Heartland Financial USA (HTLF) 10-K 28 Feb 18 2017 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($)	12 Months Ended
	Dec. 31, 2017	Feb. 27, 2018	Jun. 30, 2017
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-K
Document Period End Date	Dec. 31, 2017
Document Fiscal Year Focus	2,017
Document Fiscal Period Focus	FY
Amendment Flag	false
Entity Common Stock, Shares Outstanding		31,054,186
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Public Float			$ 1,163,696,144

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
ASSETS
Cash and due from banks	$ 168,723	$ 151,290
Interest bearing deposits with the Federal Reserve Bank and other banks and other short-term investments	27,280	7,434
Cash and cash equivalents	196,003	158,724
Time deposits in other financial institutions	9,820	2,105
Securities:
Available for sale, at fair value (cost of $2,248,181 at December 31, 2017, and cost of $1,893,947 at December 31, 2016)	2,216,753	1,845,864
Held to maturity, at cost (fair value of $265,494 at December 31, 2017, and $274,799 at December 31, 2016)	253,550	263,662
Other investments, at cost	22,563	21,560
Loans held for sale	44,560	61,261
Loans receivable:
Held to maturity	6,391,464	5,351,719
Allowance for loan losses	(55,686)	(54,324)
Loans receivable, net	6,335,778	5,297,395
Premises, furniture and equipment, net	172,324	163,614
Premises, furniture and equipment held for sale	1,977	414
Other real estate, net	10,777	9,744
Goodwill	236,615	127,699
Core deposit intangibles and customer relationship intangibles, net	35,203	22,775
Servicing rights, net	25,857	35,778
Cash surrender value on life insurance	142,818	112,615
Other assets	106,141	123,869
TOTAL ASSETS	9,810,739	8,247,079
Deposits:
Demand	2,983,128	2,202,036
Savings	4,240,328	3,788,089
Time	923,453	857,286
Total deposits	8,146,909	6,847,411
Short-term borrowings	324,691	306,459
Other borrowings	285,011	288,534
Accrued expenses and other liabilities	62,671	63,759
TOTAL LIABILITIES	8,819,282	7,506,163
STOCKHOLDERS' EQUITY:
Common stock (par value $1 per share; 40,000,000 shares authorized at December 31, 2017, and 30,000,000 shares authorized at December 31, 2016; issued 29,953,356 shares at December 31, 2017, and 26,119,929 shares at December 31, 2016)	29,953	26,120
Capital surplus	503,709	328,376
Retained earnings	481,331	416,109
Accumulated other comprehensive loss	(24,474)	(31,046)
Treasury stock at cost (0 shares at both December 31, 2017, and December 31, 2016)	0	0
TOTAL STOCKHOLDERS' EQUITY	991,457	740,916
TOTAL LIABILITIES AND EQUITY	9,810,739	8,247,079
Preferred Stock
STOCKHOLDERS' EQUITY:
Preferred stock	0	0
Series A Preferred Stock
STOCKHOLDERS' EQUITY:
Preferred stock	0	0
Series C Preferred Stock
STOCKHOLDERS' EQUITY:
Preferred stock	0	0
Series D Preferred Stock
STOCKHOLDERS' EQUITY:
Preferred stock	$ 938	$ 1,357

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parentheticals) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Cost of available for sale securities	$ 2,248,181	$ 1,893,947
Fair value of held to maturity securities	$ 265,494	$ 274,799
Common stock, par value (in usd per share)	$ 1	$ 1
Common stock, shares authorized	40,000,000	40,000,000
Common stock, shares issued	29,953,356	26,119,929
Treasury stock, shares	0	0
Preferred Stock
Preferred stock, par value (in dollars per share)	$ 1	$ 1
Preferred stock, shares authorized	17,604	17,604
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Series A Preferred Stock
Preferred stock, par value (in dollars per share)	$ 1	$ 1
Preferred stock, shares authorized	16,000	16,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Series C Preferred Stock
Preferred stock, par value (in dollars per share)	$ 1	$ 1
Preferred stock, shares authorized	81,698	81,698
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Series D Preferred Stock
Preferred stock, par value (in dollars per share)	$ 1	$ 1
Preferred stock, shares authorized	3,000	3,000
Preferred stock, shares issued	745	1,078
Preferred stock, shares outstanding	745	1,078

Consolidated Statements of Inco

Consolidated Statements of Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
INTEREST INCOME:
Interest and fees on loans	$ 304,006	$ 278,128	$ 227,106
Interest on securities:
Taxable	38,365	32,858	26,646
Nontaxable	19,698	15,085	12,178
Interest on federal funds sold	42	12	24
Interest on interest bearing deposits in other financial institutions	1,547	396	14
TOTAL INTEREST INCOME	363,658	326,479	265,968
INTEREST EXPENSE:
Interest on deposits	18,279	15,939	15,530
Interest on short-term borrowings	678	1,202	838
Interest on other borrowings (includes $1,290, $1,914 and $2,222 of interest expense related to derivatives reclassified from accumulated other comprehensive loss for the years ended December 31, 2017, 2016, and 2015, respectively)	14,393	14,672	15,602
TOTAL INTEREST EXPENSE	33,350	31,813	31,970
NET INTEREST INCOME	330,308	294,666	233,998
Provision for loan losses	15,563	11,694	12,697
NET INTEREST INCOME AFTER PROVISION FOR LOAN LOSSES	314,745	282,972	221,301
NONINTEREST INCOME:
Service charges and fees	39,183	31,590	24,308
Loan servicing income	5,636	4,501	5,276
Trust fees	15,818	14,845	14,281
Brokerage and insurance commissions	4,033	3,869	3,789
Securities gains, net (includes $6,764, $11,518, and $13,183 of net security gains reclassified from accumulated other comprehensive income for the years ended December 31, 2017, 2016, and 2015, respectively)	6,973	11,340	13,143
Impairment loss on securities (includes $0, $0, and $253 of net security losses reclassified from accumulated other comprehensive income for the years ended December 31, 2017, 2016, and 2015, respectively)	0	0	(769)
Net gains on sale of loans held for sale	22,251	39,634	45,249
Valuation allowance on commercial servicing rights	21	(33)	0
Income on bank owned life insurance	2,772	2,275	1,999
Other noninterest income	5,335	5,580	3,409
TOTAL NONINTEREST INCOME	102,022	113,601	110,685
NONINTEREST EXPENSES:
Salaries and employee benefits	171,407	163,547	144,105
Occupancy	22,244	20,398	16,928
Furniture and equipment	11,061	10,245	8,747
Professional fees	32,879	27,676	23,047
FDIC insurance assessments	3,595	4,185	3,759
Advertising	7,229	6,448	5,465
Core deposit intangibles and customer relationship intangibles amortization	6,077	5,630	2,978
Other real estate and loan collection expenses	2,461	2,443	2,437
Loss on sales/valuations of assets, net	2,475	1,478	6,821
Other noninterest expenses	38,247	37,618	36,759
TOTAL NONINTEREST EXPENSES	297,675	279,668	251,046
Income (loss) before income taxes	119,092	116,905	80,940
Income taxes (includes $2,042, $3,582, and $3,994 of income tax expense reclassified from accumulated other comprehensive income for the years ended December 31, 2017, 2016, and 2015, respectively)	43,820	36,556	20,898
NET INCOME	75,272	80,349	60,042
Preferred dividends	(58)	(292)	(817)
Interest expense on convertible preferred debt	12	51	0
NET INCOME AVAILABLE TO COMMON STOCKHOLDERS	$ 75,226	$ 80,108	$ 59,225
EARNINGS PER COMMON SHARE - BASIC (in dollars per share)	$ 2.67	$ 3.26	$ 2.87
EARNINGS PER COMMON SHARE - DILUTED (in dollars per share)	2.65	3.22	2.83
CASH DIVIDENDS DECLARED PER COMMON SHARE (in dollars per share)	$ 0.51	$ 0.50	$ 0.45

Consolidated Statements of Inc5

Consolidated Statements of Income (Parentheticals) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Interest on other borrowings	$ 14,393	$ 14,672	$ 15,602
Securities gains, net	6,973	11,340	13,143
Impairment loss on securities	0	0	769
Income taxes	43,820	36,556	20,898
Reclassification out of Accumulated Other Comprehensive Income | Accumulated Net Gain (Loss) from Derivatives
Interest on other borrowings	1,290	1,914	2,222
Reclassification out of Accumulated Other Comprehensive Income | Accumulated Net Unrealized Investment Gain (Loss)
Securities gains, net	6,764	11,518	13,138
Impairment loss on securities	0	0	253
Reclassification out of Accumulated Other Comprehensive Income | Accumulated Other Comprehensive Income (Loss)
Income taxes	$ 2,042	$ 3,582	$ 3,994

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Statement of Comprehensive Income [Abstract]
Net income	$ 75,272	$ 80,349	$ 60,042
Securities:
Net change in unrealized gain (loss) on securities	23,778	(31,271)	(195)
Reclassification adjustment for net gains realized in net income	(6,764)	(11,518)	(12,930)
Net change in non-credit related other than temporary impairment	0	7	295
Income taxes	(6,670)	16,738	5,157
Other comprehensive income (loss) on securities	10,344	(26,044)	(7,673)
Derivatives used in cash flow hedging relationships:
Net change in unrealized gain (loss) on derivatives	210	(209)	(2,016)
Reclassification adjustment for net losses on derivatives realized in net income	1,290	1,914	2,222
Income taxes	(765)	(680)	(88)
Other comprehensive income on cash flow hedges	735	1,025	118
Other comprehensive income (loss)	11,079	(25,019)	(7,555)
TOTAL COMPREHENSIVE INCOME	$ 86,351	$ 55,330	$ 52,487

Consolidated Statements of Chan

Consolidated Statements of Changes in Equity - USD ($) $ in Thousands	Total	Series C Preferred Stock	Series D Preferred Stock	Preferred Stock	Preferred StockSeries C Preferred Stock	Preferred StockSeries D Preferred Stock	Common Stock	Capital Surplus	Retained Earnings	Retained EarningsSeries C Preferred Stock	Retained EarningsSeries D Preferred Stock	Accumulated Other Comprehensive Income (Loss)	Treasury Stock
Balance at beginning of period at Dec. 31, 2014	$ 496,317			$ 81,698			$ 18,511	$ 95,816	$ 298,764			$ 1,528	$ 0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Comprehensive income (loss)	52,487								60,042			(7,555)
Cash dividends declared:
Preferred		$ (817)								$ (817)
Common	(9,359)								(9,359)
Purchase of shares of treasury stock	(2,987)												(2,987)
Issuance of shares of common stock	124,254						3,925	117,342					2,987
Stock based compensation	3,278							3,278
Balance at end of period at Dec. 31, 2015	663,173			81,698			22,436	216,436	348,630			(6,027)	0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Comprehensive income (loss)	55,330								80,349			(25,019)
Cash dividends declared:
Preferred		(168)	$ (124)							$ (168)	$ (124)
Common	(12,578)								(12,578)
Redemption of preferred stock		$ (81,698)	(2,420)		$ (81,698)	$ (2,420)
Issuance of preferred stock			3,777			3,777
Purchase of shares of treasury stock	(3,719)												(3,719)
Issuance of shares of common stock	115,865						3,684	108,462					3,719
Stock based compensation	3,478							3,478
Balance at end 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 (loss)	86,351								75,272			11,079
Reclassification of certain income tax effects from accumulated other comprehensive income (loss)	0								4,507			(4,507)
Cash dividends declared:
Preferred			(58)								$ (58)
Common	(14,499)								(14,499)
Purchase of shares of treasury stock	(625)												(625)
Issuance of shares of common stock	175,723						3,833	171,265					625
Stock based compensation	4,068							4,068
Conversion of Series D preferred stock			$ (419)			$ (419)
Balance at end of period at Dec. 31, 2017	$ 991,457			$ 938			$ 29,953	$ 503,709	$ 481,331			$ (24,474)	$ 0

Consolidated Statements of Cha8

Consolidated Statements of Changes in Equity (Parentheticals) - $ / shares	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Cash dividends per share common stock (in dollars per share)	$ 0.51	$ 0.50	$ 0.45
Purchase of treasury stock, shares	13,066	82,601	57,866
Issuance of common stock, shares	3,846,493	3,766,837	3,982,434
Series C Preferred Stock
Cash dividends per share preferred stock (in dollars per share)		$ 2.50	$ 10
Series D Preferred Stock
Cash dividends per share preferred stock (in dollars per share)	$ 52.50	$ 52.50

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	$ 75,272	$ 80,349	$ 60,042
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	30,144	30,757	24,046
Provision for loan losses	15,563	11,694	12,697
Net amortization of premium on securities	26,961	32,101	28,405
Provision for deferred taxes	13,263	7,162	2,121
Securities gains, net	(6,973)	(11,340)	(13,143)
Impairment loss on securities	0	0	769
Stock based compensation	4,068	3,478	3,278
Write down and losses on sales of assets, net	2,475	1,478	6,821
Loans originated for sale	(728,681)	(1,119,817)	(1,324,494)
Proceeds on sales of loans held for sale	760,484	1,160,079	1,351,457
Net gains on sales of loans held for sale	(15,102)	(26,740)	(30,504)
Increase in accrued interest receivable	(593)	(779)	(290)
(Increase) decrease in prepaid expenses	576	194	(3,110)
Increase (decrease) in accrued interest payable	34	(835)	(1,424)
Gain on extinguishment of debt	(1,280)	0	0
Capitalization of servicing rights	(7,358)	(12,894)	(14,745)
Valuation adjustment on commercial servicing rights	(21)	33	0
Net excess tax benefit from stock based compensation	1,246	374	676
Other, net	(14,148)	(6,769)	(440)
NET CASH PROVIDED BY OPERATING ACTIVITIES	155,930	148,525	102,162
CASH FLOWS FROM INVESTING ACTIVITIES:
Proceeds from the sale of securities available for sale	1,456,750	909,942	1,115,359
Proceeds from the sale of securities held to maturity	0	4,557	0
Proceeds from the sale of other investments	2,790	5,673	15,327
Proceeds from the sale of time deposits in other financial institutions	12,171	0	2,925
Proceeds from the maturity of and principal paydowns on securities available for sale	222,656	188,071	162,311
Proceeds from the maturity of and principal paydowns on securities held to maturity	10,621	9,683	3,071
Proceeds from the maturity of and principal paydowns on other investments	0	0	619
Proceeds from the maturity of and principal paydowns on time deposits in other financial institutions	34,904	250	250
Purchase of securities available for sale	(1,816,564)	(1,335,244)	(1,206,909)
Purchase of other investments	(1,116)	(2,250)	(9,840)
Net (increase) decrease in loans	22,109	222,874	(196,509)
Purchase of bank owned life insurance policies	(2,000)	0	(1,100)
Proceeds from bank owned life insurance policies	0	111	1,229
Proceeds from sale of mortgage servicing rights	6,290	0	0
Capital expenditures	(8,113)	(10,327)	(8,111)
Net cash and cash equivalents received in acquisitions	71,089	8,084	41,744
Proceeds from sale of equipment	4,867	947	1,181
Proceeds on sale of OREO and other repossessed assets	10,844	4,484	9,465
NET CASH PROVIDED (USED) BY INVESTING ACTIVITIES	27,298	6,855	(68,988)
CASH FLOWS FROM FINANCING ACTIVITIES:
Net increase in demand deposits	154,394	123,613	204,575
Net increase (decrease) in savings accounts	(166,733)	86,319	174,913
Net decrease in time deposit accounts	(79,733)	(416,455)	(11,592)
Proceeds on short-term revolving credit line	20,000	0	0
Repayments on short-term revolving credit line	(20,000)	0	0
Net increase (decrease) in short-term borrowings	(25,847)	(15,921)	3,152
Proceeds from short term FHLB advances	251,139	329,566	271,100
Repayments of short term FHLB advances	(241,505)	(336,850)	(336,000)
Proceeds from other borrowings	0	40,000	29,000
Repayments of other borrowings	(9,645)	(21,636)	(173,739)
Redemption of preferred stock	0	(81,698)	0
Payment for the redemption of debt	(13,800)	0	0
Purchase of treasury stock	(625)	(3,719)	(2,987)
Proceeds from issuance of common stock	963	54,196	3,508
Dividends paid	(14,557)	(12,870)	(10,176)
NET CASH PROVIDED (USED) BY FINANCING ACTIVITIES	(145,949)	(255,455)	151,754
Net increase (decrease) in cash and cash equivalents	37,279	(100,075)	184,928
Cash and cash equivalents at beginning of year	158,724	258,799	73,871
CASH AND CASH EQUIVALENTS AT END OF PERIOD	196,003	158,724	258,799
Supplemental disclosures:
Cash paid for income/franchise taxes	15,817	24,652	11,914
Cash paid for interest	33,316	32,648	33,394
Loans transferred to OREO	5,293	2,315	6,592
Transfer of premises from premises, furniture and equipment held for sale to premises, furniture and equipment, net	2,372	3,440	0
Purchases of securities available for sale, accrued, not paid	1,017	0	0
Transfer of premises from premises, furniture and equipment, net to premises, furniture and equipment held for sale	3,442	0	0
Sales of securities available for sale, accrued, not settled	0	250	0
Conversion of convertible debt to common stock	558	1,442	0
Conversion of Series D preferred stock to common stock	419	2,420	0
Stock consideration granted for acquisitions	$ 175,196	$ 57,433	$ 120,070

Summary of Significant Accounti

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2017
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Summary of Significant Accounting Policies	SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES Nature of Operations - Heartland Financial USA, Inc. ("Heartland") is a multi-bank holding company with locations in Iowa, Illinois, Wisconsin, New Mexico, Arizona, Colorado, Montana, Minnesota, Kansas, Missouri, Texas and California. The principal services of Heartland, which are provided through its subsidiaries, are FDIC-insured deposit accounts and related services, and loans to businesses and individuals. The loans consist primarily of commercial and commercial real estate, agricultural and agricultural real estate, residential real estate and consumer loans. Principles of Presentation - The consolidated financial statements include the accounts of Heartland and its subsidiaries: Dubuque Bank and Trust Company; Illinois Bank & Trust; Wisconsin Bank & Trust; New Mexico Bank & Trust; Arizona Bank & Trust; Rocky Mountain Bank; Citywide Banks; Minnesota Bank & Trust; Morrill & Janes Bank and Trust Company; Premier Valley Bank; Citizens Finance Parent Co.; DB&T Insurance, Inc.; DB&T Community Development Corp.; Heartland Community Development, Inc.; Heartland Financial USA, Inc. Insurance Services; Citizens Finance Co.; Citizens Finance of Illinois Co.; Heartland Financial Statutory Trust IV; Heartland Financial Statutory Trust V; Heartland Financial Statutory Trust VI; Heartland Financial Statutory Trust VII; Morrill Statutory Trust I; Morrill Statutory Trust II; Sheboygan Statutory Trust I, CBNM Capital Trust I, Citywide Capital Trust III, Citywide Capital Trust IV and Citywide Capital Trust V. All of Heartland’s subsidiaries are wholly-owned as of December 31, 2017 . The consolidated financial statements have been prepared in accordance with U.S. generally accepted accounting principles ("GAAP") and prevailing practices within the banking industry. In preparing such financial statements, management is required to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities as of the date of the balance sheets and revenues and expenses for the years then ended. Actual results could differ significantly from those estimates. A material estimate that is particularly susceptible to significant change relates to the determination of the allowance for loan losses. Business Combinations - Heartland applies the acquisition method of accounting in accordance with the Financial Accounting Standards Board ("FASB") Accounting Standards Codification ("ASC") Topic 805, Business Combinations. Under the acquisition method, Heartland recognizes assets acquired, including identified intangible assets, and the liabilities assumed in acquisitions at fair value as of the acquisition date, with the acquisition-related transaction costs expensed in the period incurred. Determining the fair value of assets acquired and liabilities assumed often involves estimates based on third-party valuations, such as appraisals, or internal valuations based on discounted cash flow analyses or other valuation techniques that may include estimates of attrition, inflation, asset growth rates, discount rates, multiples of earnings or other relevant factors. In addition, the determination of the useful lives over which an intangible asset will be amortized is subjective. Cash and Cash Equivalents - For purposes of reporting cash flows, cash and cash equivalents include cash on hand, amounts due from banks, interest bearing deposits held at the Federal Reserve Bank, federal funds sold to other banks and other short-term investments. Generally, federal funds are purchased and sold for one-day periods. Trading Securities - Trading securities represent those securities Heartland intends to actively trade and are stated at fair value with changes in fair value reflected in noninterest income. Securities Available for Sale - Available for sale securities consist of those securities not classified as held to maturity or trading, which management intends to hold for indefinite periods of time or that may be sold in response to changes in interest rates, prepayments or other similar factors. Available for sale securities are stated at fair value with any unrealized gain or loss, net of applicable income tax, reported as a separate component of stockholders’ equity. Security premiums and discounts are amortized/accreted using the interest method over the period from the purchase date to the expected maturity or call date of the related security. Declines in the fair value of investment securities available for sale (with certain exceptions for debt securities noted below) that are deemed to be other-than-temporary are charged to earnings as a realized loss, and a new cost basis for the securities is established. In evaluating whether impairment is other-than-temporary, Heartland considers the length of time and extent to which the fair value has been less than cost, the financial condition and near-term prospects of the issuer, and the intent and ability of Heartland to retain its investment in the issuer for a period of time sufficient to allow for any anticipated recovery in fair value in the near term. Declines in the fair value of debt securities below amortized cost are deemed to be other-than-temporary in circumstances where: (1) Heartland has the intent to sell a security; (2) it is more likely than not that Heartland will be required to sell the security before recovery of its amortized cost basis; or (3) Heartland does not expect to recover the entire amortized cost basis of the security. If Heartland intends to sell a security or if it is more likely than not that Heartland will be required to sell the security before recovery, an other-than-temporary impairment write-down is recognized in earnings equal to the difference between the security’s amortized cost basis and its fair value. If Heartland does not intend to sell the security and it is not more likely than not that it will be required to sell the security before recovery, the other-than-temporary impairment write-down is separated into an amount representing credit loss, which is recognized in noninterest income, and an amount related to all other factors, which is recognized in other comprehensive income. Realized securities gains or losses on securities sales (using specific identification method) and declines in value judged to be other-than-temporary are included in impairment loss on securities in the consolidated statements of income. Securities Held to Maturity - Securities which Heartland has the ability and positive intent to hold to maturity are classified as held to maturity. Such securities are stated at amortized cost, adjusted for premiums and discounts that are amortized/accreted using the interest method over the period from the purchase date to the expected maturity or call date of the related security. Unrealized losses determined to be other-than-temporary are charged to noninterest income. Loans - Interest on loans is accrued and credited to income based primarily on the principal balance outstanding. Loans are considered past due if the required principal and interest payments have not been received as of the date such payments were due. Heartland’s policy is to discontinue the accrual of interest income on any loan when, in the opinion of management, there is a reasonable doubt as to the timely collection of the interest and principal, normally when a loan is 90 days past due. When interest accruals are deemed uncollectible, interest credited to income in the current year is reversed and interest accrued in prior years is charged to the allowance for loan losses. A loan can be restored to accrual status if the borrower has resumed paying the full amount of the scheduled contractual interest and principal payments on the loan, and (1) all principal and interest amounts contractually due (including arrearages) are reasonably assured of repayment within a reasonable period of time, and (2) that there is a sustained period of repayment performance (generally a minimum of six months ) by the borrower in accordance with the contractual terms. Under Heartland’s credit policies, 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 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, at the observable market price of the loan or the fair value of the collateral if the loan is collateral dependent. Net nonrefundable loan origination fees and certain direct costs associated with the lending process are deferred and recognized as a yield adjustment over the life of the related loan. Acquired Loans - The FASB ASC Topic 310-30 establishes accounting standards for acquired loans with deteriorated credit quality. Heartland reviews acquired loans for differences between contractual cash flows and cash flows expected to be collected from initial investment in the acquired loans to determine if those differences are attributable, at least in part, to credit quality. If those differences are attributable to credit quality, the contractually required payments received in excess of the amount of its cash flows expected at acquisition, or nonaccretable discount, is not accreted into income. FASB ASC 310-30 requires that the excess of all cash flows expected at acquisition over the initial investment in the loan be recognized as interest income using the interest method over the term of the loan. This excess is referred to as accretable discount and is recorded as a reduction of the loan balance. When a loan is paid off, the excess of any cash received over the net investment is recorded as interest income. In addition to the amount of purchase discount that is recognized at that time, income may include interest owed by the borrower prior to the acquisition of the loan, interest collected if on nonperforming status, prepayment fees and other loan fees. At acquisition, for purchased loans not subject to ASC 310-30, the purpose of the loan (e.g., business, agricultural or personal), the type of borrower (e.g., business or individual) and the type of collateral for the loan (e.g., commercial real estate, residential real estate, general business assets or unsecured) of each loan are considered in order to assign purchased loans into one of the following five loan pools: commercial, commercial real estate, agricultural and agricultural real estate, residential real estate and consumer. These five pools are separately maintained and tracked for each acquisition, and they are consistent with the five loan categories presented in Note 5, "Loans." For purchased loans not subject to ASC 310-30, the discount, if any, representing the excess of the amount of reasonably estimable and probable discounted future cash collections over the purchase price, is accreted into interest income using the interest method over the weighted average remaining contractual life of the loan pool. Because Heartland uses the pool method as described above, no adjustment is made to the discount of an individual loan on the specific date of a credit event with respect to such loan. Additionally, the discount is not accreted on nonperforming loans. Loans not subject to ASC 310-30 migrate from the purchased loan pools to the regular loan portfolio when the borrower requests to refinance the loan prior to maturity or renews the loan at maturity, and, in either event, signs a new loan agreement. In conjunction with the refinancing or renewal process, the new loan is evaluated in accordance with Heartland’s underwriting standards, and a credit decision is made with respect to whether the new loan should be extended. Troubled Debt Restructured Loans - Loans are considered troubled debt restructured loans ("TDR") if concessions have been granted to borrowers that are experiencing financial difficulty. The concessions granted generally involve the modification of terms of the loan, such as changes in payment schedule or interest rate, which generally would not otherwise be considered. TDRs can involve loans remaining on nonaccrual, moving to nonaccrual, or continuing on accrual status, depending on the individual facts and circumstances of the borrower. Nonaccrual TDRs are included and treated consistently with all other nonaccrual loans. In addition, all accruing TDRs are reported and accounted for as impaired loans. Generally, TDRs remain on nonaccrual until the customer has attained a sustained period of repayment performance under the modified loan terms (generally a minimum of six months ). However, performance prior to the restructuring, or significant events that coincide with the restructuring, are considered in assessing whether the borrower can meet the new terms and whether the loan should be returned to or maintained on accrual status. If the borrower’s ability to meet the revised payment schedule is not reasonably assured, the loan remains on nonaccrual status. A loan that is a TDR that has an interest rate consistent with market rates at the time of restructuring and is in compliance with its modified terms in the calendar year after the year in which the restructuring took place is no longer considered a TDR but remains an impaired loan. To be considered in compliance with its modified terms, a loan that is a TDR must be in accrual status and must be current or less than 30 days past due under the modified repayment terms; however, the loan will continue to be considered impaired. A loan that has been modified at a below market rate will remain classified as a TDR and an impaired loan. If the borrower’s financial conditions improve to the extent that the borrower qualifies for a new loan with market terms, the new loan will not be considered a TDR or impaired if Heartland's credit analysis shows the borrower's ability to perform under the new market terms. Loans Held for Sale - Loans held for sale are stated at the lower of cost or fair value on an aggregate basis. Gains or losses on sales are recorded in noninterest income. Direct loan origination costs and fees are deferred at origination of the loan. These deferred costs and fees are recognized in noninterest income as part of the gain or loss on sales of loans upon sale of the loan. Mortgage Servicing and Transfers of Financial Assets - Heartland regularly sells residential mortgage loans to others, primarily government sponsored entities, on a non-recourse basis. Sold loans are not included in the accompanying consolidated balance sheets. Heartland generally retains the right to service the sold loans for a fee. At December 31, 2017 and 2016 , Heartland was servicing mortgage loans primarily for government sponsored entities with aggregate unpaid principal balances of $3.56 billion and $4.31 billion , respectively. Allowance for Loan Losses - The allowance for loan losses is maintained at a level estimated by management to provide for known and inherent risks in the loan portfolios. The allowance is based upon a continuing review of past loan loss experience, current economic conditions, volume growth, the underlying collateral value of the loans and other relevant factors. Loans which are deemed uncollectible are charged off and deducted from the allowance. Provisions for loan losses and recoveries on previously charged-off loans are added to the allowance. Reserve for Unfunded Commitments - This reserve is maintained at a level that, in the opinion of management, is appropriate to absorb probable losses associated with Heartland’s commitment to lend funds under existing agreements such as letters or lines of credit. Management determines the appropriateness of the reserve for unfunded commitments based upon reviews of delinquencies, current economic conditions, the risk characteristics of the various categories of commitments and other relevant factors. The reserve is based on estimates, and ultimate losses may vary from the current estimates. These estimates are evaluated on a regular basis and, as adjustments become necessary, they are reported in earnings in the periods in which they become known. Draws on unfunded commitments that are considered uncollectible at the time funds are advanced are charged to the allowance. Provisions for unfunded commitment losses are added to the reserve for unfunded commitments, which is included in the Accrued Expenses and Other Liabilities section of the consolidated balance sheets. Premises, Furniture and Equipment, net - Premises, furniture and equipment are stated at cost less accumulated depreciation. The provision for depreciation of premises, furniture and equipment is determined by straight-line and accelerated methods over the estimated useful lives of 18 to 39 years for buildings, 15 years for land improvements and 3 to 7 years for furniture and equipment. Other Real Estate - Other real estate represents property acquired through foreclosures and settlements of loans. Property acquired is recorded at the estimated fair value of the property less disposal costs. The excess of carrying value over fair value less disposal costs is charged against the allowance for loan losses. Subsequent write downs estimated on the basis of later valuations and gains or losses on sales are charged to loss on sales/valuation of assets, net. Expenses incurred in maintaining such properties are charged to other real estate and loan collection expenses. Goodwill - Goodwill represents the excess of the purchase price of acquired subsidiaries’ net assets over their fair value at the purchase date. Heartland assesses goodwill for impairment annually, and more frequently if events occur which may indicate possible impairment, and assesses goodwill at the reporting unit level, also giving consideration to overall enterprise value as part of that assessment. In evaluating goodwill for impairment, Heartland first assesses qualitative factors to determine whether it is more likely than not (that is, a likelihood of more than 50%) that the fair value of a reporting unit is less than its carrying amount. If Heartland concludes that it is more likely than not that the fair value of a reporting unit is more than its carrying value, then no further testing of goodwill assigned to the reporting unit is required. However, if Heartland concludes that it is more likely than not that the fair value of a reporting unit is less than its carrying value, then Heartland performs a two-step goodwill impairment test to identify potential goodwill impairment and measure the amount of goodwill impairment to recognize, if any. In the first step, the fair value of a reporting unit is compared to its carrying amount, including goodwill. If the fair value of the reporting unit exceeds its carrying amount, goodwill is not considered impaired and it is not necessary to continue to step two of the impairment process. If the fair value of the reporting unit is less than the carrying amount, step two is performed. In step two, the implied fair value of goodwill is compared to the carrying value of the reporting unit's goodwill. The implied fair value of goodwill is computed as a residual value after allocating the fair value of the reporting unit to its assets and liabilities. Heartland estimates the fair value of its reporting units using market multiples of comparable entities, including recent transactions, or a combination of market multiples and discounted cash flow methodology. These methods incorporate assumptions specific to the entity, such as the use of financial forecasts. Core Deposit Intangibles and Customer Relationship Intangibles, Net - Core deposit intangibles are amortized over 8 to 18 years on an accelerated basis. Customer relationship intangibles are amortized over 22 years on an accelerated basis. Annually, Heartland reviews these intangible assets for events or circumstances that may indicate a change in the recoverability of the underlying basis. Servicing Rights, Net - Mortgage and commercial servicing rights associated with loans originated and sold, where servicing is retained, are initially capitalized at fair value and recorded on the consolidated statements of income as a component of gains on sale of loans held for sale. The values of these capitalized servicing rights are amortized as an offset to the loan servicing income earned in relation to the servicing revenue expected to be earned. The carrying values of these rights are reviewed quarterly for impairment based on the calculation of their fair value as performed by an outside third party. For purposes of measuring impairment, the rights are stratified into certain risk characteristics including loan type and loan term. A valuation allowance of $12,000 and $33,000 , was required as of December 31, 2017 , and 2016 , respectively, for Heartland's commercial servicing rights with an original term of greater than 20 years . Cash Surrender Value on Life Insurance - Heartland and its subsidiaries have purchased life insurance policies on the lives of certain officers. The one-time premiums paid for the policies, which coincide with the initial cash surrender value, are recorded as an asset. Increases or decreases in the cash surrender value, other than proceeds from death benefits, are recorded as noninterest income in income on bank owned life insurance. Proceeds from death benefits first reduce the cash surrender value attributable to the individual policy and then any additional proceeds are recorded in other noninterest income. Income Taxes - Heartland and its subsidiaries file a consolidated federal income tax return and separate or combined income or franchise tax returns as required by the various states. Heartland recognizes certain income and expenses in different time periods for financial reporting and income tax purposes. The provision for deferred income taxes is based on an asset and liability approach and represents the change in deferred income tax accounts during the year, including the effect of enacted tax rate changes. A valuation allowance is provided to reduce deferred tax assets if their expected realization is deemed not to be more likely than not. A tax position is recognized as a benefit only if it is "more likely than not" that the tax position would be sustained in a tax examination. The amount recognized is the largest amount of tax benefit that is greater than 50% likely of being realized on examination. Heartland recognizes interest and penalties related to income tax matters in income tax expense. Derivative Financial Instruments - Heartland uses derivative financial instruments as part of its interest rate risk management, which includes interest rate swaps, certain interest rate lock commitments and forward sales of securities related to mortgage banking activities. FASB ASC Topic 815 establishes accounting and reporting standards for derivative instruments, including certain derivative instruments embedded in other contracts, and for hedging activities. As required by ASC 815, Heartland records all derivatives on the consolidated balance sheets at fair value. The accounting for changes in the fair value of derivatives depends on the intended use of the derivative and the resulting designation. Derivatives used to hedge the exposure to variability in expected future cash flows, or other types of forecasted transactions, are considered cash flow hedges. To qualify for hedge accounting, Heartland must comply with the detailed rules and documentation requirements at the inception of the hedge, and hedge effectiveness is assessed at inception and periodically throughout the life of each hedging relationship. Hedge ineffectiveness, if any, is measured periodically throughout the life of the hedging relationship. For derivatives designated as cash flow hedges, the effective portion of changes in the fair value of the derivative is initially reported in other comprehensive income (loss) and subsequently reclassified to interest income or expense when the hedged transaction affects earnings, while the ineffective portion of changes in the fair value of the derivative, if any, is recognized immediately in other noninterest income. Heartland assesses the effectiveness of each hedging relationship by comparing the cumulative changes in cash flows of the derivative hedging instrument with the cumulative changes in cash flows of the designated hedged item or transaction. No component of the change in the fair value of the hedging instrument is excluded from the assessment of hedge effectiveness. Heartland has fair value hedging relationships at December 31, 2017 . 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 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 does not use derivatives for trading or speculative purposes. Derivatives not designated as hedges are not speculative and are used to manage Heartland’s exposure to interest rate movements and other identified risks, but do not meet the strict hedge accounting requirements of ASC 815. Mortgage Derivatives - Heartland uses interest rate lock commitments to originate residential mortgage loans held for sale and forward commitments to sell residential mortgage loans and mortgage backed securities. These commitments are considered derivative instruments. 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. Segment Reporting - Public business enterprises are required to report information about operating segments in financial statements and selected information about operating segments in financial reports issued to shareholders. Operating segments are components of an enterprise about which separate financial information is available that is evaluated regularly by management in determining how to allocate resources and to assess effectiveness of the segments' performance. Generally, financial information is required to be reported on the basis that is used internally for evaluating segment performance and deciding how to allocate resources to segments. Heartland has two reporting segments, one for community banking and one for mortgage banking operations. Fair Value Measurements - Fair value represents the estimated price at which an orderly transaction to sell an asset or transfer a liability would take place between market participants at the measurement date under current market conditions (i.e. an exit price concept). Fair value measurement is based upon quoted prices, if available. If quoted prices are not available, fair values are measured using discounted cash flow or other valuation techniques. Inputs into the valuation methods are subjective in nature, involve uncertainties, and require significant judgment and therefore cannot be determined with precision. Accordingly, the derived fair value estimates presented herein are not necessarily indicative of the amounts Heartland could realize in a current market exchange. Assets and liabilities are categorized into three levels based on the markets in which the assets and liabilities are traded and the reliability of the assumptions used to determine the fair value. In instances where the determination of the fair value measurement is based on inputs from different levels of the fair value hierarchy, the level in the fair value hierarchy in which the entire fair value measurement falls is based on the lowest level input that is significant to the fair value measurement in its entirety. Heartland's assessment of the significance of a particular input to the fair value measurement in its entirety requires judgment and considers factors specific to the asset or liability. Below is a brief description of each fair value level: 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 which 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. Treasury Stock - Treasury stock is accounted for by the cost method, whereby shares of common stock reacquired are recorded at their purchase price. When treasury stock is reissued, any difference between the sales proceeds, or fair value when issued for business combinations, and the cost is recognized as a charge or credit to capital surplus. Trust Department Assets - Property held for customers in fiduciary or agency capacities is not included in the accompanying consolidated balance sheets because such items are not assets of the Heartland banks. 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 years ended December 31, 2017 , 2016 and 2015 , are shown in the table below: (Dollars and number of shares in thousands, except per share data) 2017 2016 2015 Net income attributable to Heartland $ 75,272 $ 80,349 $ 60,042 Preferred dividends (58 ) (292 ) (817 ) Interest expense on convertible preferred debt 12 51 — Net income available to common stockholders $ 75,226 $ 80,108 $ 59,225 Weighted average common shares outstanding for basic earnings per share 28,168 24,573 20,672 Assumed incremental common shares issued upon exercise of stock options and non-vested restricted stock units 258 300 257 Weighted average common shares for diluted earnings per share 28,426 24,873 20,929 Earnings per common share — basic $ 2.67 $ 3.26 $ 2.87 Earnings per common share — diluted $ 2.65 $ 3.22 $ 2.83 Subsequent Events - Heartland has evaluated subsequent events that may require recognition or disclosure through the filing date of this Annual Report on Form 10-K with the SEC. On February 23, 2018, Heartland completed the acquisition of Signature Bancshares, Inc. parent company of Signature Bank, based in Minnetonka, Minnesota. See Note 2, "Acquisitions," for further details regarding this acquisition. Effect of New Financial Accounting Standards - In May 2014, the FASB issued 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 st

Acquisitions

Acquisitions	12 Months Ended
	Dec. 31, 2017
Business Combinations [Abstract]
Acquisitions	ACQUISITIONS 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 $7.7 million was cash, and the remainder was settled by delivery of approximately 1,001,246 shares of Heartland common stock. As of December 31, 2017, Signature Bank had total assets of $409.2 million , including $339.1 million of gross loans held to maturity, and deposits of $368.1 million . Signature Bank was merged with Heartland’s wholly-owned subsidiary Minnesota Bank & Trust, and the combined entity operates under the Minnesota Bank & Trust brand name. The transaction was a tax-free reorganization with respect to the stock consideration received by the stockholders of Signature Bancshares, Inc. The systems conversion for this transaction is expected to occur in the second quarter of 2018. This transaction closed after December 31, 2017, and is not reflected in Heartland's results of operation or financial condition. 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 December 31, 2017, FirstBank & Trust Company had total assets of $929.6 million , including $669.3 million of gross loans held to maturity, and deposits of $821.9 million . FirstBank & Trust Company will operate as a wholly-owned subsidiary of Heartland. The transaction is expected to close in the second quarter of 2018. 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 sheet. The transaction was a tax-free reorganization with respect to the stock consideration received by the stockholders of Citywide Banks of Colorado, Inc. The assets and liabilities of Citywide Banks of Colorado, Inc. were recorded on the consolidated balance sheet at the estimated fair value on the acquisition date. The following table represents, in thousands, the amounts recorded on the consolidated balance sheet as of July 7, 2017: As of July 7, 2017 Fair value of consideration paid: Common stock (3,216,161 shares) $ 152,607 Cash 58,636 Total consideration paid 211,243 Fair value of assets acquired: Cash and due from banks 21,341 Interest bearing deposits with the Federal Reserve and other banks and other short-term investments 74,686 Time deposits in other financial institutions 6,304 Securities: Securities available for sale 234,390 Other securities 2,628 Loans held to maturity 985,399 Premises, furniture and equipment, net 17,206 Premises, furniture and equipment held for sale 1,350 Other real estate, net 6,916 Core deposit intangibles and customer relationship intangibles, net 16,041 Cash surrender value on life insurance 21,015 Other assets 11,263 Total assets 1,398,539 Fair value of liabilities assumed: Deposits 1,210,074 Short term borrowings 34,445 Other borrowings 21,636 Other liabilities 16,295 Total liabilities assumed 1,282,450 Fair value of net assets acquired 116,089 Goodwill resulting from acquisition $ 95,154 Heartland recognized $95.2 million of goodwill in conjunction with the acquisition of Citywide Banks of Colorado, Inc., which is calculated as the excess of both the consideration exchanged and the liabilities assumed as compared to the fair value of identifiable assets acquired. Goodwill resulted from the expected operational synergies, enhanced market area, cross-selling opportunities and expanded business lines. See Note 8 for further information on goodwill. Pro Forma Information (unaudited): The following pro forma information represents the results of operations for the years ended December 31, 2017, and 2016, as if the Citywide Banks of Colorado, Inc. acquisition occurred on January 1, 2017, and January 1, 2016, respectively: (Dollars in thousands, except per share data), unaudited For the Years Ended December 31, 2017 2016 Net interest income $ 357,341 $ 344,784 Net income available to common stockholders $ 75,599 $ 90,470 Basic earnings per share $ 2.67 $ 3.26 Diluted earnings per share $ 2.65 $ 3.22 The above pro forma results are presented for illustrative purposes and are not intended to represent or be indicative of the actual results of operations of the merged companies that would have been achieved had the acquisition occurred on January 1, 2016, nor are they intended to represent or be indicative of future results of operations. The pro forma results do not include expected operating cost savings as a result of the acquisition or adjustments for $10.1 million of transaction costs recorded by Citywide Banks of Colorado, Inc. prior to the acquisition. These pro forma results require significant estimates and judgments particularly with respect to valuation and accretion of income associated with the acquired loans. Heartland incurred $3.8 million of pre-tax merger related expenses in 2017, associated with the Citywide Banks of Colorado, Inc. acquisition. The merger expenses are reflected on the consolidated statements of income for the applicable period and are reported primarily in the categories of salaries and employee benefits, professional fees, loss on sales/valuations of assets, net and other noninterest expenses. Acquired loans were preliminarily recorded at fair value based on a discounted cash flow valuation methodology that considers, among other things, projected default rates, loss given defaults and recovery rates. No allowance for credit losses was carried over from the acquisition. The balance of nonaccrual loans on the acquisition date was $1.2 million . 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. CIC Bancshares, Inc. On February 5, 2016, Heartland completed the acquisition of CIC Bancshares, Inc., parent company of Centennial Bank, headquartered in Denver, Colorado. The purchase price was approximately $76.9 million , which was paid by delivery of 2,003,235 shares of Heartland common stock and cash of $15.7 million . In addition, Heartland issued a new series of convertible preferred stock with a fair value of $3.8 million and assumed convertible notes and subordinated debt totaling approximately $7.9 million . Simultaneous with the closing of the transaction, Centennial Bank merged into Heartland's Summit Bank & Trust, with the resulting institution operating under the name Centennial Bank and Trust. As of the close date, the transaction included, at fair value, total assets of $772.6 million , including total loans of $581.5 million , and total deposits of $648.1 million . The transaction was a tax-free reorganization with respect to the stock consideration received by the stockholders of CIC Bancshares, Inc. The assets and liabilities of CIC Bancshares, Inc. were recorded on the consolidated balance sheet at the estimated fair value on the acquisition date. The following table represents, in thousands, the amounts recorded on the consolidated balance sheet as of February 5, 2016: As of February 5, 2016 Fair value of consideration paid Common stock (2,003,235 shares) $ 57,433 Preferred stock (3,000 shares) 3,777 Cash 15,672 Total consideration paid 76,882 Fair value of assets acquired: Cash and due from banks 23,756 Securities: Securities available for sale 92,831 Other securities 3,486 Loans held to maturity 581,477 Premises, furniture and equipment, net 16,450 Other real estate, net 1,934 Core deposit intangibles and customer relationship intangibles, net 6,576 Other assets 16,276 Total assets 742,786 Fair value of liabilities assumed: Deposits 648,111 Short term borrowings 35,766 Other borrowings 7,924 Other liabilities 3,951 Total liabilities assumed 695,752 Fair value of net assets acquired 47,034 Goodwill resulting from acquisition $ 29,848 Heartland recognized $29.8 million of goodwill in conjunction with the acquisition of CIC Bancshares, Inc., which is calculated as the excess of both the consideration exchanged and the liabilities assumed as compared to the fair value of identifiable assets acquired. Goodwill resulted from the expected operational synergies, enhanced market area, cross-selling opportunities and expanded business lines. See Note 8 for further information on goodwill. Heartland incurred $551,000 of pre-tax merger related expenses in 2016 associated with the Centennial Bank acquisition. The merger expenses are reflected on the consolidated statements of income for the applicable period and are reported primarily in the categories of professional fees and other noninterest expenses. Acquired loans were preliminarily recorded at fair value based on a discounted cash flow valuation methodology that considers, among other things, projected default rates, loss given defaults and recovery rates. No allowance for credit losses was carried over from the acquisition. The balance of nonaccrual loans on the acquisition date was $1.6 million .

Cash and Due from Banks

Cash and Due from Banks	12 Months Ended
	Dec. 31, 2017
Cash and Cash Equivalents [Abstract]
Cash and Due from Banks	CASH AND DUE FROM BANKS The Heartland banks are required to maintain certain average cash reserve balances as a non-member bank of the Federal Reserve System. The reserve balance requirements at December 31, 2017 and 2016 , were $10.7 million and $9.1 million, respectively.

Securities

Securities	12 Months Ended
	Dec. 31, 2017
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 December 31, 2017 , and December 31, 2016 , are summarized in the table below, in thousands: Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Estimated Fair Value 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 December 31, 2016 U.S. government corporations and agencies $ 4,716 $ 16 $ (32 ) $ 4,700 Mortgage and asset-backed securities 1,321,760 7,026 (38,286 ) 1,290,500 Obligations of states and political subdivisions 553,020 2,436 (19,312 ) 536,144 Total debt securities 1,879,496 9,478 (57,630 ) 1,831,344 Equity securities 14,451 69 — 14,520 Total $ 1,893,947 $ 9,547 $ (57,630 ) $ 1,845,864 The amortized cost, gross unrealized gains and losses and estimated fair values of held to maturity securities as of December 31, 2017 , and December 31, 2016 , are summarized in the table below, in thousands: Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Estimated Fair Value December 31, 2017 Obligations of states and political subdivisions 253,550 12,460 (516 ) 265,494 Total $ 253,550 $ 12,460 $ (516 ) $ 265,494 December 31, 2016 Obligations of states and political subdivisions 263,662 12,282 (1,145 ) 274,799 Total $ 263,662 $ 12,282 $ (1,145 ) $ 274,799 No transfers from available for sale to held to maturity were made in 2017 or 2016. At December 31, 2017 , approximately 75% of Heartland's mortgage and asset-backed securities were issued by government-sponsored enterprises. The amortized cost and estimated fair value of securities available for sale at December 31, 2017 , 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. December 31, 2017 Amortized Cost Estimated Fair Value Due in 1 year or less $ 185 $ 185 Due in 1 to 5 years 54,630 54,741 Due in 5 to 10 years 95,345 93,393 Due after 10 years 296,258 298,024 Total debt securities 446,418 446,343 Mortgage and asset-backed securities 1,785,467 1,753,736 Equity securities 16,296 16,674 Total investment securities $ 2,248,181 $ 2,216,753 The amortized cost and estimated fair value of debt securities held to maturity at December 31, 2017 , 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. December 31, 2017 Amortized Cost Estimated Fair Value Due in 1 year or less $ 1,892 $ 1,923 Due in 1 to 5 years 26,790 27,433 Due in 5 to 10 years 98,285 101,377 Due after 10 years 126,583 134,761 Total investment securities $ 253,550 $ 265,494 As of December 31, 2017 , securities with a carrying value of $670.3 million were pledged to secure public and trust deposits, short-term borrowings and for other purposes as required and permitted by law. Gross gains and losses realized related to sales of securities available for sale for the years ended December 31, 2017 , 2016 and 2015 are summarized as follows, in thousands: 2017 2016 2015 Available for Sale Securities sold: Proceeds from sales $ 1,456,750 $ 909,942 $ 1,115,359 Gross security gains 10,585 13,200 15,205 Gross security losses 3,812 1,562 2,022 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 December 31, 2017 , and December 31, 2016 . 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 or more months. The reference point for determining how long an investment was in an unrealized loss position w as December 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 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 ) Equity securities — — — — — — Total temporarily impaired securities $ 948,929 $ (12,238 ) $ 559,158 $ (30,101 ) $ 1,508,087 $ (42,339 ) December 31, 2016 U.S. government corporations and agencies $ 4,185 $ (32 ) $ — $ — $ 4,185 $ (32 ) Mortgage and asset-backed securities 744,202 (23,527 ) 272,449 (14,759 ) 1,016,651 (38,286 ) Obligations of states and political subdivisions 414,151 (19,309 ) 251 (3 ) 414,402 (19,312 ) Total debt securities 1,162,538 (42,868 ) 272,700 (14,762 ) 1,435,238 (57,630 ) Equity securities — — — — — — Total temporarily impaired securities $ 1,162,538 $ (42,868 ) $ 272,700 $ (14,762 ) $ 1,435,238 $ (57,630 ) 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 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 ) December 31, 2016 Obligations of states and political subdivisions 31,479 (884 ) 2,017 (261 ) 33,496 (1,145 ) Total temporarily impaired securities $ 31,479 $ (884 ) $ 2,017 $ (261 ) $ 33,496 $ (1,145 ) 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. During 2015, Heartland recorded additional credit-related OTTI on two of the private label mortgage-backed securities that previously had OTTI credit losses. The underlying collateral on these securities experienced an increased level of defaults and a slowing of voluntary prepayments causing the present value of the forward expected cash flows, using prepayment and default vectors, to be below the amortized cost basis of the securities. Based on Heartland's evaluation, a $769,000 OTTI attributable to credit-related losses was recorded in December 2015. The credit-related OTTI was $716,000 , of which $200,000 was reclassified from previous non-credit related OTTI in the held to maturity category. Credit-related OTTI was $53,000 in the available for sale category. During 2016, Heartland sold the mortgage-backed securities in the held to maturity portfolio because the credit quality of the securities showed further deterioration, and it was unlikely Heartland would recover the remaining basis of the securities prior to maturity. The significant deterioration of the credit quality of these securities was inconsistent with Heartland's original intent upon purchase and classification of these held to maturity securities. The carrying value of these securities was $4.4 million , and the associated realized gross gains were $89,000 , and the realized gross losses were $439,000 . Heartland also sold the mortgage-backed security in the available for sale portfolio with previously recorded credit-related OTTI in 2016. The carrying value of this security was $483,000 , and the associated gross loss was $85,000 . The remaining unrealized losses on Heartland's mortgage-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. During 2016, Heartland sold one obligation of states and political subdivisions from the held to maturity portfolio because the credit quality of the security showed significant deterioration, and it was unlikely Heartland would recover the remaining basis of the security prior to maturity. The significant deterioration of the credit quality of this security was inconsistent with Heartland's original intent upon purchase and classification of this held to maturity security. The carrying value of this security was $503,000 , and the associated gross loss was $1,500 . 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 period ended December 31, 2017 . There were no gross realized gains and $85,000 of gross realized losses on the sale of available for sale securities with OTTI write-downs for the period ended December 31, 2016 . Additionally, there were $89,000 of gross realized gains and $439,000 of gross realized losses on the sale of held to maturity securities with OTTI write-downs for the period ended December 31, 2016 . The following table shows the detail of total OTTI write-downs included in earnings, in thousands: For the Years Ended December 31, 2017 2016 2015 OTTI write-downs included in earnings: Available for sale debt securities: Mortgage-backed securities $ — $ — $ 53 Held to maturity debt securities: Mortgage-backed securities — — 716 Total debt security OTTI write-downs included in earnings $ — $ — $ 769 The following table shows the detail of OTTI write-downs on debt securities included in earnings and the related changes in AOCI for the same securities, in thousands: For the Years Ended December 31, 2017 2016 2015 OTTI on debt securities Recorded as part of gross realized losses: Credit related OTTI $ — $ — $ 769 Intent to sell OTTI — — — Total recorded as part of gross realized losses — — 769 Recorded directly to AOCI for non-credit related impairment: Reclassification of non-credit related impairment — — (200 ) Reduction of non-credit related impairment related to security sales — (120 ) — Accretion of non-credit related impairment — (7 ) (95 ) Total changes to AOCI for non-credit related impairment — (127 ) (295 ) Total OTTI losses (accretion) recorded on debt securities $ — $ (127 ) $ 474 The following table presents a rollforward of the credit loss component of OTTI recognized in earnings for debt securities still owned by Heartland. The credit loss component of the amortized cost represents the difference between the present value of expected future cash flows discounted using the security's current effective interest rate and the amortized cost basis of the security prior to considering credit losses. OTTI recognized in earnings for credit impaired debt securities is presented as additions and is classified into one of two components based upon whether the current period is the first time the debt security was credit-impaired (initial credit impairment) or if the debt security was previously credit impaired (subsequent credit impairments). The credit loss component is reduced if Heartland sells, intends to sell, or if management believes they will be required to sell previously credit impaired debt securities. Additionally, the credit loss component is reduced if Heartland receives, expects to receive cash flows in excess of what was previously expected to be received over the remaining life of the credit impaired debt security, the security matures or is fully written down. Changes in the credit loss component of the credit impaired debt securities for the years ended December 31, 2017 , 2016 and 2015 , were as follows, in thousands: For the Years Ended December 31, 2017 2016 2015 Credit loss component, beginning of period $ — $ 1,750 $ 981 Additions: Initial credit impairments — — — Subsequent credit impairments — — 769 Total additions — — 769 Reductions: For securities sold — 1,750 — Total reductions — 1,750 — Credit loss component, end of period $ — $ — $ 1,750 Included in other securities were shares of stock in each Federal Home Loan Bank (the "FHLB") of Des Moines, Chicago, Dallas, San Francisco and Topeka at an amortized cost of $14.0 million at December 31, 2017 and $14.4 million at December 31, 2016 . The Heartland banks are required to maintain FHLB stock as members of the various FHLBs as required by these institutions. These equity securities are "restricted" in that they can only be sold back to the respective institutions or another member institution at par. Therefore, they are less liquid than other marketable equity securities and their 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 December 31, 2017 , did not consider the investments to be other than temporarily impaired.

Loans

Loans	12 Months Ended
	Dec. 31, 2017
Receivables [Abstract]
Loans	LOANS Loans as of December 31, 2017 , and December 31, 2016 , were as follows, in thousands: December 31, 2017 December 31, 2016 Loans receivable held to maturity: Commercial $ 1,646,606 $ 1,287,265 Commercial real estate 3,163,269 2,538,582 Agricultural and agricultural real estate 511,588 489,318 Residential real estate 624,279 617,924 Consumer 447,484 420,613 Gross loans receivable held to maturity 6,393,226 5,353,702 Unearned discount (556 ) (699 ) Deferred loan fees (1,206 ) (1,284 ) Total net loans receivable held to maturity 6,391,464 5,351,719 Allowance for loan losses (55,686 ) (54,324 ) Loans receivable, net $ 6,335,778 $ 5,297,395 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. See Note 1 for Heartland's accounting policy for 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 16% 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, 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 December 31, 2017 , and December 31, 2016 , 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 changes to the accounting for the allowance for loan losses policy during 2017 or 2016 . 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 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 December 31, 2016 Commercial $ 1,318 $ 13,447 $ 14,765 $ 3,712 $ 1,283,553 $ 1,287,265 Commercial real estate 2,671 21,648 24,319 45,217 2,493,365 2,538,582 Agricultural and agricultural real estate 816 3,394 4,210 16,730 472,588 489,318 Residential real estate 497 1,766 2,263 25,726 592,198 617,924 Consumer 1,451 7,316 8,767 5,988 414,625 420,613 Total $ 6,753 $ 47,571 $ 54,324 $ 97,373 $ 5,256,329 $ 5,353,702 The following table presents nonaccrual loans, accruing loans past due 90 days or more and troubled debt restructured loans at December 31, 2017 , and December 31, 2016 , in thousands. December 31, 2017 December 31, 2016 Nonaccrual loans $ 58,272 $ 62,591 Nonaccrual troubled debt restructured loans 4,309 1,708 Total nonaccrual loans $ 62,581 $ 64,299 Accruing loans past due 90 days or more $ 830 $ 86 Performing troubled debt restructured loans $ 6,617 $ 10,380 Heartland had $10.9 million of troubled debt restructured loans at December 31, 2017 , of which $4.3 million were classified as nonaccrual and $6.6 million were accruing according to the restructured terms. Heartland had $12.1 million of troubled debt restructured loans at December 31, 2016 , of which $1.7 million were classified as nonaccrual and $10.4 million were accruing according to the restructured terms. At December 31, 2017, $4.6 million of the residential real estate troubled debt restructured loans were repurchased loans under various GNMA insured or guaranteed loan programs. The following table provides information on troubled debt restructured loans that were modified during the years ended December 31, 2017 , and December 31, 2016 , in thousands: For the Years Ended December 31, 2017 December 31, 2016 Number of Loans Pre-Modification Recorded Investment Post-Modification Recorded Investment Number of Loans Pre-Modification Recorded Investment Post-Modification Recorded Investment Commercial 3 $ 124 $ 124 1 $ 95 $ 95 Commercial real estate — — — 2 641 641 Total commercial and commercial real estate 3 124 124 3 736 736 Agricultural and agricultural real estate — — — — — — Residential real estate 29 4,126 3,794 8 1,597 1,597 Consumer — — — — — — Total 32 $ 4,250 $ 3,918 11 $ 2,333 $ 2,333 The pre-modification and post-modification recorded investment represents amounts as of the date of loan modification. The change in 2017 related to the pre-modification investment and post-modification investment amounts on Heartland’s residential real estate troubled debt restructured loans is due to $503,000 of principal deferment collected from government guarantees and $170,000 of capitalized interest and escrow. At December 31, 2017 , there were no commitments to extend credit to any of the borrowers with an existing TDR. The following table provides information on troubled debt restructured loans for which there was a payment default during the years ended December 31, 2017 , and December 31, 2016 , in thousands, that had been modified during the 12-month period prior to the default: With Payment Defaults During the Following Periods For the Years Ended December 31, 2017 December 31, 2016 Number of Loans Recorded Investment Number of Loans Recorded Investment Commercial — $ — 1 $ 95 Commercial real estate — — — — Total commercial and commercial real estate — — 1 95 Agricultural and agricultural real estate — — — — Residential real estate 16 2,435 2 264 Consumer — — — — Total 16 $ 2,435 3 $ 359 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 financial trends due to borrower specific or systemic conditions that, if left uncorrected, threaten its 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 sound net worth and paying capacity of the borrower and 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 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 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 an operating entity. Specific pending events, such as capital injections, liquidations or perfection of liens on additional collateral, may strengthen the credit, thus deferring classification of the loan as loss until exact status can be determined. The "loss" rating is assigned to loans considered uncollectible. As of December 31, 2017 , Heartland had no loans classified as doubtful and no loans classified as loss. 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 December 31, 2017 , and December 31, 2016 , in thousands: Pass Nonpass Total 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 December 31, 2016 Commercial $ 1,187,557 $ 99,708 $ 1,287,265 Commercial real estate 2,379,632 158,950 2,538,582 Total commercial and commercial real estate 3,567,189 258,658 3,825,847 Agricultural and agricultural real estate 424,311 65,007 489,318 Residential real estate 584,626 33,298 617,924 Consumer 409,474 11,139 420,613 Total gross loans receivable held to maturity $ 4,985,600 $ 368,102 $ 5,353,702 The nonpass category in the table above is comprised of approximately 52% special mention and 48% substandard as of December 31, 2017 . The percentage of nonpass loans on nonaccrual status as of December 31, 2017 , was 16% . As of December 31, 2016 , the nonpass category in the table above was comprised of approximately 47% special mention and 53% substandard. The percentage of nonpass loans on nonaccrual status as of December 31, 2016 , was 17% . Loans delinquent 30-89 days as a percentage of total loans were 0 .27% at December 31, 2017 , and 0 .37% at December 31, 2016 . Changes in credit risk are monitored on a continuous basis and changes in risk ratings are made when identified. All impaired loans are reviewed at least annually. As of December 31, 2017 , Heartland had $ 3.1 million of loans secured by residential real estate property that were in the process of foreclosure. Loans are considered past due if the required principal and interest payments have not been received as of the date such payments were due. Heartland’s policy is to discontinue the accrual of interest income on any loan when, in the opinion of management, there is a reasonable doubt as to the timely collection of the interest and principal, normally when a loan is 90 days past due. When interest accruals are deemed uncollectible, interest credited to income in the current year is reversed and interest accrued in prior years is charged to the allowance for loan losses. Nonaccrual loans are returned to an accrual status when, in the opinion of management, the financial position of the borrower indicates that there is no longer any reasonable doubt as to the timely payment of interest and principal. The following table sets forth information regarding Heartland's accruing and nonaccrual loans at December 31, 2017 , and December 31, 2016 , 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 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 December 31, 2016 Commercial $ 1,127 $ 219 $ 77 $ 1,423 $ 1,281,241 $ 4,601 $ 1,287,265 Commercial real estate 886 3,929 — 4,815 2,513,069 20,698 2,538,582 Total commercial and commercial real estate 2,013 4,148 77 6,238 3,794,310 25,299 3,825,847 Agricultural and agricultural real estate 199 3,191 — 3,390 472,597 13,331 489,318 Residential real estate 4,986 846 — 5,832 590,626 21,466 617,924 Consumer 3,455 1,021 9 4,485 411,925 4,203 420,613 Total gross loans receivable held to maturity $ 10,653 $ 9,206 $ 86 $ 19,945 $ 5,269,458 $ 64,299 $ 5,353,702 The majority of Heartland's impaired loans are those that are nonaccrual, are past due 90 days or more and still accruing or have had their terms restructured in a troubled debt restructuring. The following tables present the unpaid principal balance that was contractually due at December 31, 2017 , and December 31, 2016 , the outstanding loan balance recorded on the consolidated balance sheets at December 31, 2017 , and December 31, 2016 , any related allowance recorded for those loans as of December 31, 2017 , and December 31, 2016 , the average outstanding loan balance recorded on the consolidated balance sheets during the years ended December 31, 2017 , and December 31, 2016 , and the interest income recognized on the impaired loans during the year ended December 31, 2017 , and year ended December 31, 2016 , in thousands: Unpaid Principal 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 loans held to maturity $ 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 loans held to maturity $ 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 Unpaid Principal Balance Loan Balance Related Allowance Recorded Year-to-Date Avg. Loan Balance Year-to-Date Interest Income Recognized December 31, 2016 Impaired loans with a related allowance: Commercial $ 2,852 $ 2,840 $ 1,318 $ 3,136 $ 2 Commercial real estate 14,221 14,221 2,671 10,625 21 Total commercial and commercial real estate 17,073 17,061 3,989 13,761 23 Agricultural and agricultural real estate 2,771 2,771 816 912 21 Residential real estate 3,490 3,490 497 3,371 43 Consumer 2,644 2,644 1,451 3,082 42 Total loans held to maturity $ 25,978 $ 25,966 $ 6,753 $ 21,126 $ 129 Impaired loans without a related allowance: Commercial $ 925 $ 872 $ — $ 5,329 $ 251 Commercial real estate 31,875 30,996 — 39,632 1,647 Total commercial and commercial real estate 32,800 31,868 — 44,961 1,898 Agricultural and agricultural real estate 13,959 13,959 — 12,722 157 Residential real estate 22,408 22,236 — 18,446 202 Consumer 3,344 3,344 — 2,659 68 Total loans held to maturity $ 72,511 $ 71,407 $ — $ 78,788 $ 2,325 Total impaired loans held to maturity: Commercial $ 3,777 $ 3,712 $ 1,318 $ 8,465 $ 253 Commercial real estate 46,096 45,217 2,671 50,257 1,668 Total commercial and commercial real estate 49,873 48,929 3,989 58,722 1,921 Agricultural and agricultural real estate 16,730 16,730 816 13,634 178 Residential real estate 25,898 25,726 497 21,817 245 Consumer 5,988 5,988 1,451 5,741 110 Total impaired loans held to maturity $ 98,489 $ 97,373 $ 6,753 $ 99,914 $ 2,454 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 . On February 5, 2016, Heartland acquired CIC Bancshares, Inc., parent company of Centennial Bank, in Denver, Colorado. As of February 5, 2016, Centennial Bank had loans of $594.9 million , and the estimated fair value of the loans acquired was $ 581.5 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. The carrying amount of the acquired loans at December 31, 2017 , and December 31, 2016 , consisted of purchased impaired and nonimpaired purchased loans as summarized in the following table, in thousands: December 31, 2017 December 31, 2016 Impaired Purchased Loans Non Impaired Purchased Loans Total Purchased Loans Impaired Non Impaired Total Commercial $ 952 $ 187,375 $ 188,327 $ 2,198 $ 99,082 $ 101,280 Commercial real estate 2,572 1,052,469 1,055,041 2,079 622,117 624,196 Agricultural and agricultural real estate — 1,242 1,242 — 181 181 Residential real estate 214 173,909 174,123 186 157,468 157,654 Consumer loans — 51,292 51,292 — 47,368 47,368 Total Covered Loans $ 3,738 $ 1,466,287 $ 1,470,025 $ 4,463 $ 926,216 $ 930,679 Changes in accretable yield on acquired loans with evidence of credit deterioration at the date of acquisition for the years ended December 31, 2017 , and December 31, 2016 , are presented in the table below, in thousands: For the Years Ended December 31, 2017 December 31, 2016 Balance at beginning of year $ 182 $ 557 Original yield discount, net, at date of acquisitions — 19 Accretion (1,591 ) (1,018 ) Reclassification from nonaccretable difference (1) 1,466 624 Balance at end of year $ 57 $ 182 (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 $ 21.0 million and the estimated fair value of the loans was $ 13.1 million . At December 31, 2017 , 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 underlying collateral and the timing and amount of the cash flows could not be reasonably estimated. There was an allowance for loan losses of $ 139,000 and $588,000 , at December 31, 2017 , and December 31, 2016 , respectively, related to these ASC 310-30 loans. Provision expense of $ 12,000 and $507,000 was recorded for the years ended December 31, 2017 , and 2016, respectively, related to these ASC 310-30 loans. 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 $ 2.66 billion and the estimated fair value of the loans was $2.59 billion . Loans are made in the normal course of business to directors, officers and principal holders of equity securities of Heartland. The terms of these loans, including interest rates and collateral, are similar to those prevailing for comparable transactions and do not involve more than a normal risk of collectability. Changes in such loans during the years ended December 31, 2017 and 2016 , were as follows, in thousands: 2017 2016 Balance at beginning of year $ 114,305 $ 141,465 Advances 56,652 57,165 Repayments (55,284 ) (84,325 ) Balance at end of year $ 115,673 $ 114,305

Allowance for Loan Losses

Allowance for Loan Losses	12 Months Ended
	Dec. 31, 2017
Receivables [Abstract]
Allowance for Loan Losses	ALLOWANCE FOR LOAN LOSSES Changes in the allowance for loan losses for the years ended December 31, 2017 , 2016 and 2015 were as follows, in thousands: 2017 2016 2015 Balance at beginning of year $ 54,324 $ 48,685 $ 41,449 Provision for loan losses 15,563 11,694 12,697 Recoveries on loans previously charged-off 3,670 5,339 3,553 Loans charged-off (17,871 ) (11,394 ) (9,014 ) Balance at end of year $ 55,686 $ 54,324 $ 48,685 Changes in the allowance for loan losses by loan category for the years ended December 31, 2017 , and December 31, 2016 , were as follows, in thousands: 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 (4,640 ) (2,712 ) (2,916 ) (800 ) (6,803 ) (17,871 ) Recoveries 811 1,192 18 358 1,291 3,670 Provision 7,162 (849 ) 2,946 403 5,901 15,563 Balance at December 31, 2017 $ 18,098 $ 21,950 $ 4,258 $ 2,224 $ 9,156 $ 55,686 Commercial Commercial Real Estate Agricultural Residential Real Estate Consumer Total Balance at December 31, 2015 $ 16,095 $ 19,532 $ 3,887 $ 1,934 $ 7,237 $ 48,685 Charge-offs (1,348 ) (2,868 ) (214 ) (346 ) (6,618 ) (11,394 ) Recoveries 930 3,327 10 29 1,043 5,339 Provision (912 ) 4,328 527 646 7,105 11,694 Balance at December 31, 2016 $ 14,765 $ 24,319 $ 4,210 $ 2,263 $ 8,767 $ 54,324 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.

Premises, Furniture and Equipme

Premises, Furniture and Equipment	12 Months Ended
	Dec. 31, 2017
Property, Plant and Equipment [Abstract]
Premises, Furniture and Equipment	PREMISES, FURNITURE AND EQUIPMENT Premises, furniture and equipment, excluding those held for sale, as of December 31, 2017 , and December 31, 2016 , were as follows, in thousands: 2017 2016 Land and land improvements $ 48,621 $ 42,802 Buildings and building improvements 155,209 146,628 Furniture and equipment 64,118 67,023 Total 267,948 256,453 Less accumulated depreciation (95,624 ) (92,839 ) Premises, furniture and equipment, net $ 172,324 $ 163,614 Depreciation expense on premises, furniture and equipment was $11.1 million , $10.4 million and $8.9 million for 2017 , 2016 and 2015 , respectively.

Goodwill, Core Deposit Intangib

Goodwill, Core Deposit Intangibles and Other Intangible Assets	12 Months Ended
	Dec. 31, 2017
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill, Core Deposit Intangibles and Other Intangible Assets	GOODWILL, CORE DEPOSIT INTANGIBLES AND OTHER INTANGIBLE ASSETS Heartland had goodwill of $ 236.6 million at December 31, 2017 , and $127.7 million at December 31, 2016 . Heartland conducts its annual internal assessment of the goodwill both collectively and at its subsidiaries as of September 30. There was no goodwill impairment as of the most recent assessment. 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. Heartland recorded $29.8 million of goodwill in connection with the acquisition of CIC Bancshares, Inc., parent company of Centennial Bank, based in Denver, Colorado on February 5, 2016. In addition, Heartland recognized core deposit intangibles of $6.4 million and commercial servicing rights of $190,000 with this acquisition. The core deposit intangibles recorded with the Citywide Banks of Colorado, Inc., Founders Bancorp, and CIC Bancshares, Inc. 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 Citywide Banks of Colorado, Inc., Founders Bancorp, and CIC Bancshares, Inc. acquisitions resulted from expected operational synergies, increased market presence, cross-selling opportunities, and expanded business lines. Other intangible assets consist of core deposit intangibles, mortgage servicing rights, customer relationship intangible and commercial servicing rights. The gross carrying amount of other intangible assets and the associated accumulated amortization at December 31, 2017 , and December 31, 2016 , are presented in the table below, in thousands: December 31, 2017 December 31, 2016 Gross Carrying Amount Accumulated Amortization Net Carrying Amount Gross Carrying Amount Accumulated Amortization Net Carrying Amount Amortizing intangible assets: Core deposit intangibles $ 62,008 $ 27,086 $ 34,922 $ 43,504 $ 21,049 $ 22,455 Customer relationship intangible 1,177 896 281 1,177 857 320 Mortgage servicing rights 42,139 18,891 23,248 50,467 18,379 32,088 Commercial servicing rights 6,719 4,110 2,609 6,504 2,814 3,690 Total $ 112,043 $ 50,983 $ 61,060 $ 101,652 $ 43,099 $ 58,553 The following table shows the estimated future amortization expense for amortizable intangible assets, in thousands: Core Deposit Intangibles Customer Relationship Intangible Mortgage Servicing Rights Commercial Servicing Rights Total Year ending December 31, 2018 $ 6,712 $ 39 $ 5,812 $ 685 $ 13,248 2019 5,915 38 4,982 554 11,489 2020 5,191 37 4,151 433 9,812 2021 4,425 35 3,321 371 8,152 2022 3,391 34 2,491 300 6,216 Thereafter 9,288 98 2,491 266 12,143 Total $ 34,922 $ 281 $ 23,248 $ 2,609 $ 61,060 Projections of amortization expense for mortgage servicing rights are based on existing asset balances and the existing interest rate environment as of December 31, 2017 . Heartland's actual experience may be significantly different depending upon changes in mortgage interest rates and market conditions. Mortgage loans serviced for others were $3.56 billion and $ 4.31 billion as of December 31, 2017 , and December 31, 2016 , respectively. Custodial escrow balances maintained in connection with the mortgage loan servicing portfolio were approximately $ 17.3 million and $ 21.4 million as of December 31, 2017 , and December 31, 2016 , respectively. The fair value of Heartland's mortgage servicing rights was estimated at $ 37.1 million and $ 45.2 million at December 31, 2017 , and December 31, 2016 , respectively. As of December 31, 2017, Heartland's mortgage servicing rights portfolio is comprised of loans serviced for the Federal National Mortgage Association and the Federal Home Loan Mortgage Corporation. Until the third quarter of 2017, Heartland also serviced loans for the Government National Mortgage Association. The servicing rights portfolio is separated into 15 - and 30 -year tranches. At both December 31, 2017 , and December 31, 2016 , no valuation allowance was required for any of the mortgage tranches. 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 qualifies as a sale, and $6.9 million of mortgage servicing rights have been de-recognized on the consolidated balance sheet as of December 31, 2017. Cash of $6.3 million was received during 2017, and Heartland recorded an estimated loss on the sale of this portfolio of approximately $223,000 . A receivable of approximately $427,000 was recorded due to the timing of the servicing transfer per the terms of the sale agreement and to address indemnification claims and mortgage loan documentation deficiencies. 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 9.73% and 9.63% for the valuations at December 31, 2017 , and December 31, 2016 , respectively. The discount rate was 9.06% and 9.26% for the valuations at December 31, 2017 , and December 31, 2016 , respectively. The average capitalization rate for 2017 ranged from 91 to 150 basis points and for 2016 from 88 to 150 basis points. Fees collected for the servicing of mortgage loans for others were $ 11.6 million , $ 12.1 million and $ 10.7 million for the years ended December 31, 2017 , 2016 and 2015 , respectively. The following table summarizes, in thousands, the changes in capitalized mortgage servicing rights for the twelve months ended December 31, 2017 , and December 31, 2016 : 2017 2016 Balance at January 1 $ 32,088 $ 30,314 Originations 7,149 12,266 Amortization (9,049 ) (10,492 ) Sale of mortgage servicing rights (6,940 ) — Balance at December 31 $ 23,248 $ 32,088 Fair value of mortgage servicing rights $ 37,081 $ 45,210 Mortgage servicing rights, net to servicing portfolio 0.65 % 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 $139.9 million at December 31, 2017 and $164.6 million at December 31, 2016 . The commercial servicing rights portfolio is separated into two tranches at the respective Heartland Bank, 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 $ 1.7 million and $1.9 million for the years ended December 31, 2017 and 2016 , 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 portfolio valuations was 7.27% and 8.88% as of December 31, 2017 compared to 6.96% and 7.88% as of December 31, 2016 . The discount rate range was 13.04% and 15.49% for the December 31, 2017 , valuations compared to 12.44% and 13.88% for the December 31, 2016 valuations. The capitalization rate ranged from 310 to 445 basis points at both December 31, 2017 and 2016 . The total fair value of Heartland's commercial servicing rights portfolios was estimated at $ 3.2 million as of December 31, 2017 , and $4.1 million as of December 31, 2016 . The following table summarizes, in thousands, the changes in capitalized commercial servicing rights for the twelve months ended December 31, 2017 , and December 31, 2016 : 2017 2016 Balance at January 1, $ 3,690 $ 4,611 Originations 209 628 Amortization (1,311 ) (1,706 ) Purchased commercial servicing rights — 190 Valuation allowance on commercial servicing rights 21 (33 ) Balance at December 31, $ 2,609 $ 3,690 Fair value of commercial servicing rights $ 3,221 $ 4,127 Commercial servicing rights, net to servicing portfolio 1.87 % 2.24 % 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 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 Bank. At December 31, 2017 , no valuation allowance was required on commercial servicing rights with an original term of less than 20 years and a $12,000 valuation allowance was required on commercial servicing rights with an original term of greater than 20 years. At December 31, 2016 , no valuation allowance was required on commercial servicing rights with an original term of less than 20 years and a $33,000 valuation allowance was required on commercial servicing rights with an original term of greater than 20 years. 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 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 December 31, 2016 Citywide Banks $ 19 $ 23 $ — $ 107 $ 114 $ — Premier Valley Bank 156 180 — 359 326 33 Wisconsin Bank & Trust 833 997 — 2,249 2,487 — Total $ 1,008 $ 1,200 $ — $ 2,715 $ 2,927 $ 33

Deposits

Deposits	12 Months Ended
	Dec. 31, 2017
Banking and Thrift [Abstract]
Deposits	DEPOSITS At December 31, 2017 , the scheduled maturities of time certificates of deposit were as follows, in thousands: 2018 $ 607,669 2019 154,548 2020 69,357 2021 38,179 2022 31,950 Thereafter 21,750 $ 923,453 The aggregate amount of time certificates of deposit in denominations of $100,000 or more as of December 31, 2017 , and December 31, 2016 , were $ 402.7 million and $ 369.9 million , respectively. The aggregate amount of time certificates of deposit in denominations of $250,000 or more as of December 31, 2017 , and December 31, 2016 were $ 212.4 million and $ 190.8 million . Interest expense on deposits for the years ended December 31, 2017 , 2016 , and 2015 , was as follows, in thousands: 2017 2016 2015 Savings and money market accounts $ 11,107 $ 8,000 $ 6,612 Time certificates of deposit in denominations of $100,000 or more 3,016 3,178 3,152 Other time deposits 4,156 4,761 5,766 Interest expense on deposits $ 18,279 $ 15,939 $ 15,530

Short-term Borrowings

Short-term Borrowings	12 Months Ended
	Dec. 31, 2017
Debt Disclosure [Abstract]
Short-term Borrowings	SHORT-TERM BORROWINGS Short-term borrowings, which Heartland defines as borrowings with an original maturity of one year or less, as of December 31, 2017 , and 2016 , were as follows, in thousands: 2017 2016 Securities sold under agreement to repurchase $ 107,957 $ 229,555 Federal funds purchased 168,250 40,200 Advances from the FHLB 40,000 30,367 Other short-term borrowings 8,484 6,337 Total $ 324,691 $ 306,459 At December 31, 2017 , Heartland had one revolving credit line with an unaffiliated bank with borrowing capacity of $25.0 million . A balance of $0 was outstanding at both December 31, 2017 and December 31, 2016 . In addition to the revolving credit line described above, Heartland entered into another non-revolving credit facility with the same unaffiliated bank, which provided a borrowing capacity not to exceed $75.0 million when combined with the outstanding balance on the amortizing term loan discussed in Note 11. The credit facility is non-revolving at a rate of 2.75% over LIBOR, and any outstanding balance is due on June 14, 2018. There was no outstanding balance on the short-term portion of the credit facility at December 31, 2017 , and Heartland had $39.3 million of borrowing capacity. The agreement with the unaffiliated bank for the credit facility contains specific financial covenants, all of which Heartland was in compliance with at December 31, 2017 and December 31, 2016 . All retail repurchase agreements as of December 31, 2017 , and 2016 , were due within twelve months . Average and maximum balances and rates on aggregate short-term borrowings outstanding during the years ended December 31, 2017 , December 31, 2016 , and December 31, 2015 , were as follows, in thousands: 2017 2016 2015 Maximum month-end balance $ 324,691 $ 399,490 $ 477,918 Average month-end balance 182,846 287,857 330,134 Weighted average interest rate for the year 0.36 % 0.40 % 0.25 % Weighted average interest rate at year-end 1.11 % 0.29 % 0.15 % Dubuque Bank and Trust Company and Morrill & Janes Bank and Trust Company are participants in the Borrower-In-Custody of Collateral Program at the Federal Reserve Bank of Chicago and the Federal Reserve Bank of Kansas City, respectively, which provides the capability to borrow short-term funds under the Discount Window Program. Advances under this program are collateralized by a portion of the commercial loan portfolio of Dubuque Bank and Trust Company in the amount of $ 62.2 million at December 31, 2017 , and $ 91.1 million at December 31, 2016 . Advances collateralized by a portion of Morrill & Janes Bank and Trust Company's commercial loan portfolio were $ 32.6 million at December 31, 2017 , and $ 43.7 million at December 31, 2016 . There were no borrowings under the Discount Window Program outstanding at year-end 2017 and 2016 .

Other Borrowings

Other Borrowings	12 Months Ended
	Dec. 31, 2017
Debt Disclosure [Abstract]
Other Borrowings	OTHER BORROWINGS Other borrowings, which Heartland defines as borrowings with an original maturity date of more than one year, outstanding at December 31, 2017 and 2016 , are shown in the table below, net of discount and issuance costs amortization, in thousands: 2017 2016 Advances from the FHLB; weighted average call dates at December 31, 2017 and 2016 were December 2020 and August 2020, respectively; and weighted average interest rates were 3.22% and 3.25%, respectively $ 6,702 $ 6,975 Wholesale repurchase agreements; weighted average call dates at December 31, 2017, and 2016 were May 2018 and May 2017, respectively; and weighted average interest rates were 3.76% for both December 31, 2017, and 2016 30,000 30,000 Trust preferred securities 121,886 115,232 Senior notes 11,000 16,000 Note payable to unaffiliated bank 33,667 37,667 Contracts payable for purchase of real estate and other assets 1,881 2,339 Subordinated notes 74,000 73,857 Other borrowings 5,875 6,464 Total $ 285,011 $ 288,534 The Heartland banks are members of the FHLB of Des Moines, Chicago, Dallas, San Francisco and Topeka. The advances from the FHLB are collateralized by a portion of the Heartland banks' investments in FHLB stock of $11.3 million and $9.9 million at December 31, 2017 and 2016 , respectively. In addition, the FHLB advances are collateralized with pledges of one- to four-family residential mortgages, commercial and agricultural mortgages and securities totaling $ 2.91 billion at December 31, 2017 , and $ 2.74 billion at December 31, 2016 . At December 31, 2017 , Heartland had $1.33 billion of remaining FHLB borrowing capacity. Heartland has entered into various wholesale repurchase agreements, which had balances totaling $30.0 million at both December 31, 2017 and 2016 , respectively. At December 31, 2017 , Heartland had eleven wholly-owned trust subsidiaries that were formed to issue trust preferred securities, which includes trust subsidiaries acquired in acquisitions since 2013. The proceeds from the offerings were used to purchase junior subordinated debentures from Heartland and were in turn used by Heartland for general corporate purposes. Heartland has the option to shorten the maturity date to a date not earlier than the callable date. Heartland may not shorten the maturity date without prior approval of the Board of Governors of the Federal Reserve System, if required. Prior redemption is permitted under certain circumstances, such as changes in tax or regulatory capital rules. Heartland repurchased and retired $15.0 million of Heartland Statutory Trust IV in 2017. The retired debt was part of an interest rate swap and Citywide Capital Trust V replaced the retired debt in the interest rate swap with no impact to income. Refer to Note 12, "Derivative Financial Instruments," regarding this swap replacement. In connection with these offerings of trust preferred securities, the balance of deferred issuance costs included in other borrowings was $127,000 as of December 31, 2017 . These deferred costs are amortized on a straight-line basis over the life of the debentures. The majority of the interest payments are due quarterly. A schedule of Heartland’s trust preferred offerings outstanding, excluding deferred issuance costs, as of December 31, 2017 , were as follows, in thousands: Amount Issued Interest Rate Interest Rate as (1) Maturity Date Callable Date Heartland Financial Statutory Trust IV $10,258 2.75% over LIBOR 4.35% (2) 03/17/2034 03/17/2018 Heartland Financial Statutory Trust V 20,619 1.33% over LIBOR 2.69% (3) 04/07/2036 04/07/2018 Heartland Financial Statutory Trust VI 20,619 1.48% over LIBOR 3.07% (4) 09/15/2037 03/15/2018 Heartland Financial Statutory Trust VII 20,619 1.48% over LIBOR 2.96% (5) 09/01/2037 06/01/2018 Morrill Statutory Trust I 8,900 3.25% over LIBOR 4.92% (6) 12/26/2032 03/26/2018 Morrill Statutory Trust II 8,531 2.85% over LIBOR 4.45% (7) 12/17/2033 03/17/2018 Sheboygan Statutory Trust I 6,353 2.95% over LIBOR 4.55% 09/17/2033 03/17/2018 CBNM Capital Trust I 4,309 3.25% over LIBOR 4.84% 12/15/2034 03/15/2018 Citywide Capital Trust III 6,327 2.80% over LIBOR 4.18% 12/19/2033 04/23/2018 Citywide Capital Trust IV 4,180 2.20% over LIBOR 3.65% 09/30/2034 05/23/2018 Citywide Capital Trust V 11,298 1.54% over LIBOR 3.13% (8) 07/25/2036 03/15/2018 $122,013 (1) Effective weighted average interest rate as of December 31, 2017, was 5.25% due to interest rate swap transactions as discussed in Note 12 to Heartland's consolidated financial statements. (2) Effective interest rate as of December 31, 2017, was 5.01% due to an interest rate swap transaction as discussed in Note 12 to Heartland's consolidated financial statements. (3) Effective interest rate as of December 31, 2017, was 4.69% due to an interest rate swap transaction as discussed in Note 12 to Heartland's consolidated financial statements. (4) Effective interest rate as of December 31, 2017, was 3.87% due to an interest rate swap transaction as discussed in Note 12 to Heartland's consolidated financial statements. (5) Effective interest rate as of December 31, 2017, was 3.83% due to an interest rate swap transaction as discussed in Note 12 to Heartland's consolidated financial statements. (6) Effective interest rate as of December 31, 2017, was 4.92% due to an interest rate swap transaction as discussed in Note 12 to Heartland's consolidated financial statements. (7) Effective interest rate as of December 31, 2017, was 4.51% due to an interest rate swap transaction as discussed in Note 12 to Heartland's consolidated financial statements. (8) Effective interest rate as of December 31, 2017, was 3.80% due to an interest rate swap transaction as discussed in Note 12 to Heartland's consolidated financial statements. For regulatory purposes, $121.9 million and $115.2 million of the trust preferred securities qualified as Tier 1 capital as of December 31, 2017 and 2016 , respectively. The maturity schedule of the remaining senior notes is such that $6.0 million will mature in 2018 and the remaining $5.0 million will mature in 2019. Total senior notes outstanding were $11.0 million at December 31, 2017 and $16.0 million on December 31, 2016 . In addition to the credit line described in Note 10, "Short-Term Borrowings," Heartland entered into another non-revolving credit facility with the same unaffiliated bank on December 15, 2015, which provided a borrowing capacity not to exceed $50.0 million when combined with the outstanding balance on its then existing amortizing term loan with the same unaffiliated bank. On May 10, 2016, $40.0 million of this variable rate non-revolving credit facility was swapped to a fixed rate of 2.50% over LIBOR with an amortizing term of five years , which is due in April 2021, and was reclassified as long-term debt. On July 20, 2016, the borrowing capacity on this non-revolving credit facility was increased by $25.0 million to a total borrowing capacity of $ 75.0 million . At December 31, 2017 , a balance of $33.7 million was outstanding on this term debt compared to $37.7 million at December 31, 2016 . At December 31, 2017 , $39.3 million was available on the non-revolving credit facility, of which no balance was outstanding. On December 17, 2014, Heartland issued $75.0 million of subordinated notes with a maturity date of December 30, 2024. The notes were issued at par with an underwriting discount of $1.1 million . The interest rate on the notes is fixed at 5.75% per annum, payable semi-annually. The notes were sold to qualified institutional buyers, and the proceeds are being used for general corporate purposes. For regulatory purposes, $74.0 million of the subordinated notes qualified as Tier 2 capital as of December 31, 2017 . In connection with the sale of the notes, the balance of deferred issuance costs included in other borrowings was $265,000 at December 31, 2017 and $303,000 at December 31, 2016 . These deferred costs are amortized on a straight-line basis over the life of the notes. Effective with the acquisition of CIC Bancshares, Inc. on February 5, 2016, Heartland assumed $2.0 million of subordinated convertible notes with a fair value discount of $16,000 and $6.0 million of subordinated debentures with a fair value premium of $168,000 . The interest rate is fixed at 6.50% per annum on the convertible notes and 8.00% per annum on the non-convertible notes, both payable quarterly. During the third quarter of 2016, $1.4 million of the subordinated convertible notes were converted into 52,913 shares of Heartland common stock. During the first quarter of 2017, $167,000 of subordinated convertible notes were converted into 6,128 shares of Heartland common stock, and the remaining balance of the subordinated convertible notes totaling $391,100 was converted into 14,353 shares of Heartland common stock during the third quarter of 2017. In connection with the acquisition of the notes, the balance of deferred issuance costs included in other borrowings was $28,000 at December 31, 2017 and $44,000 at December 31, 2016 . These deferred costs are amortized on a straight-line basis over the life of the notes. Future payments at December 31, 2017 , for other borrowings follow in the table below, in thousands. Callable FHLB advances, wholesale repurchase agreements, convertible debt and subordinated debt are included in the table at their call date. 2018 $ 43,217 2019 15,383 2020 5,652 2021 21,622 2022 1,657 Thereafter 197,480 Total $ 285,011

Derivative Financial Instrument

Derivative Financial Instruments	12 Months Ended
	Dec. 31, 2017
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 and 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 movement 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 large, stable financial institutions. 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 $1.2 million of cash as collateral at December 31, 2017 , and$ 2.2 million at December 31, 2016 . No collateral was required to be pledged by Heartland's counterparties at both December 31, 2017 , and December 31, 2016 . Heartland's derivative and hedging instruments are recorded at fair value on the consolidated balance sheets. See Note 20, "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 twelve months ended December 31, 2017 , 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 $1.3 million . For the next twelve months, Heartland estimates that cash payments and reclassification from accumulated other comprehensive income to interest expense will total $1.1 million . 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. During the first quarter of 2015, Heartland entered into two additional forward starting interest rate swaps. The first forward starting interest rate swap transaction relates to Heartland's $20.0 million Statutory Trust VI, which converted from a fixed interest rate subordinated debenture to a variable interest rate subordinated debenture effective on June 15, 2017. The forward-starting swap transaction expires on June 15, 2024. The second forward starting interest rate swap was effective on March 1, 2017, and replaced the interest rate swap related to Heartland Statutory Trust VII upon its expiration on March 1, 2017. Heartland entered into an interest rate swap transaction on May 10, 2016, to effectively convert $40.0 million of amortizing term debt from variable rate debt to fixed rate debt. For accounting purposes, this swap is designated as a cash flow hedge of the changes in LIBOR, the benchmark interest rate being hedged, associated with the interest payments on the amortizing term debt that resets monthly on a specified reset date. The swap expires on May 10, 2021. During 2017, as noted in Note 11, "Other Borrowings," Heartland repurchased and retired $15.0 million of Heartland Statutory Trust IV which was part of a $25.0 million interest rate swap. The retired debt was replaced with the $15.0 million Citywide Statutory Trust V, which along with the remaining $10.0 million of Heartland Statutory Trust IV constitutes the underlying hedged items. The replacement of Citywide Trust V as the underlying hedged item had no impact to income. The table below identifies the balance sheet category and fair values of Heartland's derivative instruments designated as cash flow hedges at December 31, 2017 , and December 31, 2016 , in thousands: Notional Amount Fair Value Balance Sheet Category Receive Rate Weighted Average Pay Rate Maturity 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 20,000 (177 ) Other Liabilities 1.588 2.390 06/15/2024 Interest rate swap 20,000 (149 ) Other Liabilities 1.481 2.352 03/01/2024 December 31, 2016 Interest rate swap $ 25,000 $ (447 ) Other Liabilities 0.993 % 2.255 % 03/17/2021 Interest rate swap 20,000 (114 ) Other Liabilities 0.931 3.220 03/01/2017 Interest rate swap 20,000 (1,145 ) Other Liabilities 0.868 3.355 01/07/2020 Interest rate swap 10,000 (42 ) Other Liabilities 0.997 1.674 03/26/2019 Interest rate swap 10,000 (41 ) Other Liabilities 0.993 1.658 03/18/2019 Interest rate swap 37,667 530 Other Assets 3.164 3.674 05/10/2021 Interest rate swap (1) 20,000 (214 ) Other Liabilities — 2.390 06/15/2024 Interest rate swap (2) 20,000 (262 ) Other Liabilities — 2.352 03/01/2024 (1) This swap is a forward starting swap with a weighted average pay rate of 2.390% beginning on June 15, 2017. No interest payments were required related to this swap until September 15, 2017. (2) This swap is a forward starting swap with a weighted average pay rate of 2.352% beginning on March 1, 2017. No interest payments were required on this swap until June 1, 2017. The table below identifies the gains and losses recognized on Heartland's derivative instruments designated as cash flow hedges for the years ended December 31, 2017 , and December 31, 2016 , 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) December 31, 2017 Interest rate swap $ 1,500 Interest expense $ (1,290 ) Other income $ — December 31, 2016 Interest rate swap $ 1,705 Interest expense $ (1,914 ) 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 $3.9 million and $5.0 million of cash as collateral for these fair value hedges at December 31, 2017 , and December 31, 2016 , respectively. The table below identifies the notional amount, fair value and balance sheet category of Heartland's fair value hedges at December 31, 2017 , and December 31, 2016 , in thousands: Notional Amount Fair Value Balance Sheet Category December 31, 2017 Fair value hedges $ 35,635 $ (999 ) Other liabilities December 31, 2016 Fair value hedges $ 40,807 $ (1,626 ) Other liabilities The table below identifies the gains and losses recognized on Heartland's fair value hedges for the years ended December 31, 2017 and December 31, 2016 , in thousands: Amount of Gain (Loss) Income Statement Category December 31, 2017 Fair value hedges $ 627 Interest income December 31, 2016 Fair value hedges $ (1,005 ) 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 as of December 31, 2017 , and December 31, 2016 , in thousands: Notional Amount Fair Value Balance Sheet Category December 31, 2017 Embedded derivatives $ 14,045 $ 738 Other assets December 31, 2016 Embedded derivatives $ 14,549 $ 1,104 Other assets The table below identifies the gains and losses recognized on Heartland's embedded derivatives for the years ended December 31, 2017 and December 31, 2016 , in thousands: Amount of Gain (Loss) Income Statement Category December 31, 2017 Embedded derivatives $ 366 Other noninterest income December 31, 2016 Embedded derivatives $ (470 ) Other noninterest income In conjunction with the CIC Bancshares, Inc., transaction on February 5, 2016, Heartland acquired 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 . As of December 31, 2016, the remaining shares to be issued upon conversion totaled 20,481 . 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 December 31, 2017 , and December 31, 2016 : Notional Amount Fair Value Balance Sheet Category December 31, 2017 Embedded conversion option $ — $ — Other liabilities December 31, 2016 Embedded conversion option $ 558 $ (422 ) Other liabilities The table below identifies the gains and losses recognized on Heartland's embedded conversion options for the years ended December 31, 2017 , and December 31, 2016 , in thousands: Amount of Gain (Loss) Income Statement Category December 31, 2017 Embedded conversion option $ 422 Other noninterest income December 31, 2016 Embedded conversion option $ (100 ) 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 $1.6 million and $1.8 million as of December 31, 2017 , and December 31, 2016 , respectively, as collateral related to these back-to-back swaps. Heartland's counterparties were required to pledge $ 190,000 and $768,000 as of December 31, 2017 and December 31, 2016 , respectively, related to these back-to-back swaps. Any gains and losses on these back-to-back swaps are recorded in noninterest income on the consolidated statements of income, and for the years ended December 31, 2017 , and December 31, 2016 , no gains or losses were recognized. The table below identifies the balance sheet category and fair values of Heartland's derivative instruments designated as loan swaps at December 31, 2017 and 2016 , in thousands: Notional Amount Fair Value Balance Sheet Category Weighted Average Receive Rate Weighted Average Pay Rate 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 % December 31, 2016 Customer interest rate swaps $ 69,594 $ 1,588 Other Assets 4.66 % 3.47 % Customer interest rate swaps 69,594 (1,588 ) Other Liabilities 3.47 % 4.66 % 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 $20,000 and $0 at December 31, 2017 , and December 31, 2016 , respectively, as collateral for these forward commitments. Heartland's counterparties were required to pledge $ 29,000 at December 31, 2017, and $ 2.9 million at December 31, 2016, 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 December 31, 2017 , and December 31, 2016 , in thousands: Notional Amount Fair Value Balance Sheet Category December 31, 2017 Interest rate lock commitments (mortgage) $ 53,588 $ 1,738 Other Assets Forward commitments 37,286 80 Other Assets Forward commitments 118,632 (232 ) Other Liabilities Undesignated interest rate swaps 14,045 (738 ) Other Liabilities December 31, 2016 Interest rate lock commitments (mortgage) $ 80,465 $ 2,790 Other Assets Forward commitments 142,750 2,546 Other Assets Forward commitments 59,276 (266 ) Other Liabilities Undesignated interest rate swaps 15,564 (1,126 ) Other Liabilities 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 years ended December 31, 2017 , and December 31, 2016 , in thousands: Income Statement Category Year-to-Date Gain(Loss) Recognized December 31, 2017 Interest rate lock commitments (mortgage) Net gains on sale of loans held for sale $ (1,479 ) Forward commitments Net gains on sale of loans held for sale (2,466 ) Forward commitments Net gains on sale of loans held for sale 34 Undesignated interest rate swaps Other noninterest income 388 December 31, 2016 Interest rate lock commitments (mortgage) Net gains on sale of loans held for sale $ (1,564 ) Forward commitments Net gains on sale of loans held for sale 2,023 Forward commitments Net gains on sale of loans held for sale 49 Undesignated interest rate swaps Other noninterest income 2,551

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Income Taxes	INCOME TAXES Income taxes for the years ended December 31, 2017 , 2016 , and 2015 were as follows, in thousands: 2017 2016 2015 Current: Federal $ 25,532 $ 23,724 $ 13,697 State 5,025 5,670 5,080 Total current $ 30,557 $ 29,394 $ 18,777 Deferred: Federal $ 12,370 $ 5,497 $ 1,118 State 893 1,665 1,003 Total deferred $ 13,263 $ 7,162 $ 2,121 Total income tax expense $ 43,820 $ 36,556 $ 20,898 In response to the enactment of the Tax Cuts and Jobs Act on December 22, 2017, which reduced the corporate federal tax rate from a graduated maximum 35% to a flat 21% , Heartland recorded $10.4 million of income tax expense in 2017 to adjust the value of its deferred tax assets and liabilities. Heartland adopted ASU 2016-09, " Compensation-Stock Compensation (Topic 718)," on January 1, 2017, as required, using the prospective transition method. The requirement to record the excess tax benefit or shortfall related to settlements of share-based payment awards in earnings as an increase or decrease to tax expense was applied to settlements occurring during 2017 and resulted in a reduction to income tax expense of $1.2 million . In years prior to 2017, the income tax provisions did not include the effects of income tax deductions resulting from exercises of stock options and the vesting of stock awards in the amounts of $374,000 and $676,000 in 2016 and 2015 respectively, which were recorded as increases to stockholders’ equity. Temporary differences between the amounts reported in the financial statements and the tax basis of assets and liabilities result in deferred taxes. Deferred tax assets and liabilities at December 31, 2017 and 2016 , with the 2017 amounts adjusted for the impact of the Tax Cuts and Jobs Act, were as follows, in thousands: 2017 2016 Deferred tax assets: Tax effect of net unrealized loss on securities available for sale reflected in stockholders’ equity $ 8,320 $ 19,468 Tax effect of net unrealized loss on derivatives reflected in stockholders’ equity 60 484 Allowance for loan losses 14,221 20,506 Deferred compensation 4,240 9,146 Organization and acquisitions costs 369 649 Net operating loss carryforwards 16,580 17,676 Non-accrual loan interest 710 752 OREO write-downs 1,835 1,756 Rehab tax credit projects 4,303 5,620 Mortgage repurchase obligation 68 333 Self-funded health plan — 632 Other 1,974 1,463 Gross deferred tax assets 52,680 78,485 Valuation allowance (10,493 ) (9,870 ) Gross deferred tax assets $ 42,187 $ 68,615 Deferred tax liabilities: Securities (478 ) (452 ) Premises, furniture and equipment (5,798 ) (9,284 ) Tax bad debt reserves (428 ) (13 ) Purchase accounting (4,417 ) (3,496 ) Prepaid expenses (526 ) (881 ) Mortgage servicing rights (7,045 ) (13,956 ) Deferred loan fees (2,651 ) (3,804 ) Other (255 ) (379 ) Gross deferred tax liabilities $ (21,598 ) $ (32,265 ) Net deferred tax asset $ 20,589 $ 36,350 The deferred tax assets (liabilities) related to net unrealized gains (losses) on securities available for sale and on derivatives had no effect on income tax expense as these gains and losses, net of taxes, were recorded in other comprehensive income, other than for the effect of the federal tax rate change enacted on December 22, 2017, under the Tax Cuts and Jobs Act. The effect of the enacted change in the federal corporate tax rate from a graduated maximum of 35% to a flat 21% resulted in tax expense totaling $4.5 million to adjust the deferred tax assets (liabilities) related to net unrealized gains (losses) on securities available for sale and on derivatives. As a result of acquisitions, Heartland had net operating loss carryforwards for federal income tax purposes of approximately $36.0 million at December 31, 2017 , and $34.1 million at December 31, 2016 . The associated deferred tax asset, as adjusted for the impact of the Tax Cuts and Jobs Act, was $8.4 million at December 31, 2017 , and $11.9 million at December 31, 2016 . These net carryforwards expire during the period from December 31, 2026 , through December 31, 2037 , and are subject to an annual limitation of approximately $5.8 million . Net operating loss carryforwards for state income tax purposes were approximately $113.3 million at December 31, 2017 , and $105.6 million at December 31, 2016 . The associated deferred tax asset, net of federal tax, was $8.2 million at December 31, 2017 , and $5.7 million at December 31, 2016 . These carryforwards have begun to expire and will continue to do so until December 31, 2037 . A valuation allowance against the deferred tax asset due to the uncertainty surrounding the utilization of these state net operating loss carryforwards was $6.6 million at December 31, 2017 , and $4.5 million at December 31, 2016 . During both 2017 and 2016 , Heartland had book write-downs on investments that, for tax purposes, would generate capital losses upon disposal. Due to the uncertainty of Heartland's ability to utilize the potential capital losses, a valuation allowance for these potential losses totaled $3.9 million at December 31, 2017 , and $5.4 million at December 31, 2016 . Realization of the deferred tax asset over time is dependent upon the existence of taxable income in carryback periods or the ability to generate sufficient taxable income in future periods. In determining that realization of the deferred tax asset was more likely than not, Heartland gave consideration to a number of factors, including its taxable income during carryback periods, its recent earnings history, its expectations for earnings in the future and, where applicable, the expiration dates associated with its tax carryforwards. The actual income tax expense from continuing operations differs from the expected amounts for the years ended December 31, 2017 , 2016 , and 2015 , (computed by applying the U.S. federal corporate tax rate of 35% to income before income taxes) are as follows, in thousands: 2017 2016 2015 Computed "expected" tax on net income $ 41,682 $ 40,917 $ 28,329 Increase (decrease) resulting from: Nontaxable interest income (9,282 ) (7,960 ) (6,293 ) State income taxes, net of federal tax benefit 3,846 4,768 3,954 Tax credits (2,390 ) (1,375 ) (5,975 ) Valuation allowance 405 368 1,525 Excess tax benefit on stock compensation (1,130 ) — — Deferred tax adjustment due to Tax Cuts and Jobs Act enactment 10,396 — — Other 293 (162 ) (642 ) Income taxes $ 43,820 $ 36,556 $ 20,898 Effective tax rates 36.8 % 31.3 % 25.8 % Heartland's income taxes included solar energy credits totaling $449,000 during 2017 and $160,000 during 2016 . Federal historic rehabilitation tax credits were also included in Heartland's income taxes totaling $713,000 during 2017 and $5.4 million during 2015 . Additionally, investments in certain low-income housing partnerships totaled $7.8 million at December 31, 2017 , $8.8 million at December 31, 2016 , and $10.4 million at December 31, 2015 . These investments generated federal low-income housing tax credits of $1.2 million for both the years ended December 31, 2017 , and December 31, 2016 , and $581,000 for the year ended December 31, 2015 . These investments are expected to generate federal low-income housing tax credits of approximately $1.2 million for 2018 , $1.1 million for 2019 , $779,000 for 2020 , $538,000 for 2021 through 2023 , $322,000 for 2024 , $86,000 for 2025 and $34,000 for 2026 . On December 31, 2017 , the amount of unrecognized tax benefits was $481,000 , including $64,000 of accrued interest and penalties. On December 31, 2016 , the amount of unrecognized tax benefits was $374,000 , including $48,000 of accrued interest and penalties. If recognized, the entire amount of the unrecognized tax benefits would affect the effective tax rate. A reconciliation of the beginning and ending balances for liabilities associated with unrecognized tax benefits for the years ended December 31, 2017 and 2016 , is as follows, in thousands: 2017 2016 Balance at January 1 $ 374 $ 715 Additions for tax positions related to the current year 86 63 Additions for tax positions related to prior years 106 21 Reductions for tax positions related to prior years (85 ) (425 ) Balance at December 31 $ 481 $ 374 The tax years ended December 31, 2014 , and later remain subject to examination by the Internal Revenue Service. For state purposes, the tax years ended December 31, 2012 , and later remain open for examination. Heartland does not anticipate any significant increase or decrease in unrecognized tax benefits during the next twelve months.

Employee Benefit Plans

Employee Benefit Plans	12 Months Ended
	Dec. 31, 2017
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Employee Benefit Plans	EMPLOYEE BENEFIT PLANS Heartland sponsors a defined contribution retirement plan covering substantially all employees. Contributions to this plan are subject to approval by the Heartland Board of Directors. The Heartland subsidiaries fund and record as an expense all approved contributions. Costs of these contributions, charged to operating expenses, were $4.1 million , $3.9 million , and $3.5 million for 2017 , 2016 and 2015 , respectively. This plan includes an employee savings program, under which the Heartland subsidiaries make matching contributions of up to 3% of the participants’ wages in 2017 , 2016 , and 2015 . Costs charged to operating expenses with respect to the matching contributions were $3.3 million , $2.9 million , and $2.7 million for 2017 , 2016 and 2015 , respectively. Contributions to the defined contribution retirement plan and the employee savings program are limited to a maximum amount of the participant's wages as defined by federal law.

Commitments and Contingent Liab

Commitments and Contingent Liabilities	12 Months Ended
	Dec. 31, 2017
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingent Liabilities	COMMITMENTS AND CONTINGENT LIABILITIES Heartland leases certain land and facilities under operating leases. Minimum future rental commitments at December 31, 2017 for all non-cancelable leases were as follows, in thousands: 2018 $ 5,774 2019 5,626 2020 5,411 2021 5,034 2022 4,175 Thereafter 22,817 $ 48,837 Rental expense for premises and equipment leased under operating leases was $8.0 million , $7.4 million , and $6.0 million for 2017 , 2016 and 2015 , respectively. Some of the Heartland banks lease or sublease portions of the office space they own to third parties. Occupancy expense is presented net of rental income of $1.1 million , $986,000 , and $640,000 for 2017 , 2016 and 2015 , respectively. Heartland utilizes a variety of financial instruments in the normal course of business to meet the financial needs of customers and to manage its exposure to fluctuations in interest rates. These financial instruments include lending related and other commitments as indicated below as well as derivative instruments shown in Note 12, "Derivative Financial Instruments." The Heartland banks make various commitments and incur certain contingent liabilities that are not presented in the accompanying consolidated financial statements. The commitments and contingent liabilities include various guarantees, commitments to extend credit and standby letters of credit. Commitments to extend credit are agreements to lend to a customer as long as there is no violation of any condition established in the contract. Commitments generally have fixed expiration dates or other termination clauses and may require payment of a fee. Since many of the commitments are expected to expire without being drawn upon, the total commitment amounts do not necessarily represent future cash requirements. The Heartland banks evaluate each customer’s creditworthiness on a case-by-case basis. The amount of collateral obtained, if deemed necessary by the Heartland banks upon extension of credit, is based upon management’s credit evaluation of the counterparty. Collateral held varies but may include accounts receivable, inventory, property, plant and equipment and income-producing commercial properties. Standby letters of credit and financial guarantees written are conditional commitments issued by the Heartland banks to guarantee the performance of a customer to a third party. Those guarantees are primarily issued to support public and private borrowing arrangements. The credit risk involved in issuing letters of credit is essentially the same as that involved in extending loan facilities to customers. At December 31, 2017 , and at December 31, 2016 , commitments to extend credit aggregated $1.96 billion and $1.57 billion , respectively, and standby letters of credit aggregated $55.5 million and $46.1 million , respectively. Heartland enters into commitments to sell mortgage loans to reduce interest rate risk on certain mortgage loans held for sale and loan commitments, which were recorded in the consolidated balance sheets at their fair values. Heartland does not anticipate any material loss as a result of the commitments and contingent liabilities. Residential mortgage loans sold to others are predominantly conventional residential first lien mortgages originated under Heartland's usual underwriting procedures, and are most often sold on a nonrecourse basis. Heartland's agreements to sell residential mortgage loans in the normal course of business, primarily to GSE's, which usually require certain representations and warranties on the underlying loans sold, related to credit information, loan documentation, collateral, and insurability, which if subsequently are untrue or breached, could require Heartland to repurchase certain loans affected. Heartland had a recorded repurchase obligation of $238,000 at December 31, 2017 , and $850,000 at December 31, 2016 , which is included in other liabilities on the consolidated balance sheet. Heartland had no new requests for repurchases during 2017 and 2016. Heartland has a loss reserve for unfunded commitments, including loan commitments and letters of credit. At December 31, 2017 , and December 31, 2016 , the reserve for unfunded commitments, which is included in other liabilities on the consolidated balance sheets, was approximately $153,000 and $140,000 , respectively. The appropriateness of the reserve for unfunded commitments is reviewed on a quarterly basis, based upon changes in the amounts of commitments, delinquencies and economic conditions. There are certain legal proceedings pending against Heartland and its subsidiaries at December 31, 2017 , that are ordinary routine litigation incidental to business. While the ultimate outcome of current legal proceedings cannot be predicted with certainty, it is the opinion of management that the resolution of these legal actions should not have a material effect on Heartland's consolidated financial position or results of operations.

Stock-based Compensation

Stock-based Compensation	12 Months Ended
	Dec. 31, 2017
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Stock-based Compensation	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 other equity-based incentive awards, under its 2012 Long-Term Incentive Plan (the "Plan"). The Plan was originally approved by stockholders in May 2012 and was amended and restated effective March 8, 2016, to increase the number of shares of common stock authorized for issuance and make certain other changes to the Plan. At December 31, 2017 , 503,347 shares of common stock were reserved for future issuance under awards that may be granted under the Plan to employees and directors of, and service providers to, Heartland or its subsidiaries. FASB 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 $ 1.2 million for the year ended December 31, 2017. Prior to the adoption of ASU 2016-09 on January 1, 2017, $ 374,000 of tax benefit related to the exercise, vesting and forfeiture of equity-based awards was reflected in additional paid-in-capital for the year ended December 31, 2016. Options Although the Plan provides authority to the Compensation Committee to grant stock options, no options were granted during the years ended December 31, 2017 , 2016 and 2015 . Prior to 2009, options were typically granted annually with an expiration date 10 years after the date of grant. Vesting was generally over a five -year service period with portions of a grant becoming exercisable at three years , four years and five years after the date of grant. The exercise price of stock options granted is established by the Compensation Committee, but the exercise price for the stock options may not be less than the fair market value of the shares on the date that the options are granted or, if greater, the par value of a share of common stock. A summary of the status of Heartland's common stock options as of December 31, 2017 , 2016 and 2015 , and changes during the years ended December 31, 2017 , 2016 and 2015 , follows: 2017 2016 2015 Shares Weighted-Average Exercise Price Shares Weighted-Average Exercise Price Shares Weighted-Average Exercise Price Outstanding at January 1 26,400 $ 18.60 125,950 $ 24.08 215,851 $ 23.85 Granted — — — — — — Exercised (19,400 ) 18.60 (97,800 ) 25.59 (86,651 ) 23.49 Forfeited (500 ) 18.60 (1,750 ) 21.10 (3,250 ) 23.51 Outstanding at December 31 6,500 $ 18.60 26,400 $ 18.60 125,950 $ 24.08 Options exercisable at December 31 6,500 $ 18.60 26,400 $ 18.60 125,950 $ 24.08 At December 31, 2017 , the vested options have a weighted average remaining contractual life of 0.07 years . The intrinsic value for the vested options as of December 31, 2017 , was $228,000 . The intrinsic value for the total of all options exercised during the year ended December 31, 2017 , was $561,000 . No shares under stock options vested during the year ended December 31, 2017 . There were no compensation costs recorded for stock options for the years ended December 31, 2017 , 2016 and 2015 . Cash received from options exercised for the year ended December 31, 2017 , was $361,000 . Cash received from options exercised for the year ended December 31, 2016 , was $2.5 million . Restricted Stock Units The Plan permits the Compensation Committee to grant restricted stock units ("RSUs"). In the first quarter of 2017, the Compensation Committee granted time-based RSUS with respect to 55,665 shares of common stock, and in the first quarter of 2016, the Compensation Committee granted time-based RSUs with respect to 72,644 shares of common stock to selected officers and employees. The time-based RSUs, which represent the right, without payment, to receive shares of Heartland common stock at a specified date in the future. The time-based RSUs granted in 2016 vest over three years in equal installments on the first, second and third anniversaries of the grant date, 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 27,570 shares of common stock in the first quarter of 2017, and 35,516 shares of common stock in the first quarter of 2016. These performance-based RSUs are earned based on satisfaction of performance targets for the fiscal years ended December 31, 2017 and December 31, 2016, respectively, and then fully vest on January 19 of the third calendar year following the year of the grant. The Compensation Committee also granted performance-based RSUs with respect to 9,032 shares and 11,408 shares of common stock in the first quarter of 2017 and 2016, respectively. These performance-based RSUs will be earned based upon satisfaction of performance targets for the three -year performance period ended December 31, 2019, and December 31, 2018. These performance-based RSUs will vest in 2020 and 2019, 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 2016 performance-based RSUs will fully vest upon an "Involuntary Termination" within two years after the change in control and the 2017 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 24 months after a change in control. All of Heartland's RSUs will be settled in common stock upon vesting and will not be 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 the commencement of employment, and to other employees and service providers as incentives. During the years ended December 31, 2017 , 2016 and 2015, 17,106 , 24,153 and 22,648 RSUs, respectively, were granted to directors and new employees. The related compensation expense recorded for these grants was $741,000 , $652,000 , and $665,000 for the respective years. A summary of the status of RSUs as of December 31, 2017 , 2016 and 2015 , and changes during the years ended December 31, 2017 , 2016 , and 2015 , follows: 2017 2016 2015 Shares Weighted-Average Grant Date Fair Value Shares Weighted-Average Grant Date Fair Value Shares Weighted-Average Grant Date Fair Value Outstanding at January 1 346,817 $ 27.61 353,195 $ 25.53 396,555 $ 21.48 Granted 109,373 47.22 143,721 29.75 139,943 28.90 Vested (137,394 ) 26.66 (126,614 ) 23.83 (152,981 ) 18.54 Forfeited (17,218 ) 34.02 (23,485 ) 29.80 (30,322 ) 23.38 Outstanding at December 31 301,578 $ 34.74 346,817 $ 27.61 353,195 $ 25.53 The total fair value of shares under RSUs that vested during the year ended December 31, 2017 , was $ 6.4 million . Total compensation costs recorded for RSUs were $3.2 million , $2.6 million and $2.6 million , for 2017 , 2016 and 2015 , respectively. As of December 31, 2017 , there were $3.2 million of total unrecognized compensation costs related to the Plan for RSUs which are expected to be recognized through 2020. Employee Stock Purchase Plan Heartland maintains an employee stock purchase plan (the "ESPP"), which was adopted in May 2016 and replaced the 2006 ESPP, that permits all eligible employees to purchase shares of Heartland common stock at a price of not less than 95% of the fair market value (as determined by the Compensation Committee) on the determination date. Under ASC Topic 718, compensation expense related to the ESPP of $ 153,000 was recorded in 2017 , $183,000 was recorded in 2016 , and $58,000 was recorded in 2015 because the price of the shares purchased was set at the beginning of the year for the purchases at the end of the year. A maximum of 500,000 shares is available for purchase under the ESPP, and as of December 31, 2017 , 467,755 shares remain available for purchase. Beginning in 2017, Heartland began making ESPP purchases as soon as practicable after the last day of the plan year. On January 2, 2018, 22,903 shares were purchased under the ESPP plan for employee deferrals made during the plan year ended December 31, 2017. For the year ended December 31, 2016 , 32,245 shares were purchased under the ESPP. For the year ended December 31, 2015 , 28,788 shares were purchased under the ESPP.

Stockholder Rights Plan

Stockholder Rights Plan	12 Months Ended
	Dec. 31, 2017
Temporary Equity Disclosure [Abstract]
Stockholder Rights Plan	STOCKHOLDER RIGHTS PLAN Heartland adopted an Amended and Restated Rights Agreement (the "Extended Rights Plan"), dated as of January 17, 2012, which became effective upon approval by the stockholders on May 16, 2012. The primary purpose of the Extended Rights Plan was to extend the term of the Rights Agreement dated as of June 7, 2002, for an additional ten years and to expand the definition of beneficial owners to include certain forms of indirect ownership. Under the terms of the Extended Rights Plan, a preferred share purchase right (a "Right") is automatically issued with each outstanding share of Heartland common stock and, unless redeemed or unless there is a Distribution Date, as defined below, the Rights trade with the shares of common stock until expiration of the Plan on January 17, 2022. Each Right entitles the holder to purchase from Heartland one-thousandth of a share of Series A Junior Participating Preferred Stock, $1.00 value (the "Preferred Stock"), at a price of $70.00 per one one-thousandth of a share of Preferred Stock, subject to adjustment (the "Purchase Price"). The Rights are not currently exercisable, and will not become exercisable until a Distribution Date. The Preferred Stock has a preferential quarterly dividend rate equal to the greater of $1.00 per share or 1,000 times the dividend declared on one share of common stock , a preference over common stock in liquidation equal to the greater of $1,000 per share or 1,000 times the payment made on one share of common stock , 1,000 votes per share voting together with the common stock, customary anti-dilution provisions and other rights that approximate the rights of one share of common stock. The Rights separate from the common stock and become exercisable only on the tenth day (the "Distribution Date") following the earlier of (i) a public announcement that a person or group of affiliated or associated persons (subject to certain exclusions, "Acquiring Persons") has commenced an offer to acquire "beneficial ownership" of 15% or more of Heartland's outstanding common stock, or (ii) actual acquisition of this level of beneficial ownership. If any person or group of affiliated or associated persons becomes an Acquiring Person, each holder of a Right, other than Rights that were or are beneficially owned by the Acquiring Person (which will thereafter be void), will have the right to receive upon exercise that number of shares of common stock having a market value of two times the Purchase Price. In 2002, when the Rights Plan was originally created, Heartland designated 16,000 shares, par value $1.00 per share, of Series A Junior Participating preferred stock. There are no shares issued and outstanding, and Heartland does not anticipate issuing any shares of Series A Junior Participating preferred stock, except as may be required under the Extended Rights Plan.

Capital Issuance and Redemption

Capital Issuance and Redemption	12 Months Ended
	Dec. 31, 2017
Equity [Abstract]
Capital Issuance and Redemption	CAPITAL ISSUANCE AND REDEMPTION Common Stock For a description of the issuance of shares of Heartland common stock in connection with acquisitions, see Note 2, "Acquisitions," of the consolidated financial statements. Series D Preferred Stock In connection with the acquisition of CIC Bancshares, Inc. on February 5, 2016, Heartland issued 3,000 shares of 7.0% Senior Non-Cumulative Perpetual Convertible Stock, Series D (the "Series D Preferred Stock") in exchange for 3,000 outstanding shares of 7.0% Senior Non-Cumulative Perpetual Convertible Stock, Series B, of CIC Bancshares, Inc. Holders of the Series D Preferred Stock will be entitled to receive, in any liquidation, dissolution or winding up of Heartland, and before any payment to holders of Heartland common stock, a payment of $1,000 per share plus declared and unpaid dividends on the Series D Preferred Stock (the "Series D Liquidation Amount"). Holders of Series D Preferred Stock will be entitled to non-cumulative dividends, if and when declared by the Heartland Board of Directors, at a rate of 7.0% of the Series D Liquidation Amount per annum, payable quarterly on February 15, May 15, August 15 and November 15 of each year. Heartland will be prohibited from paying any dividends on its common stock unless these non-cumulative dividends on the Series D Preferred Stock have been paid for the most recently completed dividend period. Heartland may redeem the shares of Series D Preferred Stock, subject to regulatory approval, at any time on or after September 28, 2018, at a price equal to $1,000 per share plus accrued and unpaid dividends through the date fixed for redemption. The shares of Series D Preferred Stock are convertible, at the option of the holder, in whole or in part at any time into shares of Heartland common stock plus a contingent payment right. The number of shares of Heartland common stock currently deliverable upon conversion of each share of Series D Preferred Stock is 39.8883 shares. The holders of Series D Preferred Stock will be entitled, with respect to each share of such stock, to the number of votes on all matters submitted by Heartland to a vote of holders of its common stock, as is equal to the number of shares of common stock into which each share of Series D Preferred Stock is convertible as of the record date for holders entitled to vote. The holders of Series D Preferred Stock will be entitled to vote as a separate class on such matters as are required by the Delaware General Corporation Law. Generally, these matters include any amendment to Heartland’s Certificate of Incorporation or the Certificate of Designation of the Series D Preferred Stock that would increase or decrease the number of authorized shares or par value of the Series D Preferred Stock, or that would change adversely the powers, preferences or special rights of the shares of Series D Preferred Stock. During the first quarter of 2017, 333 shares of the Heartland Series D Preferred Stock were converted to 13,283 shares of Heartland common stock. During the third quarter of 2016, 1,922 shares of the Heartland Series D Preferred Stock were converted to 76,665 shares of Heartland common stock. As of December 31, 2017 and 2016 , 745 and 1,078 shares of the Series D Preferred Stock remain outstanding. Shelf Registration Heartland filed a universal shelf registration with the SEC to register debt or equity securities on July 29, 2016, in anticipation of the expiration of a previously filed registration statement. This registration statement, which was effective immediately, provides Heartland the ability to raise capital, subject to market conditions and SEC rules and limitations, if Heartland's board of directors decides to do so. This registration statement permits Heartland, from time to time, in one more public offerings, to offer debt securities, subordinated notes, common stock, preferred stock, rights or any combination of these securities. Under this registration statement, on November 2, 2016, Heartland commenced a public offering of 1,379,690 shares of common stock at $36.24 per share, and the offering closed on November 8, 2016. The offering resulted in net proceeds of approximately $49.7 million after deducting estimated offering expenses payable by Heartland. All of the shares of common stock included in the offering are primary shares. Heartland is using the net proceeds from this offering for general corporate purposes, which may include, among other things, working capital, debt repayment or financing potential acquisitions.

Regulatory Capital Requirements

Regulatory Capital Requirements and Restrictions on Subsidiary Dividends	12 Months Ended
	Dec. 31, 2017
Banking and Thrift [Abstract]
Regulatory Capital Requirements and Restrictions on Subsidiary Dividends	REGULATORY CAPITAL REQUIREMENTS AND RESTRICTIONS ON SUBSIDIARY DIVIDENDS The Heartland banks are subject to various regulatory capital requirements administered by the federal banking agencies. Failure to meet minimum capital requirements can initiate certain mandatory, and possibly additional discretionary, actions by regulators that, if undertaken, could have a direct material effect on the Heartland banks’ financial statements. The regulations prescribe specific capital adequacy guidelines that involve quantitative measures of a bank’s assets, liabilities and certain off balance sheet items as calculated under regulatory accounting practices. Capital classification is also subject to qualitative judgments by the regulators about components, risk weightings and other factors. Quantitative measures established by regulation to ensure capital adequacy require the Heartland banks to maintain minimum amounts and ratios (set forth in the table below) of total and Tier 1 capital (as defined in the regulations) to risk-weighted assets (as defined), and of Tier 1 capital (as defined) to average assets (as defined). Under the Basel III Capital Rules, which were effective January 1, 2015, bank holding companies became subject to a common equity Tier 1 capital (as defined) to risk-weighted assets (as defined) ratio. The requirements to be categorized as well-capitalized under the Tier 1 leverage capital ratio is 4% for all banks. The minimum requirement to be well-capitalized for the Tier 1 risk-based capital ratio is 8%. The total risk-based capital ratio minimum requirement to be well-capitalized remained is 10%. The Basel III Capital Rules also prescribed a new standardized approach for risk weightings that expanded the risk weighting categories from the previous four Basel I-derived categories (0%, 20%, 50% and 100%) to a larger and more risk-sensitive number of categories. Management believes, as of December 31, 2017 and 2016 , that the Heartland banks met all capital adequacy requirements to which they were subject. As of December 31, 2017 and 2016 , the FDIC categorized each of the Heartland banks as well capitalized under the regulatory framework for prompt corrective action. To be categorized as well capitalized, the Heartland banks must maintain minimum total risk-based, Tier 1 risk-based, Tier 1 common equity and Tier 1 leverage ratios as set forth in the following table. There are no conditions or events since December 31, 2017 that management believes have changed each institution’s category. The Heartland banks’ actual capital amounts and ratios are also presented in the tables below, in thousands: Actual For Capital Adequacy Purposes To Be Well Capitalized Under Prompt Corrective Action Provisions Amount Ratio Amount Ratio Amount Ratio As of December 31, 2017 Total Capital (to Risk-Weighted Assets) Consolidated $ 1,010,116 13.45 % $ 600,924 8.00 % N/A Dubuque Bank and Trust Company 156,544 13.63 91,878 8.00 $ 114,848 10.00 % Illinois Bank & Trust 71,410 12.62 45,265 8.00 56,582 10.00 Wisconsin Bank & Trust 113,045 14.57 62,057 8.00 77,572 10.00 New Mexico Bank & Trust 133,274 11.42 93,401 8.00 116,751 10.00 Arizona Bank & Trust 61,550 13.39 36,773 8.00 45,966 10.00 Rocky Mountain Bank 50,729 13.78 29,461 8.00 36,826 10.00 Citywide Banks 226,493 13.63 132,975 8.00 166,219 10.00 Minnesota Bank & Trust 23,760 13.76 13,811 8.00 17,264 10.00 Morrill & Janes Bank and Trust Company 72,471 13.42 43,206 8.00 54,007 10.00 Premier Valley Bank 83,772 12.95 51,743 8.00 64,679 10.00 Actual For Capital Adequacy Purposes To Be Well Capitalized Under Prompt Corrective Action Provisions Amount Ratio Amount Ratio Amount Ratio As of December 31, 2017 Tier 1 Capital (to Risk-Weighted Assets) Consolidated $ 879,133 11.70 % $ 450,693 6.00 % N/A Dubuque Bank and Trust Company 148,080 12.89 68,909 6.00 $ 91,878 8.00 % Illinois Bank & Trust 66,547 11.76 33,949 6.00 45,265 8.00 Wisconsin Bank & Trust 106,236 13.70 46,543 6.00 62,057 8.00 New Mexico Bank & Trust 123,519 10.58 70,050 6.00 93,401 8.00 Arizona Bank & Trust 56,870 12.37 27,579 6.00 36,773 8.00 Rocky Mountain Bank 47,660 12.94 22,096 6.00 29,461 8.00 Citywide Banks 221,239 13.31 99,731 6.00 132,975 8.00 Minnesota Bank & Trust 22,554 13.06 10,358 6.00 13,811 8.00 Morrill & Janes Bank and Trust Company 67,328 12.47 32,404 6.00 43,206 8.00 Premier Valley Bank 81,213 12.56 38,808 6.00 51,743 8.00 Common Equity Tier 1 (to Risk-Weighted Assets) Consolidated $ 756,309 10.07 % $ 338,019 4.50 % N/A Dubuque Bank and Trust Company 148,080 12.89 51,681 4.50 $ 74,651 6.50 % Illinois Bank & Trust 66,547 11.76 25,462 4.50 36,778 6.50 Wisconsin Bank & Trust 106,236 13.70 34,907 4.50 50,422 6.50 New Mexico Bank & Trust 123,519 10.58 52,538 4.50 75,888 6.50 Arizona Bank & Trust 56,870 12.37 20,685 4.50 29,878 6.50 Rocky Mountain Bank 47,660 12.94 16,572 4.50 23,937 6.50 Citywide Banks 221,239 13.31 74,799 4.50 108,042 6.50 Minnesota Bank & Trust 22,554 13.06 7,769 4.50 11,222 6.50 Morrill & Janes Bank and Trust Company 67,328 12.47 24,303 4.50 35,104 6.50 Premier Valley Bank 81,213 12.56 29,106 4.50 42,042 6.50 Tier 1 Capital (to Average Assets) Consolidated $ 879,133 9.20 % $ 382,089 4.00 % N/A Dubuque Bank and Trust Company 148,080 10.05 58,932 4.00 $ 73,666 5.00 % Illinois Bank & Trust 66,547 8.39 31,728 4.00 39,660 5.00 Wisconsin Bank & Trust 106,236 10.53 40,373 4.00 50,466 5.00 New Mexico Bank & Trust 123,519 8.54 57,834 4.00 72,292 5.00 Arizona Bank & Trust 56,870 9.94 22,890 4.00 28,613 5.00 Rocky Mountain Bank 47,660 9.82 19,418 4.00 24,272 5.00 Citywide Banks 221,239 10.03 88,240 4.00 110,300 5.00 Minnesota Bank & Trust 22,554 10.77 8,379 4.00 10,473 5.00 Morrill & Janes Bank and Trust Company 67,328 9.47 28,435 4.00 35,543 5.00 Premier Valley Bank 81,213 9.80 33,157 4.00 41,446 5.00 Actual For Capital Adequacy Purposes To Be Well Capitalized Under Prompt Corrective Action Provisions Amount Ratio Amount Ratio Amount Ratio As of December 31, 2016 Total Capital (to Risk-Weighted Assets) Consolidated $ 887,607 14.01 % $ 506,865 8.00 % N/A Dubuque Bank and Trust Company 150,692 12.76 94,494 8.00 $ 118,117 10.00 % Illinois Bank & Trust 70,808 11.83 47,884 8.00 59,856 10.00 Wisconsin Bank & Trust 109,069 14.35 60,819 8.00 76,024 10.00 New Mexico Bank & Trust 119,246 11.20 85,208 8.00 106,510 10.00 Arizona Bank & Trust 58,741 14.64 32,108 8.00 40,135 10.00 Rocky Mountain Bank 50,188 13.72 29,254 8.00 36,568 10.00 Citywide Banks (1) 83,615 13.25 50,475 8.00 63,094 10.00 Minnesota Bank & Trust 21,693 11.86 14,628 8.00 18,285 10.00 Morrill & Janes Bank and Trust Company 85,649 12.36 55,433 8.00 69,292 10.00 Premier Valley Bank 66,132 14.44 36,649 8.00 45,811 10.00 Tier 1 Capital (to Risk-Weighted Assets) Consolidated $ 756,056 11.93 % $ 380,148 6.00 % N/A Dubuque Bank and Trust Company 140,970 11.93 70,870 6.00 $ 94,494 8.00 % Illinois Bank & Trust 66,101 11.04 35,913 6.00 47,884 8.00 Wisconsin Bank & Trust 102,523 13.49 45,614 6.00 60,819 8.00 New Mexico Bank & Trust 109,185 10.25 63,906 6.00 85,208 8.00 Arizona Bank & Trust 54,970 13.70 24,081 6.00 32,108 8.00 Rocky Mountain Bank 46,702 12.77 21,941 6.00 29,254 8.00 Citywide Banks (1) 81,260 12.88 37,857 6.00 50,475 8.00 Minnesota Bank & Trust 20,315 11.11 10,971 6.00 14,628 8.00 Morrill & Janes Bank and Trust Company 78,615 11.35 41,575 6.00 55,433 8.00 Premier Valley Bank 64,735 14.13 27,487 6.00 36,649 8.00 Common Equity Tier 1 (to Risk Weighted Assets) Consolidated $ 639,467 10.09 % $ 285,111 4.50 % N/A Dubuque Bank and Trust Company 140,970 11.93 53,153 4.50 $ 76,776 6.50 % Illinois Bank & Trust 66,101 11.04 26,935 4.50 38,906 6.50 Wisconsin Bank & Trust 102,523 13.49 34,211 4.50 49,416 6.50 New Mexico Bank & Trust 109,185 10.25 47,929 4.50 69,231 6.50 Arizona Bank & Trust 54,970 13.70 18,061 4.50 26,088 6.50 Rocky Mountain Bank 46,702 12.77 16,455 4.50 23,769 6.50 Citywide Banks (1) 81,260 12.88 28,392 4.50 41,011 6.50 Minnesota Bank & Trust 20,315 11.11 8,228 4.50 11,885 6.50 Morrill & Janes Bank and Trust Company 78,615 11.35 31,181 4.50 45,040 6.50 Premier Valley Bank 64,735 14.13 20,615 4.50 29,777 6.50 Tier 1 Capital (to Average Assets) Consolidated $ 756,056 9.28 % $ 325,894 4.00 % N/A Dubuque Bank and Trust Company 140,970 9.41 59,896 4.00 $ 74,870 5.00 % Illinois Bank & Trust 66,101 8.80 30,059 4.00 37,573 5.00 Wisconsin Bank & Trust 102,523 9.96 41,155 4.00 51,443 5.00 New Mexico Bank & Trust 109,185 8.16 53,529 4.00 66,911 5.00 Actual For Capital Adequacy Purposes To Be Well Capitalized Under Prompt Corrective Action Provisions Amount Ratio Amount Ratio Amount Ratio December 31, 2016 Tier 1 Capital (to Average Assets) Arizona Bank & Trust $ 54,970 9.59 % $ 22,922 4.00 % $ 28,653 5.00 % Rocky Mountain Bank 46,702 9.79 19,078 4.00 23,848 5.00 Citywide Banks (1) 81,260 9.33 34,827 4.00 43,534 5.00 Minnesota Bank & Trust 20,315 8.72 9,315 4.00 11,644 5.00 Morrill & Janes Bank and Trust Company 78,615 9.12 34,463 4.00 43,079 5.00 Premier Valley Bank 64,735 10.91 23,729 4.00 29,661 5.00 (1) Centennial Bank and Trust changed its name to Citywide Banks upon the acquisition of Citywide Banks of Colorado, Inc., on July 7, 2017. The ability of Heartland to pay dividends to its stockholders is dependent upon dividends paid by its subsidiaries. The Heartland banks are subject to certain statutory and regulatory restrictions on the amount they may pay in dividends. To maintain acceptable capital ratios for the Banks, certain portions of their retained earnings are not available for the payment of dividends. Retained earnings that could be available for the payment of dividends to Heartland totaled approximately $392.5 million as of December 31, 2017 , under the most restrictive minimum capital requirements. Retained earnings that could be available for the payment of dividends to Heartland totaled approximately $242.3 million as of December 31, 2017 , under the capital requirements to remain well capitalized.

Fair Value

Fair Value	12 Months Ended
	Dec. 31, 2017
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, servicing rights and other real estate owned. These nonrecurring fair value adjustments typically involve application of 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 which 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 only recorded at fair value 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, equity securities and corporate debt securities. The Level 3 securities consisted primarily of Z tranche mortgage-backed securities 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. 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 these assumptions 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 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 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 December 31, 2017 , and December 31, 2016 , 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 December 31, 2017 , and December 31, 2016 , 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 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 $ — December 31, 2016 Assets Securities available for sale U.S. government corporations and agencies $ 4,700 $ 517 $ 4,183 $ — Mortgage-backed securities 1,290,500 — 1,288,276 2,224 Obligations of states and political subdivisions 536,144 — 536,144 — Equity securities 14,520 — 14,520 — Derivative financial instruments (1) 3,222 — 3,222 — Interest rate lock commitments 2,790 — — 2,790 Forward commitments 2,546 — 2,546 — Total assets at fair value $ 1,854,422 $ 517 $ 1,848,891 $ 5,014 Liabilities Derivative financial instruments (2) $ 7,027 $ — $ 7,027 $ — Forward commitments 266 — 266 — Total liabilities at fair value $ 7,293 $ — $ 7,293 $ — (1) Includes embedded derivatives, back-to-back loan swaps and cash flow hedges (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 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) (Gains)/Losses 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 Measurements at December 31, 2016 Total Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) (Gains)/Losses Collateral dependent impaired loans: Commercial $ 1,683 $ — $ — $ 1,683 $ 41 Commercial real estate 3,026 — — 3,026 527 Agricultural and agricultural real estate 1,955 — — 1,955 — Residential real estate 3,565 — — 3,565 85 Consumer 1,193 — — 1,193 — Total collateral dependent impaired loans $ 11,422 $ — $ — $ 11,422 $ 653 Loans held for sale $ 61,261 $ — $ 61,261 $ — $ (640 ) Other real estate owned $ 9,744 $ — $ — $ 9,744 $ 1,341 Premises, furniture and equipment held for sale $ 414 $ — $ — $ 414 $ 35 Commercial servicing rights $ 326 $ — $ — $ 326 $ 33 The following tables present additional quantitative information about assets measured at fair value on a recurring and nonrecurring basis and for which Heartland has utilized Level 3 inputs to determine fair value, in thousands: Fair Value at 12/31/17 Valuation Technique Unobservable Input Range (Weighted Average) Z-TRANCHE Securities $ — Discounted cash flows Pretax discount rate — Actual defaults — Actual deferrals — 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) Appraisal discount 0-10% (4) Other real estate owned 10,777 Modified appraised value Third party appraisal (2) Appraisal discounts 0-10% Commercial servicing rights 291 Discounted cash flows Third party valuation (3) 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 at 12/31/16 Valuation Technique Unobservable Input Range (Weighted Average) Z-TRANCHE Securities $ 2,224 Discounted cash flows Pretax discount rate 7.50 - 9.50% Actual defaults 21.77 - 37.62% (33.11%) Actual deferrals 10.44 - 26.29% (14.81%) Interest rate lock commitments 2,790 Discounted cash flows Closing ratio 0 - 99% (89%) (1) Premises, furniture and equipment held for sale 414 Modified appraised value Third party appraisal (2) Appraisal discount 0-8% (4) Other real estate owned 9,744 Modified appraised value Third party appraisal (2) Appraisal discounts 0-10% Commercial servicing rights 326 Discounted cash flows Third party valuation (3) Collateral dependent impaired loans: Commercial 1,683 Modified appraised value Third party appraisal (2) Appraisal discount 0-8% (4) Commercial real estate 3,026 Modified appraised value Third party appraisal (2) Appraisal discount 0-7% (4) Agricultural and agricultural real estate 1,955 Modified appraised value Third party appraisal (2) Appraisal discount 0-10% (4) Residential real estate 3,565 Modified appraised value Third party appraisal (2) Appraisal discount 0-8% (4) Consumer 1,193 Modified appraised value Third party valuation (2) Valuation discount 0-11% (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 that 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 Z-TRANCHE, a Level 3 asset that is measured at fair value on a recurring basis, are summarized in the following table, in thousands: For the Years Ended December 31, 2017 December 31, 2016 Balance at January 1, $ 2,224 $ 2,039 Total gains (losses), net: Included in earnings 2,810 — Included in other comprehensive income (2,166 ) 185 Purchases, issuances, sales and settlements: Purchases — — Sales (2,868 ) — Settlements — — Balance at period end, $ — $ 2,224 The changes in fair value of the corporate debt securities, Level 3 assets that are measured on a recurring basis, are summarized in the following table, in thousands: For the Years Ended December 31, 2017 December 31, 2016 Balance at January 1, $ — $ 846 Total gains (losses), net: Included in earnings — 56 Included in other comprehensive income — (106 ) Purchases, issuances, sales and settlements: Purchases — — Acquired — — Sales — (796 ) Settlements — — Balance at period end, $ — $ — The changes in fair value of the interest rate lock commitments, which are Level 3 financial instruments and are measured on a recurring basis, are summarized in the following table, in thousands: For the Years Ended December 31, 2017 December 31, 2016 Balance at January 1, $ 2,790 $ 3,168 Total gains (losses), net, included in earnings (1,479 ) (1,564 ) Issuances 1,875 5,373 Settlements (1,448 ) (4,187 ) Balance at period end, $ 1,738 $ 2,790 Gains included in net gains on sale of loans held for sale attributable to interest rate lock commitments held at December 31, 2017 , and December 31, 2016 , were $1.7 million and $2.8 million , respectively. The table below is a summary of the estimated fair value of Heartland's financial instruments (as defined by ASC 825) as of December 31, 2017 , and December 31, 2016 , in thousands. The carrying amounts in the following table 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, including the value of the commercial and mortgage servicing rights, premises, furniture and equipment, premises, furniture and equipment held for sale, OREO, goodwill, other intangibles and other liabilities. Heartland does not believe that the estimated information presented below 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, obtaining deposits or fee generating activities. Many of the estimates presented below 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 Carrying Estimated Quoted Prices in Significant Other Significant 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 Fair Value Measurements at 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 $ 158,724 $ 158,724 $ 158,724 $ — $ — Time deposits in other financial institutions 2,105 2,105 2,105 — — Securities: Available for sale 1,845,864 1,845,864 517 1,843,123 2,224 Held to maturity 263,662 274,799 — 274,799 — Other investments 21,560 21,560 — 21,365 195 Loans held for sale 61,261 61,261 — 61,261 — Loans, net: Commercial 1,272,089 1,258,754 — 1,257,071 1,683 Commercial real estate 2,513,446 2,506,858 — 2,503,832 3,026 Agricultural and agricultural real estate 485,820 487,001 — 485,046 1,955 Residential real estate 614,207 604,233 — 600,668 3,565 Consumer 411,833 414,266 — 413,073 1,193 Total Loans, net 5,297,395 5,271,112 — 5,259,690 11,422 Cash surrender value on life insurance 112,615 112,615 — 112,615 — Derivative financial instruments (1) 3,222 3,222 — 3,222 — Interest rate lock commitments 2,790 2,790 — — 2,790 Forward commitments 2,546 2,546 — 2,546 — Financial liabilities: Deposits Demand deposits 2,202,036 2,202,036 — 2,202,036 — Savings deposits 3,788,089 3,788,089 — 3,788,089 — Time deposits 857,286 857,286 — 857,286 — Short term borrowings 306,459 306,459 — 306,459 — Other borrowings 288,534 288,534 — 288,534 — Derivative financial instruments (2) 7,027 7,027 — 7,027 — Forward commitments 266 266 — 266 — (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 the 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. The market for these securities is restricted to the issuer of the stock and subject to impairment evaluation. Loans — The fair value of loans is estimated using an entrance price concept by discounting the future cash flows using the current rates at which similar loans would be made to borrowers with similar credit ratings and for the same remaining maturities. 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. Cash surrender value on life insurance — Life insurance policies are held on certain officers. The carrying value of these policies approximates fair value as it is based on the cash surrender value adjusted for other charges or amounts due that are probable at settlement. As such, Heartland classifies the estimated fair value of the cash surrender value on life insurance as Level 2. 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 when appropriate, the current creditworthiness of the counter-party. 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. 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.

Segment Reporting

Segment Reporting	12 Months Ended
	Dec. 31, 2017
Segment Reporting [Abstract]
Segment Reporting	SEGMENT REPORTING Reportable segments include community banking and retail mortgage banking services. These segments were determined based on the products and services provided or the type of customers served and are consistent with the information that is used by Heartland's key decision makers to make operating decisions and to assess Heartland's performance. Community banking involves making loans to, and generating deposits from, individuals and businesses in the markets where Heartland has banks. Retail mortgage banking involves the origination of residential loans and the subsequent sale of those loans to investors. The mortgage banking segment is a strategic business unit that offers different products and services. It is managed separately because the segment is aimed at different markets and, accordingly, requires different technology and marketing strategies. The segment's most significant revenue and expense is non-interest income and non-interest expense, respectively. Heartland does not have other reportable operating segments. The accounting policies of the mortgage banking segment are the same as those described in the summary of significant accounting policies. All intersegment sales prices are market based. All of Heartland's goodwill is associated with the community banking segment. The following table presents the financial information from Heartland's operating segments for the years ending December 31, 2017 , December 31, 2016 , and December 31, 2015 , in thousands. Community and Other Banking Mortgage Banking Total December 31, 2017 Net Interest Income $ 326,130 $ 4,178 $ 330,308 Provision for loan losses 15,563 — 15,563 Total noninterest income 77,837 24,185 102,022 Total noninterest expense 264,929 32,746 297,675 Income (loss) before income taxes $ 123,475 $ (4,383 ) $ 119,092 December 31, 2016 Net Interest Income $ 290,088 $ 4,578 $ 294,666 Provision for loan losses 11,694 — 11,694 Total noninterest income 74,145 39,456 113,601 Total noninterest expense 237,198 42,470 279,668 Income (loss) before income taxes $ 115,341 $ 1,564 $ 116,905 December 31, 2015 Net Interest Income $ 228,422 $ 5,576 $ 233,998 Provision for loan losses 12,697 — 12,697 Total noninterest income 65,414 45,271 110,685 Total noninterest expense 201,063 49,983 251,046 Income (loss) before income taxes $ 80,076 $ 864 $ 80,940 Segment Assets December 31, 2017 $ 9,757,575 $ 53,164 $ 9,810,739 December 31, 2016 8,149,465 97,614 8,247,079 December 31, 2015 7,585,130 109,624 7,694,754 Average Loans, Net of Unearned December 31, 2017 $ 5,810,308 $ 36,753 $ 5,847,061 December 31, 2016 5,418,169 69,943 5,488,112 December 31, 2015 4,466,528 84,480 4,551,008

Parent Company Only Financial I

Parent Company Only Financial Information	12 Months Ended
	Dec. 31, 2017
Condensed Financial Information of Parent Company Only Disclosure [Abstract]
Parent Company Only Financial Information	PARENT COMPANY ONLY FINANCIAL INFORMATION Condensed financial information for Heartland Financial USA, Inc. is as follows: BALANCE SHEETS (Dollars in thousands) December 31, 2017 2016 Assets: Cash and interest bearing deposits $ 24,310 $ 65,007 Securities available for sale — 2,224 Other investments, at cost — 195 Investment in subsidiaries 1,194,747 901,310 Other assets 28,536 26,154 Due from subsidiaries 6,000 6,000 Total assets $ 1,253,593 $ 1,000,890 Liabilities and stockholders’ equity: Other borrowings 246,438 249,245 Accrued expenses and other liabilities 15,698 10,729 Total liabilities 262,136 259,974 Stockholders’ equity: Preferred stock 938 1,357 Common stock 29,953 26,120 Capital surplus 503,709 328,376 Retained earnings 481,331 416,109 Accumulated other comprehensive loss (24,474 ) (31,046 ) Total stockholders’ equity 991,457 740,916 Total liabilities and stockholders’ equity $ 1,253,593 $ 1,000,890 INCOME STATEMENTS (Dollars in thousands) For the Years Ended December 31, 2017 2016 2015 Operating revenues: Dividends from subsidiaries $ 70,850 $ 55,250 $ 70,000 Securities gains, net 3,021 54 3,038 Other 2,292 1,712 712 Total operating revenues 76,163 57,016 73,750 Operating expenses: Interest 13,269 13,840 12,996 Salaries and employee benefits 3,146 3,044 5,028 Professional fees 2,379 2,487 4,735 Other operating expenses 7,889 2,664 4,234 Total operating expenses 26,683 22,035 26,993 Equity in undistributed earnings 16,212 37,926 2,570 Income before income tax benefit 65,692 72,907 49,327 Income tax benefit 9,580 7,442 10,715 Net income 75,272 80,349 60,042 Preferred dividends (58 ) (292 ) (817 ) Interest expense on convertible preferred debt 12 51 $ — Net income available to common stockholders $ 75,226 $ 80,108 $ 59,225 STATEMENTS OF CASH FLOWS (Dollars in thousands) For the Years Ended December 31, 2017 2016 2015 Cash flows from operating activities: Net income $ 75,272 $ 80,349 $ 60,042 Adjustments to reconcile net income to net cash provided by operating activities: Undistributed (earnings) losses of subsidiaries (16,212 ) (37,926 ) (2,570 ) Security gains, net (3,021 ) (54 ) (3,038 ) Gain on extinguishment of debt (1,200 ) — — Increase (decrease) in accrued expenses and other liabilities (4,160 ) (7,039 ) 4,550 (Increase) decrease in other assets (567 ) 1,948 (7,379 ) Excess tax benefits on exercised stock options 1,246 374 676 Other, net 4,714 4,892 5,014 Net cash provided by operating activities 56,072 42,544 57,295 Cash flows from investing activities: Capital contributions to subsidiaries — (18,000 ) (114,602 ) Proceeds from sales of available for sale securities 2,868 — 3,774 Proceeds from the maturity of and principal paydowns on other investments — — 619 Proceeds from sale of other investments 211 94 — Net assets acquired (62,813 ) (14,587 ) 44,066 Net cash used by investing activities (59,734 ) (32,493 ) (66,143 ) Cash flows from financing activities: Proceeds on short-term revolving credit line 20,000 — — Proceeds from borrowings — 40,000 15,000 Repayments on short-term revolving credit line (20,000 ) — — Repayments of borrowings (9,016 ) (26,280 ) (35,557 ) Payment for the redemption of debt (13,800 ) — — Redemption of preferred stock — (81,698 ) — Cash dividends paid (14,557 ) (12,870 ) (10,176 ) Purchase of treasury stock (625 ) (3,719 ) (2,987 ) Proceeds from issuance of common stock 963 54,196 3,508 Net cash used by financing activities (37,035 ) (30,371 ) (30,212 ) Net decrease in cash and cash equivalents (40,697 ) (20,320 ) (39,060 ) Cash and cash equivalents at beginning of year 65,007 85,327 124,387 Cash and cash equivalents at end of year $ 24,310 $ 65,007 $ 85,327 Supplemental disclosure: Conversion of convertible debt to common stock $ 558 $ 1,442 $ — Conversion of Series D preferred stock to common stock $ 419 $ 2,420 $ — Stock consideration granted for acquisition $ 175,196 $ 57,433 $ 120,070

Summary of Quarterly Financial

Summary of Quarterly Financial Information (Unaudited)	12 Months Ended
	Dec. 31, 2017
Quarterly Financial Information Disclosure [Abstract]
Summary of Quarterly Financial Information (Unaudited)	SUMMARY OF QUARTERLY FINANCIAL INFORMATION (UNAUDITED) (Dollars in thousands, except per share data) 2017 December 31 September 30 June 30 March 31 Net interest income $ 92,856 $ 89,844 $ 74,580 $ 73,028 Provision for loan losses 5,328 5,705 889 3,641 Net interest income after provision for loan losses 87,528 84,139 73,691 69,387 Noninterest income 25,528 24,977 25,624 25,893 Noninterest expense 77,878 78,759 69,298 71,740 Income taxes 21,506 8,725 8,059 5,530 Net income 13,672 21,632 21,958 18,010 Preferred dividends (13 ) (13 ) (13 ) (19 ) Interest expense on convertible preferred debt — 3 4 5 Net income available to common stockholders 13,659 21,622 21,949 17,996 Per share: Earnings per share-basic $ 0.46 $ 0.73 $ 0.82 $ 0.68 Earnings per share-diluted 0.45 0.72 0.81 0.68 Cash dividends declared on common stock 0.18 0.11 0.11 0.11 Book value per common share 33.07 32.75 30.15 29.26 Weighted average common shares outstanding 29,948,536 29,647,534 26,686,845 26,334,788 Weighted average diluted common shares outstanding 30,209,043 29,910,437 26,972,580 26,627,830 (Dollars in thousands, except per share data) 2016 December 31 September 30 June 30 March 31 Net interest income $ 75,160 $ 73,681 $ 73,118 $ 72,707 Provision for loan losses 2,181 5,328 2,118 2,067 Net interest income after provision for loan losses 72,979 68,353 71,000 70,640 Noninterest income 24,455 28,542 31,026 29,578 Noninterest expense 69,912 68,427 71,020 70,309 Income taxes 8,360 8,260 10,036 9,900 Net income 19,162 20,208 20,970 20,009 Preferred dividends (19 ) (53 ) (52 ) (168 ) Interest expense on convertible preferred debt 3 17 31 — Net income available to common stockholders 19,146 20,172 20,949 19,841 Per share: Earnings per share-basic $ 0.75 $ 0.82 $ 0.85 $ 0.84 Earnings per share-diluted 0.74 0.81 0.84 0.82 Cash dividends declared on common stock 0.20 0.10 0.10 0.10 Book value per common share 28.31 28.48 27.88 27.15 Weighted average common shares outstanding 25,498,423 24,601,016 24,524,273 23,657,234 Weighted average diluted common shares outstanding 25,800,472 24,922,946 24,974,995 24,117,384

Summary of Significant Accoun33

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2017
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Principles of Presentation	Principles of Presentation - The consolidated financial statements include the accounts of Heartland and its subsidiaries: Dubuque Bank and Trust Company; Illinois Bank & Trust; Wisconsin Bank & Trust; New Mexico Bank & Trust; Arizona Bank & Trust; Rocky Mountain Bank; Citywide Banks; Minnesota Bank & Trust; Morrill & Janes Bank and Trust Company; Premier Valley Bank; Citizens Finance Parent Co.; DB&T Insurance, Inc.; DB&T Community Development Corp.; Heartland Community Development, Inc.; Heartland Financial USA, Inc. Insurance Services; Citizens Finance Co.; Citizens Finance of Illinois Co.; Heartland Financial Statutory Trust IV; Heartland Financial Statutory Trust V; Heartland Financial Statutory Trust VI; Heartland Financial Statutory Trust VII; Morrill Statutory Trust I; Morrill Statutory Trust II; Sheboygan Statutory Trust I, CBNM Capital Trust I, Citywide Capital Trust III, Citywide Capital Trust IV and Citywide Capital Trust V. All of Heartland’s subsidiaries are wholly-owned as of December 31, 2017 . The consolidated financial statements have been prepared in accordance with U.S. generally accepted accounting principles ("GAAP") and prevailing practices within the banking industry. In preparing such financial statements, management is required to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities as of the date of the balance sheets and revenues and expenses for the years then ended. Actual results could differ significantly from those estimates. A material estimate that is particularly susceptible to significant change relates to the determination of the allowance for loan losses.
Business Combinations	Business Combinations - Heartland applies the acquisition method of accounting in accordance with the Financial Accounting Standards Board ("FASB") Accounting Standards Codification ("ASC") Topic 805, Business Combinations. Under the acquisition method, Heartland recognizes assets acquired, including identified intangible assets, and the liabilities assumed in acquisitions at fair value as of the acquisition date, with the acquisition-related transaction costs expensed in the period incurred. Determining the fair value of assets acquired and liabilities assumed often involves estimates based on third-party valuations, such as appraisals, or internal valuations based on discounted cash flow analyses or other valuation techniques that may include estimates of attrition, inflation, asset growth rates, discount rates, multiples of earnings or other relevant factors. In addition, the determination of the useful lives over which an intangible asset will be amortized is subjective.
Cash and Cash Equivalents	Cash and Cash Equivalents - For purposes of reporting cash flows, cash and cash equivalents include cash on hand, amounts due from banks, interest bearing deposits held at the Federal Reserve Bank, federal funds sold to other banks and other short-term investments. Generally, federal funds are purchased and sold for one-day periods.
Trading Securities	Trading Securities - Trading securities represent those securities Heartland intends to actively trade and are stated at fair value with changes in fair value reflected in noninterest income.
Securities Available for Sale	Securities Available for Sale - Available for sale securities consist of those securities not classified as held to maturity or trading, which management intends to hold for indefinite periods of time or that may be sold in response to changes in interest rates, prepayments or other similar factors. Available for sale securities are stated at fair value with any unrealized gain or loss, net of applicable income tax, reported as a separate component of stockholders’ equity. Security premiums and discounts are amortized/accreted using the interest method over the period from the purchase date to the expected maturity or call date of the related security. Declines in the fair value of investment securities available for sale (with certain exceptions for debt securities noted below) that are deemed to be other-than-temporary are charged to earnings as a realized loss, and a new cost basis for the securities is established. In evaluating whether impairment is other-than-temporary, Heartland considers the length of time and extent to which the fair value has been less than cost, the financial condition and near-term prospects of the issuer, and the intent and ability of Heartland to retain its investment in the issuer for a period of time sufficient to allow for any anticipated recovery in fair value in the near term. Declines in the fair value of debt securities below amortized cost are deemed to be other-than-temporary in circumstances where: (1) Heartland has the intent to sell a security; (2) it is more likely than not that Heartland will be required to sell the security before recovery of its amortized cost basis; or (3) Heartland does not expect to recover the entire amortized cost basis of the security. If Heartland intends to sell a security or if it is more likely than not that Heartland will be required to sell the security before recovery, an other-than-temporary impairment write-down is recognized in earnings equal to the difference between the security’s amortized cost basis and its fair value. If Heartland does not intend to sell the security and it is not more likely than not that it will be required to sell the security before recovery, the other-than-temporary impairment write-down is separated into an amount representing credit loss, which is recognized in noninterest income, and an amount related to all other factors, which is recognized in other comprehensive income. Realized securities gains or losses on securities sales (using specific identification method) and declines in value judged to be other-than-temporary are included in impairment loss on securities in the consolidated statements of income.
Securities Held to Maturity	Securities Held to Maturity - Securities which Heartland has the ability and positive intent to hold to maturity are classified as held to maturity. Such securities are stated at amortized cost, adjusted for premiums and discounts that are amortized/accreted using the interest method over the period from the purchase date to the expected maturity or call date of the related security. Unrealized losses determined to be other-than-temporary are charged to noninterest income.
Loans, Loans Held for Sale, Allowance for Loan Losses and Other Real Estate	Other Real Estate - Other real estate represents property acquired through foreclosures and settlements of loans. Property acquired is recorded at the estimated fair value of the property less disposal costs. The excess of carrying value over fair value less disposal costs is charged against the allowance for loan losses. Subsequent write downs estimated on the basis of later valuations and gains or losses on sales are charged to loss on sales/valuation of assets, net. Expenses incurred in maintaining such properties are charged to other real estate and loan collection expenses. Loans Held for Sale - Loans held for sale are stated at the lower of cost or fair value on an aggregate basis. Gains or losses on sales are recorded in noninterest income. Direct loan origination costs and fees are deferred at origination of the loan. These deferred costs and fees are recognized in noninterest income as part of the gain or loss on sales of loans upon sale of the loan. Allowance for Loan Losses - The allowance for loan losses is maintained at a level estimated by management to provide for known and inherent risks in the loan portfolios. The allowance is based upon a continuing review of past loan loss experience, current economic conditions, volume growth, the underlying collateral value of the loans and other relevant factors. Loans which are deemed uncollectible are charged off and deducted from the allowance. Provisions for loan losses and recoveries on previously charged-off loans are added to the allowance. Loans - Interest on loans is accrued and credited to income based primarily on the principal balance outstanding. Loans are considered past due if the required principal and interest payments have not been received as of the date such payments were due. Heartland’s policy is to discontinue the accrual of interest income on any loan when, in the opinion of management, there is a reasonable doubt as to the timely collection of the interest and principal, normally when a loan is 90 days past due. When interest accruals are deemed uncollectible, interest credited to income in the current year is reversed and interest accrued in prior years is charged to the allowance for loan losses. A loan can be restored to accrual status if the borrower has resumed paying the full amount of the scheduled contractual interest and principal payments on the loan, and (1) all principal and interest amounts contractually due (including arrearages) are reasonably assured of repayment within a reasonable period of time, and (2) that there is a sustained period of repayment performance (generally a minimum of six months ) by the borrower in accordance with the contractual terms. Under Heartland’s credit policies, 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 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, at the observable market price of the loan or the fair value of the collateral if the loan is collateral dependent. Net nonrefundable loan origination fees and certain direct costs associated with the lending process are deferred and recognized as a yield adjustment over the life of the related loan.
Acquired Loans	Acquired Loans - The FASB ASC Topic 310-30 establishes accounting standards for acquired loans with deteriorated credit quality. Heartland reviews acquired loans for differences between contractual cash flows and cash flows expected to be collected from initial investment in the acquired loans to determine if those differences are attributable, at least in part, to credit quality. If those differences are attributable to credit quality, the contractually required payments received in excess of the amount of its cash flows expected at acquisition, or nonaccretable discount, is not accreted into income. FASB ASC 310-30 requires that the excess of all cash flows expected at acquisition over the initial investment in the loan be recognized as interest income using the interest method over the term of the loan. This excess is referred to as accretable discount and is recorded as a reduction of the loan balance. When a loan is paid off, the excess of any cash received over the net investment is recorded as interest income. In addition to the amount of purchase discount that is recognized at that time, income may include interest owed by the borrower prior to the acquisition of the loan, interest collected if on nonperforming status, prepayment fees and other loan fees. At acquisition, for purchased loans not subject to ASC 310-30, the purpose of the loan (e.g., business, agricultural or personal), the type of borrower (e.g., business or individual) and the type of collateral for the loan (e.g., commercial real estate, residential real estate, general business assets or unsecured) of each loan are considered in order to assign purchased loans into one of the following five loan pools: commercial, commercial real estate, agricultural and agricultural real estate, residential real estate and consumer. These five pools are separately maintained and tracked for each acquisition, and they are consistent with the five loan categories presented in Note 5, "Loans." For purchased loans not subject to ASC 310-30, the discount, if any, representing the excess of the amount of reasonably estimable and probable discounted future cash collections over the purchase price, is accreted into interest income using the interest method over the weighted average remaining contractual life of the loan pool. Because Heartland uses the pool method as described above, no adjustment is made to the discount of an individual loan on the specific date of a credit event with respect to such loan. Additionally, the discount is not accreted on nonperforming loans. Loans not subject to ASC 310-30 migrate from the purchased loan pools to the regular loan portfolio when the borrower requests to refinance the loan prior to maturity or renews the loan at maturity, and, in either event, signs a new loan agreement. In conjunction with the refinancing or renewal process, the new loan is evaluated in accordance with Heartland’s underwriting standards, and a credit decision is made with respect to whether the new loan should be extended.
Troubled Debt Restructured Loans	Troubled Debt Restructured Loans - Loans are considered troubled debt restructured loans ("TDR") if concessions have been granted to borrowers that are experiencing financial difficulty. The concessions granted generally involve the modification of terms of the loan, such as changes in payment schedule or interest rate, which generally would not otherwise be considered. TDRs can involve loans remaining on nonaccrual, moving to nonaccrual, or continuing on accrual status, depending on the individual facts and circumstances of the borrower. Nonaccrual TDRs are included and treated consistently with all other nonaccrual loans. In addition, all accruing TDRs are reported and accounted for as impaired loans. Generally, TDRs remain on nonaccrual until the customer has attained a sustained period of repayment performance under the modified loan terms (generally a minimum of six months ). However, performance prior to the restructuring, or significant events that coincide with the restructuring, are considered in assessing whether the borrower can meet the new terms and whether the loan should be returned to or maintained on accrual status. If the borrower’s ability to meet the revised payment schedule is not reasonably assured, the loan remains on nonaccrual status. A loan that is a TDR that has an interest rate consistent with market rates at the time of restructuring and is in compliance with its modified terms in the calendar year after the year in which the restructuring took place is no longer considered a TDR but remains an impaired loan. To be considered in compliance with its modified terms, a loan that is a TDR must be in accrual status and must be current or less than 30 days past due under the modified repayment terms; however, the loan will continue to be considered impaired. A loan that has been modified at a below market rate will remain classified as a TDR and an impaired loan. If the borrower’s financial conditions improve to the extent that the borrower qualifies for a new loan with market terms, the new loan will not be considered a TDR or impaired if Heartland's credit analysis shows the borrower's ability to perform under the new market terms.
Reserve for Unfunded Commitments	Reserve for Unfunded Commitments - This reserve is maintained at a level that, in the opinion of management, is appropriate to absorb probable losses associated with Heartland’s commitment to lend funds under existing agreements such as letters or lines of credit. Management determines the appropriateness of the reserve for unfunded commitments based upon reviews of delinquencies, current economic conditions, the risk characteristics of the various categories of commitments and other relevant factors. The reserve is based on estimates, and ultimate losses may vary from the current estimates. These estimates are evaluated on a regular basis and, as adjustments become necessary, they are reported in earnings in the periods in which they become known. Draws on unfunded commitments that are considered uncollectible at the time funds are advanced are charged to the allowance. Provisions for unfunded commitment losses are added to the reserve for unfunded commitments, which is included in the Accrued Expenses and Other Liabilities section of the consolidated balance sheets.
Premises, Furniture and Equipment, net	Premises, Furniture and Equipment, net - Premises, furniture and equipment are stated at cost less accumulated depreciation. The provision for depreciation of premises, furniture and equipment is determined by straight-line and accelerated methods over the estimated useful lives of 18 to 39 years for buildings, 15 years for land improvements and 3 to 7 years for furniture and equipment.
Goodwill and Core Deposit Intangibles and Customer Relationship Intangibles, Net	Goodwill - Goodwill represents the excess of the purchase price of acquired subsidiaries’ net assets over their fair value at the purchase date. Heartland assesses goodwill for impairment annually, and more frequently if events occur which may indicate possible impairment, and assesses goodwill at the reporting unit level, also giving consideration to overall enterprise value as part of that assessment. In evaluating goodwill for impairment, Heartland first assesses qualitative factors to determine whether it is more likely than not (that is, a likelihood of more than 50%) that the fair value of a reporting unit is less than its carrying amount. If Heartland concludes that it is more likely than not that the fair value of a reporting unit is more than its carrying value, then no further testing of goodwill assigned to the reporting unit is required. However, if Heartland concludes that it is more likely than not that the fair value of a reporting unit is less than its carrying value, then Heartland performs a two-step goodwill impairment test to identify potential goodwill impairment and measure the amount of goodwill impairment to recognize, if any. In the first step, the fair value of a reporting unit is compared to its carrying amount, including goodwill. If the fair value of the reporting unit exceeds its carrying amount, goodwill is not considered impaired and it is not necessary to continue to step two of the impairment process. If the fair value of the reporting unit is less than the carrying amount, step two is performed. In step two, the implied fair value of goodwill is compared to the carrying value of the reporting unit's goodwill. The implied fair value of goodwill is computed as a residual value after allocating the fair value of the reporting unit to its assets and liabilities. Heartland estimates the fair value of its reporting units using market multiples of comparable entities, including recent transactions, or a combination of market multiples and discounted cash flow methodology. These methods incorporate assumptions specific to the entity, such as the use of financial forecasts. Core Deposit Intangibles and Customer Relationship Intangibles, Net - Core deposit intangibles are amortized over 8 to 18 years on an accelerated basis. Customer relationship intangibles are amortized over 22 years on an accelerated basis. Annually, Heartland reviews these intangible assets for events or circumstances that may indicate a change in the recoverability of the underlying basis.
Mortgage Servicing and Transfers of Financial Assets and Servicing Rights, Net	Servicing Rights, Net - Mortgage and commercial servicing rights associated with loans originated and sold, where servicing is retained, are initially capitalized at fair value and recorded on the consolidated statements of income as a component of gains on sale of loans held for sale. The values of these capitalized servicing rights are amortized as an offset to the loan servicing income earned in relation to the servicing revenue expected to be earned. The carrying values of these rights are reviewed quarterly for impairment based on the calculation of their fair value as performed by an outside third party. For purposes of measuring impairment, the rights are stratified into certain risk characteristics including loan type and loan term. Mortgage Servicing and Transfers of Financial Assets - Heartland regularly sells residential mortgage loans to others, primarily government sponsored entities, on a non-recourse basis. Sold loans are not included in the accompanying consolidated balance sheets. Heartland generally retains the right to service the sold loans for a fee.
Cash Surrender Value on Life Insurance	Cash Surrender Value on Life Insurance - Heartland and its subsidiaries have purchased life insurance policies on the lives of certain officers. The one-time premiums paid for the policies, which coincide with the initial cash surrender value, are recorded as an asset. Increases or decreases in the cash surrender value, other than proceeds from death benefits, are recorded as noninterest income in income on bank owned life insurance. Proceeds from death benefits first reduce the cash surrender value attributable to the individual policy and then any additional proceeds are recorded in other noninterest income.
Income Taxes	Income Taxes - Heartland and its subsidiaries file a consolidated federal income tax return and separate or combined income or franchise tax returns as required by the various states. Heartland recognizes certain income and expenses in different time periods for financial reporting and income tax purposes. The provision for deferred income taxes is based on an asset and liability approach and represents the change in deferred income tax accounts during the year, including the effect of enacted tax rate changes. A valuation allowance is provided to reduce deferred tax assets if their expected realization is deemed not to be more likely than not. A tax position is recognized as a benefit only if it is "more likely than not" that the tax position would be sustained in a tax examination. The amount recognized is the largest amount of tax benefit that is greater than 50% likely of being realized on examination. Heartland recognizes interest and penalties related to income tax matters in income tax expense.
Derivative Financial Instruments and Mortgage Derivatives	Derivative Financial Instruments - Heartland uses derivative financial instruments as part of its interest rate risk management, which includes interest rate swaps, certain interest rate lock commitments and forward sales of securities related to mortgage banking activities. FASB ASC Topic 815 establishes accounting and reporting standards for derivative instruments, including certain derivative instruments embedded in other contracts, and for hedging activities. As required by ASC 815, Heartland records all derivatives on the consolidated balance sheets at fair value. The accounting for changes in the fair value of derivatives depends on the intended use of the derivative and the resulting designation. Derivatives used to hedge the exposure to variability in expected future cash flows, or other types of forecasted transactions, are considered cash flow hedges. To qualify for hedge accounting, Heartland must comply with the detailed rules and documentation requirements at the inception of the hedge, and hedge effectiveness is assessed at inception and periodically throughout the life of each hedging relationship. Hedge ineffectiveness, if any, is measured periodically throughout the life of the hedging relationship. For derivatives designated as cash flow hedges, the effective portion of changes in the fair value of the derivative is initially reported in other comprehensive income (loss) and subsequently reclassified to interest income or expense when the hedged transaction affects earnings, while the ineffective portion of changes in the fair value of the derivative, if any, is recognized immediately in other noninterest income. Heartland assesses the effectiveness of each hedging relationship by comparing the cumulative changes in cash flows of the derivative hedging instrument with the cumulative changes in cash flows of the designated hedged item or transaction. No component of the change in the fair value of the hedging instrument is excluded from the assessment of hedge effectiveness. Heartland has fair value hedging relationships at December 31, 2017 . 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 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 does not use derivatives for trading or speculative purposes. Derivatives not designated as hedges are not speculative and are used to manage Heartland’s exposure to interest rate movements and other identified risks, but do not meet the strict hedge accounting requirements of ASC 815. Mortgage Derivatives - Heartland uses interest rate lock commitments to originate residential mortgage loans held for sale and forward commitments to sell residential mortgage loans and mortgage backed securities. These commitments are considered derivative instruments. 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.
Segment Reporting	Segment Reporting - Public business enterprises are required to report information about operating segments in financial statements and selected information about operating segments in financial reports issued to shareholders. Operating segments are components of an enterprise about which separate financial information is available that is evaluated regularly by management in determining how to allocate resources and to assess effectiveness of the segments' performance. Generally, financial information is required to be reported on the basis that is used internally for evaluating segment performance and deciding how to allocate resources to segments. Heartland has two reporting segments, one for community banking and one for mortgage banking operations.
Fair Value Measurements	Fair Value Measurements - Fair value represents the estimated price at which an orderly transaction to sell an asset or transfer a liability would take place between market participants at the measurement date under current market conditions (i.e. an exit price concept). Fair value measurement is based upon quoted prices, if available. If quoted prices are not available, fair values are measured using discounted cash flow or other valuation techniques. Inputs into the valuation methods are subjective in nature, involve uncertainties, and require significant judgment and therefore cannot be determined with precision. Accordingly, the derived fair value estimates presented herein are not necessarily indicative of the amounts Heartland could realize in a current market exchange. Assets and liabilities are categorized into three levels based on the markets in which the assets and liabilities are traded and the reliability of the assumptions used to determine the fair value. In instances where the determination of the fair value measurement is based on inputs from different levels of the fair value hierarchy, the level in the fair value hierarchy in which the entire fair value measurement falls is based on the lowest level input that is significant to the fair value measurement in its entirety. Heartland's assessment of the significance of a particular input to the fair value measurement in its entirety requires judgment and considers factors specific to the asset or liability. Below is a brief description of each fair value level: 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 which 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.
Treasury Stock	Treasury Stock - Treasury stock is accounted for by the cost method, whereby shares of common stock reacquired are recorded at their purchase price. When treasury stock is reissued, any difference between the sales proceeds, or fair value when issued for business combinations, and the cost is recognized as a charge or credit to capital surplus.
Trust Department Assets	Trust Department Assets - Property held for customers in fiduciary or agency capacities is not included in the accompanying consolidated balance sheets because such items are not assets of the Heartland banks.
Earnings Per Share	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.
Subsequent Events	Subsequent Events - Heartland has evaluated subsequent events that may require recognition or disclosure through the filing date of this Annual Report on Form 10-K with the SEC.
Effect of New Financial Accounting Standards	Effect of New Financial Accounting Standards - In May 2014, the FASB issued 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 intends to adopt the accounting standard effective January 1, 2018, as required, using a modified retrospective approach. However, the adoption of these amendments will not have a significant effect on Heartland's results of operations, financial position and liquidity other than expanded disclosure requirements. 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; (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 intends to apply 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 should be applied prospectively to equity investments that exist as of the adoption date. Heartland intends to adopt the accounting standard in 2018, as required, and determined these amendments will not have a material impact on its results of operations, financial position and liquidity. 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. In March 2016, the FASB issued ASU 2016-09, " Compensation-Stock Compensation (Topic 718) ." The amendments in this ASU simplify several aspects of the accounting for share-based payments, including income tax consequences, classification of awards as either equity or liabilities and classification on the statement of cash flows. The amendments in this ASU are effective for annual periods beginning after December 15, 2016 and interim periods within those annual periods. Early adoption was permitted for any interim or annual period prior to the effective date. Heartland adopted this ASU on January 1, 2017, as required, using a prospective transition method. The requirement to report the excess tax benefit or shortfall related to settlements of share-based payment awards in earnings as an increase or decrease to tax expense has been applied to settlements occurring on or after January 1, 2017, and the impact of applying the guidance reduced reported income tax expense by $1.2 million . ASU 2016-09 also requires that all income tax related cash flows resulting from share-based payments be reported as an operating activity in the consolidated statements of cash flows. Previously income tax benefits resulting from the settlement of a share-based award were reported as a reduction of operating cash flows and an increase to financing cash flows to the extent that those benefits exceeded the income tax benefits reported in earnings during the period in which the share-based awards vested. Heartland elected to adopt the change in cash flow classification on a retrospective basis, which resulted in a $374,000 and $676,000 increase to net cash from operating activities and a corresponding decrease to net cash from financing activities in the accompanying consolidated statement of cash flows for the years ended December 31 2016, and 2015, respectively. Heartland has elected to account for forfeitures as they occur. 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. 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 intends to adopt this ASU in 2018, as required, and determined the adoption of these amendments will 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 intends to apply these amendments using a modified retrospective basis through a cumulative-effect adjustment to retained earnings as of the beginning of the fiscal year of adoption. Heartland intends to adopt this ASU in 2018, as required, and determined the adoption of this amendment will 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. The amendments must be applied and Heartland intends to apply these amendments prospectively. The adoption of ASU 2017-01 is not expected to 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. The amendment should be applied and Heartland intends to apply the amendment 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; (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 intends to apply these amendments prospectively to an award modified on or after the adoption date. Heartland intends to adopt this ASU in 2018, as required, and determined the adoption of these amendments will 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 statement of financial position as of the date of adoption. Heartland currently 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	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 which 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 only recorded at fair value 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, equity securities and corporate debt securities. The Level 3 securities consisted primarily of Z tranche mortgage-backed securities 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. 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 these assumptions 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 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 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 December 31, 2017 , and December 31, 2016 , 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.

Summary of Significant Accoun34

Summary of Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2017
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 years ended December 31, 2017 , 2016 and 2015 , are shown in the table below: (Dollars and number of shares in thousands, except per share data) 2017 2016 2015 Net income attributable to Heartland $ 75,272 $ 80,349 $ 60,042 Preferred dividends (58 ) (292 ) (817 ) Interest expense on convertible preferred debt 12 51 — Net income available to common stockholders $ 75,226 $ 80,108 $ 59,225 Weighted average common shares outstanding for basic earnings per share 28,168 24,573 20,672 Assumed incremental common shares issued upon exercise of stock options and non-vested restricted stock units 258 300 257 Weighted average common shares for diluted earnings per share 28,426 24,873 20,929 Earnings per common share — basic $ 2.67 $ 3.26 $ 2.87 Earnings per common share — diluted $ 2.65 $ 3.22 $ 2.83

Acquisitions (Tables)

Acquisitions (Tables)	12 Months Ended
	Dec. 31, 2017
Business Combinations [Abstract]
Schedule of Recognized Identified Assets Acquired and Liabilities Assumed	The following table represents, in thousands, the amounts recorded on the consolidated balance sheet as of July 7, 2017: As of July 7, 2017 Fair value of consideration paid: Common stock (3,216,161 shares) $ 152,607 Cash 58,636 Total consideration paid 211,243 Fair value of assets acquired: Cash and due from banks 21,341 Interest bearing deposits with the Federal Reserve and other banks and other short-term investments 74,686 Time deposits in other financial institutions 6,304 Securities: Securities available for sale 234,390 Other securities 2,628 Loans held to maturity 985,399 Premises, furniture and equipment, net 17,206 Premises, furniture and equipment held for sale 1,350 Other real estate, net 6,916 Core deposit intangibles and customer relationship intangibles, net 16,041 Cash surrender value on life insurance 21,015 Other assets 11,263 Total assets 1,398,539 Fair value of liabilities assumed: Deposits 1,210,074 Short term borrowings 34,445 Other borrowings 21,636 Other liabilities 16,295 Total liabilities assumed 1,282,450 Fair value of net assets acquired 116,089 Goodwill resulting from acquisition $ 95,154 The following table represents, in thousands, the amounts recorded on the consolidated balance sheet as of February 5, 2016: As of February 5, 2016 Fair value of consideration paid Common stock (2,003,235 shares) $ 57,433 Preferred stock (3,000 shares) 3,777 Cash 15,672 Total consideration paid 76,882 Fair value of assets acquired: Cash and due from banks 23,756 Securities: Securities available for sale 92,831 Other securities 3,486 Loans held to maturity 581,477 Premises, furniture and equipment, net 16,450 Other real estate, net 1,934 Core deposit intangibles and customer relationship intangibles, net 6,576 Other assets 16,276 Total assets 742,786 Fair value of liabilities assumed: Deposits 648,111 Short term borrowings 35,766 Other borrowings 7,924 Other liabilities 3,951 Total liabilities assumed 695,752 Fair value of net assets acquired 47,034 Goodwill resulting from acquisition $ 29,848
Summary of Pro Forma Information	The following pro forma information represents the results of operations for the years ended December 31, 2017, and 2016, as if the Citywide Banks of Colorado, Inc. acquisition occurred on January 1, 2017, and January 1, 2016, respectively: (Dollars in thousands, except per share data), unaudited For the Years Ended December 31, 2017 2016 Net interest income $ 357,341 $ 344,784 Net income available to common stockholders $ 75,599 $ 90,470 Basic earnings per share $ 2.67 $ 3.26 Diluted earnings per share $ 2.65 $ 3.22

Securities (Tables)

Securities (Tables)	12 Months Ended
	Dec. 31, 2017
Investments, Debt and Equity Securities [Abstract]
Schedule of Securities Available for Sale	The amortized cost and estimated fair value of securities available for sale at December 31, 2017 , 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. December 31, 2017 Amortized Cost Estimated Fair Value Due in 1 year or less $ 185 $ 185 Due in 1 to 5 years 54,630 54,741 Due in 5 to 10 years 95,345 93,393 Due after 10 years 296,258 298,024 Total debt securities 446,418 446,343 Mortgage and asset-backed securities 1,785,467 1,753,736 Equity securities 16,296 16,674 Total investment securities $ 2,248,181 $ 2,216,753 The amortized cost, gross unrealized gains and losses and estimated fair values of securities available for sale as of December 31, 2017 , and December 31, 2016 , are summarized in the table below, in thousands: Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Estimated Fair Value 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 December 31, 2016 U.S. government corporations and agencies $ 4,716 $ 16 $ (32 ) $ 4,700 Mortgage and asset-backed securities 1,321,760 7,026 (38,286 ) 1,290,500 Obligations of states and political subdivisions 553,020 2,436 (19,312 ) 536,144 Total debt securities 1,879,496 9,478 (57,630 ) 1,831,344 Equity securities 14,451 69 — 14,520 Total $ 1,893,947 $ 9,547 $ (57,630 ) $ 1,845,864
Schedule of Securities Held to Maturity	The amortized cost and estimated fair value of debt securities held to maturity at December 31, 2017 , 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. December 31, 2017 Amortized Cost Estimated Fair Value Due in 1 year or less $ 1,892 $ 1,923 Due in 1 to 5 years 26,790 27,433 Due in 5 to 10 years 98,285 101,377 Due after 10 years 126,583 134,761 Total investment securities $ 253,550 $ 265,494 The amortized cost, gross unrealized gains and losses and estimated fair values of held to maturity securities as of December 31, 2017 , and December 31, 2016 , are summarized in the table below, in thousands: Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Estimated Fair Value December 31, 2017 Obligations of states and political subdivisions 253,550 12,460 (516 ) 265,494 Total $ 253,550 $ 12,460 $ (516 ) $ 265,494 December 31, 2016 Obligations of states and political subdivisions 263,662 12,282 (1,145 ) 274,799 Total $ 263,662 $ 12,282 $ (1,145 ) $ 274,799
Schedule of Realized Gross Gains and Losses on Sales of Securities Available for Sale	Gross gains and losses realized related to sales of securities available for sale for the years ended December 31, 2017 , 2016 and 2015 are summarized as follows, in thousands: 2017 2016 2015 Available for Sale Securities sold: Proceeds from sales $ 1,456,750 $ 909,942 $ 1,115,359 Gross security gains 10,585 13,200 15,205 Gross security losses 3,812 1,562 2,022
Summary of Unrealized Losses on Securities Available for Sale	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 December 31, 2017 , and December 31, 2016 . 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 or more months. The reference point for determining how long an investment was in an unrealized loss position w as December 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 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 ) Equity securities — — — — — — Total temporarily impaired securities $ 948,929 $ (12,238 ) $ 559,158 $ (30,101 ) $ 1,508,087 $ (42,339 ) December 31, 2016 U.S. government corporations and agencies $ 4,185 $ (32 ) $ — $ — $ 4,185 $ (32 ) Mortgage and asset-backed securities 744,202 (23,527 ) 272,449 (14,759 ) 1,016,651 (38,286 ) Obligations of states and political subdivisions 414,151 (19,309 ) 251 (3 ) 414,402 (19,312 ) Total debt securities 1,162,538 (42,868 ) 272,700 (14,762 ) 1,435,238 (57,630 ) Equity securities — — — — — — Total temporarily impaired securities $ 1,162,538 $ (42,868 ) $ 272,700 $ (14,762 ) $ 1,435,238 $ (57,630 )
Schedule of Unrealized Losses on Securities Held to Maturity	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 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 ) December 31, 2016 Obligations of states and political subdivisions 31,479 (884 ) 2,017 (261 ) 33,496 (1,145 ) Total temporarily impaired securities $ 31,479 $ (884 ) $ 2,017 $ (261 ) $ 33,496 $ (1,145 )
OTTI Write-downs on Debt Securities Included in Earnings and AOCI	Changes in the credit loss component of the credit impaired debt securities for the years ended December 31, 2017 , 2016 and 2015 , were as follows, in thousands: For the Years Ended December 31, 2017 2016 2015 Credit loss component, beginning of period $ — $ 1,750 $ 981 Additions: Initial credit impairments — — — Subsequent credit impairments — — 769 Total additions — — 769 Reductions: For securities sold — 1,750 — Total reductions — 1,750 — Credit loss component, end of period $ — $ — $ 1,750 The following table shows the detail of total OTTI write-downs included in earnings, in thousands: For the Years Ended December 31, 2017 2016 2015 OTTI write-downs included in earnings: Available for sale debt securities: Mortgage-backed securities $ — $ — $ 53 Held to maturity debt securities: Mortgage-backed securities — — 716 Total debt security OTTI write-downs included in earnings $ — $ — $ 769 The following table shows the detail of OTTI write-downs on debt securities included in earnings and the related changes in AOCI for the same securities, in thousands: For the Years Ended December 31, 2017 2016 2015 OTTI on debt securities Recorded as part of gross realized losses: Credit related OTTI $ — $ — $ 769 Intent to sell OTTI — — — Total recorded as part of gross realized losses — — 769 Recorded directly to AOCI for non-credit related impairment: Reclassification of non-credit related impairment — — (200 ) Reduction of non-credit related impairment related to security sales — (120 ) — Accretion of non-credit related impairment — (7 ) (95 ) Total changes to AOCI for non-credit related impairment — (127 ) (295 ) Total OTTI losses (accretion) recorded on debt securities $ — $ (127 ) $ 474

Loans (Tables)

Loans (Tables)	12 Months Ended
	Dec. 31, 2017
Receivables [Abstract]
Schedule of Loans and Leases	The following table shows the balance in the allowance for loan losses at December 31, 2017 , and December 31, 2016 , 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 changes to the accounting for the allowance for loan losses policy during 2017 or 2016 . 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 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 December 31, 2016 Commercial $ 1,318 $ 13,447 $ 14,765 $ 3,712 $ 1,283,553 $ 1,287,265 Commercial real estate 2,671 21,648 24,319 45,217 2,493,365 2,538,582 Agricultural and agricultural real estate 816 3,394 4,210 16,730 472,588 489,318 Residential real estate 497 1,766 2,263 25,726 592,198 617,924 Consumer 1,451 7,316 8,767 5,988 414,625 420,613 Total $ 6,753 $ 47,571 $ 54,324 $ 97,373 $ 5,256,329 $ 5,353,702 Loans as of December 31, 2017 , and December 31, 2016 , were as follows, in thousands: December 31, 2017 December 31, 2016 Loans receivable held to maturity: Commercial $ 1,646,606 $ 1,287,265 Commercial real estate 3,163,269 2,538,582 Agricultural and agricultural real estate 511,588 489,318 Residential real estate 624,279 617,924 Consumer 447,484 420,613 Gross loans receivable held to maturity 6,393,226 5,353,702 Unearned discount (556 ) (699 ) Deferred loan fees (1,206 ) (1,284 ) Total net loans receivable held to maturity 6,391,464 5,351,719 Allowance for loan losses (55,686 ) (54,324 ) Loans receivable, net $ 6,335,778 $ 5,297,395
Schedule of Loans Not Covered Under Loss Share Agreements	The following table presents nonaccrual loans, accruing loans past due 90 days or more and troubled debt restructured loans at December 31, 2017 , and December 31, 2016 , in thousands. December 31, 2017 December 31, 2016 Nonaccrual loans $ 58,272 $ 62,591 Nonaccrual troubled debt restructured loans 4,309 1,708 Total nonaccrual loans $ 62,581 $ 64,299 Accruing loans past due 90 days or more $ 830 $ 86 Performing troubled debt restructured loans $ 6,617 $ 10,380
Schedule of Troubled Debt Restructured Loans Modified	The following table provides information on troubled debt restructured loans that were modified during the years ended December 31, 2017 , and December 31, 2016 , in thousands: For the Years Ended December 31, 2017 December 31, 2016 Number of Loans Pre-Modification Recorded Investment Post-Modification Recorded Investment Number of Loans Pre-Modification Recorded Investment Post-Modification Recorded Investment Commercial 3 $ 124 $ 124 1 $ 95 $ 95 Commercial real estate — — — 2 641 641 Total commercial and commercial real estate 3 124 124 3 736 736 Agricultural and agricultural real estate — — — — — — Residential real estate 29 4,126 3,794 8 1,597 1,597 Consumer — — — — — — Total 32 $ 4,250 $ 3,918 11 $ 2,333 $ 2,333
Schedule of Troubled Debt Restructured Loans with Payment Default	The following table provides information on troubled debt restructured loans for which there was a payment default during the years ended December 31, 2017 , and December 31, 2016 , in thousands, that had been modified during the 12-month period prior to the default: With Payment Defaults During the Following Periods For the Years Ended December 31, 2017 December 31, 2016 Number of Loans Recorded Investment Number of Loans Recorded Investment Commercial — $ — 1 $ 95 Commercial real estate — — — — Total commercial and commercial real estate — — 1 95 Agricultural and agricultural real estate — — — — Residential real estate 16 2,435 2 264 Consumer — — — — Total 16 $ 2,435 3 $ 359
Schedule of Loans and Leases Not Covered by Loss Share Agreements by Credit Quality Indicator	The following table presents loans by credit quality indicator at December 31, 2017 , and December 31, 2016 , in thousands: Pass Nonpass Total 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 December 31, 2016 Commercial $ 1,187,557 $ 99,708 $ 1,287,265 Commercial real estate 2,379,632 158,950 2,538,582 Total commercial and commercial real estate 3,567,189 258,658 3,825,847 Agricultural and agricultural real estate 424,311 65,007 489,318 Residential real estate 584,626 33,298 617,924 Consumer 409,474 11,139 420,613 Total gross loans receivable held to maturity $ 4,985,600 $ 368,102 $ 5,353,702
Schedule of Accruing and Nonaccrual Loans and Leases Not Covered by Loss Share Agreements	The following table sets forth information regarding Heartland's accruing and nonaccrual loans at December 31, 2017 , and December 31, 2016 , 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 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 December 31, 2016 Commercial $ 1,127 $ 219 $ 77 $ 1,423 $ 1,281,241 $ 4,601 $ 1,287,265 Commercial real estate 886 3,929 — 4,815 2,513,069 20,698 2,538,582 Total commercial and commercial real estate 2,013 4,148 77 6,238 3,794,310 25,299 3,825,847 Agricultural and agricultural real estate 199 3,191 — 3,390 472,597 13,331 489,318 Residential real estate 4,986 846 — 5,832 590,626 21,466 617,924 Consumer 3,455 1,021 9 4,485 411,925 4,203 420,613 Total gross loans receivable held to maturity $ 10,653 $ 9,206 $ 86 $ 19,945 $ 5,269,458 $ 64,299 $ 5,353,702
Summary of Impaired Loans	The following tables present the unpaid principal balance that was contractually due at December 31, 2017 , and December 31, 2016 , the outstanding loan balance recorded on the consolidated balance sheets at December 31, 2017 , and December 31, 2016 , any related allowance recorded for those loans as of December 31, 2017 , and December 31, 2016 , the average outstanding loan balance recorded on the consolidated balance sheets during the years ended December 31, 2017 , and December 31, 2016 , and the interest income recognized on the impaired loans during the year ended December 31, 2017 , and year ended December 31, 2016 , in thousands: Unpaid Principal 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 loans held to maturity $ 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 loans held to maturity $ 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 Unpaid Principal Balance Loan Balance Related Allowance Recorded Year-to-Date Avg. Loan Balance Year-to-Date Interest Income Recognized December 31, 2016 Impaired loans with a related allowance: Commercial $ 2,852 $ 2,840 $ 1,318 $ 3,136 $ 2 Commercial real estate 14,221 14,221 2,671 10,625 21 Total commercial and commercial real estate 17,073 17,061 3,989 13,761 23 Agricultural and agricultural real estate 2,771 2,771 816 912 21 Residential real estate 3,490 3,490 497 3,371 43 Consumer 2,644 2,644 1,451 3,082 42 Total loans held to maturity $ 25,978 $ 25,966 $ 6,753 $ 21,126 $ 129 Impaired loans without a related allowance: Commercial $ 925 $ 872 $ — $ 5,329 $ 251 Commercial real estate 31,875 30,996 — 39,632 1,647 Total commercial and commercial real estate 32,800 31,868 — 44,961 1,898 Agricultural and agricultural real estate 13,959 13,959 — 12,722 157 Residential real estate 22,408 22,236 — 18,446 202 Consumer 3,344 3,344 — 2,659 68 Total loans held to maturity $ 72,511 $ 71,407 $ — $ 78,788 $ 2,325 Total impaired loans held to maturity: Commercial $ 3,777 $ 3,712 $ 1,318 $ 8,465 $ 253 Commercial real estate 46,096 45,217 2,671 50,257 1,668 Total commercial and commercial real estate 49,873 48,929 3,989 58,722 1,921 Agricultural and agricultural real estate 16,730 16,730 816 13,634 178 Residential real estate 25,898 25,726 497 21,817 245 Consumer 5,988 5,988 1,451 5,741 110 Total impaired loans held to maturity $ 98,489 $ 97,373 $ 6,753 $ 99,914 $ 2,454 The carrying amount of the acquired loans at December 31, 2017 , and December 31, 2016 , consisted of purchased impaired and nonimpaired purchased loans as summarized in the following table, in thousands: December 31, 2017 December 31, 2016 Impaired Purchased Loans Non Impaired Purchased Loans Total Purchased Loans Impaired Non Impaired Total Commercial $ 952 $ 187,375 $ 188,327 $ 2,198 $ 99,082 $ 101,280 Commercial real estate 2,572 1,052,469 1,055,041 2,079 622,117 624,196 Agricultural and agricultural real estate — 1,242 1,242 — 181 181 Residential real estate 214 173,909 174,123 186 157,468 157,654 Consumer loans — 51,292 51,292 — 47,368 47,368 Total Covered Loans $ 3,738 $ 1,466,287 $ 1,470,025 $ 4,463 $ 926,216 $ 930,679
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 years ended December 31, 2017 , and December 31, 2016 , are presented in the table below, in thousands: For the Years Ended December 31, 2017 December 31, 2016 Balance at beginning of year $ 182 $ 557 Original yield discount, net, at date of acquisitions — 19 Accretion (1,591 ) (1,018 ) Reclassification from nonaccretable difference (1) 1,466 624 Balance at end of year $ 57 $ 182 (1) Represents increases in estimated cash flows expected to be received, primarily due to lower estimated credit losses.
Summary of Changes in Related Party Loans	Loans are made in the normal course of business to directors, officers and principal holders of equity securities of Heartland. The terms of these loans, including interest rates and collateral, are similar to those prevailing for comparable transactions and do not involve more than a normal risk of collectability. Changes in such loans during the years ended December 31, 2017 and 2016 , were as follows, in thousands: 2017 2016 Balance at beginning of year $ 114,305 $ 141,465 Advances 56,652 57,165 Repayments (55,284 ) (84,325 ) Balance at end of year $ 115,673 $ 114,305

Allowance for Loan Losses (Tabl

Allowance for Loan Losses (Tables)	12 Months Ended
	Dec. 31, 2017
Receivables [Abstract]
Changes in Allowance for Loan Losses	Changes in the allowance for loan losses for the years ended December 31, 2017 , 2016 and 2015 were as follows, in thousands: 2017 2016 2015 Balance at beginning of year $ 54,324 $ 48,685 $ 41,449 Provision for loan losses 15,563 11,694 12,697 Recoveries on loans previously charged-off 3,670 5,339 3,553 Loans charged-off (17,871 ) (11,394 ) (9,014 ) Balance at end of year $ 55,686 $ 54,324 $ 48,685 Changes in the allowance for loan losses by loan category for the years ended December 31, 2017 , and December 31, 2016 , were as follows, in thousands: 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 (4,640 ) (2,712 ) (2,916 ) (800 ) (6,803 ) (17,871 ) Recoveries 811 1,192 18 358 1,291 3,670 Provision 7,162 (849 ) 2,946 403 5,901 15,563 Balance at December 31, 2017 $ 18,098 $ 21,950 $ 4,258 $ 2,224 $ 9,156 $ 55,686 Commercial Commercial Real Estate Agricultural Residential Real Estate Consumer Total Balance at December 31, 2015 $ 16,095 $ 19,532 $ 3,887 $ 1,934 $ 7,237 $ 48,685 Charge-offs (1,348 ) (2,868 ) (214 ) (346 ) (6,618 ) (11,394 ) Recoveries 930 3,327 10 29 1,043 5,339 Provision (912 ) 4,328 527 646 7,105 11,694 Balance at December 31, 2016 $ 14,765 $ 24,319 $ 4,210 $ 2,263 $ 8,767 $ 54,324

Premises, Furniture and Equip39

Premises, Furniture and Equipment (Tables)	12 Months Ended
	Dec. 31, 2017
Property, Plant and Equipment [Abstract]
Schedule of Premises, Furniture and Equipment	Premises, furniture and equipment, excluding those held for sale, as of December 31, 2017 , and December 31, 2016 , were as follows, in thousands: 2017 2016 Land and land improvements $ 48,621 $ 42,802 Buildings and building improvements 155,209 146,628 Furniture and equipment 64,118 67,023 Total 267,948 256,453 Less accumulated depreciation (95,624 ) (92,839 ) Premises, furniture and equipment, net $ 172,324 $ 163,614

Goodwill, Core Deposit Intang40

Goodwill, Core Deposit Intangibles and Other Intangible Assets (Tables)	12 Months Ended
	Dec. 31, 2017
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of Gross Carrying Amount and Accumulated Amortization of Other Intangible Assets	The gross carrying amount of other intangible assets and the associated accumulated amortization at December 31, 2017 , and December 31, 2016 , are presented in the table below, in thousands: December 31, 2017 December 31, 2016 Gross Carrying Amount Accumulated Amortization Net Carrying Amount Gross Carrying Amount Accumulated Amortization Net Carrying Amount Amortizing intangible assets: Core deposit intangibles $ 62,008 $ 27,086 $ 34,922 $ 43,504 $ 21,049 $ 22,455 Customer relationship intangible 1,177 896 281 1,177 857 320 Mortgage servicing rights 42,139 18,891 23,248 50,467 18,379 32,088 Commercial servicing rights 6,719 4,110 2,609 6,504 2,814 3,690 Total $ 112,043 $ 50,983 $ 61,060 $ 101,652 $ 43,099 $ 58,553
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 Intangible Mortgage Servicing Rights Commercial Servicing Rights Total Year ending December 31, 2018 $ 6,712 $ 39 $ 5,812 $ 685 $ 13,248 2019 5,915 38 4,982 554 11,489 2020 5,191 37 4,151 433 9,812 2021 4,425 35 3,321 371 8,152 2022 3,391 34 2,491 300 6,216 Thereafter 9,288 98 2,491 266 12,143 Total $ 34,922 $ 281 $ 23,248 $ 2,609 $ 61,060
Summary of Changes in Servicing Rights	The following table summarizes, in thousands, the changes in capitalized commercial servicing rights for the twelve months ended December 31, 2017 , and December 31, 2016 : 2017 2016 Balance at January 1, $ 3,690 $ 4,611 Originations 209 628 Amortization (1,311 ) (1,706 ) Purchased commercial servicing rights — 190 Valuation allowance on commercial servicing rights 21 (33 ) Balance at December 31, $ 2,609 $ 3,690 Fair value of commercial servicing rights $ 3,221 $ 4,127 Commercial servicing rights, net to servicing portfolio 1.87 % 2.24 % The following table summarizes, in thousands, the changes in capitalized mortgage servicing rights for the twelve months ended December 31, 2017 , and December 31, 2016 : 2017 2016 Balance at January 1 $ 32,088 $ 30,314 Originations 7,149 12,266 Amortization (9,049 ) (10,492 ) Sale of mortgage servicing rights (6,940 ) — Balance at December 31 $ 23,248 $ 32,088 Fair value of mortgage servicing rights $ 37,081 $ 45,210 Mortgage servicing rights, net to servicing portfolio 0.65 % 0.74 %
Schedule of Servicing Asset at Fair Value and Amortized Cost	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 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 December 31, 2016 Citywide Banks $ 19 $ 23 $ — $ 107 $ 114 $ — Premier Valley Bank 156 180 — 359 326 33 Wisconsin Bank & Trust 833 997 — 2,249 2,487 — Total $ 1,008 $ 1,200 $ — $ 2,715 $ 2,927 $ 33

Deposits (Tables)

Deposits (Tables)	12 Months Ended
	Dec. 31, 2017
Banking and Thrift [Abstract]
Schedule of Maturities of Time Certificates of Deposit	At December 31, 2017 , the scheduled maturities of time certificates of deposit were as follows, in thousands: 2018 $ 607,669 2019 154,548 2020 69,357 2021 38,179 2022 31,950 Thereafter 21,750 $ 923,453
Schedule of Interest Expense on Deposits	Interest expense on deposits for the years ended December 31, 2017 , 2016 , and 2015 , was as follows, in thousands: 2017 2016 2015 Savings and money market accounts $ 11,107 $ 8,000 $ 6,612 Time certificates of deposit in denominations of $100,000 or more 3,016 3,178 3,152 Other time deposits 4,156 4,761 5,766 Interest expense on deposits $ 18,279 $ 15,939 $ 15,530

Short-term Borrowings (Tables)

Short-term Borrowings (Tables)	12 Months Ended
	Dec. 31, 2017
Debt Disclosure [Abstract]
Schedule of Short-term Borrowings	Average and maximum balances and rates on aggregate short-term borrowings outstanding during the years ended December 31, 2017 , December 31, 2016 , and December 31, 2015 , were as follows, in thousands: 2017 2016 2015 Maximum month-end balance $ 324,691 $ 399,490 $ 477,918 Average month-end balance 182,846 287,857 330,134 Weighted average interest rate for the year 0.36 % 0.40 % 0.25 % Weighted average interest rate at year-end 1.11 % 0.29 % 0.15 % Short-term borrowings, which Heartland defines as borrowings with an original maturity of one year or less, as of December 31, 2017 , and 2016 , were as follows, in thousands: 2017 2016 Securities sold under agreement to repurchase $ 107,957 $ 229,555 Federal funds purchased 168,250 40,200 Advances from the FHLB 40,000 30,367 Other short-term borrowings 8,484 6,337 Total $ 324,691 $ 306,459

Other Borrowings (Tables)

Other Borrowings (Tables)	12 Months Ended
	Dec. 31, 2017
Debt Disclosure [Abstract]
Schedule of Other Borrowings	Other borrowings, which Heartland defines as borrowings with an original maturity date of more than one year, outstanding at December 31, 2017 and 2016 , are shown in the table below, net of discount and issuance costs amortization, in thousands: 2017 2016 Advances from the FHLB; weighted average call dates at December 31, 2017 and 2016 were December 2020 and August 2020, respectively; and weighted average interest rates were 3.22% and 3.25%, respectively $ 6,702 $ 6,975 Wholesale repurchase agreements; weighted average call dates at December 31, 2017, and 2016 were May 2018 and May 2017, respectively; and weighted average interest rates were 3.76% for both December 31, 2017, and 2016 30,000 30,000 Trust preferred securities 121,886 115,232 Senior notes 11,000 16,000 Note payable to unaffiliated bank 33,667 37,667 Contracts payable for purchase of real estate and other assets 1,881 2,339 Subordinated notes 74,000 73,857 Other borrowings 5,875 6,464 Total $ 285,011 $ 288,534
Schedule of Trust Preferred Offerings Outstanding	A schedule of Heartland’s trust preferred offerings outstanding, excluding deferred issuance costs, as of December 31, 2017 , were as follows, in thousands: Amount Issued Interest Rate Interest Rate as (1) Maturity Date Callable Date Heartland Financial Statutory Trust IV $10,258 2.75% over LIBOR 4.35% (2) 03/17/2034 03/17/2018 Heartland Financial Statutory Trust V 20,619 1.33% over LIBOR 2.69% (3) 04/07/2036 04/07/2018 Heartland Financial Statutory Trust VI 20,619 1.48% over LIBOR 3.07% (4) 09/15/2037 03/15/2018 Heartland Financial Statutory Trust VII 20,619 1.48% over LIBOR 2.96% (5) 09/01/2037 06/01/2018 Morrill Statutory Trust I 8,900 3.25% over LIBOR 4.92% (6) 12/26/2032 03/26/2018 Morrill Statutory Trust II 8,531 2.85% over LIBOR 4.45% (7) 12/17/2033 03/17/2018 Sheboygan Statutory Trust I 6,353 2.95% over LIBOR 4.55% 09/17/2033 03/17/2018 CBNM Capital Trust I 4,309 3.25% over LIBOR 4.84% 12/15/2034 03/15/2018 Citywide Capital Trust III 6,327 2.80% over LIBOR 4.18% 12/19/2033 04/23/2018 Citywide Capital Trust IV 4,180 2.20% over LIBOR 3.65% 09/30/2034 05/23/2018 Citywide Capital Trust V 11,298 1.54% over LIBOR 3.13% (8) 07/25/2036 03/15/2018 $122,013 (1) Effective weighted average interest rate as of December 31, 2017, was 5.25% due to interest rate swap transactions as discussed in Note 12 to Heartland's consolidated financial statements. (2) Effective interest rate as of December 31, 2017, was 5.01% due to an interest rate swap transaction as discussed in Note 12 to Heartland's consolidated financial statements. (3) Effective interest rate as of December 31, 2017, was 4.69% due to an interest rate swap transaction as discussed in Note 12 to Heartland's consolidated financial statements. (4) Effective interest rate as of December 31, 2017, was 3.87% due to an interest rate swap transaction as discussed in Note 12 to Heartland's consolidated financial statements. (5) Effective interest rate as of December 31, 2017, was 3.83% due to an interest rate swap transaction as discussed in Note 12 to Heartland's consolidated financial statements. (6) Effective interest rate as of December 31, 2017, was 4.92% due to an interest rate swap transaction as discussed in Note 12 to Heartland's consolidated financial statements. (7) Effective interest rate as of December 31, 2017, was 4.51% due to an interest rate swap transaction as discussed in Note 12 to Heartland's consolidated financial statements. (8) Effective interest rate as of December 31, 2017, was 3.80% due to an interest rate swap transaction as discussed in Note 12 to Heartland's consolidated financial statements.
Schedule of Future Payments of Other Borrowings	Future payments at December 31, 2017 , for other borrowings follow in the table below, in thousands. Callable FHLB advances, wholesale repurchase agreements, convertible debt and subordinated debt are included in the table at their call date. 2018 $ 43,217 2019 15,383 2020 5,652 2021 21,622 2022 1,657 Thereafter 197,480 Total $ 285,011

Derivative Financial Instrume44

Derivative Financial Instruments (Tables)	12 Months Ended
	Dec. 31, 2017
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Balance Sheet Category and Fair Value of Derivative Instruments Designated as Cash Flow Hedges	The table below identifies the balance sheet category and fair values of Heartland's derivative instruments designated as cash flow hedges at December 31, 2017 , and December 31, 2016 , in thousands: Notional Amount Fair Value Balance Sheet Category Receive Rate Weighted Average Pay Rate Maturity 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 20,000 (177 ) Other Liabilities 1.588 2.390 06/15/2024 Interest rate swap 20,000 (149 ) Other Liabilities 1.481 2.352 03/01/2024 December 31, 2016 Interest rate swap $ 25,000 $ (447 ) Other Liabilities 0.993 % 2.255 % 03/17/2021 Interest rate swap 20,000 (114 ) Other Liabilities 0.931 3.220 03/01/2017 Interest rate swap 20,000 (1,145 ) Other Liabilities 0.868 3.355 01/07/2020 Interest rate swap 10,000 (42 ) Other Liabilities 0.997 1.674 03/26/2019 Interest rate swap 10,000 (41 ) Other Liabilities 0.993 1.658 03/18/2019 Interest rate swap 37,667 530 Other Assets 3.164 3.674 05/10/2021 Interest rate swap (1) 20,000 (214 ) Other Liabilities — 2.390 06/15/2024 Interest rate swap (2) 20,000 (262 ) Other Liabilities — 2.352 03/01/2024 (1) This swap is a forward starting swap with a weighted average pay rate of 2.390% beginning on June 15, 2017. No interest payments were required related to this swap until September 15, 2017. (2) This swap is a forward starting swap with a weighted average pay rate of 2.352% beginning on March 1, 2017. No interest payments were required on this swap until June 1, 2017. The table below identifies the balance sheet category and fair values of Heartland's derivative instruments designated as loan swaps at December 31, 2017 and 2016 , in thousands: Notional Amount Fair Value Balance Sheet Category Weighted Average Receive Rate Weighted Average Pay Rate 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 % December 31, 2016 Customer interest rate swaps $ 69,594 $ 1,588 Other Assets 4.66 % 3.47 % Customer interest rate swaps 69,594 (1,588 ) Other Liabilities 3.47 % 4.66 %
Gains and Losses Recognized on Derivative Instruments Designated as Cash Flow Hedges	The table below identifies the gains and losses recognized on Heartland's derivative instruments designated as cash flow hedges for the years ended December 31, 2017 , and December 31, 2016 , 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) December 31, 2017 Interest rate swap $ 1,500 Interest expense $ (1,290 ) Other income $ — December 31, 2016 Interest rate swap $ 1,705 Interest expense $ (1,914 ) Other income $ —
Balance Sheet Category and Fair Values of Embedded Derivatives	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 December 31, 2017 , and December 31, 2016 : Notional Amount Fair Value Balance Sheet Category December 31, 2017 Embedded conversion option $ — $ — Other liabilities December 31, 2016 Embedded conversion option $ 558 $ (422 ) Other liabilities The table below identifies the gains and losses recognized on Heartland's embedded conversion options for the years ended December 31, 2017 , and December 31, 2016 , in thousands: Amount of Gain (Loss) Income Statement Category December 31, 2017 Embedded conversion option $ 422 Other noninterest income December 31, 2016 Embedded conversion option $ (100 ) Other noninterest income The table below identifies the notional amount, fair value and balance sheet category of Heartland's fair value hedges at December 31, 2017 , and December 31, 2016 , in thousands: Notional Amount Fair Value Balance Sheet Category December 31, 2017 Fair value hedges $ 35,635 $ (999 ) Other liabilities December 31, 2016 Fair value hedges $ 40,807 $ (1,626 ) Other liabilities The table below identifies the gains and losses recognized on Heartland's fair value hedges for the years ended December 31, 2017 and December 31, 2016 , in thousands: Amount of Gain (Loss) Income Statement Category December 31, 2017 Fair value hedges $ 627 Interest income December 31, 2016 Fair value hedges $ (1,005 ) Interest income The table below identifies the notional amount, fair value and balance sheet category of Heartland's embedded derivatives as of December 31, 2017 , and December 31, 2016 , in thousands: Notional Amount Fair Value Balance Sheet Category December 31, 2017 Embedded derivatives $ 14,045 $ 738 Other assets December 31, 2016 Embedded derivatives $ 14,549 $ 1,104 Other assets The table below identifies the gains and losses recognized on Heartland's embedded derivatives for the years ended December 31, 2017 and December 31, 2016 , in thousands: Amount of Gain (Loss) Income Statement Category December 31, 2017 Embedded derivatives $ 366 Other noninterest income December 31, 2016 Embedded derivatives $ (470 ) Other noninterest income
Balance Sheet Category and Fair Values of Derivative Instruments Not Designated as Hedging Instruments	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 December 31, 2017 , and December 31, 2016 , in thousands: Notional Amount Fair Value Balance Sheet Category December 31, 2017 Interest rate lock commitments (mortgage) $ 53,588 $ 1,738 Other Assets Forward commitments 37,286 80 Other Assets Forward commitments 118,632 (232 ) Other Liabilities Undesignated interest rate swaps 14,045 (738 ) Other Liabilities December 31, 2016 Interest rate lock commitments (mortgage) $ 80,465 $ 2,790 Other Assets Forward commitments 142,750 2,546 Other Assets Forward commitments 59,276 (266 ) Other Liabilities Undesignated interest rate swaps 15,564 (1,126 ) Other Liabilities 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 years ended December 31, 2017 , and December 31, 2016 , in thousands: Income Statement Category Year-to-Date Gain(Loss) Recognized December 31, 2017 Interest rate lock commitments (mortgage) Net gains on sale of loans held for sale $ (1,479 ) Forward commitments Net gains on sale of loans held for sale (2,466 ) Forward commitments Net gains on sale of loans held for sale 34 Undesignated interest rate swaps Other noninterest income 388 December 31, 2016 Interest rate lock commitments (mortgage) Net gains on sale of loans held for sale $ (1,564 ) Forward commitments Net gains on sale of loans held for sale 2,023 Forward commitments Net gains on sale of loans held for sale 49 Undesignated interest rate swaps Other noninterest income 2,551

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Schedule of Components of Income Tax Expense	Income taxes for the years ended December 31, 2017 , 2016 , and 2015 were as follows, in thousands: 2017 2016 2015 Current: Federal $ 25,532 $ 23,724 $ 13,697 State 5,025 5,670 5,080 Total current $ 30,557 $ 29,394 $ 18,777 Deferred: Federal $ 12,370 $ 5,497 $ 1,118 State 893 1,665 1,003 Total deferred $ 13,263 $ 7,162 $ 2,121 Total income tax expense $ 43,820 $ 36,556 $ 20,898
Schedule of Deferred Tax Assets and Liabilities	Deferred tax assets and liabilities at December 31, 2017 and 2016 , with the 2017 amounts adjusted for the impact of the Tax Cuts and Jobs Act, were as follows, in thousands: 2017 2016 Deferred tax assets: Tax effect of net unrealized loss on securities available for sale reflected in stockholders’ equity $ 8,320 $ 19,468 Tax effect of net unrealized loss on derivatives reflected in stockholders’ equity 60 484 Allowance for loan losses 14,221 20,506 Deferred compensation 4,240 9,146 Organization and acquisitions costs 369 649 Net operating loss carryforwards 16,580 17,676 Non-accrual loan interest 710 752 OREO write-downs 1,835 1,756 Rehab tax credit projects 4,303 5,620 Mortgage repurchase obligation 68 333 Self-funded health plan — 632 Other 1,974 1,463 Gross deferred tax assets 52,680 78,485 Valuation allowance (10,493 ) (9,870 ) Gross deferred tax assets $ 42,187 $ 68,615 Deferred tax liabilities: Securities (478 ) (452 ) Premises, furniture and equipment (5,798 ) (9,284 ) Tax bad debt reserves (428 ) (13 ) Purchase accounting (4,417 ) (3,496 ) Prepaid expenses (526 ) (881 ) Mortgage servicing rights (7,045 ) (13,956 ) Deferred loan fees (2,651 ) (3,804 ) Other (255 ) (379 ) Gross deferred tax liabilities $ (21,598 ) $ (32,265 ) Net deferred tax asset $ 20,589 $ 36,350
Schedule of Effective Income Tax Rate Reconciliation	The actual income tax expense from continuing operations differs from the expected amounts for the years ended December 31, 2017 , 2016 , and 2015 , (computed by applying the U.S. federal corporate tax rate of 35% to income before income taxes) are as follows, in thousands: 2017 2016 2015 Computed "expected" tax on net income $ 41,682 $ 40,917 $ 28,329 Increase (decrease) resulting from: Nontaxable interest income (9,282 ) (7,960 ) (6,293 ) State income taxes, net of federal tax benefit 3,846 4,768 3,954 Tax credits (2,390 ) (1,375 ) (5,975 ) Valuation allowance 405 368 1,525 Excess tax benefit on stock compensation (1,130 ) — — Deferred tax adjustment due to Tax Cuts and Jobs Act enactment 10,396 — — Other 293 (162 ) (642 ) Income taxes $ 43,820 $ 36,556 $ 20,898 Effective tax rates 36.8 % 31.3 % 25.8 %
Schedule of Unrecognized Tax Benefits Roll Forward	A reconciliation of the beginning and ending balances for liabilities associated with unrecognized tax benefits for the years ended December 31, 2017 and 2016 , is as follows, in thousands: 2017 2016 Balance at January 1 $ 374 $ 715 Additions for tax positions related to the current year 86 63 Additions for tax positions related to prior years 106 21 Reductions for tax positions related to prior years (85 ) (425 ) Balance at December 31 $ 481 $ 374

Commitments and Contingent Li46

Commitments and Contingent Liabilities (Tables)	12 Months Ended
	Dec. 31, 2017
Commitments and Contingencies Disclosure [Abstract]
Schedule of Future Minimum Rental Payments for Operating Leases	Heartland leases certain land and facilities under operating leases. Minimum future rental commitments at December 31, 2017 for all non-cancelable leases were as follows, in thousands: 2018 $ 5,774 2019 5,626 2020 5,411 2021 5,034 2022 4,175 Thereafter 22,817 $ 48,837

Stock-based Compensation (Table

Stock-based Compensation (Tables)	12 Months Ended
	Dec. 31, 2017
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Schedule of Stock Options Activity	A summary of the status of Heartland's common stock options as of December 31, 2017 , 2016 and 2015 , and changes during the years ended December 31, 2017 , 2016 and 2015 , follows: 2017 2016 2015 Shares Weighted-Average Exercise Price Shares Weighted-Average Exercise Price Shares Weighted-Average Exercise Price Outstanding at January 1 26,400 $ 18.60 125,950 $ 24.08 215,851 $ 23.85 Granted — — — — — — Exercised (19,400 ) 18.60 (97,800 ) 25.59 (86,651 ) 23.49 Forfeited (500 ) 18.60 (1,750 ) 21.10 (3,250 ) 23.51 Outstanding at December 31 6,500 $ 18.60 26,400 $ 18.60 125,950 $ 24.08 Options exercisable at December 31 6,500 $ 18.60 26,400 $ 18.60 125,950 $ 24.08
Summary of Status of RSUs	A summary of the status of RSUs as of December 31, 2017 , 2016 and 2015 , and changes during the years ended December 31, 2017 , 2016 , and 2015 , follows: 2017 2016 2015 Shares Weighted-Average Grant Date Fair Value Shares Weighted-Average Grant Date Fair Value Shares Weighted-Average Grant Date Fair Value Outstanding at January 1 346,817 $ 27.61 353,195 $ 25.53 396,555 $ 21.48 Granted 109,373 47.22 143,721 29.75 139,943 28.90 Vested (137,394 ) 26.66 (126,614 ) 23.83 (152,981 ) 18.54 Forfeited (17,218 ) 34.02 (23,485 ) 29.80 (30,322 ) 23.38 Outstanding at December 31 301,578 $ 34.74 346,817 $ 27.61 353,195 $ 25.53

Regulatory Capital Requiremen48

Regulatory Capital Requirements and Restrictions on Subsidiary Dividends (Tables)	12 Months Ended
	Dec. 31, 2017
Banking and Thrift [Abstract]
Schedule of Actual Capital Amounts and Ratios	The Heartland banks’ actual capital amounts and ratios are also presented in the tables below, in thousands: Actual For Capital Adequacy Purposes To Be Well Capitalized Under Prompt Corrective Action Provisions Amount Ratio Amount Ratio Amount Ratio As of December 31, 2017 Total Capital (to Risk-Weighted Assets) Consolidated $ 1,010,116 13.45 % $ 600,924 8.00 % N/A Dubuque Bank and Trust Company 156,544 13.63 91,878 8.00 $ 114,848 10.00 % Illinois Bank & Trust 71,410 12.62 45,265 8.00 56,582 10.00 Wisconsin Bank & Trust 113,045 14.57 62,057 8.00 77,572 10.00 New Mexico Bank & Trust 133,274 11.42 93,401 8.00 116,751 10.00 Arizona Bank & Trust 61,550 13.39 36,773 8.00 45,966 10.00 Rocky Mountain Bank 50,729 13.78 29,461 8.00 36,826 10.00 Citywide Banks 226,493 13.63 132,975 8.00 166,219 10.00 Minnesota Bank & Trust 23,760 13.76 13,811 8.00 17,264 10.00 Morrill & Janes Bank and Trust Company 72,471 13.42 43,206 8.00 54,007 10.00 Premier Valley Bank 83,772 12.95 51,743 8.00 64,679 10.00 Actual For Capital Adequacy Purposes To Be Well Capitalized Under Prompt Corrective Action Provisions Amount Ratio Amount Ratio Amount Ratio As of December 31, 2017 Tier 1 Capital (to Risk-Weighted Assets) Consolidated $ 879,133 11.70 % $ 450,693 6.00 % N/A Dubuque Bank and Trust Company 148,080 12.89 68,909 6.00 $ 91,878 8.00 % Illinois Bank & Trust 66,547 11.76 33,949 6.00 45,265 8.00 Wisconsin Bank & Trust 106,236 13.70 46,543 6.00 62,057 8.00 New Mexico Bank & Trust 123,519 10.58 70,050 6.00 93,401 8.00 Arizona Bank & Trust 56,870 12.37 27,579 6.00 36,773 8.00 Rocky Mountain Bank 47,660 12.94 22,096 6.00 29,461 8.00 Citywide Banks 221,239 13.31 99,731 6.00 132,975 8.00 Minnesota Bank & Trust 22,554 13.06 10,358 6.00 13,811 8.00 Morrill & Janes Bank and Trust Company 67,328 12.47 32,404 6.00 43,206 8.00 Premier Valley Bank 81,213 12.56 38,808 6.00 51,743 8.00 Common Equity Tier 1 (to Risk-Weighted Assets) Consolidated $ 756,309 10.07 % $ 338,019 4.50 % N/A Dubuque Bank and Trust Company 148,080 12.89 51,681 4.50 $ 74,651 6.50 % Illinois Bank & Trust 66,547 11.76 25,462 4.50 36,778 6.50 Wisconsin Bank & Trust 106,236 13.70 34,907 4.50 50,422 6.50 New Mexico Bank & Trust 123,519 10.58 52,538 4.50 75,888 6.50 Arizona Bank & Trust 56,870 12.37 20,685 4.50 29,878 6.50 Rocky Mountain Bank 47,660 12.94 16,572 4.50 23,937 6.50 Citywide Banks 221,239 13.31 74,799 4.50 108,042 6.50 Minnesota Bank & Trust 22,554 13.06 7,769 4.50 11,222 6.50 Morrill & Janes Bank and Trust Company 67,328 12.47 24,303 4.50 35,104 6.50 Premier Valley Bank 81,213 12.56 29,106 4.50 42,042 6.50 Tier 1 Capital (to Average Assets) Consolidated $ 879,133 9.20 % $ 382,089 4.00 % N/A Dubuque Bank and Trust Company 148,080 10.05 58,932 4.00 $ 73,666 5.00 % Illinois Bank & Trust 66,547 8.39 31,728 4.00 39,660 5.00 Wisconsin Bank & Trust 106,236 10.53 40,373 4.00 50,466 5.00 New Mexico Bank & Trust 123,519 8.54 57,834 4.00 72,292 5.00 Arizona Bank & Trust 56,870 9.94 22,890 4.00 28,613 5.00 Rocky Mountain Bank 47,660 9.82 19,418 4.00 24,272 5.00 Citywide Banks 221,239 10.03 88,240 4.00 110,300 5.00 Minnesota Bank & Trust 22,554 10.77 8,379 4.00 10,473 5.00 Morrill & Janes Bank and Trust Company 67,328 9.47 28,435 4.00 35,543 5.00 Premier Valley Bank 81,213 9.80 33,157 4.00 41,446 5.00 Actual For Capital Adequacy Purposes To Be Well Capitalized Under Prompt Corrective Action Provisions Amount Ratio Amount Ratio Amount Ratio As of December 31, 2016 Total Capital (to Risk-Weighted Assets) Consolidated $ 887,607 14.01 % $ 506,865 8.00 % N/A Dubuque Bank and Trust Company 150,692 12.76 94,494 8.00 $ 118,117 10.00 % Illinois Bank & Trust 70,808 11.83 47,884 8.00 59,856 10.00 Wisconsin Bank & Trust 109,069 14.35 60,819 8.00 76,024 10.00 New Mexico Bank & Trust 119,246 11.20 85,208 8.00 106,510 10.00 Arizona Bank & Trust 58,741 14.64 32,108 8.00 40,135 10.00 Rocky Mountain Bank 50,188 13.72 29,254 8.00 36,568 10.00 Citywide Banks (1) 83,615 13.25 50,475 8.00 63,094 10.00 Minnesota Bank & Trust 21,693 11.86 14,628 8.00 18,285 10.00 Morrill & Janes Bank and Trust Company 85,649 12.36 55,433 8.00 69,292 10.00 Premier Valley Bank 66,132 14.44 36,649 8.00 45,811 10.00 Tier 1 Capital (to Risk-Weighted Assets) Consolidated $ 756,056 11.93 % $ 380,148 6.00 % N/A Dubuque Bank and Trust Company 140,970 11.93 70,870 6.00 $ 94,494 8.00 % Illinois Bank & Trust 66,101 11.04 35,913 6.00 47,884 8.00 Wisconsin Bank & Trust 102,523 13.49 45,614 6.00 60,819 8.00 New Mexico Bank & Trust 109,185 10.25 63,906 6.00 85,208 8.00 Arizona Bank & Trust 54,970 13.70 24,081 6.00 32,108 8.00 Rocky Mountain Bank 46,702 12.77 21,941 6.00 29,254 8.00 Citywide Banks (1) 81,260 12.88 37,857 6.00 50,475 8.00 Minnesota Bank & Trust 20,315 11.11 10,971 6.00 14,628 8.00 Morrill & Janes Bank and Trust Company 78,615 11.35 41,575 6.00 55,433 8.00 Premier Valley Bank 64,735 14.13 27,487 6.00 36,649 8.00 Common Equity Tier 1 (to Risk Weighted Assets) Consolidated $ 639,467 10.09 % $ 285,111 4.50 % N/A Dubuque Bank and Trust Company 140,970 11.93 53,153 4.50 $ 76,776 6.50 % Illinois Bank & Trust 66,101 11.04 26,935 4.50 38,906 6.50 Wisconsin Bank & Trust 102,523 13.49 34,211 4.50 49,416 6.50 New Mexico Bank & Trust 109,185 10.25 47,929 4.50 69,231 6.50 Arizona Bank & Trust 54,970 13.70 18,061 4.50 26,088 6.50 Rocky Mountain Bank 46,702 12.77 16,455 4.50 23,769 6.50 Citywide Banks (1) 81,260 12.88 28,392 4.50 41,011 6.50 Minnesota Bank & Trust 20,315 11.11 8,228 4.50 11,885 6.50 Morrill & Janes Bank and Trust Company 78,615 11.35 31,181 4.50 45,040 6.50 Premier Valley Bank 64,735 14.13 20,615 4.50 29,777 6.50 Tier 1 Capital (to Average Assets) Consolidated $ 756,056 9.28 % $ 325,894 4.00 % N/A Dubuque Bank and Trust Company 140,970 9.41 59,896 4.00 $ 74,870 5.00 % Illinois Bank & Trust 66,101 8.80 30,059 4.00 37,573 5.00 Wisconsin Bank & Trust 102,523 9.96 41,155 4.00 51,443 5.00 New Mexico Bank & Trust 109,185 8.16 53,529 4.00 66,911 5.00 Actual For Capital Adequacy Purposes To Be Well Capitalized Under Prompt Corrective Action Provisions Amount Ratio Amount Ratio Amount Ratio December 31, 2016 Tier 1 Capital (to Average Assets) Arizona Bank & Trust $ 54,970 9.59 % $ 22,922 4.00 % $ 28,653 5.00 % Rocky Mountain Bank 46,702 9.79 19,078 4.00 23,848 5.00 Citywide Banks (1) 81,260 9.33 34,827 4.00 43,534 5.00 Minnesota Bank & Trust 20,315 8.72 9,315 4.00 11,644 5.00 Morrill & Janes Bank and Trust Company 78,615 9.12 34,463 4.00 43,079 5.00 Premier Valley Bank 64,735 10.91 23,729 4.00 29,661 5.00 (1) Centennial Bank and Trust changed its name to Citywide Banks upon the acquisition of Citywide Banks of Colorado, Inc., on July 7, 2017.

Fair Value (Tables)

Fair Value (Tables)	12 Months Ended
	Dec. 31, 2017
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 December 31, 2017 , and December 31, 2016 , 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 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 $ — December 31, 2016 Assets Securities available for sale U.S. government corporations and agencies $ 4,700 $ 517 $ 4,183 $ — Mortgage-backed securities 1,290,500 — 1,288,276 2,224 Obligations of states and political subdivisions 536,144 — 536,144 — Equity securities 14,520 — 14,520 — Derivative financial instruments (1) 3,222 — 3,222 — Interest rate lock commitments 2,790 — — 2,790 Forward commitments 2,546 — 2,546 — Total assets at fair value $ 1,854,422 $ 517 $ 1,848,891 $ 5,014 Liabilities Derivative financial instruments (2) $ 7,027 $ — $ 7,027 $ — Forward commitments 266 — 266 — Total liabilities at fair value $ 7,293 $ — $ 7,293 $ — (1) Includes embedded derivatives, back-to-back loan swaps and cash flow hedges (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 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) (Gains)/Losses 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 Measurements at December 31, 2016 Total Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) (Gains)/Losses Collateral dependent impaired loans: Commercial $ 1,683 $ — $ — $ 1,683 $ 41 Commercial real estate 3,026 — — 3,026 527 Agricultural and agricultural real estate 1,955 — — 1,955 — Residential real estate 3,565 — — 3,565 85 Consumer 1,193 — — 1,193 — Total collateral dependent impaired loans $ 11,422 $ — $ — $ 11,422 $ 653 Loans held for sale $ 61,261 $ — $ 61,261 $ — $ (640 ) Other real estate owned $ 9,744 $ — $ — $ 9,744 $ 1,341 Premises, furniture and equipment held for sale $ 414 $ — $ — $ 414 $ 35 Commercial servicing rights $ 326 $ — $ — $ 326 $ 33
Quantitative Information on Assets Measured at Fair Value on Recurring and Nonrecurring Basis Using Level 3	The following tables present additional quantitative information about assets measured at fair value on a recurring and nonrecurring basis and for which Heartland has utilized Level 3 inputs to determine fair value, in thousands: Fair Value at 12/31/17 Valuation Technique Unobservable Input Range (Weighted Average) Z-TRANCHE Securities $ — Discounted cash flows Pretax discount rate — Actual defaults — Actual deferrals — 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) Appraisal discount 0-10% (4) Other real estate owned 10,777 Modified appraised value Third party appraisal (2) Appraisal discounts 0-10% Commercial servicing rights 291 Discounted cash flows Third party valuation (3) 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 at 12/31/16 Valuation Technique Unobservable Input Range (Weighted Average) Z-TRANCHE Securities $ 2,224 Discounted cash flows Pretax discount rate 7.50 - 9.50% Actual defaults 21.77 - 37.62% (33.11%) Actual deferrals 10.44 - 26.29% (14.81%) Interest rate lock commitments 2,790 Discounted cash flows Closing ratio 0 - 99% (89%) (1) Premises, furniture and equipment held for sale 414 Modified appraised value Third party appraisal (2) Appraisal discount 0-8% (4) Other real estate owned 9,744 Modified appraised value Third party appraisal (2) Appraisal discounts 0-10% Commercial servicing rights 326 Discounted cash flows Third party valuation (3) Collateral dependent impaired loans: Commercial 1,683 Modified appraised value Third party appraisal (2) Appraisal discount 0-8% (4) Commercial real estate 3,026 Modified appraised value Third party appraisal (2) Appraisal discount 0-7% (4) Agricultural and agricultural real estate 1,955 Modified appraised value Third party appraisal (2) Appraisal discount 0-10% (4) Residential real estate 3,565 Modified appraised value Third party appraisal (2) Appraisal discount 0-8% (4) Consumer 1,193 Modified appraised value Third party valuation (2) Valuation discount 0-11% (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 that 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.
Summary of Changes in Fair Value of Level 3 Assets Measured at Fair Value on Recurring Basis	The changes in fair value of the Z-TRANCHE, a Level 3 asset that is measured at fair value on a recurring basis, are summarized in the following table, in thousands: For the Years Ended December 31, 2017 December 31, 2016 Balance at January 1, $ 2,224 $ 2,039 Total gains (losses), net: Included in earnings 2,810 — Included in other comprehensive income (2,166 ) 185 Purchases, issuances, sales and settlements: Purchases — — Sales (2,868 ) — Settlements — — Balance at period end, $ — $ 2,224 The changes in fair value of the corporate debt securities, Level 3 assets that are measured on a recurring basis, are summarized in the following table, in thousands: For the Years Ended December 31, 2017 December 31, 2016 Balance at January 1, $ — $ 846 Total gains (losses), net: Included in earnings — 56 Included in other comprehensive income — (106 ) Purchases, issuances, sales and settlements: Purchases — — Acquired — — Sales — (796 ) Settlements — — Balance at period end, $ — $ — The changes in fair value of the interest rate lock commitments, which are Level 3 financial instruments and are measured on a recurring basis, are summarized in the following table, in thousands: For the Years Ended December 31, 2017 December 31, 2016 Balance at January 1, $ 2,790 $ 3,168 Total gains (losses), net, included in earnings (1,479 ) (1,564 ) Issuances 1,875 5,373 Settlements (1,448 ) (4,187 ) Balance at period end, $ 1,738 $ 2,790
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, obtaining deposits or fee generating activities. Many of the estimates presented below 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 Carrying Estimated Quoted Prices in Significant Other Significant 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 Fair Value Measurements at 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 $ 158,724 $ 158,724 $ 158,724 $ — $ — Time deposits in other financial institutions 2,105 2,105 2,105 — — Securities: Available for sale 1,845,864 1,845,864 517 1,843,123 2,224 Held to maturity 263,662 274,799 — 274,799 — Other investments 21,560 21,560 — 21,365 195 Loans held for sale 61,261 61,261 — 61,261 — Loans, net: Commercial 1,272,089 1,258,754 — 1,257,071 1,683 Commercial real estate 2,513,446 2,506,858 — 2,503,832 3,026 Agricultural and agricultural real estate 485,820 487,001 — 485,046 1,955 Residential real estate 614,207 604,233 — 600,668 3,565 Consumer 411,833 414,266 — 413,073 1,193 Total Loans, net 5,297,395 5,271,112 — 5,259,690 11,422 Cash surrender value on life insurance 112,615 112,615 — 112,615 — Derivative financial instruments (1) 3,222 3,222 — 3,222 — Interest rate lock commitments 2,790 2,790 — — 2,790 Forward commitments 2,546 2,546 — 2,546 — Financial liabilities: Deposits Demand deposits 2,202,036 2,202,036 — 2,202,036 — Savings deposits 3,788,089 3,788,089 — 3,788,089 — Time deposits 857,286 857,286 — 857,286 — Short term borrowings 306,459 306,459 — 306,459 — Other borrowings 288,534 288,534 — 288,534 — Derivative financial instruments (2) 7,027 7,027 — 7,027 — Forward commitments 266 266 — 266 — (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

Segment Reporting (Tables)

Segment Reporting (Tables)	12 Months Ended
	Dec. 31, 2017
Segment Reporting [Abstract]
Financial Information of Operating Segments	The following table presents the financial information from Heartland's operating segments for the years ending December 31, 2017 , December 31, 2016 , and December 31, 2015 , in thousands. Community and Other Banking Mortgage Banking Total December 31, 2017 Net Interest Income $ 326,130 $ 4,178 $ 330,308 Provision for loan losses 15,563 — 15,563 Total noninterest income 77,837 24,185 102,022 Total noninterest expense 264,929 32,746 297,675 Income (loss) before income taxes $ 123,475 $ (4,383 ) $ 119,092 December 31, 2016 Net Interest Income $ 290,088 $ 4,578 $ 294,666 Provision for loan losses 11,694 — 11,694 Total noninterest income 74,145 39,456 113,601 Total noninterest expense 237,198 42,470 279,668 Income (loss) before income taxes $ 115,341 $ 1,564 $ 116,905 December 31, 2015 Net Interest Income $ 228,422 $ 5,576 $ 233,998 Provision for loan losses 12,697 — 12,697 Total noninterest income 65,414 45,271 110,685 Total noninterest expense 201,063 49,983 251,046 Income (loss) before income taxes $ 80,076 $ 864 $ 80,940 Segment Assets December 31, 2017 $ 9,757,575 $ 53,164 $ 9,810,739 December 31, 2016 8,149,465 97,614 8,247,079 December 31, 2015 7,585,130 109,624 7,694,754 Average Loans, Net of Unearned December 31, 2017 $ 5,810,308 $ 36,753 $ 5,847,061 December 31, 2016 5,418,169 69,943 5,488,112 December 31, 2015 4,466,528 84,480 4,551,008

Parent Company Only Financial51

Parent Company Only Financial Information (Tables)	12 Months Ended
	Dec. 31, 2017
Condensed Financial Information of Parent Company Only Disclosure [Abstract]
Schedule of Condensed Balance Sheets	Condensed financial information for Heartland Financial USA, Inc. is as follows: BALANCE SHEETS (Dollars in thousands) December 31, 2017 2016 Assets: Cash and interest bearing deposits $ 24,310 $ 65,007 Securities available for sale — 2,224 Other investments, at cost — 195 Investment in subsidiaries 1,194,747 901,310 Other assets 28,536 26,154 Due from subsidiaries 6,000 6,000 Total assets $ 1,253,593 $ 1,000,890 Liabilities and stockholders’ equity: Other borrowings 246,438 249,245 Accrued expenses and other liabilities 15,698 10,729 Total liabilities 262,136 259,974 Stockholders’ equity: Preferred stock 938 1,357 Common stock 29,953 26,120 Capital surplus 503,709 328,376 Retained earnings 481,331 416,109 Accumulated other comprehensive loss (24,474 ) (31,046 ) Total stockholders’ equity 991,457 740,916 Total liabilities and stockholders’ equity $ 1,253,593 $ 1,000,890
Schedule of Condensed Income Statements	INCOME STATEMENTS (Dollars in thousands) For the Years Ended December 31, 2017 2016 2015 Operating revenues: Dividends from subsidiaries $ 70,850 $ 55,250 $ 70,000 Securities gains, net 3,021 54 3,038 Other 2,292 1,712 712 Total operating revenues 76,163 57,016 73,750 Operating expenses: Interest 13,269 13,840 12,996 Salaries and employee benefits 3,146 3,044 5,028 Professional fees 2,379 2,487 4,735 Other operating expenses 7,889 2,664 4,234 Total operating expenses 26,683 22,035 26,993 Equity in undistributed earnings 16,212 37,926 2,570 Income before income tax benefit 65,692 72,907 49,327 Income tax benefit 9,580 7,442 10,715 Net income 75,272 80,349 60,042 Preferred dividends (58 ) (292 ) (817 ) Interest expense on convertible preferred debt 12 51 $ — Net income available to common stockholders $ 75,226 $ 80,108 $ 59,225
Schedule of Condensed Statements of Cash Flows	STATEMENTS OF CASH FLOWS (Dollars in thousands) For the Years Ended December 31, 2017 2016 2015 Cash flows from operating activities: Net income $ 75,272 $ 80,349 $ 60,042 Adjustments to reconcile net income to net cash provided by operating activities: Undistributed (earnings) losses of subsidiaries (16,212 ) (37,926 ) (2,570 ) Security gains, net (3,021 ) (54 ) (3,038 ) Gain on extinguishment of debt (1,200 ) — — Increase (decrease) in accrued expenses and other liabilities (4,160 ) (7,039 ) 4,550 (Increase) decrease in other assets (567 ) 1,948 (7,379 ) Excess tax benefits on exercised stock options 1,246 374 676 Other, net 4,714 4,892 5,014 Net cash provided by operating activities 56,072 42,544 57,295 Cash flows from investing activities: Capital contributions to subsidiaries — (18,000 ) (114,602 ) Proceeds from sales of available for sale securities 2,868 — 3,774 Proceeds from the maturity of and principal paydowns on other investments — — 619 Proceeds from sale of other investments 211 94 — Net assets acquired (62,813 ) (14,587 ) 44,066 Net cash used by investing activities (59,734 ) (32,493 ) (66,143 ) Cash flows from financing activities: Proceeds on short-term revolving credit line 20,000 — — Proceeds from borrowings — 40,000 15,000 Repayments on short-term revolving credit line (20,000 ) — — Repayments of borrowings (9,016 ) (26,280 ) (35,557 ) Payment for the redemption of debt (13,800 ) — — Redemption of preferred stock — (81,698 ) — Cash dividends paid (14,557 ) (12,870 ) (10,176 ) Purchase of treasury stock (625 ) (3,719 ) (2,987 ) Proceeds from issuance of common stock 963 54,196 3,508 Net cash used by financing activities (37,035 ) (30,371 ) (30,212 ) Net decrease in cash and cash equivalents (40,697 ) (20,320 ) (39,060 ) Cash and cash equivalents at beginning of year 65,007 85,327 124,387 Cash and cash equivalents at end of year $ 24,310 $ 65,007 $ 85,327 Supplemental disclosure: Conversion of convertible debt to common stock $ 558 $ 1,442 $ — Conversion of Series D preferred stock to common stock $ 419 $ 2,420 $ — Stock consideration granted for acquisition $ 175,196 $ 57,433 $ 120,070

Summary of Quarterly Financia52

Summary of Quarterly Financial Information (Unaudited) (Tables)	12 Months Ended
	Dec. 31, 2017
Quarterly Financial Information Disclosure [Abstract]
Summary of Quarterly Financial Information (Unaudited)	(Dollars in thousands, except per share data) 2017 December 31 September 30 June 30 March 31 Net interest income $ 92,856 $ 89,844 $ 74,580 $ 73,028 Provision for loan losses 5,328 5,705 889 3,641 Net interest income after provision for loan losses 87,528 84,139 73,691 69,387 Noninterest income 25,528 24,977 25,624 25,893 Noninterest expense 77,878 78,759 69,298 71,740 Income taxes 21,506 8,725 8,059 5,530 Net income 13,672 21,632 21,958 18,010 Preferred dividends (13 ) (13 ) (13 ) (19 ) Interest expense on convertible preferred debt — 3 4 5 Net income available to common stockholders 13,659 21,622 21,949 17,996 Per share: Earnings per share-basic $ 0.46 $ 0.73 $ 0.82 $ 0.68 Earnings per share-diluted 0.45 0.72 0.81 0.68 Cash dividends declared on common stock 0.18 0.11 0.11 0.11 Book value per common share 33.07 32.75 30.15 29.26 Weighted average common shares outstanding 29,948,536 29,647,534 26,686,845 26,334,788 Weighted average diluted common shares outstanding 30,209,043 29,910,437 26,972,580 26,627,830 (Dollars in thousands, except per share data) 2016 December 31 September 30 June 30 March 31 Net interest income $ 75,160 $ 73,681 $ 73,118 $ 72,707 Provision for loan losses 2,181 5,328 2,118 2,067 Net interest income after provision for loan losses 72,979 68,353 71,000 70,640 Noninterest income 24,455 28,542 31,026 29,578 Noninterest expense 69,912 68,427 71,020 70,309 Income taxes 8,360 8,260 10,036 9,900 Net income 19,162 20,208 20,970 20,009 Preferred dividends (19 ) (53 ) (52 ) (168 ) Interest expense on convertible preferred debt 3 17 31 — Net income available to common stockholders 19,146 20,172 20,949 19,841 Per share: Earnings per share-basic $ 0.75 $ 0.82 $ 0.85 $ 0.84 Earnings per share-diluted 0.74 0.81 0.84 0.82 Cash dividends declared on common stock 0.20 0.10 0.10 0.10 Book value per common share 28.31 28.48 27.88 27.15 Weighted average common shares outstanding 25,498,423 24,601,016 24,524,273 23,657,234 Weighted average diluted common shares outstanding 25,800,472 24,922,946 24,974,995 24,117,384

Summary of Significant Accoun53

Summary of Significant Accounting Policies (Loans) (Details)	12 Months Ended
	Dec. 31, 2017
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Threshold period past due, nonperforming status of loans and leases	90 days
Period of repayment performance, minimum	6 months

Summary of Significant Accoun54

Summary of Significant Accounting Policies (Troubled Debt Restructured Loans) (Details)	12 Months Ended
	Dec. 31, 2017
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Threshold period of consecutive payments to remove from nonaccrual status	6 months
Threshold period after modification holding current status to be considered in compliance with modified terms	30 days

Summary of Significant Accoun55

Summary of Significant Accounting Policies (Mortgage Servicing and Transfers of Financial Assets and Servicing Rights, Net) (Details) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Servicing Asset at Amortized Cost [Line Items]
Aggregate unpaid principal balance	$ 3,560,000,000	$ 4,310,000,000
Term of commercial servicing rights	20 years	20 years
Commercial Servicing Rights more than 20 Years
Servicing Asset at Amortized Cost [Line Items]
Servicing rights, valuation allowance	$ 12,000	$ 33,000

Summary of Significant Accoun56

Summary of Significant Accounting Policies (Premises, Furniture and Equipment) (Details)	12 Months Ended
	Dec. 31, 2017
Building | Minimum
Property, Plant and Equipment [Line Items]
Useful life	18 years
Building | Maximum
Property, Plant and Equipment [Line Items]
Useful life	39 years
Land Improvements
Property, Plant and Equipment [Line Items]
Useful life	15 years
Furniture and equipment | Minimum
Property, Plant and Equipment [Line Items]
Useful life	3 years
Furniture and equipment | Maximum
Property, Plant and Equipment [Line Items]
Useful life	7 years

Summary of Significant Accoun57

Summary of Significant Accounting Policies (Goodwill and Intangible Assets) (Details)	12 Months Ended
	Dec. 31, 2017
Core Deposit Intangibles | Minimum
Finite-Lived Intangible Assets [Line Items]
Useful life	8 years
Core Deposit Intangibles | Maximum
Finite-Lived Intangible Assets [Line Items]
Useful life	18 years
Customer Relationship Intangible
Finite-Lived Intangible Assets [Line Items]
Useful life	22 years

Summary of Significant Accoun58

Summary of Significant Accounting Policies (Segment Reporting) (Details)	12 Months Ended
	Dec. 31, 2017segment
Segment Reporting Information [Line Items]
Number of reportable segments (segment)	2
Community Banking
Segment Reporting Information [Line Items]
Number of reportable segments (segment)	1
Mortgage Banking Operations
Segment Reporting Information [Line Items]
Number of reportable segments (segment)	1

Summary of Significant Accoun59

Summary of Significant Accounting Policies (Earnings per Share) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Net income attributable to Heartland	$ 13,672	$ 21,632	$ 21,958	$ 18,010	$ 19,162	$ 20,208	$ 20,970	$ 20,009	$ 75,272	$ 80,349	$ 60,042
Preferred dividends	(13)	(13)	(13)	(19)	(19)	(53)	(52)	(168)	(58)	(292)	(817)
Interest expense on convertible preferred debt	0	3	4	5	3	17	31	0	12	51	0
NET INCOME AVAILABLE TO COMMON STOCKHOLDERS	$ 13,659	$ 21,622	$ 21,949	$ 17,996	$ 19,146	$ 20,172	$ 20,949	$ 19,841	$ 75,226	$ 80,108	$ 59,225
Weighted average common shares outstanding for basic earnings per share (in shares)	29,948,536	29,647,534	26,686,845	26,334,788	25,498,423	24,601,016	24,524,273	23,657,234	28,168,000	24,573,000	20,672,000
Assumed incremental common shares issued upon exercise of stock options and non-vested restricted stock units (in shares)									258,000	300,000	257,000
Weighted average common shares for diluted earnings per share (in shares)	30,209,043	29,910,437	26,972,580	26,627,830	25,800,472	24,922,946	24,974,995	24,117,384	28,426,000	24,873,000	20,929,000
Earnings per common share — basic (in dollars per share)	$ 0.46	$ 0.73	$ 0.82	$ 0.68	$ 0.75	$ 0.82	$ 0.85	$ 0.84	$ 2.67	$ 3.26	$ 2.87
Earnings per common share — diluted (in dollars per share)	$ 0.45	$ 0.72	$ 0.81	$ 0.68	$ 0.74	$ 0.81	$ 0.84	$ 0.82	$ 2.65	$ 3.22	$ 2.83

Summary of Significant Accoun60

Summary of Significant Accounting Policies (Effect of New Financial Accounting Standards) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Excess tax benefit related to share-based payment awards	$ 1,200
Increase to net cash from operating activities	(155,930)	$ (148,525)	$ (102,162)
Decrease to net cash from financing activities	(145,949)	(255,455)	151,754
Accounting Standards Update 2016-09
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Increase to net cash from operating activities		374	676
Decrease to net cash from financing activities		$ 374	$ 676
Retained Earnings | Accounting Standards Update 2018-02
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Tax Act, cumulative-effect adjustment	4,500
AOCI | Accounting Standards Update 2018-02
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Tax Act, cumulative-effect adjustment	$ (4,500)

Acquisitions (Narrative) (Detai

Acquisitions (Narrative) (Details) $ in Thousands	Feb. 23, 2018USD ($)shares	Jul. 07, 2017USD ($)buildingshares	Feb. 28, 2017USD ($)shares	Feb. 05, 2016USD ($)shares	Jun. 30, 2017USD ($)building	Jun. 30, 2018USD ($)	Dec. 31, 2017USD ($)	Dec. 31, 2016USD ($)	Dec. 31, 2015USD ($)
Business Acquisition [Line Items]
Assets							$ 9,810,739	$ 8,247,079	$ 7,694,754
Held to maturity							6,391,464	5,351,719
Deposits							8,146,909	6,847,411
Loans outstanding							6,335,778	5,297,395
Goodwill							236,615	127,699
Nonaccrual loans							58,272	62,591
Fair value of one bank building held for sale							1,977	414
Signature Bancshares, Inc.
Business Acquisition [Line Items]
Assets							409,200
Held to maturity							339,100
Deposits							368,100
First Bank Lubbock Bancshares, Inc.
Business Acquisition [Line Items]
Assets							929,600
Held to maturity							669,300
Deposits							821,900
Citywide Banks of Colorado, Inc.
Business Acquisition [Line Items]
Total consideration paid		$ 211,243
Cash payments to acquire business		58,636
Assets		1,490,000
Deposits		$ 1,210,000
Business acquisition, number of shares issued (in shares) | shares		3,216,161
Loans outstanding		$ 985,400
Number of buildings | building		1
Fair value of sold building		$ 1,400
Goodwill		95,154
Merger related expenses							3,800
Nonaccrual loans		1,200
Other borrowings		$ 21,636
Founders Bancorp
Business Acquisition [Line Items]
Total consideration paid			$ 31,000
Cash payments to acquire business			8,400
Assets			213,900
Deposits			$ 181,500
Business acquisition, number of shares issued (in shares) | shares			455,877
Number of buildings | building					1
Fair value of sold building					$ 576
Goodwill			$ 13,800
Estimated fair value of loans acquired			$ 96,400
CIC Bancshares, Inc.
Business Acquisition [Line Items]
Total consideration paid				$ 76,882
Cash payments to acquire business				15,672
Assets				772,600
Deposits				$ 648,100
Business acquisition, number of shares issued (in shares) | shares				2,003,235
Goodwill				$ 29,848
Merger related expenses								$ 551
Nonaccrual loans				1,600
Other borrowings				7,924
Estimated fair value of loans acquired				581,500
CIC Bancshares, Inc. | Preferred Stock
Business Acquisition [Line Items]
Common stock				$ 3,800
Transaction costs | Citywide Banks of Colorado, Inc.
Business Acquisition [Line Items]
Transaction costs							$ (10,100)
Common Stock | CIC Bancshares, Inc.
Business Acquisition [Line Items]
Business acquisition, number of shares issued (in shares) | shares				2,003,235
Subsequent Event | Signature Bancshares, Inc.
Business Acquisition [Line Items]
Total consideration paid	$ 61,400
Cash payments to acquire business	$ 7,700
Business acquisition, number of shares issued (in shares) | shares	1,001,246
Scenario, Forecast | First Bank Lubbock Bancshares, Inc.
Business Acquisition [Line Items]
Total consideration paid						$ 185,600

Acquisitions (Acquisitions Fair

Acquisitions (Acquisitions Fair Values) (Details) - USD ($) $ in Thousands	Jul. 07, 2017	Feb. 05, 2016	Dec. 31, 2017	Dec. 31, 2016
Fair value of liabilities assumed
Goodwill resulting from acquisition			$ 236,615	$ 127,699
Citywide Banks of Colorado, Inc.
Fair value of consideration paid
Common stock (in shares)	3,216,161
Common stock	$ 152,607
Cash	58,636
Total consideration paid	211,243
Fair value of assets acquired
Cash and due from banks	21,341
Interest bearing deposits with the Federal Reserve and other banks and other short-term investments	74,686
Time deposits in other financial institutions	6,304
Securities:
Securities available for sale	234,390
Other securities	2,628
Loans held to maturity	985,399
Premises, furniture and equipment, net	17,206
Premises, furniture and equipment held for sale	1,350
Other real estate, net	6,916
Core deposit intangibles and customer relationship intangibles, net	16,041
Cash surrender value on life insurance	21,015
Other assets	11,263
Total assets	1,398,539
Fair value of liabilities assumed
Deposits	1,210,074
Short term borrowings	34,445
Other borrowings	21,636
Other liabilities	16,295
Total liabilities assumed	1,282,450
Fair value of net assets acquired	116,089
Goodwill resulting from acquisition	$ 95,154
CIC Bancshares, Inc.
Fair value of consideration paid
Common stock (in shares)		2,003,235
Cash		$ 15,672
Total consideration paid		76,882
Fair value of assets acquired
Cash and due from banks		23,756
Securities:
Securities available for sale		92,831
Other securities		3,486
Loans held to maturity		581,477
Premises, furniture and equipment, net		16,450
Other real estate, net		1,934
Core deposit intangibles and customer relationship intangibles, net		6,576
Other assets		16,276
Total assets		742,786
Fair value of liabilities assumed
Deposits		648,111
Short term borrowings		35,766
Other borrowings		7,924
Other liabilities		3,951
Total liabilities assumed		695,752
Fair value of net assets acquired		47,034
Goodwill resulting from acquisition		$ 29,848
Common Stock | CIC Bancshares, Inc.
Fair value of consideration paid
Common stock (in shares)		2,003,235
Common stock		$ 57,433
Preferred Stock | CIC Bancshares, Inc.
Fair value of consideration paid
Common stock (in shares)		3,000
Common stock		$ 3,777

Acquisitions (Pro Forma) (Detai

Acquisitions (Pro Forma) (Details) - Citywide Banks of Colorado, Inc. - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Business Acquisition [Line Items]
Net interest income	$ 357,341	$ 344,784
Net income available to common stockholders	$ 75,599	$ 90,470
Basic earnings per share (in dollars per share)	$ 2.67	$ 3.26
Diluted earnings per share (in dollars per share)	$ 2.65	$ 3.22

Cash and Due from Banks (Detail

Cash and Due from Banks (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Cash and Cash Equivalents [Abstract]
Reserve balance requirement	$ 10.7	$ 9.1

Securities (Available-for-sale

Securities (Available-for-sale Securities) (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Schedule of Available-for-sale Securities [Line Items]
Total investment securities	$ 2,248,181	$ 1,893,947
Gross Unrealized Gains	10,911	9,547
Gross Unrealized Losses	(42,339)	(57,630)
Securities available for sale	2,216,753	1,845,864
Debt securities
Schedule of Available-for-sale Securities [Line Items]
Total investment securities	2,231,885	1,879,496
Gross Unrealized Gains	10,533	9,478
Gross Unrealized Losses	(42,339)	(57,630)
Securities available for sale	2,200,079	1,831,344
U.S. government corporations and agencies
Schedule of Available-for-sale Securities [Line Items]
Total investment securities	5,358	4,716
Gross Unrealized Gains	8	16
Gross Unrealized Losses	(38)	(32)
Securities available for sale	5,328	4,700
Mortgage and asset-backed securities
Schedule of Available-for-sale Securities [Line Items]
Total investment securities	1,785,467	1,321,760
Gross Unrealized Gains	5,856	7,026
Gross Unrealized Losses	(37,587)	(38,286)
Securities available for sale	1,753,736	1,290,500
Obligations of states and political subdivisions
Schedule of Available-for-sale Securities [Line Items]
Total investment securities	441,060	553,020
Gross Unrealized Gains	4,669	2,436
Gross Unrealized Losses	(4,714)	(19,312)
Securities available for sale	441,015	536,144
Equity securities
Schedule of Available-for-sale Securities [Line Items]
Total investment securities	16,296	14,451
Gross Unrealized Gains	378	69
Gross Unrealized Losses	0	0
Securities available for sale	$ 16,674	$ 14,520

Securities (Held-to-maturity Se

Securities (Held-to-maturity Securities) (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Schedule of Held-to-maturity Securities [Line Items]
Total investment securities	$ 253,550	$ 263,662
Gross Unrealized Gains	12,460	12,282
Gross Unrealized Losses	(516)	(1,145)
Estimated Fair Value	265,494	274,799
Obligations of states and political subdivisions
Schedule of Held-to-maturity Securities [Line Items]
Total investment securities	253,550	263,662
Gross Unrealized Gains	12,460	12,282
Gross Unrealized Losses	(516)	(1,145)
Estimated Fair Value	$ 265,494	$ 274,799

Securities (Narrative) (Details

Securities (Narrative) (Details)	12 Months Ended
	Dec. 31, 2017USD ($)	Dec. 31, 2016USD ($)	Dec. 31, 2015USD ($)security
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Line Items]
Securities pledged as collateral	$ 670,300,000
Number of OTTI investments | security			2
Impairment loss on securities	0	$ 0	$ 769,000
Held to maturity debt securities			716,000
Other-than-temporary impairment			53,000
Held to maturity securities sold, carrying value		4,400,000
Loss on held to maturity securities sold		89,000
Gross security losses	3,812,000	1,562,000	2,022,000
Gross security gains	0
FHLB stock	$ 14,000,000	14,400,000
Held-to-maturity Securities
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Line Items]
Amount reclassified from non-credit OTTI to held to maturity			200,000
Mortgage-backed Securities, Issued by US Government Sponsored Enterprises
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Line Items]
Percent of mortgage-backed securities issued by government-sponsored entities	75.00%
Mortgage and asset-backed securities
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Line Items]
Held to maturity debt securities	$ 0	0	716,000
Other-than-temporary impairment	0	0	$ 53,000
Gain on held-to-maturity securities sold		89,000
Loss on held to maturity securities sold		(439,000)
Carrying value of available for sale security sold		483,000
Gross security losses	$ 85,000	85,000
Obligations of states and political subdivisions
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Line Items]
Held to maturity securities sold, carrying value		503,000
Loss on held to maturity securities sold		$ (1,500)

Securities (Available-for-sal68

Securities (Available-for-sale Securities, Debt Maturities) (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Amortized Cost
Due in 1 year or less	$ 185
Due in 1 to 5 years	54,630
Due in 5 to 10 years	95,345
Due after 10 years	296,258
Total debt securities	446,418
Mortgage and asset-backed securities	1,785,467
Equity securities	16,296
Total investment securities	2,248,181	$ 1,893,947
Estimated Fair Value
Due in 1 year or less	185
Due in 1 to 5 years	54,741
Due in 5 to 10 years	93,393
Due after 10 years	298,024
Total debt securities	446,343
Mortgage and asset-backed securities	1,753,736
Equity securities	16,674
Total investment securities	$ 2,216,753	$ 1,845,864

Securities (Held-to-maturity 69

Securities (Held-to-maturity Securities, Debt Maturities) (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Amortized Cost
Due in 1 year or less	$ 1,892
Due in 1 to 5 years	26,790
Due in 5 to 10 years	98,285
Due after 10 years	126,583
Total investment securities	253,550	$ 263,662
Estimated Fair Value
Due in 1 year or less	1,923
Due in 1 to 5 years	27,433
Due in 5 to 10 years	101,377
Due after 10 years	134,761
Total investment securities	$ 265,494	$ 274,799

Securities (Gross Realized Gain

Securities (Gross Realized Gain (Loss)) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Available for Sale Securities sold:
Proceeds from sales	$ 1,456,750	$ 909,942	$ 1,115,359
Gross security gains	10,585	13,200	15,205
Gross security losses	$ 3,812	$ 1,562	$ 2,022

Securities (Available for Sale

Securities (Available for Sale Securities Losses) (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Fair Value
Less than 12 months	$ 948,929	$ 1,162,538
12 months or longer	559,158	272,700
Total	1,508,087	1,435,238
Unrealized Losses
Less than 12 months	(12,238)	(42,868)
12 months or longer	(30,101)	(14,762)
Total	(42,339)	(57,630)
U.S. government corporations and agencies
Fair Value
Less than 12 months	4,819	4,185
12 months or longer	0	0
Total	4,819	4,185
Unrealized Losses
Less than 12 months	(38)	(32)
12 months or longer	0	0
Total	(38)	(32)
Mortgage and asset-backed securities
Fair Value
Less than 12 months	851,070	744,202
12 months or longer	399,978	272,449
Total	1,251,048	1,016,651
Unrealized Losses
Less than 12 months	(11,533)	(23,527)
12 months or longer	(26,054)	(14,759)
Total	(37,587)	(38,286)
Obligations of states and political subdivisions
Fair Value
Less than 12 months	93,040	414,151
12 months or longer	159,180	251
Total	252,220	414,402
Unrealized Losses
Less than 12 months	(667)	(19,309)
12 months or longer	(4,047)	(3)
Total	(4,714)	(19,312)
Debt securities
Fair Value
Less than 12 months	948,929	1,162,538
12 months or longer	559,158	272,700
Total	1,508,087	1,435,238
Unrealized Losses
Less than 12 months	(12,238)	(42,868)
12 months or longer	(30,101)	(14,762)
Total	(42,339)	(57,630)
Equity securities
Fair Value
Less than 12 months	0	0
12 months or longer	0	0
Total	0	0
Unrealized Losses
Less than 12 months	0	0
12 months or longer	0	0
Total	$ 0	$ 0

Securities (Held to Maturity Se

Securities (Held to Maturity Securities Losses) (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Fair Value
Less than 12 months	$ 8,512	$ 31,479
12 months or longer	8,989	2,017
Total	17,501	33,496
Unrealized Losses
Less than 12 months	(49)	(884)
12 months or longer	(467)	(261)
Total	(516)	(1,145)
Obligations of states and political subdivisions
Fair Value
Less than 12 months	8,512	31,479
12 months or longer	8,989	2,017
Total	17,501	33,496
Unrealized Losses
Less than 12 months	(49)	(884)
12 months or longer	(467)	(261)
Total	$ (516)	$ (1,145)

Securities (OTTI Write-downs In

Securities (OTTI Write-downs Includes in Earnings) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
OTTI write-downs included in earnings:
Available for sale debt securities			$ 53
Held to maturity debt securities			716
Total debt security OTTI write-downs included in earnings	$ 0	$ 0	769
Mortgage and asset-backed securities
OTTI write-downs included in earnings:
Available for sale debt securities	0	0	53
Held to maturity debt securities	$ 0	$ 0	$ 716

Securities (Other-Than-Temporar

Securities (Other-Than-Temporary Impairments) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Investments, Debt and Equity Securities [Abstract]
Credit related OTTI	$ 0	$ 0	$ 769
Intent to sell OTTI	0	0	0
Total debt security OTTI write-downs included in earnings	0	0	769
Reclassification of non-credit related impairment	0	0	(200)
Reduction of non-credit related impairment related to security sales	0	(120)	0
Accretion of non-credit related impairment	0	(7)	(95)
Total changes to AOCI for non-credit related impairment	0	(127)	(295)
Total OTTI losses (accretion) recorded on debt securities	$ 0	$ (127)	$ 474

Securities (Change in Credit Lo

Securities (Change in Credit Loss Component of Credit Impaired Debt Securities) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Roll Forward]
Credit loss component, beginning of period	$ 0	$ 1,750	$ 981
Additions:
Initial credit impairments	0	0	0
Subsequent credit impairments	0	0	769
Total additions	0	0	769
Reductions:
For securities sold	0	1,750	0
Total reductions	0	1,750	0
Credit loss component, end of period	$ 0	$ 0	$ 1,750

Loans (Loans Receivable) (Detai

Loans (Loans Receivable) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Loans and Leases Receivable Disclosure [Line Items]
Loans and leases receivable held to maturity	$ 6,393,226	$ 5,353,702
Unearned discount	(556)	(699)
Deferred loan fees	(1,206)	(1,284)
Total net loans receivable held to maturity	6,391,464	5,351,719
Allowance for loan losses	(55,686)	(54,324)
Loans receivable, net	6,335,778	5,297,395
Commercial
Loans and Leases Receivable Disclosure [Line Items]
Loans and leases receivable held to maturity	4,809,875	3,825,847
Commercial | Commercial
Loans and Leases Receivable Disclosure [Line Items]
Loans and leases receivable held to maturity	1,646,606	1,287,265
Commercial | Commercial real estate
Loans and Leases Receivable Disclosure [Line Items]
Loans and leases receivable held to maturity	3,163,269	2,538,582
Agricultural and agricultural real estate
Loans and Leases Receivable Disclosure [Line Items]
Loans and leases receivable held to maturity	511,588	489,318
Residential real estate
Loans and Leases Receivable Disclosure [Line Items]
Loans and leases receivable held to maturity	624,279	617,924
Consumer
Loans and Leases Receivable Disclosure [Line Items]
Loans and leases receivable held to maturity	$ 447,484	$ 420,613
Consumer | Citizens Finance Co | Loans and Finance Receivables
Loans and Leases Receivable Disclosure [Line Items]
Concentration risk, percentage	16.00%

Loans (Allowance for Credit Los

Loans (Allowance for Credit Losses on Financing Receivables) (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Allowance For Loan Losses
Ending Balance Under ASC 310-10-35	$ 4,755	$ 6,753
Ending Balance Under ASC 450-20	50,931	47,571
Total	55,686	54,324	$ 48,685	$ 41,449
Gross Loans Receivable Held to Maturity
Ending Balance Evaluated for Impairment Under ASC 310-10-35	78,468	97,373
Ending Balance Evaluated for Impairment Under ASC 450-20	6,314,758	5,256,329
Total	6,393,226	5,353,702
Commercial
Gross Loans Receivable Held to Maturity
Total	4,809,875	3,825,847
Commercial | Commercial
Allowance For Loan Losses
Ending Balance Under ASC 310-10-35	1,613	1,318
Ending Balance Under ASC 450-20	16,485	13,447
Total	18,098	14,765	16,095
Gross Loans Receivable Held to Maturity
Ending Balance Evaluated for Impairment Under ASC 310-10-35	7,415	3,712
Ending Balance Evaluated for Impairment Under ASC 450-20	1,639,191	1,283,553
Total	1,646,606	1,287,265
Commercial | Commercial real estate
Allowance For Loan Losses
Ending Balance Under ASC 310-10-35	766	2,671
Ending Balance Under ASC 450-20	21,184	21,648
Total	21,950	24,319	19,532
Gross Loans Receivable Held to Maturity
Ending Balance Evaluated for Impairment Under ASC 310-10-35	23,705	45,217
Ending Balance Evaluated for Impairment Under ASC 450-20	3,139,564	2,493,365
Total	3,163,269	2,538,582
Agricultural and agricultural real estate
Allowance For Loan Losses
Ending Balance Under ASC 310-10-35	546	816
Ending Balance Under ASC 450-20	3,712	3,394
Total	4,258	4,210	3,887
Gross Loans Receivable Held to Maturity
Ending Balance Evaluated for Impairment Under ASC 310-10-35	13,304	16,730
Ending Balance Evaluated for Impairment Under ASC 450-20	498,284	472,588
Total	511,588	489,318
Residential real estate
Allowance For Loan Losses
Ending Balance Under ASC 310-10-35	430	497
Ending Balance Under ASC 450-20	1,794	1,766
Total	2,224	2,263	1,934
Gross Loans Receivable Held to Maturity
Ending Balance Evaluated for Impairment Under ASC 310-10-35	27,141	25,726
Ending Balance Evaluated for Impairment Under ASC 450-20	597,138	592,198
Total	624,279	617,924
Consumer
Allowance For Loan Losses
Ending Balance Under ASC 310-10-35	1,400	1,451
Ending Balance Under ASC 450-20	7,756	7,316
Total	9,156	8,767	$ 7,237
Gross Loans Receivable Held to Maturity
Ending Balance Evaluated for Impairment Under ASC 310-10-35	6,903	5,988
Ending Balance Evaluated for Impairment Under ASC 450-20	440,581	414,625
Total	$ 447,484	$ 420,613

Loans (Financing Receivables, N

Loans (Financing Receivables, Non accrual Status) (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual loans	$ 58,272	$ 62,591
Nonaccrual troubled debt restructured loans	4,309	1,708
Nonaccrual loans	62,581	64,299
Accruing loans past due 90 days or more	830	86
Performing troubled debt restructured loans	$ 6,617	$ 10,380

Loans (Troubled Debt Restructur

Loans (Troubled Debt Restructured Loans) (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Financing Receivable, Recorded Investment [Line Items]
Troubled debt restructured loans	$ 10,900	$ 12,100
Nonperforming Financial Instruments
Financing Receivable, Recorded Investment [Line Items]
Troubled debt restructured loans	4,300	1,700
Performing Financial Instruments
Financing Receivable, Recorded Investment [Line Items]
Troubled debt restructured loans	6,617	$ 10,400
GNMA insured or guaranteed loan programs | Residential real estate
Financing Receivable, Recorded Investment [Line Items]
Troubled debt restructured loans	$ 4,600

Loans (Troubled Debt Restruct80

Loans (Troubled Debt Restructurings on Financing Receivables) (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2017USD ($)loan	Dec. 31, 2016USD ($)loan
Financing Receivable, Modifications [Line Items]
Number of Loans | loan	32	11
Pre-Modification Recorded Investment	$ 4,250	$ 2,333
Post-Modification Recorded Investment	3,918	$ 2,333
Principal deferment collected from government guarantees	503
Capitalized interest and escrow	$ 170
Commercial
Financing Receivable, Modifications [Line Items]
Number of Loans | loan	3	3
Pre-Modification Recorded Investment	$ 124	$ 736
Post-Modification Recorded Investment	$ 124	$ 736
Commercial | Commercial
Financing Receivable, Modifications [Line Items]
Number of Loans | loan	3	1
Pre-Modification Recorded Investment	$ 124	$ 95
Post-Modification Recorded Investment	$ 124	$ 95
Commercial | Commercial real estate
Financing Receivable, Modifications [Line Items]
Number of Loans | loan	0	2
Pre-Modification Recorded Investment	$ 0	$ 641
Post-Modification Recorded Investment	$ 0	$ 641
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
Residential real estate
Financing Receivable, Modifications [Line Items]
Number of Loans | loan	29	8
Pre-Modification Recorded Investment	$ 4,126	$ 1,597
Post-Modification Recorded Investment	$ 3,794	$ 1,597
Consumer
Financing Receivable, Modifications [Line Items]
Number of Loans | loan	0	0
Pre-Modification Recorded Investment	$ 0	$ 0
Post-Modification Recorded Investment	$ 0	$ 0

Loans (Troubled Debt Restruct81

Loans (Troubled Debt Restructured Loans with Payment Default) (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2017USD ($)loan	Dec. 31, 2016USD ($)loan
Financing Receivable, Modifications [Line Items]
Number of Loans | loan	16	3
Recorded Investment | $	$ 2,435	$ 359
Commercial
Financing Receivable, Modifications [Line Items]
Number of Loans | loan	0	1
Recorded Investment | $	$ 0	$ 95
Commercial | Commercial
Financing Receivable, Modifications [Line Items]
Number of Loans | loan	0	1
Recorded Investment | $	$ 0	$ 95
Commercial | Commercial real estate
Financing Receivable, Modifications [Line Items]
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
Recorded Investment | $	$ 0	$ 0
Residential real estate
Financing Receivable, Modifications [Line Items]
Number of Loans | loan	16	2
Recorded Investment | $	$ 2,435	$ 264
Consumer
Financing Receivable, Modifications [Line Items]
Number of Loans | loan	0	0
Recorded Investment | $	$ 0	$ 0

Loans (Not Covered by Share Agr

Loans (Not Covered by Share Agreements (Credit Quality Indicator)) (Details) $ in Thousands	Dec. 31, 2017USD ($)loan	Dec. 31, 2016USD ($)
Financing Receivable, Recorded Investment [Line Items]
Number of loans classified as doubtful | loan	0
Number of loans classified as loss | loan	0
Loans and leases receivable	$ 6,393,226	$ 5,353,702
Pass
Financing Receivable, Recorded Investment [Line Items]
Loans and leases receivable	6,009,382	4,985,600
Nonpass
Financing Receivable, Recorded Investment [Line Items]
Loans and leases receivable	383,844	368,102
Commercial
Financing Receivable, Recorded Investment [Line Items]
Loans and leases receivable	4,809,875	3,825,847
Commercial | Pass
Financing Receivable, Recorded Investment [Line Items]
Loans and leases receivable	4,538,284	3,567,189
Commercial | Nonpass
Financing Receivable, Recorded Investment [Line Items]
Loans and leases receivable	271,591	258,658
Commercial | Commercial
Financing Receivable, Recorded Investment [Line Items]
Loans and leases receivable	1,646,606	1,287,265
Commercial | Commercial | Pass
Financing Receivable, Recorded Investment [Line Items]
Loans and leases receivable	1,552,783	1,187,557
Commercial | Commercial | Nonpass
Financing Receivable, Recorded Investment [Line Items]
Loans and leases receivable	93,823	99,708
Commercial | Commercial real estate
Financing Receivable, Recorded Investment [Line Items]
Loans and leases receivable	3,163,269	2,538,582
Commercial | Commercial real estate | Pass
Financing Receivable, Recorded Investment [Line Items]
Loans and leases receivable	2,985,501	2,379,632
Commercial | Commercial real estate | Nonpass
Financing Receivable, Recorded Investment [Line Items]
Loans and leases receivable	177,768	158,950
Agricultural and agricultural real estate
Financing Receivable, Recorded Investment [Line Items]
Loans and leases receivable	511,588	489,318
Agricultural and agricultural real estate | Pass
Financing Receivable, Recorded Investment [Line Items]
Loans and leases receivable	451,539	424,311
Agricultural and agricultural real estate | Nonpass
Financing Receivable, Recorded Investment [Line Items]
Loans and leases receivable	60,049	65,007
Residential real estate
Financing Receivable, Recorded Investment [Line Items]
Loans and leases receivable	624,279	617,924
Residential real estate | Pass
Financing Receivable, Recorded Investment [Line Items]
Loans and leases receivable	586,623	584,626
Residential real estate | Nonpass
Financing Receivable, Recorded Investment [Line Items]
Loans and leases receivable	37,656	33,298
Consumer
Financing Receivable, Recorded Investment [Line Items]
Loans and leases receivable	447,484	420,613
Consumer | Pass
Financing Receivable, Recorded Investment [Line Items]
Loans and leases receivable	432,936	409,474
Consumer | Nonpass
Financing Receivable, Recorded Investment [Line Items]
Loans and leases receivable	$ 14,548	$ 11,139

Loans (Not Covered by Share A83

Loans (Not Covered by Share Agreements (Percentage)) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Financing Receivable, Recorded Investment [Line Items]
Loans delinquent 30-89 days as a percentage of total loans	0.27%	0.37%
Loans secured by real estate property in process of foreclosure	$ 3.1
Threshold period past due, nonperforming status of loans and leases	90 days
Nonpass
Financing Receivable, Recorded Investment [Line Items]
Percent of nonaccrual loans	16.00%	17.00%
Special Mention
Financing Receivable, Recorded Investment [Line Items]
Percent of loans	52.00%	47.00%
Substandard
Financing Receivable, Recorded Investment [Line Items]
Percent of loans	48.00%	53.00%

Loans (Not Covered by Share A84

Loans (Not Covered by Share Agreements (Past Due Financing Receivables)) (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	$ 18,137	$ 19,945
Current	6,312,508	5,269,458
Nonaccrual	62,581	64,299
Total	6,393,226	5,353,702
30-59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	13,375	10,653
60-89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	3,932	9,206
90 Days or More Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	830	86
Commercial
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	8,700	6,238
Current	4,777,349	3,794,310
Nonaccrual	23,826	25,299
Total	4,809,875	3,825,847
Commercial | Commercial
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	1,605	1,423
Current	1,637,773	1,281,241
Nonaccrual	7,228	4,601
Total	1,646,606	1,287,265
Commercial | Commercial real estate
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	7,095	4,815
Current	3,139,576	2,513,069
Nonaccrual	16,598	20,698
Total	3,163,269	2,538,582
Commercial | 30-59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	6,015	2,013
Commercial | 30-59 Days Past Due | Commercial
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	1,246	1,127
Commercial | 30-59 Days Past Due | Commercial real estate
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	4,769	886
Commercial | 60-89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	2,585	4,148
Commercial | 60-89 Days Past Due | Commercial
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	259	219
Commercial | 60-89 Days Past Due | Commercial real estate
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	2,326	3,929
Commercial | 90 Days or More Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	100	77
Commercial | 90 Days or More Past Due | Commercial
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	100	77
Commercial | 90 Days or More Past Due | Commercial real estate
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	0	0
Agricultural and agricultural real estate
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	738	3,390
Current	497,546	472,597
Nonaccrual	13,304	13,331
Total	511,588	489,318
Agricultural and agricultural real estate | 30-59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	604	199
Agricultural and agricultural real estate | 60-89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	134	3,191
Agricultural and agricultural real estate | 90 Days or More Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	0	0
Residential real estate
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	2,292	5,832
Current	601,120	590,626
Nonaccrual	20,867	21,466
Total	624,279	617,924
Residential real estate | 30-59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	2,022	4,986
Residential real estate | 60-89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	270	846
Residential real estate | 90 Days or More Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	0	0
Consumer
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	6,407	4,485
Current	436,493	411,925
Nonaccrual	4,584	4,203
Total	447,484	420,613
Consumer | 30-59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	4,734	3,455
Consumer | 60-89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	943	1,021
Consumer | 90 Days or More Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	$ 730	$ 9

Loans (Impaired Loans Not Cover

Loans (Impaired Loans Not Covered by Loss Share Agreements) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Unpaid Principal Balance
Impaired loans with a related allowance	$ 19,958	$ 25,978
Impaired loans without a related allowance	64,121	72,511
Total impaired loans held to maturity	84,079	98,489
Loan Balance
Impaired loans with a related allowance	18,101	25,966
Impaired loans without a related allowance	60,367	71,407
Total impaired loans held to maturity	78,468	97,373
Impaired loans, related allowance recorded	4,755	6,753
Year-to-Date Avg. Loan Balance
Impaired loans with a related allowance	22,949	21,126
Impaired loans without a related allowance	62,296	78,788
Total impaired loans held to maturity	85,245	99,914
Year-to-Date Interest Income Recognized
Impaired loans with a related allowance	129	129
Impaired loans without a related allowance	1,029	2,325
Total loans held to maturity	1,158	2,454
Commercial
Unpaid Principal Balance
Impaired loans with a related allowance	14,217	17,073
Impaired loans without a related allowance	20,486	32,800
Total impaired loans held to maturity	34,703	49,873
Loan Balance
Impaired loans with a related allowance	12,360	17,061
Impaired loans without a related allowance	18,760	31,868
Total impaired loans held to maturity	31,120	48,929
Impaired loans, related allowance recorded	2,379	3,989
Year-to-Date Avg. Loan Balance
Impaired loans with a related allowance	15,086	13,761
Impaired loans without a related allowance	22,734	44,961
Total impaired loans held to maturity	37,820	58,722
Year-to-Date Interest Income Recognized
Impaired loans with a related allowance	73	23
Impaired loans without a related allowance	679	1,898
Total loans held to maturity	752	1,921
Commercial | Commercial
Unpaid Principal Balance
Impaired loans with a related allowance	2,292	2,852
Impaired loans without a related allowance	6,243	925
Total impaired loans held to maturity	8,535	3,777
Loan Balance
Impaired loans with a related allowance	2,292	2,840
Impaired loans without a related allowance	5,123	872
Total impaired loans held to maturity	7,415	3,712
Impaired loans, related allowance recorded	1,613	1,318
Year-to-Date Avg. Loan Balance
Impaired loans with a related allowance	3,607	3,136
Impaired loans without a related allowance	2,586	5,329
Total impaired loans held to maturity	6,193	8,465
Year-to-Date Interest Income Recognized
Impaired loans with a related allowance	39	2
Impaired loans without a related allowance	165	251
Total loans held to maturity	204	253
Commercial | Commercial real estate
Unpaid Principal Balance
Impaired loans with a related allowance	11,925	14,221
Impaired loans without a related allowance	14,243	31,875
Total impaired loans held to maturity	26,168	46,096
Loan Balance
Impaired loans with a related allowance	10,068	14,221
Impaired loans without a related allowance	13,637	30,996
Total impaired loans held to maturity	23,705	45,217
Impaired loans, related allowance recorded	766	2,671
Year-to-Date Avg. Loan Balance
Impaired loans with a related allowance	11,479	10,625
Impaired loans without a related allowance	20,148	39,632
Total impaired loans held to maturity	31,627	50,257
Year-to-Date Interest Income Recognized
Impaired loans with a related allowance	34	21
Impaired loans without a related allowance	514	1,647
Total loans held to maturity	548	1,668
Agricultural and agricultural real estate
Unpaid Principal Balance
Impaired loans with a related allowance	1,539	2,771
Impaired loans without a related allowance	13,793	13,959
Total impaired loans held to maturity	15,332	16,730
Loan Balance
Impaired loans with a related allowance	1,539	2,771
Impaired loans without a related allowance	11,765	13,959
Total impaired loans held to maturity	13,304	16,730
Impaired loans, related allowance recorded	546	816
Year-to-Date Avg. Loan Balance
Impaired loans with a related allowance	3,437	912
Impaired loans without a related allowance	9,654	12,722
Total impaired loans held to maturity	13,091	13,634
Year-to-Date Interest Income Recognized
Impaired loans with a related allowance	0	21
Impaired loans without a related allowance	0	157
Total loans held to maturity	0	178
Residential real estate
Unpaid Principal Balance
Impaired loans with a related allowance	1,568	3,490
Impaired loans without a related allowance	25,573	22,408
Total impaired loans held to maturity	27,141	25,898
Loan Balance
Impaired loans with a related allowance	1,568	3,490
Impaired loans without a related allowance	25,573	22,236
Total impaired loans held to maturity	27,141	25,726
Impaired loans, related allowance recorded	430	497
Year-to-Date Avg. Loan Balance
Impaired loans with a related allowance	2,056	3,371
Impaired loans without a related allowance	26,024	18,446
Total impaired loans held to maturity	28,080	21,817
Year-to-Date Interest Income Recognized
Impaired loans with a related allowance	15	43
Impaired loans without a related allowance	277	202
Total loans held to maturity	292	245
Consumer
Unpaid Principal Balance
Impaired loans with a related allowance	2,634	2,644
Impaired loans without a related allowance	4,269	3,344
Total impaired loans held to maturity	6,903	5,988
Loan Balance
Impaired loans with a related allowance	2,634	2,644
Impaired loans without a related allowance	4,269	3,344
Total impaired loans held to maturity	6,903	5,988
Impaired loans, related allowance recorded	1,400	1,451
Year-to-Date Avg. Loan Balance
Impaired loans with a related allowance	2,370	3,082
Impaired loans without a related allowance	3,884	2,659
Total impaired loans held to maturity	6,254	5,741
Year-to-Date Interest Income Recognized
Impaired loans with a related allowance	41	42
Impaired loans without a related allowance	73	68
Total loans held to maturity	$ 114	$ 110

Loans (Purchased Impaired Loans

Loans (Purchased Impaired Loans (Narrative)) (Details) - USD ($) $ in Millions	Jul. 07, 2017	Feb. 28, 2017	Feb. 05, 2016
Citywide Banks of Colorado, Inc.
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans acquired, gross	$ 1,000
Estimated fair value of loans acquired	$ 985.4
Founders Bancorp
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans acquired, gross		$ 98.9
Estimated fair value of loans acquired		$ 96.4
Centennial Bank
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans acquired, gross			$ 594.9
Estimated fair value of loans acquired			$ 581.5

Loans (Summary of Purchased Imp

Loans (Summary of Purchased Impaired and Nonimpaired Loans Acquired) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Financing Receivable, Allowance for Credit Losses [Line Items]
Purchased Loans	$ 1,470,025	$ 930,679
Agricultural and agricultural real estate
Financing Receivable, Allowance for Credit Losses [Line Items]
Purchased Loans	1,242	181
Residential real estate
Financing Receivable, Allowance for Credit Losses [Line Items]
Purchased Loans	174,123	157,654
Consumer
Financing Receivable, Allowance for Credit Losses [Line Items]
Purchased Loans	51,292	47,368
Commercial | Commercial
Financing Receivable, Allowance for Credit Losses [Line Items]
Purchased Loans	188,327	101,280
Commercial real estate | Commercial
Financing Receivable, Allowance for Credit Losses [Line Items]
Purchased Loans	1,055,041	624,196
Non Impaired Purchased Loans
Financing Receivable, Allowance for Credit Losses [Line Items]
Purchased Loans	1,466,287	926,216
Non Impaired Purchased Loans | Agricultural and agricultural real estate
Financing Receivable, Allowance for Credit Losses [Line Items]
Purchased Loans	1,242	181
Non Impaired Purchased Loans | Residential real estate
Financing Receivable, Allowance for Credit Losses [Line Items]
Purchased Loans	173,909	157,468
Non Impaired Purchased Loans | Consumer
Financing Receivable, Allowance for Credit Losses [Line Items]
Purchased Loans	51,292	47,368
Non Impaired Purchased Loans | Commercial | Commercial
Financing Receivable, Allowance for Credit Losses [Line Items]
Purchased Loans	187,375	99,082
Non Impaired Purchased Loans | Commercial real estate | Commercial
Financing Receivable, Allowance for Credit Losses [Line Items]
Purchased Loans	1,052,469	622,117
Impaired Purchased Loans
Financing Receivable, Allowance for Credit Losses [Line Items]
Purchased Loans	3,738	4,463
Impaired Purchased Loans | Agricultural and agricultural real estate
Financing Receivable, Allowance for Credit Losses [Line Items]
Purchased Loans	0	0
Impaired Purchased Loans | Residential real estate
Financing Receivable, Allowance for Credit Losses [Line Items]
Purchased Loans	214	186
Impaired Purchased Loans | Consumer
Financing Receivable, Allowance for Credit Losses [Line Items]
Purchased Loans	0	0
Impaired Purchased Loans | Commercial | Commercial
Financing Receivable, Allowance for Credit Losses [Line Items]
Purchased Loans	952	2,198
Impaired Purchased Loans | Commercial real estate | Commercial
Financing Receivable, Allowance for Credit Losses [Line Items]
Purchased Loans	$ 2,572	$ 2,079

Loans (Change in Accretable Yie

Loans (Change in Accretable Yield) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Accretable Yield Movement Schedule [Roll Forward]
Balance at beginning of period	$ 182	$ 557
Original yield discount, net, at date of acquisitions	0	19
Accretion	(1,591)	(1,018)
Reclassification from nonaccretable difference	1,466	624
Balance at end of period	$ 57	$ 182

Loans (Carrying Amounts of Purc

Loans (Carrying Amounts of Purchased Impaired and Nonimpaired Loans Acquired and Carrying Amount of Loans Covered by Loss Share Agreements (Narrative)) (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for loan and lease losses	$ 55,686				$ 54,324				$ 55,686	$ 54,324
Provision expense	5,328	$ 5,705	$ 889	$ 3,641	2,181	$ 5,328	$ 2,118	$ 2,067	15,563	11,694	$ 12,697
2015 Acquisitions
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for loan and lease losses	139				$ 588				139	588
Provision expense									12	$ 507
Receivables acquired with deteriorated credit quality | 2015 Acquisitions
Accounts, Notes, Loans and Financing Receivable [Line Items]
Contractually required payments of loans acquired	21,000								21,000
Estimated fair value of loans acquired	13,100								13,100
Receivables acquired excluding receivables with deteriorated credit quality | 2015 Acquisitions
Accounts, Notes, Loans and Financing Receivable [Line Items]
Contractually required payments of loans acquired	2,660,000								2,660,000
Estimated fair value of loans acquired	$ 2,590,000								$ 2,590,000

Loans (Related Parties Roll For

Loans (Related Parties Roll Forward) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Loans and Leases Receivable, Related Parties [Roll Forward]
Balance at beginning of year	$ 114,305	$ 141,465
Advances	56,652	57,165
Repayments	(55,284)	(84,325)
Balance at end of year	$ 115,673	$ 114,305

Allowance for Loan Losses (Deta

Allowance for Loan Losses (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Balance at beginning of year				$ 54,324				$ 48,685	$ 54,324	$ 48,685	$ 41,449
Provision for loan losses	$ 5,328	$ 5,705	$ 889	3,641	$ 2,181	$ 5,328	$ 2,118	2,067	15,563	11,694	12,697
Recoveries on loans previously charged-off									3,670	5,339	3,553
Loans charged-off									(17,871)	(11,394)	(9,014)
Balance at end of year	55,686				54,324				55,686	54,324	48,685
Commercial | Commercial
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Balance at beginning of year				14,765				16,095	14,765	16,095
Provision for loan losses									7,162	(912)
Recoveries on loans previously charged-off									811	930
Loans charged-off									(4,640)	(1,348)
Balance at end of year	18,098				14,765				18,098	14,765	16,095
Commercial | Commercial real estate
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Balance at beginning of year				24,319				19,532	24,319	19,532
Provision for loan losses									(849)	4,328
Recoveries on loans previously charged-off									1,192	3,327
Loans charged-off									(2,712)	(2,868)
Balance at end of year	21,950				24,319				21,950	24,319	19,532
Agricultural and agricultural real estate
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Balance at beginning of year				4,210				3,887	4,210	3,887
Provision for loan losses									2,946	527
Recoveries on loans previously charged-off									18	10
Loans charged-off									(2,916)	(214)
Balance at end of year	4,258				4,210				4,258	4,210	3,887
Residential real estate
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Balance at beginning of year				2,263				1,934	2,263	1,934
Provision for loan losses									403	646
Recoveries on loans previously charged-off									358	29
Loans charged-off									(800)	(346)
Balance at end of year	2,224				2,263				2,224	2,263	1,934
Consumer
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Balance at beginning of year				$ 8,767				$ 7,237	8,767	7,237
Provision for loan losses									5,901	7,105
Recoveries on loans previously charged-off									1,291	1,043
Loans charged-off									(6,803)	(6,618)
Balance at end of year	$ 9,156				$ 8,767				$ 9,156	$ 8,767	$ 7,237

Premises, Furniture and Equip92

Premises, Furniture and Equipment (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Property, Plant and Equipment [Line Items]
Total	$ 267,948	$ 256,453
Less accumulated depreciation	(95,624)	(92,839)
Premises, furniture and equipment, net	172,324	163,614
Depreciation expense	11,100	10,400	$ 8,900
Land and land improvements
Property, Plant and Equipment [Line Items]
Total	48,621	42,802
Buildings and building improvements
Property, Plant and Equipment [Line Items]
Total	155,209	146,628
Furniture and equipment
Property, Plant and Equipment [Line Items]
Total	$ 64,118	$ 67,023

Goodwill, Core Deposit Intang93

Goodwill, Core Deposit Intangibles and Other Intangible Assets (Goodwill) (Details) - USD ($)	Jul. 07, 2017	Feb. 28, 2017	Feb. 05, 2016	Sep. 30, 2017	Dec. 31, 2017	Dec. 31, 2016
Goodwill [Line Items]
Goodwill resulting from acquisition					$ 236,615,000	$ 127,699,000
Goodwill, impairment loss				$ 0
Citywide Banks of Colorado, Inc.
Goodwill [Line Items]
Goodwill resulting from acquisition	$ 95,154,000
Citywide Banks of Colorado, Inc. | Core Deposit Intangibles
Goodwill [Line Items]
Recognized intangibles	$ 16,000,000
Intangibles amortization period	10 years
Founders Bancorp
Goodwill [Line Items]
Goodwill resulting from acquisition		$ 13,800,000
Founders Bancorp | Core Deposit Intangibles
Goodwill [Line Items]
Recognized intangibles		$ 2,500,000
Intangibles amortization period		10 years
CIC Bancshares, Inc.
Goodwill [Line Items]
Goodwill resulting from acquisition			$ 29,848,000
CIC Bancshares, Inc. | Core Deposit Intangibles
Goodwill [Line Items]
Recognized intangibles			$ 6,400,000
Intangibles amortization period			10 years
CIC Bancshares, Inc. | Commercial Servicing Rights
Goodwill [Line Items]
Recognized intangibles			$ 190,000

Goodwill, Core Deposit Intang94

Goodwill, Core Deposit Intangibles and Other Intangible Assets (Carrying Amount of Intangible Assets) (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 112,043	$ 101,652
Accumulated Amortization	50,983	43,099
Net Carrying Amount	61,060	58,553
Core Deposit Intangibles
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	62,008	43,504
Accumulated Amortization	27,086	21,049
Net Carrying Amount	34,922	22,455
Customer Relationship Intangible
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	1,177	1,177
Accumulated Amortization	896	857
Net Carrying Amount	281	320
Mortgage Servicing Rights
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	42,139	50,467
Accumulated Amortization	18,891	18,379
Net Carrying Amount	23,248	32,088
Commercial Servicing Rights
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	6,719	6,504
Accumulated Amortization	4,110	2,814
Net Carrying Amount	$ 2,609	$ 3,690

Goodwill, Core Deposit Intang95

Goodwill, Core Deposit Intangibles and Other Intangible Assets (Estimated Future Amortization Expense for Amortizable Intangible Assets) (Details) $ in Thousands	Dec. 31, 2017USD ($)
Year ending December 31,
2,018	$ 13,248
2,019	11,489
2,020	9,812
2,021	8,152
2,022	6,216
Thereafter	12,143
Total	61,060
Core Deposit Intangibles
Year ending December 31,
2,018	6,712
2,019	5,915
2,020	5,191
2,021	4,425
2,022	3,391
Thereafter	9,288
Total	34,922
Customer Relationship Intangible
Year ending December 31,
2,018	39
2,019	38
2,020	37
2,021	35
2,022	34
Thereafter	98
Total	281
Mortgage Servicing Rights
Year ending December 31,
2,018	5,812
2,019	4,982
2,020	4,151
2,021	3,321
2,022	2,491
Thereafter	2,491
Total	23,248
Commercial Servicing Rights
Year ending December 31,
2,018	685
2,019	554
2,020	433
2,021	371
2,022	300
Thereafter	266
Total	$ 2,609

Goodwill, Core Deposit Intang96

Goodwill, Core Deposit Intangibles and Other Intangible Assets (Mortgage and Commercial Loans Servicing Narrative) (Details) - USD ($)	3 Months Ended	12 Months Ended
	Sep. 30, 2017	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Valuation servicing rights in tranches [Line Items]
Mortgage loans serviced for others		$ 3,560,000,000	$ 4,310,000,000
Custodial escrow balances maintained		17,300,000	21,400,000
Servicing rights, valuation allowance		0	0
Unpaid principal balance	$ 773,900,000
Mortgage servicing rights		6,900,000
Cash received from sale of mortgage servicing rights		6,300,000
Estimated loss on sale of portfolio		223,000
Mortgage servicing rights receivable		427,000
Servicing rights, net		25,857,000	35,778,000
Commercial Servicing Rights less than 20 Years
Valuation servicing rights in tranches [Line Items]
Fair value of mortgage servicing rights		$ 740,000	1,200,000
Servicing rights, term		20 years
Servicing rights, valuation allowance		$ 0	0
Commercial Servicing Rights more than 20 Years
Valuation servicing rights in tranches [Line Items]
Fair value of mortgage servicing rights		$ 2,481,000	2,927,000
Servicing rights, term		20 years
Servicing rights, valuation allowance		$ 12,000	33,000
Mortgage Servicing Rights
Valuation servicing rights in tranches [Line Items]
Fair value of mortgage servicing rights		37,081,000	45,210,000
Mortgage servicing rights		$ 6,940,000	$ 0
Prepayment rate (as a percent)		9.73%	9.63%
Discount rate (as a percent)		9.06%	9.26%
Fees collected for servicing of mortgage loans		$ 11,600,000	$ 12,100,000	$ 10,700,000
Mortgage Servicing Rights | Minimum
Valuation servicing rights in tranches [Line Items]
Capitalization rate (as a percent)		0.91%	0.88%
Mortgage Servicing Rights | Maximum
Valuation servicing rights in tranches [Line Items]
Capitalization rate (as a percent)		1.50%	1.50%
Mortgage Servicing Rights 15-year Tranche
Valuation servicing rights in tranches [Line Items]
Servicing rights, term		15 years
Mortgage Servicing Rights 30-year Tranche
Valuation servicing rights in tranches [Line Items]
Servicing rights, term		30 years
Commercial Servicing Rights
Valuation servicing rights in tranches [Line Items]
Fair value of mortgage servicing rights		$ 3,221,000	$ 4,127,000
Fees collected for servicing of mortgage loans		1,700,000	1,900,000
Servicing rights, net		$ 139,900,000	$ 164,600,000
Commercial Servicing Rights | Minimum
Valuation servicing rights in tranches [Line Items]
Prepayment rate (as a percent)		7.27%	6.96%
Discount rate (as a percent)		13.04%	12.44%
Capitalization rate (as a percent)		3.10%	3.10%
Commercial Servicing Rights | Maximum
Valuation servicing rights in tranches [Line Items]
Prepayment rate (as a percent)		8.88%	7.88%
Discount rate (as a percent)		15.49%	13.88%
Capitalization rate (as a percent)		4.45%	4.45%

Goodwill, Core Deposit Intang97

Goodwill, Core Deposit Intangibles and Other Intangible Assets (Changes in Capitalized Mortgage and Commercial Servicing Rights) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Servicing Asset at Fair Value, Amount [Roll Forward]
Sale of mortgage servicing rights	$ (6,900)
Mortgage Servicing Rights
Servicing Asset at Fair Value, Amount [Roll Forward]
Balance at beginning of period	32,088	$ 30,314
Originations	7,149	12,266
Amortization	(9,049)	(10,492)
Sale of mortgage servicing rights	(6,940)	0
Balance at end of period	23,248	32,088
Fair value of mortgage servicing rights	$ 37,081	$ 45,210
Servicing rights, net to servicing portfolio (as a percent)	0.65%	0.74%
Commercial Servicing Rights
Servicing Asset at Fair Value, Amount [Roll Forward]
Balance at beginning of period	$ 3,690	$ 4,611
Originations	209	628
Amortization	(1,311)	(1,706)
Purchased commercial servicing rights	0	190
Valuation allowance on commercial servicing rights	21	(33)
Balance at end of period	2,609	3,690
Fair value of mortgage servicing rights	$ 3,221	$ 4,127
Servicing rights, net to servicing portfolio (as a percent)	1.87%	2.24%

Goodwill, Core Deposit Intang98

Goodwill, Core Deposit Intangibles and Other Intangible Assets (Servicing Rights) (Details) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Servicing Asset at Amortized Cost [Line Items]
Impairment	$ 0	$ 0
Commercial Servicing Rights less than 20 Years
Servicing Asset at Amortized Cost [Line Items]
Book Value	537,000	1,008,000
Fair Value	740,000	1,200,000
Impairment	0	0
Commercial Servicing Rights more than 20 Years
Servicing Asset at Amortized Cost [Line Items]
Book Value	2,084,000	2,715,000
Fair Value	2,481,000	2,927,000
Impairment	12,000	33,000
Citywide Banks | Commercial Servicing Rights less than 20 Years
Servicing Asset at Amortized Cost [Line Items]
Book Value	8,000	19,000
Fair Value	11,000	23,000
Impairment	0	0
Citywide Banks | Commercial Servicing Rights more than 20 Years
Servicing Asset at Amortized Cost [Line Items]
Book Value	34,000	107,000
Fair Value	37,000	114,000
Impairment	0	0
Premier Valley Bank | Commercial Servicing Rights less than 20 Years
Servicing Asset at Amortized Cost [Line Items]
Book Value	83,000	156,000
Fair Value	110,000	180,000
Impairment	0	0
Premier Valley Bank | Commercial Servicing Rights more than 20 Years
Servicing Asset at Amortized Cost [Line Items]
Book Value	303,000	359,000
Fair Value	291,000	326,000
Impairment	12,000	33,000
Wisconsin Bank & Trust | Commercial Servicing Rights less than 20 Years
Servicing Asset at Amortized Cost [Line Items]
Book Value	446,000	833,000
Fair Value	619,000	997,000
Impairment	0	0
Wisconsin Bank & Trust | Commercial Servicing Rights more than 20 Years
Servicing Asset at Amortized Cost [Line Items]
Book Value	1,747,000	2,249,000
Fair Value	2,153,000	2,487,000
Impairment	$ 0	$ 0

Deposits (Scheduled Maturities

Deposits (Scheduled Maturities of Time Certificates of Deposit) (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Banking and Thrift [Abstract]
2,018	$ 607,669
2,019	154,548
2,020	69,357
2,021	38,179
2,022	31,950
Thereafter	21,750
Total	923,453	$ 857,286
Time deposits, $100,000 or more	402,700	369,900
Time deposits over $250,000	$ 212,400	$ 190,800

Deposits (Interest Expense on D

Deposits (Interest Expense on Deposits) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Banking and Thrift [Abstract]
Savings and money market accounts	$ 11,107	$ 8,000	$ 6,612
Time certificates of deposit in denominations of $100,000 or more	3,016	3,178	3,152
Other time deposits	4,156	4,761	5,766
Interest expense on deposits	$ 18,279	$ 15,939	$ 15,530

Short-term Borrowings (Short-te

Short-term Borrowings (Short-term Borrowings) (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Short-term Debt [Line Items]
Short-term borrowings	$ 324,691	$ 306,459
Securities sold under agreement to repurchase
Short-term Debt [Line Items]
Short-term borrowings	107,957	229,555
Federal funds purchased
Short-term Debt [Line Items]
Short-term borrowings	168,250	40,200
Advances from the FHLB
Short-term Debt [Line Items]
Short-term borrowings	40,000	30,367
Other short-term borrowings
Short-term Debt [Line Items]
Short-term borrowings	$ 8,484	$ 6,337

Short-term Borrowings (Narrativ

Short-term Borrowings (Narrative) (Details)	Jul. 20, 2016USD ($)	Dec. 31, 2017USD ($)credit_line	Dec. 31, 2016USD ($)credit_line	Dec. 15, 2015USD ($)
Short-term Debt [Line Items]
Number of credit lines | credit_line		1	1
Borrowing capacity			$ 20,000,000
Dubuque Bank and Trust Company
Short-term Debt [Line Items]
Collateralized short-term borrowing under Discount Window Program		$ 62,200,000	91,100,000
Morrill & Janes Bank and Trust Company
Short-term Debt [Line Items]
Collateralized short-term borrowing under Discount Window Program		$ 32,600,000	$ 43,700,000
Retail Repurchase Agreements
Short-term Debt [Line Items]
Debt term		12 months	12 months
Revolving Credit Facility
Short-term Debt [Line Items]
Borrowing capacity		$ 25,000,000
Line of credit outstanding		0	$ 0
Nonrevolving Credit Facility
Short-term Debt [Line Items]
Borrowing capacity	$ 75,000,000	75,000,000		$ 50,000,000
Line of credit outstanding		0
Basis spread on variable rate (as a percent)	2.75%
Borrowing capacity		$ 39,300,000

Short-term Borrowings (Balances

Short-term Borrowings (Balances and Rates) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Debt Disclosure [Abstract]
Maximum month-end balance	$ 324,691	$ 399,490	$ 477,918
Average month-end balance	$ 182,846	$ 287,857	$ 330,134
Weighted average interest rate for the year	0.36%	0.40%	0.25%
Weighted average interest rate at year-end	1.11%	0.29%	0.15%

Other Borrowings (Schedule of O

Other Borrowings (Schedule of Other Borrowings) (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Debt Instrument [Line Items]
Long-term debt	$ 285,011	$ 288,534
Advances from the FHLB
Debt Instrument [Line Items]
Long-term debt	$ 6,702	$ 6,975
Weighted average interest rate	3.22%	3.25%
Wholesale repurchase agreements
Debt Instrument [Line Items]
Long-term debt	$ 30,000	$ 30,000
Weighted average interest rate	3.76%	3.76%
Trust preferred securities
Debt Instrument [Line Items]
Long-term debt	$ 121,886	$ 115,232
Senior notes
Debt Instrument [Line Items]
Long-term debt	11,000	16,000
Note payable to unaffiliated bank
Debt Instrument [Line Items]
Long-term debt	33,667	37,667
Contracts payable for purchase of real estate and other assets
Debt Instrument [Line Items]
Long-term debt	1,881	2,339
Subordinated notes
Debt Instrument [Line Items]
Long-term debt	74,000	73,857
Other borrowings
Debt Instrument [Line Items]
Long-term debt	$ 5,875	$ 6,464

Other Borrowings (Narrative) (D

Other Borrowings (Narrative) (Details)	Jul. 20, 2016USD ($)	May 10, 2016USD ($)	Sep. 30, 2017USD ($)shares	Mar. 31, 2017USD ($)shares	Sep. 30, 2016USD ($)shares	Dec. 31, 2017USD ($)subsidiary	Dec. 31, 2016USD ($)	Feb. 05, 2016USD ($)	Dec. 15, 2015USD ($)	Dec. 17, 2014USD ($)
Debt Instrument [Line Items]
FHLB stock, required collateral						$ 11,300,000	$ 9,900,000
Additional collateral, aggregate fair value						2,910,000,000	2,740,000,000
FHLB borrowing capacity						1,330,000,000
Long-term debt						$ 285,011,000	288,534,000
Number of wholly-owned trust subsidiaries that issue preferred securities | subsidiary						11
Senior notes						$ 11,000,000	16,000,000
Borrowing capacity							20,000,000
CIC Bancshares, Inc.
Debt Instrument [Line Items]
Deferred issuance costs						28,000	44,000
CIC Bancshares, Inc. | Common Stock
Debt Instrument [Line Items]
Number of shares issued upon conversion (in shares) | shares			14,353	6,128	52,913
Nonrevolving Credit Facility
Debt Instrument [Line Items]
Borrowing capacity	$ 75,000,000					75,000,000			$ 50,000,000
Increase in available capacity	$ 25,000,000
Available borrowings						39,300,000
Line of credit outstanding						0
Interest Rate Swap
Debt Instrument [Line Items]
Amount of hedged debt		$ 40,000,000
Interest Rate Swap | Cash Flow Hedging
Debt Instrument [Line Items]
Amount of hedged debt						85,000,000
Interest Rate Swap | Designated as Hedging Instrument | Cash Flow Hedging | Nonrevolving Credit Facility
Debt Instrument [Line Items]
Amount of hedged debt		$ 40,000,000				33,667,000	37,667,000
Fixed interest rate on derivative (as a percent)		2.50%
Term of derivative instrument		5 years
Tier 1
Debt Instrument [Line Items]
Subordinated notes qualified as Tier 2 capital						74,000,000
Wholesale repurchase agreements
Debt Instrument [Line Items]
Long-term debt						30,000,000	30,000,000
Trust preferred securities
Debt Instrument [Line Items]
Long-term debt						121,886,000	115,232,000
Deferred issuance costs						127,000
Trust preferred securities | Tier 1
Debt Instrument [Line Items]
Long-term debt						121,900,000	115,200,000
Senior notes
Debt Instrument [Line Items]
Long-term debt						11,000,000	16,000,000
Senior notes | February 1, 2018
Debt Instrument [Line Items]
Debt instrument, maturity amount						6,000,000
Senior notes | February 1, 2019
Debt Instrument [Line Items]
Debt instrument, maturity amount						5,000,000
Contracts payable for purchase of real estate and other assets
Debt Instrument [Line Items]
Long-term debt						1,881,000	2,339,000
Stated interest rate (as a percent)										5.75%
Debt issued										$ 75,000,000
Debt discount										$ 1,100,000
Contracts payable for purchase of real estate and other assets | CIC Bancshares, Inc.
Debt Instrument [Line Items]
Stated interest rate (as a percent)								8.00%
Debt discount								$ 168,000
Debt assumed								$ 6,000,000
Contracts payable for purchase of real estate and other assets | Other Assets
Debt Instrument [Line Items]
Unamortized debt issuance expense						265,000	$ 303,000
Subordinated convertible notes | CIC Bancshares, Inc.
Debt Instrument [Line Items]
Stated interest rate (as a percent)								6.50%
Debt discount								$ 16,000
Debt assumed								$ 2,000,000
Amount of debt			$ 391,000	$ 167,000	$ 1,400,000
Heartland Financial Statutory Trust IV | Interest Rate Swap | Cash Flow Hedging
Debt Instrument [Line Items]
Amount of hedged debt						25,000,000
Heartland Financial Statutory Trust IV | Trust preferred securities
Debt Instrument [Line Items]
Long-term debt						10,000,000
Repurchased debt amount						$ 15,000,000

Other Borrowings (Trust Preferr

Other Borrowings (Trust Preferred Offerings) (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2017USD ($)
Trust preferred securities
Debt Instrument [Line Items]
Trust preferred offerings outstanding	$ 122,013
Interest Rate Swap
Debt Instrument [Line Items]
Fixed interest rate on derivative (as a percent)	5.25%
Heartland Financial Statutory Trust IV | Trust preferred securities
Debt Instrument [Line Items]
Trust preferred offerings outstanding	$ 10,258
Interest rate (as a percent)	4.35%
Basis spread on variable rate (as a percent)	2.75%
Description of variable rate basis	LIBOR
Heartland Financial Statutory Trust IV | Interest Rate Swap
Debt Instrument [Line Items]
Fixed interest rate on derivative (as a percent)	5.01%
Heartland Financial Statutory Trust V | Trust preferred securities
Debt Instrument [Line Items]
Trust preferred offerings outstanding	$ 20,619
Interest rate (as a percent)	2.69%
Basis spread on variable rate (as a percent)	1.33%
Description of variable rate basis	LIBOR
Heartland Financial Statutory Trust V | Interest Rate Swap
Debt Instrument [Line Items]
Fixed interest rate on derivative (as a percent)	4.69%
Heartland Financial Statutory Trust VI | Trust preferred securities
Debt Instrument [Line Items]
Trust preferred offerings outstanding	$ 20,619
Interest rate (as a percent)	3.07%
Basis spread on variable rate (as a percent)	1.48%
Description of variable rate basis	LIBOR
Heartland Financial Statutory Trust VI | Interest Rate Swap
Debt Instrument [Line Items]
Fixed interest rate on derivative (as a percent)	3.87%
Heartland Financial Statutory Trust VII | Trust preferred securities
Debt Instrument [Line Items]
Trust preferred offerings outstanding	$ 20,619
Interest rate (as a percent)	2.96%
Basis spread on variable rate (as a percent)	1.48%
Description of variable rate basis	LIBOR
Heartland Financial Statutory Trust VII | Interest Rate Swap
Debt Instrument [Line Items]
Fixed interest rate on derivative (as a percent)	3.83%
Morrill Statutory Trust I | Trust preferred securities
Debt Instrument [Line Items]
Trust preferred offerings outstanding	$ 8,900
Interest rate (as a percent)	4.92%
Basis spread on variable rate (as a percent)	3.25%
Description of variable rate basis	LIBOR
Morrill Statutory Trust I | Interest Rate Swap
Debt Instrument [Line Items]
Fixed interest rate on derivative (as a percent)	4.92%
Morrill Statutory Trust II | Trust preferred securities
Debt Instrument [Line Items]
Trust preferred offerings outstanding	$ 8,531
Interest rate (as a percent)	4.45%
Basis spread on variable rate (as a percent)	2.85%
Description of variable rate basis	LIBOR
Morrill Statutory Trust II | Interest Rate Swap
Debt Instrument [Line Items]
Fixed interest rate on derivative (as a percent)	4.51%
Sheboygan Statutory Trust I | Trust preferred securities
Debt Instrument [Line Items]
Trust preferred offerings outstanding	$ 6,353
Interest rate (as a percent)	4.55%
Basis spread on variable rate (as a percent)	2.95%
Description of variable rate basis	LIBOR
CBNM Capital Trust I | Trust preferred securities
Debt Instrument [Line Items]
Trust preferred offerings outstanding	$ 4,309
Interest rate (as a percent)	4.84%
Basis spread on variable rate (as a percent)	3.25%
Description of variable rate basis	LIBOR
Citywide Capital Trust III | Trust preferred securities
Debt Instrument [Line Items]
Trust preferred offerings outstanding	$ 6,327
Interest rate (as a percent)	4.18%
Basis spread on variable rate (as a percent)	2.80%
Description of variable rate basis	LIBOR
Citywide Capital Trust IV | Trust preferred securities
Debt Instrument [Line Items]
Trust preferred offerings outstanding	$ 4,180
Interest rate (as a percent)	3.65%
Basis spread on variable rate (as a percent)	2.20%
Description of variable rate basis	LIBOR
Citywide Capital Trust V | Trust preferred securities
Debt Instrument [Line Items]
Trust preferred offerings outstanding	$ 11,298
Interest rate (as a percent)	3.13%
Basis spread on variable rate (as a percent)	1.54%
Description of variable rate basis	LIBOR
Citywide Capital Trust V | Interest Rate Swap
Debt Instrument [Line Items]
Fixed interest rate on derivative (as a percent)	3.80%

Other Borrowings (Schedule of M

Other Borrowings (Schedule of Maturities) (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Debt Disclosure [Abstract]
2,018	$ 43,217
2,019	15,383
2,020	5,652
2,021	21,622
2,022	1,657
Thereafter	197,480
Total	$ 285,011	$ 288,534

Derivative Financial Instrum108

Derivative Financial Instruments (Cash Collateral on Derivative Financial Instruments) (Details) - USD ($)	Dec. 31, 2017	Dec. 31, 2016
Derivative [Line Items]
Cash pledged as collateral	$ 1,200,000	$ 2,200,000
Counterparties
Derivative [Line Items]
Cash pledged as collateral	$ 0

Derivative Financial Instrum109

Derivative Financial Instruments (Estimated Cash Payments and Reclassification to Interest Expense) (Details) $ in Millions	12 Months Ended
	Dec. 31, 2017USD ($)
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Change in net unrealized losses on cash flow hedges	$ 1.3
Estimated amount to be reclassified from accumulated other comprehensive income to interest expense within the next twelve months	$ 1.1

Derivative Financial Instrum110

Derivative Financial Instruments (Executed Interest Rate Swap) (Details) $ in Thousands	Dec. 31, 2017USD ($)transaction	Dec. 31, 2016USD ($)	May 10, 2016USD ($)	Mar. 31, 2015USD ($)transaction
Derivative [Line Items]
Long-term debt	$ 285,011	$ 288,534
Forward-starting Interest Rate Swap | Cash Flow Hedging
Derivative [Line Items]
Number of interest rate swap transactions | transaction	5
Interest Rate Swap
Derivative [Line Items]
Derivative, notional amount			$ 40,000
Interest Rate Swap | Heartland Financial Statutory Trust VI
Derivative [Line Items]
Number of interest rate swap transactions | transaction				2
Derivative, notional amount				$ 20,000
Interest Rate Swap | Cash Flow Hedging
Derivative [Line Items]
Number of interest rate swap transactions | transaction	5
Derivative, notional amount	$ 85,000
Interest Rate Swap | Cash Flow Hedging | Heartland Financial Statutory Trust IV, V and VII
Derivative [Line Items]
Derivative, notional amount	65,000
Interest Rate Swap | Cash Flow Hedging | Morrill Statutory Trust I and II
Derivative [Line Items]
Derivative, notional amount	20,000
Interest Rate Swap | Cash Flow Hedging | Heartland Financial Statutory Trust IV
Derivative [Line Items]
Derivative, notional amount	25,000
Trust preferred securities
Derivative [Line Items]
Long-term debt	121,886	$ 115,232
Trust preferred securities | Heartland Financial Statutory Trust IV
Derivative [Line Items]
Repurchased debt amount	15,000
Long-term debt	10,000
Trust preferred securities | Citywide Statutory Trust V
Derivative [Line Items]
Long-term debt	$ 15,000

Derivative Financial Instrum111

Derivative Financial Instruments (Balance Sheet Category and Fair Values of Derivative Instruments (Cash Flow Hedges)) (Details) - USD ($)	Dec. 31, 2017	Dec. 31, 2016	Feb. 05, 2016
Other Liabilities
Derivatives, Fair Value [Line Items]
Notional Amount			$ 2,000,000
Other Liabilities | Interest Rate Swap due March 17, 2021
Derivatives, Fair Value [Line Items]
Notional Amount	$ 25,000,000	$ 25,000,000
Fair Value	$ (106,000)	$ (447,000)
Receive Rate	1.60%	0.993%
Weighted Average Pay Rate	2.255%	2.255%
Other Liabilities | Interest Rate Swap due March 1, 2017
Derivatives, Fair Value [Line Items]
Notional Amount		$ 20,000,000
Fair Value		$ (114,000)
Receive Rate		0.931%
Weighted Average Pay Rate		3.22%
Other Liabilities | Interest Rate Swap due January 7, 2020
Derivatives, Fair Value [Line Items]
Notional Amount	$ 20,000,000	$ 20,000,000
Fair Value	$ (621,000)	$ (1,145,000)
Receive Rate	1.35%	0.868%
Weighted Average Pay Rate	3.355%	3.355%
Other Liabilities | Interest Rate Swap due March 26, 2019
Derivatives, Fair Value [Line Items]
Notional Amount		$ 10,000,000
Fair Value		$ (42,000)
Receive Rate		0.997%
Weighted Average Pay Rate		1.674%
Other Liabilities | Interest Rate Swap due March 18, 2019
Derivatives, Fair Value [Line Items]
Notional Amount		$ 10,000,000
Fair Value		$ (41,000)
Receive Rate		0.993%
Weighted Average Pay Rate		1.658%
Other Liabilities | Interest Rate Swap due June 15, 2024
Derivatives, Fair Value [Line Items]
Notional Amount	$ 20,000,000	$ 20,000,000
Fair Value	$ (177,000)	$ (214,000)
Receive Rate	1.588%	0.00%
Weighted Average Pay Rate	2.39%	2.39%
Other Liabilities | Interest Rate Swap due March 1, 2024
Derivatives, Fair Value [Line Items]
Notional Amount	$ 20,000,000	$ 20,000,000
Fair Value	$ (149,000)	$ (262,000)
Receive Rate	1.481%	0.00%
Weighted Average Pay Rate	2.352%	2.352%
Other Assets
Derivatives, Fair Value [Line Items]
Notional Amount	$ 14,045,000	$ 14,549,000
Other Assets | Interest Rate Swap due March 26, 2019
Derivatives, Fair Value [Line Items]
Notional Amount	10,000,000
Fair Value	$ 30,000
Receive Rate	1.329%
Weighted Average Pay Rate	1.674%
Other Assets | Interest Rate Swap due March 18, 2019
Derivatives, Fair Value [Line Items]
Notional Amount	$ 10,000,000
Fair Value	$ 29,000
Receive Rate	1.60%
Weighted Average Pay Rate	1.658%
Other Assets | Interest Rate Swap due May 10, 2021
Derivatives, Fair Value [Line Items]
Notional Amount	$ 33,667,000	37,667,000
Fair Value	$ 759,000	$ 530,000
Receive Rate	3.932%	3.164%
Weighted Average Pay Rate	3.674%	3.674%

Derivative Financial Instrum112

Derivative Financial Instruments (Gains (Losses) Recognized on Derivatives (Cash Flow Hedges)) (Details) - Interest Rate Swap - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Interest Expense
Trading Activity, Gains and Losses, Net [Line Items]
Effective Portion, Recognized in OCI, Amount of Gain (Loss)	$ 1,500	$ 1,705
Effective Portion, Reclassified from AOCI into Income, Amount of Gain (Loss)	(1,290)	(1,914)
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 Instrum113

Derivative Financial Instruments (Fair Value Hedge) (Details) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Feb. 05, 2016
Derivative [Line Items]
Cash pledged as collateral	$ 1,200,000	$ 2,200,000
Other Liabilities
Derivative [Line Items]
Notional amount			$ 2,000,000
Fair Value Hedging | Other Liabilities
Derivative [Line Items]
Notional amount	35,635,000	40,807,000
Fair Value	(999,000)	(1,626,000)
Fair Value Hedging | Interest income
Derivative [Line Items]
Amount of Gain (Loss)	627,000	(1,005,000)
Fair Value Hedging | Interest Rate Swap
Derivative [Line Items]
Cash pledged as collateral	$ 3,900,000	$ 5,000,000

Derivative Financial Instrum114

Derivative Financial Instruments (Balance Sheet Category and Fair Values of Embedded Derivatives) (Details)	Dec. 31, 2017USD ($)shares	Dec. 31, 2016USD ($)shares	Feb. 05, 2016USD ($)shares	Dec. 31, 2017USD ($)	Dec. 31, 2016USD ($)
Derivative [Line Items]
Number of shares to be issued upon conversion (in shares) | shares	20,481	20,481	73,394
Other noninterest income
Derivative [Line Items]
Amount of gain (loss)				$ 366,000	$ (470,000)
Other noninterest income | Embedded conversion option
Derivative [Line Items]
Amount of gain (loss)				422,000	(100,000)
Other assets
Derivative [Line Items]
Notional Amount	$ 14,045,000	$ 14,549,000		14,045,000	14,549,000
Fair Value	738,000	1,104,000		738,000	1,104,000
Other liabilities
Derivative [Line Items]
Notional Amount			$ 2,000,000
Other liabilities | Embedded conversion option
Derivative [Line Items]
Notional Amount	0	558,000		0	558,000
Fair Value	$ 0	$ (422,000)		$ 0	$ (422,000)

Derivative Financial Instrum115

Derivative Financial Instruments (Loan Swaps) (Details) - USD ($)	Dec. 31, 2017	Dec. 31, 2016	Feb. 05, 2016
Derivative [Line Items]
Cash pledged as collateral	$ 1,200,000	$ 2,200,000
Other Assets
Derivative [Line Items]
Notional Amount	14,045,000	14,549,000
Other Liabilities
Derivative [Line Items]
Notional Amount			$ 2,000,000
Back-to-back Swaps
Derivative [Line Items]
Cash pledged as collateral	1,600,000	1,800,000
Back-to-back Swaps | Other Assets
Derivative [Line Items]
Notional Amount	126,766,000	69,594,000
Fair Value	2,377,000	1,588,000
Back-to-back Swaps | Other Liabilities
Derivative [Line Items]
Notional Amount	126,766,000	69,594,000
Fair Value	(2,377,000)	(1,588,000)
Counterparties
Derivative [Line Items]
Cash pledged as collateral	0
Counterparties | Back-to-back Swaps
Derivative [Line Items]
Cash pledged as collateral	$ 190,000	$ 768,000
Receive Rate | Back-to-back Swaps | Other Assets
Derivative [Line Items]
Weighted Average Rate	4.70%	4.66%
Receive Rate | Back-to-back Swaps | Other Liabilities
Derivative [Line Items]
Weighted Average Rate	4.03%	3.47%
Pay Rate | Back-to-back Swaps | Other Assets
Derivative [Line Items]
Weighted Average Rate	4.03%	3.47%
Pay Rate | Back-to-back Swaps | Other Liabilities
Derivative [Line Items]
Weighted Average Rate	4.70%	4.66%

Derivative Financial Instrum116

Derivative Financial Instruments (Balance Sheet Category and Fair Values of Derivative Instruments (Not Designated as Hedging Instruments)) (Details) - USD ($)	Dec. 31, 2017	Dec. 31, 2016
Derivatives, Fair Value [Line Items]
Cash pledged as collateral	$ 1,200,000	$ 2,200,000
Counterparties
Derivatives, Fair Value [Line Items]
Cash pledged as collateral	0
Not Designated as Hedging Instrument
Derivatives, Fair Value [Line Items]
Cash pledged as collateral	20,000	0
Not Designated as Hedging Instrument | Other Assets | Interest rate lock commitments (mortgage)
Assets:
Notional Amount	53,588,000	80,465,000
Fair Value	1,738,000	2,790,000
Not Designated as Hedging Instrument | Other Assets | Forward commitments
Assets:
Notional Amount	37,286,000	142,750,000
Fair Value	80,000	2,546,000
Not Designated as Hedging Instrument | Other Liabilities | Forward commitments
Liabilities:
Notional Amount	118,632,000	59,276,000
Fair Value	(232,000)	(266,000)
Not Designated as Hedging Instrument | Other Liabilities | Undesignated interest rate swaps
Liabilities:
Notional Amount	14,045,000	15,564,000
Fair Value	(738,000)	(1,126,000)
Not Designated as Hedging Instrument | Counterparties
Derivatives, Fair Value [Line Items]
Cash pledged as collateral	$ 29,000	$ 2,900,000

Derivative Financial Instrum117

Derivative Financial Instruments (Derivative Instruments Gains and Losses Recognized (Not Designated as Hedging Instruments)) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Net gains on sale of loans held for sale | Interest rate lock commitments (mortgage)
Trading Activity, Gains and Losses, Net [Line Items]
Year-to-Date Gain(Loss) Recognized	$ (1,479)	$ (1,564)
Net gains on sale of loans held for sale | Forward commitments
Trading Activity, Gains and Losses, Net [Line Items]
Year-to-Date Gain(Loss) Recognized	(2,466)	2,023
Net gains on sale of loans held for sale | Forward commitments
Trading Activity, Gains and Losses, Net [Line Items]
Year-to-Date Gain(Loss) Recognized	34	49
Other noninterest income | Undesignated interest rate swaps
Trading Activity, Gains and Losses, Net [Line Items]
Year-to-Date Gain(Loss) Recognized	$ 388	$ 2,551

Income Taxes (Components of Inc

Income Taxes (Components of Income Tax Expense) (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Current:
Federal									$ 25,532	$ 23,724	$ 13,697
State									5,025	5,670	5,080
Total current									30,557	29,394	18,777
Deferred:
Federal									12,370	5,497	1,118
State									893	1,665	1,003
Total deferred									13,263	7,162	2,121
Total income tax expense	$ 21,506	$ 8,725	$ 8,059	$ 5,530	$ 8,360	$ 8,260	$ 10,036	$ 9,900	$ 43,820	$ 36,556	$ 20,898

Income Taxes (Narrative) (Detai

Income Taxes (Narrative) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Operating Loss Carryforwards [Line Items]
Tax reform, provisional income tax expense	$ 10,400
Exercise of stock options and vesting of stock awards, amount	1,200	$ 374	$ 676
Tax reform, change in tax rate, provisional income tax expense	4,500
Annual limitation on deferred tax asset	5,800
Deferred tax assets, state operating loss carryforwards	8,200	5,700
Valuation allowance	10,493	9,870
Tax credits	2,390	1,375	5,975
Investment in low-income housing	7,800	8,800	10,400
Unrecognized tax benefits	481	374	715
Unrecognized tax benefits, accrued interest and penalties	64	48
Capital Loss Carryforward
Operating Loss Carryforwards [Line Items]
Valuation allowance	3,900	5,400
State and Local Jurisdiction
Operating Loss Carryforwards [Line Items]
Net operating loss carryforwards	113,300	105,600
State and Local Jurisdiction | Operating Loss Carryforwards
Operating Loss Carryforwards [Line Items]
Valuation allowance	6,600	4,500
FSI
Operating Loss Carryforwards [Line Items]
Deferred tax assets, federal operating loss carryforwards	8,400	11,900
FSI | Federal
Operating Loss Carryforwards [Line Items]
Net operating loss carryforwards	36,000	34,100
Solar Energy Tax Credit
Operating Loss Carryforwards [Line Items]
Tax credits	449	160
Historic Rehabilitation Credit
Operating Loss Carryforwards [Line Items]
Tax credits	713		5,400
Low-income Housing
Operating Loss Carryforwards [Line Items]
Tax credits	1,200	$ 1,200	$ 581
Tax credits, expected utilization, 2018	1,200
Tax credits, expected utilization, 2019	1,100
Tax credits, expected utilization, 2020	779
Tax credits, expected utilization, 2021	538
Tax credits, expected utilization, 2022	538
Tax credits, expected utilization, 2023	538
Tax credits, expected utilization, 2024	322
Tax credits, expected utilization, 2025	86
Tax credits, expected utilization, 2026	$ 34

Income Taxes (Deferred Tax Asse

Income Taxes (Deferred Tax Assets and Liabilities) (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Deferred tax assets:
Tax effect of net unrealized loss on securities available for sale reflected in stockholders’ equity	$ 8,320	$ 19,468
Tax effect of net unrealized loss on derivatives reflected in stockholders’ equity	60	484
Allowance for loan losses	14,221	20,506
Deferred compensation	4,240	9,146
Organization and acquisitions costs	369	649
Net operating loss carryforwards	16,580	17,676
Non-accrual loan interest	710	752
OREO write-downs	1,835	1,756
Rehab tax credit projects	4,303	5,620
Mortgage repurchase obligation	68	333
Self-funded health plan	0	632
Other	1,974	1,463
Gross deferred tax assets	52,680	78,485
Valuation allowance	(10,493)	(9,870)
Gross deferred tax assets	42,187	68,615
Deferred tax liabilities:
Securities	(478)	(452)
Premises, furniture and equipment	(5,798)	(9,284)
Tax bad debt reserves	(428)	(13)
Purchase accounting	(4,417)	(3,496)
Prepaid expenses	(526)	(881)
Mortgage servicing rights	(7,045)	(13,956)
Deferred loan fees	(2,651)	(3,804)
Other	(255)	(379)
Gross deferred tax liabilities	(21,598)	(32,265)
Net deferred tax asset	$ 20,589	$ 36,350

Income Taxes (Effective Income

Income Taxes (Effective Income Tax Rate Reconciliation) (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Tax Disclosure [Abstract]
Federal corporate tax rate										35.00%	35.00%
Computed expected tax on net income									$ 41,682	$ 40,917	$ 28,329
Increase (decrease) resulting from:
Nontaxable interest income									(9,282)	(7,960)	(6,293)
State income taxes, net of federal tax benefit									3,846	4,768	3,954
Tax credits									(2,390)	(1,375)	(5,975)
Valuation allowance									405	368	1,525
Excess tax benefit on stock compensation									(1,130)	0	0
Deferred tax adjustment due to Tax Cuts and Jobs Act enactment									10,396	0	0
Other									293	(162)	(642)
Total income tax expense	$ 21,506	$ 8,725	$ 8,059	$ 5,530	$ 8,360	$ 8,260	$ 10,036	$ 9,900	$ 43,820	$ 36,556	$ 20,898
Effective tax rates									36.80%	31.30%	25.80%

Income Taxes (Unrecognized Tax

Income Taxes (Unrecognized Tax Benefits Roll Forward) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Reconciliation of Unrecognized Tax Benefits [Roll Forward]
Balance at beginning of period	$ 374	$ 715
Additions for tax positions related to the current year	86	63
Additions for tax positions related to prior years	106	21
Reductions for tax positions related to prior years	(85)	(425)
Balance at end of period	$ 481	$ 374

Employee Benefit Plans (Details

Employee Benefit Plans (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Cost recognized	$ 4.1	$ 3.9	$ 3.5
Employer matching contribution, percent	3.00%	3.00%	3.00%
Contributions by employer	$ 3.3	$ 2.9	$ 2.7

Commitments and Contingent L124

Commitments and Contingent Liabilities (Operating Leases) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Operating Leases, Future Minimum Payments Due, Fiscal Year Maturity [Abstract]
2,018	$ 5,774
2,019	5,626
2,020	5,411
2,021	5,034
2,022	4,175
Thereafter	22,817
Total	48,837
Rent expense	8,000	$ 7,400	$ 6,000
Lease revenue	$ 1,100	$ 986	$ 640

Commitments and Contingent L125

Commitments and Contingent Liabilities (Commitments to Extend Credit) (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2017USD ($)request	Dec. 31, 2016USD ($)request
Long-term Credit Commitments [Line Items]
Residential mortgage loans, repurchase obligation amount	$ 238	$ 850
Number of repurchase requests | request	0	0
Reserve for Off-balance Sheet Activities
Long-term Credit Commitments [Line Items]
Reserve for unfunded commitments	$ 153	$ 140
Commitments to Extend Credit
Long-term Credit Commitments [Line Items]
Commitments to extend credit, amount	1,960,000	1,570,000
Standby Letters of Credit
Long-term Credit Commitments [Line Items]
Commitments to extend credit, amount	$ 55,500	$ 46,100

Stock-based Compensation (Narra

Stock-based Compensation (Narrative) (Details) - USD ($)	Jan. 02, 2018	May 31, 2016	Mar. 31, 2017	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Excess tax benefit related to share-based payment awards					$ 1,200,000
Adjustment to additional paid in capital, income tax effect from share-based compensation, net						$ 374,000
Number of options granted (in shares)					0	0	0
Typical options expiration period after date of grant					10 years
Vested options, weighted average remaining contractual life					25 days
Intrinsic value for vested options					$ 228,000
Intrinsic value for the total of all options exercised					561,000
Fair value of shares under vested stock options and awards					0
Cash received from options exercised					361,000	$ 2,500,000
Director
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation costs					$ 741,000	$ 652,000	$ 665,000
Number of shares of stock awarded for services performed					17,106	24,153	22,648
Period One
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation, award vesting periods					3 years
Period Two
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation, award vesting periods					4 years
Period Three
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation, award vesting periods					5 years
Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation, award service periods					5 years
Share-based compensation costs					$ 0	$ 0	$ 0
RSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation costs					$ 3,200,000	$ 2,600,000	$ 2,600,000
Equity instruments other than options, granted (in shares)			55,665	72,644
Number of shares of stock awarded for services performed					109,373	143,721	139,943
Total fair value of shares vested during period					$ 6,400,000
Performance-based RSUs | Period One
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation, award vesting periods					1 year
Equity instruments other than options, granted (in shares)			27,570	35,516
Performance-based RSUs | Period Two
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation, award vesting periods					3 years
Equity instruments other than options, granted (in shares)			9,032	11,408
Long-Term Incentive Plan 2012
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares available for issuance (in shares)					503,347
Long-Term Incentive Plan 2012 | RSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based unrecognized compensation costs					$ 3,200,000
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%
ESPP
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares available for issuance (in shares)					467,755
Share-based compensation costs					$ 153,000	$ 183,000	$ 58,000
Maximum number of shares issuable (in shares)		500,000
Stocks purchased under the plan (in shares)						32,245	28,788
ESPP | Fair Market Value at Investment Date
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Purchase price of common stock, percent		95.00%
2016 RSUs | RSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation, award vesting periods					3 years
2016 RSUs | Long-Term Incentive Plan 2012 | Performance-based RSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation, vesting period after change in control					2 years
2017 RSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation, period before change in control					6 months
2017 RSUs | RSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation, award vesting periods					3 years
2017 RSUs | 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%
Share-based compensation, vesting period after change in control					24 months
Subsequent Event | ESPP
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stocks purchased under the plan (in shares)	22,903

Stock-based Compensation (Summa

Stock-based Compensation (Summary of Stock Options Activity) (Details) - $ / shares	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Shares
Outstanding at beginning of period (in shares)	26,400	125,950	215,851
Granted (in shares)	0	0	0
Exercised (in shares)	(19,400)	(97,800)	(86,651)
Forfeited (in shares)	(500)	(1,750)	(3,250)
Outstanding at end of period (in shares)	6,500	26,400	125,950
Options exercisable at end of period (in shares)	6,500	26,400	125,950
Weighted-Average Exercise Price
Outstanding at beginning of period (in dollars per share)	$ 18.60	$ 24.08	$ 23.85
Granted (in dollars per share)	0	0	0
Exercised (in dollars per share)	18.60	25.59	23.49
Forfeited (in dollars per share)	18.60	21.10	23.51
Outstanding at end of period (in dollars per share)	18.60	18.60	24.08
Options exercisable at end of period (in dollars per share)	$ 18.60	$ 18.60	$ 24.08

Stock-based Compensation (Su128

Stock-based Compensation (Summary of RSUs Activity) (Details) - RSUs - $ / shares	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Shares
Outstanding at beginning of period (in shares)	346,817	353,195	396,555
Granted (in shares)	109,373	143,721	139,943
Vested (in shares)	(137,394)	(126,614)	(152,981)
Forfeited (in shares)	(17,218)	(23,485)	(30,322)
Outstanding at end of period (in shares)	301,578	346,817	353,195
Weighted-Average Grant Date Fair Value
Outstanding at beginning of period (in dollars per share)	$ 27.61	$ 25.53	$ 21.48
Granted (in dollars per share)	47.22	29.75	28.90
Vested (in dollars per share)	26.66	23.83	18.54
Forfeited (in dollars per share)	34.02	29.80	23.38
Outstanding at end of period (in dollars per share)	$ 34.74	$ 27.61	$ 25.53

Stockholder Rights Plan (Detail

Stockholder Rights Plan (Details)	Jan. 17, 2012votes$ / shares	Dec. 31, 2017$ / sharesshares	Dec. 31, 2016$ / sharesshares	Dec. 31, 2002$ / sharesshares
Temporary Equity [Line Items]
Original Rights Agreement, extended term	10 years
Ratio of preferred stock that can be purchased per right	0.001
Preferred stock, dividend rate (in dollars per share)	$ 1
Dividends, preferred stock, common share equivalents per share	1,000
Liquidation value per share (in dollars per share)	$ 1,000
Preferred stock, liquidation preference per share of common stock	1,000
Preferred stock, number of voting rights | votes	1,000
Distribution date	10 days
Common stock shares, market value as a percentage of purchase price	2
Minimum
Temporary Equity [Line Items]
Beneficial ownership, percentage	15.00%
Series A Preferred Stock
Temporary Equity [Line Items]
Preferred stock, par value (in dollars per share)	$ 1	$ 1	$ 1	$ 1
Preferred stock, redemption price (in dollars per share)	$ 70,000
Preferred stock, shares authorized | shares		16,000	16,000	16,000
Preferred stock, shares issued | shares		0	0
Preferred stock, shares outstanding | shares		0	0

Capital Issuance and Redempt130

Capital Issuance and Redemption (Details) $ / shares in Units, $ in Millions	Nov. 08, 2016shares	Nov. 08, 2016USD ($)	Feb. 05, 2016$ / sharesshares	Mar. 31, 2017shares	Sep. 30, 2016shares	Dec. 31, 2017shares	Dec. 31, 2016shares	Nov. 02, 2016$ / shares	Jan. 17, 2012$ / shares
Class of Stock [Line Items]
Liquidation value per share (in dollars per share) | $ / shares									$ 1,000
Series D Preferred Stock
Class of Stock [Line Items]
Number of shares issued in connection with the acquisition			3,000
Preferred stock, dividend rate			7.00%
Liquidation value per share (in dollars per share) | $ / shares			$ 1,000
Preferred stock, redemption price (in dollars per share) | $ / shares			$ 1,000
Preferred stock, shares outstanding						745	1,078
Number of shares currently deliverable upon conversion			39.8883
Number of shares converted				333	1,922
Series B Senior Non-cumulative Perpetual Convertible Stock | CIC Bancshares, Inc.
Class of Stock [Line Items]
Number of shares issued in connection with the acquisition			3,000
Preferred stock, dividend rate			7.00%
Common Stock
Class of Stock [Line Items]
Number of shares issued upon conversion				13,283	76,665
Public Stock Offering
Class of Stock [Line Items]
Number of shares sold in public offering	1,379,690
Proceeds from issuance of common stock | $		$ 49.7
Public Stock Offering | Common Stock
Class of Stock [Line Items]
Common stock, share price (in dollars per share) | $ / shares								$ 36.24

Regulatory Capital Requireme131

Regulatory Capital Requirements and Restrictions on Subsidiary Dividends (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Total Capital (to Risk-Weighted Assets)
Actual - Amount	$ 1,010,116	$ 887,607
Actual - Ratio	13.45%	14.01%
For Capital Adequacy Purposes - Amount	$ 600,924	$ 506,865
For Capital Adequacy Purposes - Ratio	8.00%	8.00%
Tier 1 Capital (to Risk-Weighted Assets)
Actual - Amount	$ 879,133	$ 756,056
Actual - Ratio	11.70%	11.93%
For Capital Adequacy Purposes - Amount	$ 450,693	$ 380,148
For Capital Adequacy Purposes - Ratio	6.00%	6.00%
Common Equity Tier 1 (to Risk-Weighted Assets)
Actual - Amount	$ 756,309	$ 639,467
Actual - Ratio	10.07%	10.09%
For Capital Adequacy Purposes - Amount	$ 338,019	$ 285,111
For Capital Adequacy Purposes - Ratio	4.50%	4.50%
Tier 1 Capital (to Average Assets)
Actual - Amount	$ 879,133	$ 756,056
Actual - Ratio	9.20%	9.28%
For Capital Adequacy Purposes - Amount	$ 382,089	$ 325,894
For Capital Adequacy Purposes - Ratio	4.00%	4.00%
Minimum Capital Requirement
Tier 1 Capital (to Average Assets)
Retained earnings available for dividend payments	$ 392,500
Capital Requirement to Remain Well Capitalized
Tier 1 Capital (to Average Assets)
Retained earnings available for dividend payments	242,300
Dubuque Bank and Trust Company
Total Capital (to Risk-Weighted Assets)
Actual - Amount	$ 156,544	$ 150,692
Actual - Ratio	13.63%	12.76%
For Capital Adequacy Purposes - Amount	$ 91,878	$ 94,494
For Capital Adequacy Purposes - Ratio	8.00%	8.00%
To Be Well Capitalized Under Prompt Corrective Action - Amount	$ 114,848	$ 118,117
To Be Well Capitalized Under Prompt Corrective Action - Ratio	10.00%	10.00%
Tier 1 Capital (to Risk-Weighted Assets)
Actual - Amount	$ 148,080	$ 140,970
Actual - Ratio	12.89%	11.93%
For Capital Adequacy Purposes - Amount	$ 68,909	$ 70,870
For Capital Adequacy Purposes - Ratio	6.00%	6.00%
To Be Well Capitalized Under Prompt Corrective Action Provisions - Amount	$ 91,878	$ 94,494
To Be Well Capitalized Under Prompt Corrective Action Provisions - Ratio	8.00%	8.00%
Common Equity Tier 1 (to Risk-Weighted Assets)
Actual - Amount	$ 148,080	$ 140,970
Actual - Ratio	12.89%	11.93%
For Capital Adequacy Purposes - Amount	$ 51,681	$ 53,153
For Capital Adequacy Purposes - Ratio	4.50%	4.50%
To Be Well Capitalized Under Prompt Corrective Action Provisions - Amount	$ 74,651	$ 76,776
To Be Well Capitalized Under Prompt Corrective Action Provisions - Ratio	6.50%	6.50%
Tier 1 Capital (to Average Assets)
Actual - Amount	$ 148,080	$ 140,970
Actual - Ratio	10.05%	9.41%
For Capital Adequacy Purposes - Amount	$ 58,932	$ 59,896
For Capital Adequacy Purposes - Ratio	4.00%	4.00%
To Be Well Capitalized Under Prompt Corrective Action Provisions - Amount	$ 73,666	$ 74,870
To Be Well Capitalized Under Prompt Corrective Action Provisions - Ratio	5.00%	5.00%
Illinois Bank & Trust
Total Capital (to Risk-Weighted Assets)
Actual - Amount	$ 71,410	$ 70,808
Actual - Ratio	12.62%	11.83%
For Capital Adequacy Purposes - Amount	$ 45,265	$ 47,884
For Capital Adequacy Purposes - Ratio	8.00%	8.00%
To Be Well Capitalized Under Prompt Corrective Action - Amount	$ 56,582	$ 59,856
To Be Well Capitalized Under Prompt Corrective Action - Ratio	10.00%	10.00%
Tier 1 Capital (to Risk-Weighted Assets)
Actual - Amount	$ 66,547	$ 66,101
Actual - Ratio	11.76%	11.04%
For Capital Adequacy Purposes - Amount	$ 33,949	$ 35,913
For Capital Adequacy Purposes - Ratio	6.00%	6.00%
To Be Well Capitalized Under Prompt Corrective Action Provisions - Amount	$ 45,265	$ 47,884
To Be Well Capitalized Under Prompt Corrective Action Provisions - Ratio	8.00%	8.00%
Common Equity Tier 1 (to Risk-Weighted Assets)
Actual - Amount	$ 66,547	$ 66,101
Actual - Ratio	11.76%	11.04%
For Capital Adequacy Purposes - Amount	$ 25,462	$ 26,935
For Capital Adequacy Purposes - Ratio	4.50%	4.50%
To Be Well Capitalized Under Prompt Corrective Action Provisions - Amount	$ 36,778	$ 38,906
To Be Well Capitalized Under Prompt Corrective Action Provisions - Ratio	6.50%	6.50%
Tier 1 Capital (to Average Assets)
Actual - Amount	$ 66,547	$ 66,101
Actual - Ratio	8.39%	8.80%
For Capital Adequacy Purposes - Amount	$ 31,728	$ 30,059
For Capital Adequacy Purposes - Ratio	4.00%	4.00%
To Be Well Capitalized Under Prompt Corrective Action Provisions - Amount	$ 39,660	$ 37,573
To Be Well Capitalized Under Prompt Corrective Action Provisions - Ratio	5.00%	5.00%
Wisconsin Bank & Trust
Total Capital (to Risk-Weighted Assets)
Actual - Amount	$ 113,045	$ 109,069
Actual - Ratio	14.57%	14.35%
For Capital Adequacy Purposes - Amount	$ 62,057	$ 60,819
For Capital Adequacy Purposes - Ratio	8.00%	8.00%
To Be Well Capitalized Under Prompt Corrective Action - Amount	$ 77,572	$ 76,024
To Be Well Capitalized Under Prompt Corrective Action - Ratio	10.00%	10.00%
Tier 1 Capital (to Risk-Weighted Assets)
Actual - Amount	$ 106,236	$ 102,523
Actual - Ratio	13.70%	13.49%
For Capital Adequacy Purposes - Amount	$ 46,543	$ 45,614
For Capital Adequacy Purposes - Ratio	6.00%	6.00%
To Be Well Capitalized Under Prompt Corrective Action Provisions - Amount	$ 62,057	$ 60,819
To Be Well Capitalized Under Prompt Corrective Action Provisions - Ratio	8.00%	8.00%
Common Equity Tier 1 (to Risk-Weighted Assets)
Actual - Amount	$ 106,236	$ 102,523
Actual - Ratio	13.70%	13.49%
For Capital Adequacy Purposes - Amount	$ 34,907	$ 34,211
For Capital Adequacy Purposes - Ratio	4.50%	4.50%
To Be Well Capitalized Under Prompt Corrective Action Provisions - Amount	$ 50,422	$ 49,416
To Be Well Capitalized Under Prompt Corrective Action Provisions - Ratio	6.50%	6.50%
Tier 1 Capital (to Average Assets)
Actual - Amount	$ 106,236	$ 102,523
Actual - Ratio	10.53%	9.96%
For Capital Adequacy Purposes - Amount	$ 40,373	$ 41,155
For Capital Adequacy Purposes - Ratio	4.00%	4.00%
To Be Well Capitalized Under Prompt Corrective Action Provisions - Amount	$ 50,466	$ 51,443
To Be Well Capitalized Under Prompt Corrective Action Provisions - Ratio	5.00%	5.00%
New Mexico Bank & Trust
Total Capital (to Risk-Weighted Assets)
Actual - Amount	$ 133,274	$ 119,246
Actual - Ratio	11.42%	11.20%
For Capital Adequacy Purposes - Amount	$ 93,401	$ 85,208
For Capital Adequacy Purposes - Ratio	8.00%	8.00%
To Be Well Capitalized Under Prompt Corrective Action - Amount	$ 116,751	$ 106,510
To Be Well Capitalized Under Prompt Corrective Action - Ratio	10.00%	10.00%
Tier 1 Capital (to Risk-Weighted Assets)
Actual - Amount	$ 123,519	$ 109,185
Actual - Ratio	10.58%	10.25%
For Capital Adequacy Purposes - Amount	$ 70,050	$ 63,906
For Capital Adequacy Purposes - Ratio	6.00%	6.00%
To Be Well Capitalized Under Prompt Corrective Action Provisions - Amount	$ 93,401	$ 85,208
To Be Well Capitalized Under Prompt Corrective Action Provisions - Ratio	8.00%	8.00%
Common Equity Tier 1 (to Risk-Weighted Assets)
Actual - Amount	$ 123,519	$ 109,185
Actual - Ratio	10.58%	10.25%
For Capital Adequacy Purposes - Amount	$ 52,538	$ 47,929
For Capital Adequacy Purposes - Ratio	4.50%	4.50%
To Be Well Capitalized Under Prompt Corrective Action Provisions - Amount	$ 75,888	$ 69,231
To Be Well Capitalized Under Prompt Corrective Action Provisions - Ratio	6.50%	6.50%
Tier 1 Capital (to Average Assets)
Actual - Amount	$ 123,519	$ 109,185
Actual - Ratio	8.54%	8.16%
For Capital Adequacy Purposes - Amount	$ 57,834	$ 53,529
For Capital Adequacy Purposes - Ratio	4.00%	4.00%
To Be Well Capitalized Under Prompt Corrective Action Provisions - Amount	$ 72,292	$ 66,911
To Be Well Capitalized Under Prompt Corrective Action Provisions - Ratio	5.00%	5.00%
Arizona Bank & Trust
Total Capital (to Risk-Weighted Assets)
Actual - Amount	$ 61,550	$ 58,741
Actual - Ratio	13.39%	14.64%
For Capital Adequacy Purposes - Amount	$ 36,773	$ 32,108
For Capital Adequacy Purposes - Ratio	8.00%	8.00%
To Be Well Capitalized Under Prompt Corrective Action - Amount	$ 45,966	$ 40,135
To Be Well Capitalized Under Prompt Corrective Action - Ratio	10.00%	10.00%
Tier 1 Capital (to Risk-Weighted Assets)
Actual - Amount	$ 56,870	$ 54,970
Actual - Ratio	12.37%	13.70%
For Capital Adequacy Purposes - Amount	$ 27,579	$ 24,081
For Capital Adequacy Purposes - Ratio	6.00%	6.00%
To Be Well Capitalized Under Prompt Corrective Action Provisions - Amount	$ 36,773	$ 32,108
To Be Well Capitalized Under Prompt Corrective Action Provisions - Ratio	8.00%	8.00%
Common Equity Tier 1 (to Risk-Weighted Assets)
Actual - Amount	$ 56,870	$ 54,970
Actual - Ratio	12.37%	13.70%
For Capital Adequacy Purposes - Amount	$ 20,685	$ 18,061
For Capital Adequacy Purposes - Ratio	4.50%	4.50%
To Be Well Capitalized Under Prompt Corrective Action Provisions - Amount	$ 29,878	$ 26,088
To Be Well Capitalized Under Prompt Corrective Action Provisions - Ratio	6.50%	6.50%
Tier 1 Capital (to Average Assets)
Actual - Amount	$ 56,870	$ 54,970
Actual - Ratio	9.94%	9.59%
For Capital Adequacy Purposes - Amount	$ 22,890	$ 22,922
For Capital Adequacy Purposes - Ratio	4.00%	4.00%
To Be Well Capitalized Under Prompt Corrective Action Provisions - Amount	$ 28,613	$ 28,653
To Be Well Capitalized Under Prompt Corrective Action Provisions - Ratio	5.00%	5.00%
Rocky Mountain Bank
Total Capital (to Risk-Weighted Assets)
Actual - Amount	$ 50,729	$ 50,188
Actual - Ratio	13.78%	13.72%
For Capital Adequacy Purposes - Amount	$ 29,461	$ 29,254
For Capital Adequacy Purposes - Ratio	8.00%	8.00%
To Be Well Capitalized Under Prompt Corrective Action - Amount	$ 36,826	$ 36,568
To Be Well Capitalized Under Prompt Corrective Action - Ratio	10.00%	10.00%
Tier 1 Capital (to Risk-Weighted Assets)
Actual - Amount	$ 47,660	$ 46,702
Actual - Ratio	12.94%	12.77%
For Capital Adequacy Purposes - Amount	$ 22,096	$ 21,941
For Capital Adequacy Purposes - Ratio	6.00%	6.00%
To Be Well Capitalized Under Prompt Corrective Action Provisions - Amount	$ 29,461	$ 29,254
To Be Well Capitalized Under Prompt Corrective Action Provisions - Ratio	8.00%	8.00%
Common Equity Tier 1 (to Risk-Weighted Assets)
Actual - Amount	$ 47,660	$ 46,702
Actual - Ratio	12.94%	12.77%
For Capital Adequacy Purposes - Amount	$ 16,572	$ 16,455
For Capital Adequacy Purposes - Ratio	4.50%	4.50%
To Be Well Capitalized Under Prompt Corrective Action Provisions - Amount	$ 23,937	$ 23,769
To Be Well Capitalized Under Prompt Corrective Action Provisions - Ratio	6.50%	6.50%
Tier 1 Capital (to Average Assets)
Actual - Amount	$ 47,660	$ 46,702
Actual - Ratio	9.82%	9.79%
For Capital Adequacy Purposes - Amount	$ 19,418	$ 19,078
For Capital Adequacy Purposes - Ratio	4.00%	4.00%
To Be Well Capitalized Under Prompt Corrective Action Provisions - Amount	$ 24,272	$ 23,848
To Be Well Capitalized Under Prompt Corrective Action Provisions - Ratio	5.00%	5.00%
Citywide Banks
Total Capital (to Risk-Weighted Assets)
Actual - Amount	$ 226,493	$ 83,615
Actual - Ratio	13.63%	13.25%
For Capital Adequacy Purposes - Amount	$ 132,975	$ 50,475
For Capital Adequacy Purposes - Ratio	8.00%	8.00%
To Be Well Capitalized Under Prompt Corrective Action - Amount	$ 166,219	$ 63,094
To Be Well Capitalized Under Prompt Corrective Action - Ratio	10.00%	10.00%
Tier 1 Capital (to Risk-Weighted Assets)
Actual - Amount	$ 221,239	$ 81,260
Actual - Ratio	13.31%	12.88%
For Capital Adequacy Purposes - Amount	$ 99,731	$ 37,857
For Capital Adequacy Purposes - Ratio	6.00%	6.00%
To Be Well Capitalized Under Prompt Corrective Action Provisions - Amount	$ 132,975	$ 50,475
To Be Well Capitalized Under Prompt Corrective Action Provisions - Ratio	8.00%	8.00%
Common Equity Tier 1 (to Risk-Weighted Assets)
Actual - Amount	$ 221,239	$ 81,260
Actual - Ratio	13.31%	12.88%
For Capital Adequacy Purposes - Amount	$ 74,799	$ 28,392
For Capital Adequacy Purposes - Ratio	4.50%	4.50%
To Be Well Capitalized Under Prompt Corrective Action Provisions - Amount	$ 108,042	$ 41,011
To Be Well Capitalized Under Prompt Corrective Action Provisions - Ratio	6.50%	6.50%
Tier 1 Capital (to Average Assets)
Actual - Amount	$ 221,239	$ 81,260
Actual - Ratio	10.03%	9.33%
For Capital Adequacy Purposes - Amount	$ 88,240	$ 34,827
For Capital Adequacy Purposes - Ratio	4.00%	4.00%
To Be Well Capitalized Under Prompt Corrective Action Provisions - Amount	$ 110,300	$ 43,534
To Be Well Capitalized Under Prompt Corrective Action Provisions - Ratio	5.00%	5.00%
Minnesota Bank & Trust
Total Capital (to Risk-Weighted Assets)
Actual - Amount	$ 23,760	$ 21,693
Actual - Ratio	13.76%	11.86%
For Capital Adequacy Purposes - Amount	$ 13,811	$ 14,628
For Capital Adequacy Purposes - Ratio	8.00%	8.00%
To Be Well Capitalized Under Prompt Corrective Action - Amount	$ 17,264	$ 18,285
To Be Well Capitalized Under Prompt Corrective Action - Ratio	10.00%	10.00%
Tier 1 Capital (to Risk-Weighted Assets)
Actual - Amount	$ 22,554	$ 20,315
Actual - Ratio	13.06%	11.11%
For Capital Adequacy Purposes - Amount	$ 10,358	$ 10,971
For Capital Adequacy Purposes - Ratio	6.00%	6.00%
To Be Well Capitalized Under Prompt Corrective Action Provisions - Amount	$ 13,811	$ 14,628
To Be Well Capitalized Under Prompt Corrective Action Provisions - Ratio	8.00%	8.00%
Common Equity Tier 1 (to Risk-Weighted Assets)
Actual - Amount	$ 22,554	$ 20,315
Actual - Ratio	13.06%	11.11%
For Capital Adequacy Purposes - Amount	$ 7,769	$ 8,228
For Capital Adequacy Purposes - Ratio	4.50%	4.50%
To Be Well Capitalized Under Prompt Corrective Action Provisions - Amount	$ 11,222	$ 11,885
To Be Well Capitalized Under Prompt Corrective Action Provisions - Ratio	6.50%	6.50%
Tier 1 Capital (to Average Assets)
Actual - Amount	$ 22,554	$ 20,315
Actual - Ratio	10.77%	8.72%
For Capital Adequacy Purposes - Amount	$ 8,379	$ 9,315
For Capital Adequacy Purposes - Ratio	4.00%	4.00%
To Be Well Capitalized Under Prompt Corrective Action Provisions - Amount	$ 10,473	$ 11,644
To Be Well Capitalized Under Prompt Corrective Action Provisions - Ratio	5.00%	5.00%
Morrill & Janes Bank and Trust Company
Total Capital (to Risk-Weighted Assets)
Actual - Amount	$ 72,471	$ 85,649
Actual - Ratio	13.42%	12.36%
For Capital Adequacy Purposes - Amount	$ 43,206	$ 55,433
For Capital Adequacy Purposes - Ratio	8.00%	8.00%
To Be Well Capitalized Under Prompt Corrective Action - Amount	$ 54,007	$ 69,292
To Be Well Capitalized Under Prompt Corrective Action - Ratio	10.00%	10.00%
Tier 1 Capital (to Risk-Weighted Assets)
Actual - Amount	$ 67,328	$ 78,615
Actual - Ratio	12.47%	11.35%
For Capital Adequacy Purposes - Amount	$ 32,404	$ 41,575
For Capital Adequacy Purposes - Ratio	6.00%	6.00%
To Be Well Capitalized Under Prompt Corrective Action Provisions - Amount	$ 43,206	$ 55,433
To Be Well Capitalized Under Prompt Corrective Action Provisions - Ratio	8.00%	8.00%
Common Equity Tier 1 (to Risk-Weighted Assets)
Actual - Amount	$ 67,328	$ 78,615
Actual - Ratio	12.47%	11.35%
For Capital Adequacy Purposes - Amount	$ 24,303	$ 31,181
For Capital Adequacy Purposes - Ratio	4.50%	4.50%
To Be Well Capitalized Under Prompt Corrective Action Provisions - Amount	$ 35,104	$ 45,040
To Be Well Capitalized Under Prompt Corrective Action Provisions - Ratio	6.50%	6.50%
Tier 1 Capital (to Average Assets)
Actual - Amount	$ 67,328	$ 78,615
Actual - Ratio	9.47%	9.12%
For Capital Adequacy Purposes - Amount	$ 28,435	$ 34,463
For Capital Adequacy Purposes - Ratio	4.00%	4.00%
To Be Well Capitalized Under Prompt Corrective Action Provisions - Amount	$ 35,543	$ 43,079
To Be Well Capitalized Under Prompt Corrective Action Provisions - Ratio	5.00%	5.00%
Premier Valley Bank
Total Capital (to Risk-Weighted Assets)
Actual - Amount	$ 83,772	$ 66,132
Actual - Ratio	12.95%	14.44%
For Capital Adequacy Purposes - Amount	$ 51,743	$ 36,649
For Capital Adequacy Purposes - Ratio	8.00%	8.00%
To Be Well Capitalized Under Prompt Corrective Action - Amount	$ 64,679	$ 45,811
To Be Well Capitalized Under Prompt Corrective Action - Ratio	10.00%	10.00%
Tier 1 Capital (to Risk-Weighted Assets)
Actual - Amount	$ 81,213	$ 64,735
Actual - Ratio	12.56%	14.13%
For Capital Adequacy Purposes - Amount	$ 38,808	$ 27,487
For Capital Adequacy Purposes - Ratio	6.00%	6.00%
To Be Well Capitalized Under Prompt Corrective Action Provisions - Amount	$ 51,743	$ 36,649
To Be Well Capitalized Under Prompt Corrective Action Provisions - Ratio	8.00%	8.00%
Common Equity Tier 1 (to Risk-Weighted Assets)
Actual - Amount	$ 81,213	$ 64,735
Actual - Ratio	12.56%	14.13%
For Capital Adequacy Purposes - Amount	$ 29,106	$ 20,615
For Capital Adequacy Purposes - Ratio	4.50%	4.50%
To Be Well Capitalized Under Prompt Corrective Action Provisions - Amount	$ 42,042	$ 29,777
To Be Well Capitalized Under Prompt Corrective Action Provisions - Ratio	6.50%	6.50%
Tier 1 Capital (to Average Assets)
Actual - Amount	$ 81,213	$ 64,735
Actual - Ratio	9.80%	10.91%
For Capital Adequacy Purposes - Amount	$ 33,157	$ 23,729
For Capital Adequacy Purposes - Ratio	4.00%	4.00%
To Be Well Capitalized Under Prompt Corrective Action Provisions - Amount	$ 41,446	$ 29,661
To Be Well Capitalized Under Prompt Corrective Action Provisions - Ratio	5.00%	5.00%

Fair Value (Fair Value Measurem

Fair Value (Fair Value Measurement Recurring) (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale	$ 2,216,753	$ 1,845,864
Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale	3,484	517
Derivative financial instruments	0	0
Derivative liabilities	0	0
Level 1 | Interest rate lock commitments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative financial instruments	0	0
Level 1 | Forward commitments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative financial instruments	0	0
Derivative liabilities	0	0
Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale	2,213,269	1,843,123
Derivative financial instruments	3,933	3,222
Derivative liabilities	5,167	7,027
Level 2 | Interest rate lock commitments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative financial instruments	0	0
Level 2 | Forward commitments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative financial instruments	80	2,546
Derivative liabilities	232	266
Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale	0	2,224
Derivative financial instruments	0	0
Derivative liabilities	0	0
Level 3 | Interest rate lock commitments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative financial instruments	1,738	2,790
Level 3 | Forward commitments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative financial instruments	0	0
Derivative liabilities	0	0
Recurring Basis
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets at fair value	2,222,504	1,854,422
Total liabilities at fair value	5,399	7,293
Recurring Basis | Embedded Derivatives and Loan Swaps
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative financial instruments	3,933	3,222
Recurring Basis | Interest rate lock commitments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative financial instruments	1,738	2,790
Recurring Basis | Cash Flow Hedges, Loan Swaps and Free Standing Derivative Instruments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liabilities	5,167	7,027
Recurring Basis | Forward commitments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative financial instruments	80	2,546
Derivative liabilities	232	266
Recurring Basis | U.S. government corporations and agencies
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale	5,328	4,700
Recurring Basis | Mortgage and asset-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale	1,753,736	1,290,500
Recurring Basis | Obligations of states and political subdivisions
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale	441,015	536,144
Recurring Basis | Equity securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale	16,674	14,520
Recurring Basis | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets at fair value	3,484	517
Total liabilities at fair value	0	0
Recurring Basis | Level 1 | Embedded Derivatives and Loan Swaps
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative financial instruments	0	0
Recurring Basis | Level 1 | Interest rate lock commitments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative financial instruments	0	0
Recurring Basis | Level 1 | Cash Flow Hedges, Loan Swaps and Free Standing Derivative Instruments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liabilities	0	0
Recurring Basis | Level 1 | Forward commitments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative financial instruments	0	0
Derivative liabilities	0	0
Recurring Basis | Level 1 | U.S. government corporations and agencies
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale	3,484	517
Recurring Basis | Level 1 | Mortgage and asset-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale	0	0
Recurring Basis | Level 1 | Obligations of states and political subdivisions
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale	0	0
Recurring Basis | Level 1 | Equity securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale	0	0
Recurring Basis | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets at fair value	2,217,282	1,848,891
Total liabilities at fair value	5,399	7,293
Recurring Basis | Level 2 | Embedded Derivatives and Loan Swaps
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative financial instruments	3,933	3,222
Recurring Basis | Level 2 | Interest rate lock commitments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative financial instruments	0	0
Recurring Basis | Level 2 | Cash Flow Hedges, Loan Swaps and Free Standing Derivative Instruments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liabilities	5,167	7,027
Recurring Basis | Level 2 | Forward commitments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative financial instruments	80	2,546
Derivative liabilities	232	266
Recurring Basis | Level 2 | U.S. government corporations and agencies
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale	1,844	4,183
Recurring Basis | Level 2 | Mortgage and asset-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale	1,753,736	1,288,276
Recurring Basis | Level 2 | Obligations of states and political subdivisions
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale	441,015	536,144
Recurring Basis | Level 2 | Equity securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale	16,674	14,520
Recurring Basis | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets at fair value	1,738	5,014
Total liabilities at fair value	0	0
Recurring Basis | Level 3 | Embedded Derivatives and Loan Swaps
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative financial instruments	0	0
Recurring Basis | Level 3 | Interest rate lock commitments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative financial instruments	1,738	2,790
Recurring Basis | Level 3 | Cash Flow Hedges, Loan Swaps and Free Standing Derivative Instruments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liabilities	0	0
Recurring Basis | Level 3 | Forward commitments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative financial instruments	0	0
Derivative liabilities	0	0
Recurring Basis | Level 3 | U.S. government corporations and agencies
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale	0	0
Recurring Basis | Level 3 | Mortgage and asset-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale	0	2,224
Recurring Basis | Level 3 | Obligations of states and political subdivisions
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale	0	0
Recurring Basis | Level 3 | Equity securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale	$ 0	$ 0

Fair Value (Fair Value Measu133

Fair Value (Fair Value Measurement Non-recurring) (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Premises, furniture and equipment held for sale	$ 1,977	$ 414
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	44,560	61,261
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	10,777	9,744
Commercial Servicing Rights | Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Commercial servicing rights	291	326
Commercial | Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Collateral dependent impaired loans	3,212	1,683
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	9,480	3,026
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	8,406	1,955
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	1,137	3,565
Consumer | Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Collateral dependent impaired loans	1,234	1,193
Nonrecurring Basis
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Collateral dependent impaired loans	23,469	11,422
Loans held for sale	44,560	61,261
Other real estate owned	10,777	9,744
Premises, furniture and equipment held for sale	1,977	414
Nonrecurring Basis | (Gains)/Losses
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Collateral dependent impaired loans	3,469	653
Loans held for sale	190	(640)
Other real estate owned	737	1,341
Premises, furniture and equipment held for sale	192	35
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
Premises, furniture and equipment held for sale	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	44,560	61,261
Other real estate owned	0	0
Premises, furniture and equipment held for sale	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	23,469	11,422
Loans held for sale	0	0
Other real estate owned	10,777	9,744
Premises, furniture and equipment held for sale	1,977	414
Nonrecurring Basis | Commercial Servicing Rights
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Commercial servicing rights	291	326
Nonrecurring Basis | Commercial Servicing Rights | (Gains)/Losses
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Commercial servicing rights	(21)	33
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	291	326
Nonrecurring Basis | Commercial
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Collateral dependent impaired loans	3,212	1,683
Nonrecurring Basis | Commercial | (Gains)/Losses
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Collateral dependent impaired loans	1,119	41
Nonrecurring Basis | 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 | 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 | Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Collateral dependent impaired loans	3,212	1,683
Nonrecurring Basis | Commercial Real Estate
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Collateral dependent impaired loans	9,480	3,026
Nonrecurring Basis | Commercial Real Estate | (Gains)/Losses
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Collateral dependent impaired loans	322	527
Nonrecurring Basis | 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 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 Real Estate | Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Collateral dependent impaired loans	9,480	3,026
Nonrecurring Basis | Agricultural and Agricultural Real Estate
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Collateral dependent impaired loans	8,406	1,955
Nonrecurring Basis | Agricultural and Agricultural Real Estate | (Gains)/Losses
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Collateral dependent impaired loans	2,028	0
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	8,406	1,955
Nonrecurring Basis | Residential Real Estate
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Collateral dependent impaired loans	1,137	3,565
Nonrecurring Basis | Residential Real Estate | (Gains)/Losses
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Collateral dependent impaired loans	0	85
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	1,137	3,565
Nonrecurring Basis | Consumer
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Collateral dependent impaired loans	1,234	1,193
Nonrecurring Basis | Consumer | (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	$ 1,234	$ 1,193

Fair Value (Quantitative Inform

Fair Value (Quantitative Information About Level 3 Fair Value Measurements) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Securities available for sale	$ 2,216,753	$ 1,845,864
Premises, furniture and equipment held for sale	1,977	414
Level 3
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Securities available for sale	0	2,224
Derivative financial instruments	0	0
Other real estate owned	$ 10,777	9,744
Level 3 | Minimum
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Discount rates	0.00%
Level 3 | Maximum
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Discount rates	10.00%
Level 3 | Commercial
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Collateral dependent impaired loans	$ 3,212	$ 1,683
Level 3 | Commercial | Minimum
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Discount rates	0.00%	0.00%
Level 3 | Commercial | Maximum
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Discount rates	15.00%	8.00%
Level 3 | Commercial Real Estate
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Collateral dependent impaired loans	$ 9,480	$ 3,026
Level 3 | Commercial Real Estate | Minimum
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Discount rates	0.00%	0.00%
Level 3 | Commercial Real Estate | Maximum
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Discount rates	12.00%	7.00%
Level 3 | Agricultural and Agricultural Real Estate
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Collateral dependent impaired loans	$ 8,406	$ 1,955
Level 3 | Agricultural and Agricultural Real Estate | Minimum
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Discount rates	0.00%	0.00%
Level 3 | Agricultural and Agricultural Real Estate | Maximum
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Discount rates	10.00%	10.00%
Level 3 | Residential Real Estate
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Collateral dependent impaired loans	$ 1,137	$ 3,565
Level 3 | Residential Real Estate | Minimum
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Discount rates	0.00%	0.00%
Level 3 | Residential Real Estate | Maximum
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Discount rates	12.00%	8.00%
Level 3 | Consumer
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Collateral dependent impaired loans	$ 1,234	$ 1,193
Level 3 | Consumer | Minimum
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Discount rates	0.00%	0.00%
Level 3 | Consumer | Maximum
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Discount rates	12.00%	11.00%
Level 3 | Commercial Servicing Rights
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Commercial servicing rights	$ 291	$ 326
Level 3 | Premises, Furniture and Equipment Held for Sale | Minimum
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Discount rates	0.00%	0.00%
Level 3 | Premises, Furniture and Equipment Held for Sale | Maximum
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Discount rates	10.00%	8.00%
Level 3 | Other Real Estate | Minimum
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Discount rates		0.00%
Level 3 | Other Real Estate | Maximum
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Discount rates		10.00%
Level 3 | Interest rate lock commitments
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Derivative financial instruments	$ 1,738	$ 2,790
Level 3 | Interest rate lock commitments | Weighted Average
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Closing ratio	89.00%	89.00%
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 | Z-Tranche Securities
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Securities available for sale	$ 0	$ 2,224
Discount rates	0.00%
Actual defaults	0.00%
Actual deferrals	0.00%
Level 3 | Z-Tranche Securities | Weighted Average
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Actual defaults		33.11%
Actual deferrals		14.81%
Level 3 | Z-Tranche Securities | Minimum
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Discount rates		7.50%
Actual defaults		21.77%
Actual deferrals		10.44%
Level 3 | Z-Tranche Securities | Maximum
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Discount rates		9.50%
Actual defaults		37.62%
Actual deferrals		26.29%
Level 3 | Recurring Basis | Premises, Furniture and Equipment Held for Sale
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Premises, furniture and equipment held for sale	$ 1,977	$ 414

Fair Value (Changes Level 3 Ass

Fair Value (Changes Level 3 Assets (Fair Value, Recurring)) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Interest rate lock commitments
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance at beginning of period	$ 2,790	$ 3,168
Total gains (losses), net:
Included in earnings	(1,479)	(1,564)
Purchases, issuances, sales and settlements:
Issuances	1,875	5,373
Settlements	(1,448)	(4,187)
Balance at end of period	1,738	2,790
Z-Tranche Securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance at beginning of period	2,224	2,039
Total gains (losses), net:
Included in earnings	2,810	0
Included in other comprehensive income	(2,166)	185
Purchases, issuances, sales and settlements:
Purchases	0	0
Sales	(2,868)	0
Settlements	0	0
Balance at end of period	0	2,224
Corporate Debt Securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance at beginning of period	0	846
Total gains (losses), net:
Included in earnings	0	56
Included in other comprehensive income	0	(106)
Purchases, issuances, sales and settlements:
Purchases	0	0
Acquired	0	0
Sales	0	(796)
Settlements	0	0
Balance at end of period	$ 0	$ 0

Fair Value (Estimated Fair Valu

Fair Value (Estimated Fair Value Financial Instruments (Including Carrying Amounts)) (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Financial assets:
Available for sale	$ 2,216,753	$ 1,845,864
Held to maturity	265,494	274,799
Quoted Prices in Active Markets for Identical Assets (Level 1)
Financial assets:
Cash and cash equivalents	196,003	158,724
Time deposits in other financial institutions	9,820	2,105
Available for sale	3,484	517
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
Derivatives	0	0
Financial liabilities:
Short term borrowings	0	0
Other borrowings	0	0
Derivatives	0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) | Interest rate lock commitments
Financial assets:
Derivatives	0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) | Forward commitments
Financial assets:
Derivatives	0	0
Financial liabilities:
Derivatives	0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) | Demand deposits
Financial liabilities:
Deposits	0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) | Savings deposits
Financial liabilities:
Deposits	0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) | Time deposits
Financial liabilities:
Deposits	0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) | Commercial | Commercial
Financial assets:
Loans, net	0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) | Commercial | Commercial real estate
Financial assets:
Loans, net	0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) | Agricultural and agricultural real estate
Financial assets:
Loans, net	0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) | Residential real estate
Financial assets:
Loans, net	0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) | Consumer
Financial assets:
Loans, net	0	0
Significant Other Observable Inputs (Level 2)
Financial assets:
Cash and cash equivalents	0	0
Time deposits in other financial institutions	0	0
Available for sale	2,213,269	1,843,123
Held to maturity	265,494	274,799
Other investments	22,563	21,365
Loans held for sale	44,560	61,261
Loans, net	6,291,503	5,259,690
Cash surrender value on life insurance	142,818	112,615
Derivatives	3,933	3,222
Financial liabilities:
Short term borrowings	324,691	306,459
Other borrowings	285,609	288,534
Derivatives	5,167	7,027
Significant Other Observable Inputs (Level 2) | Interest rate lock commitments
Financial assets:
Derivatives	0	0
Significant Other Observable Inputs (Level 2) | Forward commitments
Financial assets:
Derivatives	80	2,546
Financial liabilities:
Derivatives	232	266
Significant Other Observable Inputs (Level 2) | Demand deposits
Financial liabilities:
Deposits	2,983,128	2,202,036
Significant Other Observable Inputs (Level 2) | Savings deposits
Financial liabilities:
Deposits	4,240,328	3,788,089
Significant Other Observable Inputs (Level 2) | Time deposits
Financial liabilities:
Deposits	923,453	857,286
Significant Other Observable Inputs (Level 2) | Commercial | Commercial
Financial assets:
Loans, net	1,614,744	1,257,071
Significant Other Observable Inputs (Level 2) | Commercial | Commercial real estate
Financial assets:
Loans, net	3,123,062	2,503,832
Significant Other Observable Inputs (Level 2) | Agricultural and agricultural real estate
Financial assets:
Loans, net	500,581	485,046
Significant Other Observable Inputs (Level 2) | Residential real estate
Financial assets:
Loans, net	613,530	600,668
Significant Other Observable Inputs (Level 2) | Consumer
Financial assets:
Loans, net	439,586	413,073
Significant Unobservable Inputs (Level 3)
Financial assets:
Cash and cash equivalents	0	0
Time deposits in other financial institutions	0	0
Available for sale	0	2,224
Held to maturity	0	0
Other investments	0	195
Loans held for sale	0	0
Loans, net	23,469	11,422
Cash surrender value on life insurance	0	0
Derivatives	0	0
Financial liabilities:
Short term borrowings	0	0
Other borrowings	0	0
Derivatives	0	0
Significant Unobservable Inputs (Level 3) | Interest rate lock commitments
Financial assets:
Derivatives	1,738	2,790
Significant Unobservable Inputs (Level 3) | Forward commitments
Financial assets:
Derivatives	0	0
Financial liabilities:
Derivatives	0	0
Significant Unobservable Inputs (Level 3) | Demand deposits
Financial liabilities:
Deposits	0	0
Significant Unobservable Inputs (Level 3) | Savings deposits
Financial liabilities:
Deposits	0	0
Significant Unobservable Inputs (Level 3) | Time deposits
Financial liabilities:
Deposits	0	0
Significant Unobservable Inputs (Level 3) | Commercial | Commercial
Financial assets:
Loans, net	3,212	1,683
Significant Unobservable Inputs (Level 3) | Commercial | Commercial real estate
Financial assets:
Loans, net	9,480	3,026
Significant Unobservable Inputs (Level 3) | Agricultural and agricultural real estate
Financial assets:
Loans, net	8,406	1,955
Significant Unobservable Inputs (Level 3) | Residential real estate
Financial assets:
Loans, net	1,137	3,565
Significant Unobservable Inputs (Level 3) | Consumer
Financial assets:
Loans, net	1,234	1,193
Carrying Amount
Financial assets:
Cash and cash equivalents	196,003	158,724
Time deposits in other financial institutions	9,820	2,105
Available for sale	2,216,753	1,845,864
Held to maturity	253,550	263,662
Other investments	22,563	21,560
Loans held for sale	44,560	61,261
Loans, net	6,335,778	5,297,395
Cash surrender value on life insurance	142,818	112,615
Derivatives	3,933	3,222
Financial liabilities:
Short term borrowings	324,691	306,459
Other borrowings	285,011	288,534
Derivatives	5,167	7,027
Carrying Amount | Interest rate lock commitments
Financial assets:
Derivatives	1,738	2,790
Carrying Amount | Forward commitments
Financial assets:
Derivatives	80	2,546
Financial liabilities:
Derivatives	232	266
Carrying Amount | Demand deposits
Financial liabilities:
Deposits	2,983,128	2,202,036
Carrying Amount | Savings deposits
Financial liabilities:
Deposits	4,240,328	3,788,089
Carrying Amount | Time deposits
Financial liabilities:
Deposits	923,453	857,286
Carrying Amount | Commercial | Commercial
Financial assets:
Loans, net	1,628,043	1,272,089
Carrying Amount | Commercial | Commercial real estate
Financial assets:
Loans, net	3,140,427	2,513,446
Carrying Amount | Agricultural and agricultural real estate
Financial assets:
Loans, net	508,075	485,820
Carrying Amount | Residential real estate
Financial assets:
Loans, net	620,939	614,207
Carrying Amount | Consumer
Financial assets:
Loans, net	438,294	411,833
Estimated Fair Value
Financial assets:
Cash and cash equivalents	196,003	158,724
Time deposits in other financial institutions	9,820	2,105
Available for sale	2,216,753	1,845,864
Held to maturity	265,494	274,799
Other investments	22,563	21,560
Loans held for sale	44,560	61,261
Loans, net	6,314,972	5,271,112
Cash surrender value on life insurance	142,818	112,615
Derivatives	3,933	3,222
Financial liabilities:
Short term borrowings	324,691	306,459
Other borrowings	285,609	288,534
Derivatives	5,167	7,027
Estimated Fair Value | Interest rate lock commitments
Financial assets:
Derivatives	1,738	2,790
Estimated Fair Value | Forward commitments
Financial assets:
Derivatives	80	2,546
Financial liabilities:
Derivatives	232	266
Estimated Fair Value | Demand deposits
Financial liabilities:
Deposits	2,983,128	2,202,036
Estimated Fair Value | Savings deposits
Financial liabilities:
Deposits	4,240,328	3,788,089
Estimated Fair Value | Time deposits
Financial liabilities:
Deposits	923,453	857,286
Estimated Fair Value | Commercial | Commercial
Financial assets:
Loans, net	1,617,956	1,258,754
Estimated Fair Value | Commercial | Commercial real estate
Financial assets:
Loans, net	3,132,542	2,506,858
Estimated Fair Value | Agricultural and agricultural real estate
Financial assets:
Loans, net	508,987	487,001
Estimated Fair Value | Residential real estate
Financial assets:
Loans, net	614,667	604,233
Estimated Fair Value | Consumer
Financial assets:
Loans, net	$ 440,820	$ 414,266

Segment Reporting (Details)

Segment Reporting (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Segment Reporting Information [Line Items]
Net Interest Income	$ 92,856	$ 89,844	$ 74,580	$ 73,028	$ 75,160	$ 73,681	$ 73,118	$ 72,707	$ 330,308	$ 294,666	$ 233,998
Provision for loan losses	5,328	5,705	889	3,641	2,181	5,328	2,118	2,067	15,563	11,694	12,697
Total noninterest income	25,528	24,977	25,624	25,893	24,455	28,542	31,026	29,578	102,022	113,601	110,685
Total noninterest expense	77,878	$ 78,759	$ 69,298	$ 71,740	69,912	$ 68,427	$ 71,020	$ 70,309	297,675	279,668	251,046
Income (loss) before income taxes									119,092	116,905	80,940
Segment Assets
Segment Assets	9,810,739				8,247,079				9,810,739	8,247,079	7,694,754
Average Loans, Net of Unearned
Average Loans, Net of Unearned									5,847,061	5,488,112	4,551,008
Community and Other Banking
Segment Reporting Information [Line Items]
Net Interest Income									326,130	290,088	228,422
Provision for loan losses									15,563	11,694	12,697
Total noninterest income									77,837	74,145	65,414
Total noninterest expense									264,929	237,198	201,063
Income (loss) before income taxes									123,475	115,341	80,076
Segment Assets
Segment Assets	9,757,575				8,149,465				9,757,575	8,149,465	7,585,130
Average Loans, Net of Unearned
Average Loans, Net of Unearned									5,810,308	5,418,169	4,466,528
Mortgage Banking
Segment Reporting Information [Line Items]
Net Interest Income									4,178	4,578	5,576
Provision for loan losses									0	0	0
Total noninterest income									24,185	39,456	45,271
Total noninterest expense									32,746	42,470	49,983
Income (loss) before income taxes									(4,383)	1,564	864
Segment Assets
Segment Assets	$ 53,164				$ 97,614				53,164	97,614	109,624
Average Loans, Net of Unearned
Average Loans, Net of Unearned									$ 36,753	$ 69,943	$ 84,480

Parent Company Only Financia138

Parent Company Only Financial Information (Balance Sheets) (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Assets:
Cash and interest bearing deposits	$ 196,003	$ 158,724	$ 258,799	$ 73,871
Securities available for sale	2,216,753	1,845,864
Other investments, at cost	22,563	21,560
Other assets	106,141	123,869
TOTAL ASSETS	9,810,739	8,247,079	7,694,754
Liabilities and stockholders’ equity:
Other borrowings	285,011	288,534
Accrued expenses and other liabilities	62,671	63,759
TOTAL LIABILITIES	8,819,282	7,506,163
Stockholders’ equity:
Common stock	29,953	26,120
Capital surplus	503,709	328,376
Retained earnings	481,331	416,109
Accumulated other comprehensive loss	(24,474)	(31,046)
Treasury stock	0	0
TOTAL STOCKHOLDERS' EQUITY	991,457	740,916	663,173	496,317
TOTAL LIABILITIES AND EQUITY	9,810,739	8,247,079
Parent
Assets:
Cash and interest bearing deposits	24,310	65,007	$ 85,327	$ 124,387
Securities available for sale	0	2,224
Other investments, at cost	0	195
Investment in subsidiaries	1,194,747	901,310
Other assets	28,536	26,154
Due from subsidiaries	6,000	6,000
TOTAL ASSETS	1,253,593	1,000,890
Liabilities and stockholders’ equity:
Other borrowings	246,438	249,245
Accrued expenses and other liabilities	15,698	10,729
TOTAL LIABILITIES	262,136	259,974
Stockholders’ equity:
Preferred stock	938	1,357
Common stock	29,953	26,120
Capital surplus	503,709	328,376
Retained earnings	481,331	416,109
Accumulated other comprehensive loss	(24,474)	(31,046)
TOTAL STOCKHOLDERS' EQUITY	991,457	740,916
TOTAL LIABILITIES AND EQUITY	$ 1,253,593	$ 1,000,890

Parent Company Only Financia139

Parent Company Only Financial Information (Income Statements) (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Operating revenues:
Securities gains, net									$ 6,973	$ 11,340	$ 13,143
Operating expenses:
Interest									33,350	31,813	31,970
Salaries and employee benefits									171,407	163,547	144,105
Professional fees									32,879	27,676	23,047
Income (loss) before income taxes									119,092	116,905	80,940
Income tax benefit	$ (21,506)	$ (8,725)	$ (8,059)	$ (5,530)	$ (8,360)	$ (8,260)	$ (10,036)	$ (9,900)	(43,820)	(36,556)	(20,898)
NET INCOME	13,672	21,632	21,958	18,010	19,162	20,208	20,970	20,009	75,272	80,349	60,042
Preferred dividends	(13)	(13)	(13)	(19)	(19)	(53)	(52)	(168)	(58)	(292)	(817)
Interest expense on convertible preferred debt	0	3	4	5	3	17	31	0	12	51	0
NET INCOME AVAILABLE TO COMMON STOCKHOLDERS	$ 13,659	$ 21,622	$ 21,949	$ 17,996	$ 19,146	$ 20,172	$ 20,949	$ 19,841	75,226	80,108	59,225
Parent
Operating revenues:
Dividends from subsidiaries									70,850	55,250	70,000
Securities gains, net									3,021	54	3,038
Other									2,292	1,712	712
Total operating revenues									76,163	57,016	73,750
Operating expenses:
Interest									13,269	13,840	12,996
Salaries and employee benefits									3,146	3,044	5,028
Professional fees									2,379	2,487	4,735
Other operating expenses									7,889	2,664	4,234
Total operating expenses									26,683	22,035	26,993
Equity in undistributed earnings									16,212	37,926	2,570
Income (loss) before income taxes									65,692	72,907	49,327
Income tax benefit									9,580	7,442	10,715
NET INCOME									75,272	80,349	60,042
Preferred dividends									(58)	(292)	(817)
Interest expense on convertible preferred debt									12	51	0
NET INCOME AVAILABLE TO COMMON STOCKHOLDERS									$ 75,226	$ 80,108	$ 59,225

Parent Company Only Financia140

Parent Company Only Financial Information (Cash Flows) (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Cash flows from operating activities:
Net income	$ 13,672	$ 21,632	$ 21,958	$ 18,010	$ 19,162	$ 20,208	$ 20,970	$ 20,009	$ 75,272	$ 80,349	$ 60,042
Adjustments to reconcile net income to net cash provided by operating activities:
Securities gains, net									(6,973)	(11,340)	(13,143)
Gain on extinguishment of debt									(1,280)	0	0
Other, net									(14,148)	(6,769)	(440)
NET CASH PROVIDED BY OPERATING ACTIVITIES									155,930	148,525	102,162
Cash flows from investing activities:
Proceeds from sales of available for sale securities									1,456,750	909,942	1,115,359
Proceeds from the maturity of and principal paydowns on other investments									0	0	619
Proceeds from the sale of other investments									2,790	5,673	15,327
Net assets acquired									71,089	8,084	41,744
NET CASH PROVIDED (USED) BY INVESTING ACTIVITIES									27,298	6,855	(68,988)
Cash flows from financing activities:
Proceeds on short-term revolving credit line									20,000	0	0
Proceeds from other borrowings									0	40,000	29,000
Repayments on short-term revolving credit line									(20,000)	0	0
Repayments of other borrowings									(9,645)	(21,636)	(173,739)
Payment for the redemption of debt									(13,800)	0	0
Redemption of preferred stock									0	(81,698)	0
Cash dividends paid									(14,557)	(12,870)	(10,176)
Purchase of treasury stock									(625)	(3,719)	(2,987)
Proceeds from issuance of common stock									963	54,196	3,508
NET CASH PROVIDED (USED) BY FINANCING ACTIVITIES									(145,949)	(255,455)	151,754
Net increase (decrease) in cash and cash equivalents									37,279	(100,075)	184,928
Cash and cash equivalents at beginning of year				158,724				258,799	158,724	258,799	73,871
CASH AND CASH EQUIVALENTS AT END OF PERIOD	196,003				158,724				196,003	158,724	258,799
Supplemental disclosure:
Conversion of convertible debt to common stock									558	1,442	0
Conversion of Series D preferred stock to common stock									419	2,420	0
Stock consideration granted for acquisitions									175,196	57,433	120,070
Parent
Cash flows from operating activities:
Net income									75,272	80,349	60,042
Adjustments to reconcile net income to net cash provided by operating activities:
Undistributed (earnings) losses of subsidiaries									(16,212)	(37,926)	(2,570)
Securities gains, net									(3,021)	(54)	(3,038)
Gain on extinguishment of debt									(1,200)	0	0
Increase (decrease) in accrued expenses and other liabilities									(4,160)	(7,039)	4,550
(Increase) decrease in other assets									(567)	1,948	(7,379)
Excess tax benefits on exercised stock options									1,246	374	676
Other, net									4,714	4,892	5,014
NET CASH PROVIDED BY OPERATING ACTIVITIES									56,072	42,544	57,295
Cash flows from investing activities:
Capital contributions to subsidiaries									0	(18,000)	(114,602)
Proceeds from sales of available for sale securities									2,868	0	3,774
Proceeds from the maturity of and principal paydowns on other investments									0	0	619
Proceeds from the sale of other investments									211	94	0
Net assets acquired									(62,813)	(14,587)	44,066
NET CASH PROVIDED (USED) BY INVESTING ACTIVITIES									(59,734)	(32,493)	(66,143)
Cash flows from financing activities:
Proceeds on short-term revolving credit line									20,000	0	0
Proceeds from other borrowings									0	40,000	15,000
Repayments on short-term revolving credit line									(20,000)	0	0
Repayments of other borrowings									(9,016)	(26,280)	(35,557)
Payment for the redemption of debt									(13,800)	0	0
Redemption of preferred stock									0	(81,698)	0
Cash dividends paid									(14,557)	(12,870)	(10,176)
Purchase of treasury stock									(625)	(3,719)	(2,987)
Proceeds from issuance of common stock									963	54,196	3,508
NET CASH PROVIDED (USED) BY FINANCING ACTIVITIES									(37,035)	(30,371)	(30,212)
Net increase (decrease) in cash and cash equivalents									(40,697)	(20,320)	(39,060)
Cash and cash equivalents at beginning of year				$ 65,007				$ 85,327	65,007	85,327	124,387
CASH AND CASH EQUIVALENTS AT END OF PERIOD	$ 24,310				$ 65,007				24,310	65,007	85,327
Supplemental disclosure:
Conversion of convertible debt to common stock									558	1,442	0
Conversion of Series D preferred stock to common stock									419	2,420	0
Stock consideration granted for acquisitions									$ 175,196	$ 57,433	$ 120,070

Summary of Quarterly Financi141

Summary of Quarterly Financial Information (Unaudited) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Quarterly Financial Information Disclosure [Abstract]
Net Interest Income	$ 92,856	$ 89,844	$ 74,580	$ 73,028	$ 75,160	$ 73,681	$ 73,118	$ 72,707	$ 330,308	$ 294,666	$ 233,998
Provision for loan losses	5,328	5,705	889	3,641	2,181	5,328	2,118	2,067	15,563	11,694	12,697
NET INTEREST INCOME AFTER PROVISION FOR LOAN LOSSES	87,528	84,139	73,691	69,387	72,979	68,353	71,000	70,640	314,745	282,972	221,301
Noninterest income	25,528	24,977	25,624	25,893	24,455	28,542	31,026	29,578	102,022	113,601	110,685
Noninterest expense	77,878	78,759	69,298	71,740	69,912	68,427	71,020	70,309	297,675	279,668	251,046
Income taxes	21,506	8,725	8,059	5,530	8,360	8,260	10,036	9,900	43,820	36,556	20,898
NET INCOME	13,672	21,632	21,958	18,010	19,162	20,208	20,970	20,009	75,272	80,349	60,042
Preferred dividends	(13)	(13)	(13)	(19)	(19)	(53)	(52)	(168)	(58)	(292)	(817)
Interest expense on convertible preferred debt	0	3	4	5	3	17	31	0	12	51	0
NET INCOME AVAILABLE TO COMMON STOCKHOLDERS	$ 13,659	$ 21,622	$ 21,949	$ 17,996	$ 19,146	$ 20,172	$ 20,949	$ 19,841	$ 75,226	$ 80,108	$ 59,225
Per share:
Earnings per share — basic (in dollars per share)	$ 0.46	$ 0.73	$ 0.82	$ 0.68	$ 0.75	$ 0.82	$ 0.85	$ 0.84	$ 2.67	$ 3.26	$ 2.87
Earnings per share — diluted (in dollars per share)	0.45	0.72	0.81	0.68	0.74	0.81	0.84	0.82	2.65	3.22	2.83
Cash dividends declared on common stock (in dollars per share)	0.18	0.11	0.11	0.11	0.20	0.10	0.10	0.10	$ 0.51	$ 0.50	$ 0.45
Book value per common share (in dollars per share)	$ 33.07	$ 32.75	$ 30.15	$ 29.26	$ 28.31	$ 28.48	$ 27.88	$ 27.15
Weighted average common shares outstanding (in shares)	29,948,536	29,647,534	26,686,845	26,334,788	25,498,423	24,601,016	24,524,273	23,657,234	28,168,000	24,573,000	20,672,000
Weighted average diluted common shares outstanding (in shares)	30,209,043	29,910,437	26,972,580	26,627,830	25,800,472	24,922,946	24,974,995	24,117,384	28,426,000	24,873,000	20,929,000