment held for sale | Maximum
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Pretax discount rate (percent)	10.00%	10.00%
Level 3 | Interest rate lock commitments
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Derivative assets	$ 1,959	$ 1,738
Level 3 | Interest rate lock commitments | Minimum
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Closing ratio	0.00%	0.00%
Level 3 | Interest rate lock commitments | Maximum
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Closing ratio	99.00%	99.00%
Level 3 | Interest rate lock commitments | Weighted Average
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Closing ratio	89.00%	89.00%

Fair Value (Changes Level 3 ass

Fair Value (Changes Level 3 assets (fair value, recurring)) (Details) - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Gains included in net gains on sale of loans held for sale	$ 2,889	$ 3,828
Interest rate lock commitments
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance at beginning of period	1,738	$ 2,790	$ 2,790
Total gains (losses) included in earnings	17		(1,479)
Issuances	492		1,875
Settlements	(288)		(1,448)
Balance at period end	1,959		1,738
Gains included in net gains on sale of loans held for sale	$ 2,000		$ 1,700

Fair Value (Estimated fair valu

Fair Value (Estimated fair value financial instruments (incl. carrying amounts)) (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Securities:
Securities available for sale	$ 2,027,665	$ 2,216,753
Held to maturity	258,638	265,494
Quoted Prices in Active Markets for Identical Assets (Level 1)
Financial assets:
Cash and cash equivalents	266,346	196,003
Securities:
Securities available for sale	9,421	3,484
Held to maturity	0	0
Other investments	0	0
Loans held for sale	0	0
Loans, net	0	0
Cash surrender value on life insurance	0	0
Derivative assets	0	0
Financial liabilities:
Short term borrowings	0	0
Other borrowings	0	0
Derivative liabilities	0	0
Significant Other Observable Inputs (Level 2)
Financial assets:
Cash and cash equivalents	0	0
Securities:
Securities available for sale	2,018,244	2,213,269
Held to maturity	258,638	265,494
Other investments	22,982	22,563
Loans held for sale	24,376	44,560
Loans, net	6,612,732	6,291,503
Cash surrender value on life insurance	143,444	142,818
Derivative assets	6,265	3,933
Financial liabilities:
Short term borrowings	131,240	324,691
Other borrowings	276,193	285,609
Derivative liabilities	4,709	5,167
Significant Unobservable Inputs (Level 3)
Financial assets:
Cash and cash equivalents	0	0
Securities:
Securities available for sale	0	0
Held to maturity	0	0
Other investments	0	0
Loans held for sale	0	0
Loans, net	22,422	23,469
Cash surrender value on life insurance	0	0
Derivative assets	0	0
Financial liabilities:
Short term borrowings	0	0
Other borrowings	0	0
Derivative liabilities	0	0
Carrying Amount
Financial assets:
Cash and cash equivalents	266,346	196,003
Securities:
Securities available for sale	2,027,665	2,216,753
Held to maturity	249,766	253,550
Other investments	22,982	22,563
Loans held for sale	24,376	44,560
Loans, net	6,687,359	6,335,778
Cash surrender value on life insurance	143,444	142,818
Derivative assets	6,265	3,933
Financial liabilities:
Short term borrowings	131,240	324,691
Other borrowings	276,118	285,011
Derivative liabilities	4,709	5,167
Estimated Fair Value
Financial assets:
Cash and cash equivalents	266,346	196,003
Securities:
Securities available for sale	2,027,665	2,216,753
Held to maturity	258,638	265,494
Other investments	22,982	22,563
Loans held for sale	24,376	44,560
Loans, net	6,635,154	6,314,972
Cash surrender value on life insurance	143,444	142,818
Derivative assets	6,265	3,933
Financial liabilities:
Short term borrowings	131,240	324,691
Other borrowings	276,193	285,609
Derivative liabilities	4,709	5,167
Interest rate lock commitments | Quoted Prices in Active Markets for Identical Assets (Level 1)
Securities:
Derivative assets	0	0
Interest rate lock commitments | Significant Other Observable Inputs (Level 2)
Securities:
Derivative assets	0	0
Interest rate lock commitments | Significant Unobservable Inputs (Level 3)
Securities:
Derivative assets	1,959	1,738
Interest rate lock commitments | Carrying Amount
Securities:
Derivative assets	1,959	1,738
Interest rate lock commitments | Estimated Fair Value
Securities:
Derivative assets	1,959	1,738
Forward commitments | Quoted Prices in Active Markets for Identical Assets (Level 1)
Securities:
Derivative assets	0	0
Financial liabilities:
Derivative liabilities	0	0
Forward commitments | Significant Other Observable Inputs (Level 2)
Securities:
Derivative assets	283	80
Financial liabilities:
Derivative liabilities	320	232
Forward commitments | Significant Unobservable Inputs (Level 3)
Securities:
Derivative assets	0	0
Financial liabilities:
Derivative liabilities	0	0
Forward commitments | Carrying Amount
Securities:
Derivative assets	283	80
Financial liabilities:
Derivative liabilities	320	232
Forward commitments | Estimated Fair Value
Securities:
Derivative assets	283	80
Financial liabilities:
Derivative liabilities	320	232
Commercial | Commercial | Quoted Prices in Active Markets for Identical Assets (Level 1)
Securities:
Loans, net	0	0
Commercial | Commercial | Significant Other Observable Inputs (Level 2)
Securities:
Loans, net	1,763,837	1,614,744
Commercial | Commercial | Significant Unobservable Inputs (Level 3)
Securities:
Loans, net	2,923	3,212
Commercial | Commercial | Carrying Amount
Securities:
Loans, net	1,786,838	1,628,043
Commercial | Commercial | Estimated Fair Value
Securities:
Loans, net	1,766,760	1,617,956
Commercial | Commercial real estate | Quoted Prices in Active Markets for Identical Assets (Level 1)
Securities:
Loans, net	0	0
Commercial | Commercial real estate | Significant Other Observable Inputs (Level 2)
Securities:
Loans, net	3,272,469	3,123,062
Commercial | Commercial real estate | Significant Unobservable Inputs (Level 3)
Securities:
Loans, net	8,316	9,480
Commercial | Commercial real estate | Carrying Amount
Securities:
Loans, net	3,298,798	3,140,427
Commercial | Commercial real estate | Estimated Fair Value
Securities:
Loans, net	3,280,785	3,132,542
Agricultural and agricultural real estate | Quoted Prices in Active Markets for Identical Assets (Level 1)
Securities:
Loans, net	0	0
Agricultural and agricultural real estate | Significant Other Observable Inputs (Level 2)
Securities:
Loans, net	500,541	500,581
Agricultural and agricultural real estate | Significant Unobservable Inputs (Level 3)
Securities:
Loans, net	8,041	8,406
Agricultural and agricultural real estate | Carrying Amount
Securities:
Loans, net	514,471	508,075
Agricultural and agricultural real estate | Estimated Fair Value
Securities:
Loans, net	508,582	508,987
Residential real estate | Quoted Prices in Active Markets for Identical Assets (Level 1)
Securities:
Loans, net	0	0
Residential real estate | Significant Other Observable Inputs (Level 2)
Securities:
Loans, net	612,813	613,530
Residential real estate | Significant Unobservable Inputs (Level 3)
Securities:
Loans, net	1,421	1,137
Residential real estate | Carrying Amount
Securities:
Loans, net	621,295	620,939
Residential real estate | Estimated Fair Value
Securities:
Loans, net	614,234	614,667
Consumer | Quoted Prices in Active Markets for Identical Assets (Level 1)
Securities:
Loans, net	0	0
Consumer | Significant Other Observable Inputs (Level 2)
Securities:
Loans, net	463,072	439,586
Consumer | Significant Unobservable Inputs (Level 3)
Securities:
Loans, net	1,721	1,234
Consumer | Carrying Amount
Securities:
Loans, net	465,957	438,294
Consumer | Estimated Fair Value
Securities:
Loans, net	464,793	440,820
Time deposits in other financial institutions | Quoted Prices in Active Markets for Identical Assets (Level 1)
Financial assets:
Time deposits in other financial institutions	6,297	9,820
Time deposits in other financial institutions | Significant Other Observable Inputs (Level 2)
Financial assets:
Time deposits in other financial institutions	0	0
Time deposits in other financial institutions | Significant Unobservable Inputs (Level 3)
Financial assets:
Time deposits in other financial institutions	0	0
Time deposits in other financial institutions | Carrying Amount
Financial assets:
Time deposits in other financial institutions	6,297	9,820
Time deposits in other financial institutions | Estimated Fair Value
Financial assets:
Time deposits in other financial institutions	6,297	9,820
Demand deposits | Quoted Prices in Active Markets for Identical Assets (Level 1)
Financial liabilities:
Deposits	0	0
Demand deposits | Significant Other Observable Inputs (Level 2)
Financial liabilities:
Deposits	3,094,457	2,983,128
Demand deposits | Significant Unobservable Inputs (Level 3)
Financial liabilities:
Deposits	0	0
Demand deposits | Carrying Amount
Financial liabilities:
Deposits	3,094,457	2,983,128
Demand deposits | Estimated Fair Value
Financial liabilities:
Deposits	3,094,457	2,983,128
Savings deposits | Quoted Prices in Active Markets for Identical Assets (Level 1)
Financial liabilities:
Deposits	0	0
Savings deposits | Significant Other Observable Inputs (Level 2)
Financial liabilities:
Deposits	4,536,106	4,240,328
Savings deposits | Significant Unobservable Inputs (Level 3)
Financial liabilities:
Deposits	0	0
Savings deposits | Carrying Amount
Financial liabilities:
Deposits	4,536,106	4,240,328
Savings deposits | Estimated Fair Value
Financial liabilities:
Deposits	4,536,106	4,240,328
Time deposits | Quoted Prices in Active Markets for Identical Assets (Level 1)
Financial liabilities:
Deposits	0	0
Time deposits | Significant Other Observable Inputs (Level 2)
Financial liabilities:
Deposits	910,977	923,453
Time deposits | Significant Unobservable Inputs (Level 3)
Financial liabilities:
Deposits	0	0
Time deposits | Carrying Amount
Financial liabilities:
Deposits	910,977	923,453
Time deposits | Estimated Fair Value
Financial liabilities:
Deposits	$ 910,977	$ 923,453

Revenue (Details)

Revenue (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Disaggregation of Revenue [Line Items]
Trust fees	$ 4,680	$ 3,631
Brokerage and insurance commissions	907	1,036
Total noninterest income	15,666	14,124
Loan servicing income	1,754	1,724
Securities gains, net	1,441	2,482
Unrealized loss on equity securities, net	(28)	0
Net gains on sale of loans held for sale	4,051	6,147
Valuation adjustment on commercial servicing rights	(2)	5
Income on bank owned life insurance	614	617
Other noninterest income	1,220	794
Total noninterest income out-of-scope of Topic 606	9,050	11,769
TOTAL NONINTEREST INCOME	24,716	25,893
Service charges and fees on deposit accounts
Disaggregation of Revenue [Line Items]
Total noninterest income	2,618	2,160
Overdraft fees
Disaggregation of Revenue [Line Items]
Total noninterest income	2,208	2,193
Customer service fees
Disaggregation of Revenue [Line Items]
Total noninterest income	77	49
Credit card fee income
Disaggregation of Revenue [Line Items]
Total noninterest income	2,190	2,033
Debit card income
Disaggregation of Revenue [Line Items]
Total noninterest income	2,985	3,021
Other service charges
Disaggregation of Revenue [Line Items]
Total noninterest income	1	1
Total service charges and fees
Disaggregation of Revenue [Line Items]
Total noninterest income	$ 10,079	$ 9,457