MidWestOne Financial (MOFG) 10-Q 5 Nov 18 2018 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information Document - shares	9 Months Ended
	Sep. 30, 2018	Oct. 31, 2018
Document Information [Line Items]
Entity Registrant Name	MIDWESTONE FINANCIAL GROUP, INC.
Entity Central Index Key	1,412,665
Trading Symbol	MOFG
Document Type	10-Q
Document Period End Date	Sep. 30, 2018
Amendment Flag	false
Current Fiscal Year End Date	--12-31
Entity Current Reporting Status	Yes
Entity Filer Category	Accelerated Filer
Document Fiscal Year Focus	2,018
Document Fiscal Period Focus	Q3
Entity Emerging Growth Company	false
Entity Small Business	false
Entity Common Stock, Shares Outstanding		12,221,547

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
ASSETS
Cash and due from banks	$ 49,229	$ 44,818
Interest-earning deposits in banks	4,150	5,474
Federal funds sold	0	680
Cash and cash equivalents	53,379	50,972
Investment securities:
Equity securities, at fair value	2,797	2,336
Debt securities available for sale, at fair value	407,766	445,324
Held to maturity securities at amortized cost (fair value of $186,057 at September 30, 2018 and $194,343 at December 31, 2017)	191,733	195,619
Loans held for sale	1,124	856
Loans held for investment, net of unearned fees	2,377,649	2,286,695
Less: Allowance for loan losses	(31,278)	(28,059)
Loans held for investment, net	2,346,371	2,258,636
Premises and equipment, net	76,497	75,969
Interest receivable	14,800	14,732
Goodwill	64,654	64,654
Other intangible assets, net	10,378	12,046
Bank-owned life insurance	60,609	59,831
Other real estate owned	549	2,010
Deferred income taxes	9,993	6,525
Other assets	27,315	22,761
Total assets	3,267,965	3,212,271
Deposits:
Non-interest-bearing demand	458,576	461,969
Interest-bearing checking	1,236,922	1,228,112
Savings	211,591	213,430
Certificates of deposit under $100,000	348,099	324,681
Certificates of deposit $100,000 and over	377,071	377,127
Total deposits	2,632,259	2,605,319
Federal funds purchased	19,056	1,000
Securities sold under agreements to repurchase	68,922	96,229
Federal Home Loan Bank borrowings	143,000	115,000
Junior subordinated notes issued to capital trusts	23,865	23,793
Long-term debt	8,750	12,500
Deferred compensation liability	5,305	5,199
Interest payable	2,054	1,428
Other liabilities	15,565	11,499
Total liabilities	2,918,776	2,871,967
Shareholders' equity:
Preferred stock, no par value; authorized 500,000 shares; no shares issued and outstanding at September 30, 2018 and December 31, 2017	0	0
Common stock, $1.00 par value; authorized 30,000,000 shares at September 30, 2018 and December 31, 2017; issued 12,463,481 shares at September 30, 2018 and December 31, 2017; 12,221,107 outstanding shares at September 30, 2018 and 12,219,611 shares at December 31, 2017	12,463	12,463
Additional paid-in capital	187,581	187,486
Treasury stock at cost, 242,374 shares as of September 30, 2018 and 243,870 shares as of December 31, 2017	(5,474)	(5,121)
Retained earnings	163,709	148,078
Accumulated other comprehensive income	(9,090)	(2,602)
Total shareholders' equity	349,189	340,304
Total liabilities and shareholders' equity	$ 3,267,965	$ 3,212,271

Consolidated Balance Sheets Par

Consolidated Balance Sheets Parenthetical (Parentheticals) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Debt securities held to maturity, estimated fair value	$ 186,057	$ 194,343
Shareholders' equity:
Preferred stock, par value	$ 0	$ 0
Preferred stock, shares authorized	500,000	500,000
Preferred stock, shares issued	0	0
Common stock, par value	$ 1	$ 1
Common stock, shares authorized	30,000,000	30,000,000
Common stock, shares issued	12,463,481	12,463,481
Common stock, shares outstanding	12,221,107	12,219,611
Shares of Treasury stock	242,374	243,870

Consolidated Statements of Inco

Consolidated Statements of Income - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Interest income:
Loans	$ 28,088	$ 26,206	$ 82,141	$ 76,135
Bank deposits	12	19	38	50
Federal funds sold	0	0	1	1
Taxable securities	2,965	2,589	8,793	7,897
Tax-exempt securities	1,395	1,547	4,452	4,699
Total interest income	32,460	30,361	95,425	88,782
Interest expense:
Interest-bearing checking	1,622	913	3,998	2,623
Savings	63	53	189	155
Certificates of deposit under $100,000	1,270	893	3,399	2,638
Certificates of deposit $100,000 and over	1,670	1,041	4,584	2,953
Total interest expense on deposits	4,625	2,900	12,170	8,369
Federal funds purchased	144	81	480	152
Securities sold under agreements to repurchase	173	53	451	125
Federal Home Loan Bank borrowings	741	474	1,873	1,321
Other borrowings	3	3	9	9
Junior subordinated notes issued to capital trusts	313	243	878	704
Long-term debt	100	115	309	338
Total interest expense	6,099	3,869	16,170	11,018
Net interest income	26,361	26,492	79,255	77,764
Provision for loan losses	950	4,384	4,050	6,665
Net interest income after provision for loan losses	25,411	22,108	75,205	71,099
Noninterest income:
Trust, investment and insurance fees	1,526	1,454	4,703	4,594
Service charges and fees on deposit accounts	1,148	1,295	3,474	3,835
Loan origination and servicing fees	891	1,012	2,738	2,532
Other service charges and fees	1,502	1,625	4,464	4,580
Bank-owned life insurance income	399	344	1,229	990
Gain on sale or call of debt securities	192	176	197	239
Other gain	326	10	338	66
Total noninterest income	5,984	5,916	17,143	16,836
Noninterest expense:
Salaries and employee benefits	13,051	12,039	37,647	35,712
Occupancy and equipment, net	3,951	2,986	10,440	9,323
Professional fees	1,861	933	3,614	2,991
Data processing	697	723	2,076	1,982
FDIC insurance	393	238	1,104	957
Amortization of intangibles	547	759	1,793	2,412
Other	2,311	2,066	7,026	6,666
Total noninterest expense	22,811	19,744	63,700	60,043
Income before income tax expense	8,584	8,280	28,648	27,892
Income tax expense	1,806	1,938	5,921	7,603
Net income	$ 6,778	$ 6,342	$ 22,727	$ 20,289
Per share information:
Earnings per common share - basic	$ 0.55	$ 0.52	$ 1.86	$ 1.69
Earnings per common share - diluted	0.55	0.52	1.86	1.69
Dividends paid per common share	$ 0.195	$ 0.170	$ 0.585	$ 0.500

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income Statement - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Net income	$ 6,778	$ 6,342	$ 22,727	$ 20,289
Other comprehensive income, available for sale debt securities:
Unrealized holding gains (losses) arising during period	(2,085)	(1,158)	(8,501)	3,154
Reclassification adjustment for gains included in net income	(192)	(176)	(201)	(196)
Income tax (expense) benefit	594	526	2,271	(1,160)
Other comprehensive income (loss) on available for sale debt securities	(1,683)	(808)	(6,431)	1,798
Other comprehensive income (loss), net of tax	(1,683)	(808)	(6,431)	1,798
Comprehensive income	$ 5,095	$ 5,534	16,296	22,087
AOCI Attributable to Parent [Member]
Net income			0	0
Other comprehensive income, available for sale debt securities:
Other comprehensive income (loss), net of tax			$ (6,431)	$ 1,798

Consolidated Statements of Shar

Consolidated Statements of Shareholders' Equity - USD ($) $ in Thousands	Total		Preferred Stock	Common Stock	Additional Paid-in Capital	Treasury Stock	Retained Earnings	Accumulated Other Comprehensive Income (Loss)
Balance at Dec. 31, 2016	$ 305,456		$ 0	$ 11,713	$ 163,667	$ (5,766)	$ 136,975	$ (1,133)
Net income	20,289		0	0	0	0	20,289	0
Issuance of common stock, net of expenses	24,360		0	750	23,610	0	0	0
Dividends paid on common stock	(5,984)		0	0	0	0	(5,984)	0
Stock options exercised	91		0	0	(81)	172	0	0
Release/lapse of restriction on RSUs	(107)		0	0	(560)	453	0	0
Stock compensation	660		0	0	660	0	0
Other comprehensive income (loss), net of tax	1,798		0	0	0	0	0	1,798
Balance at Sep. 30, 2017	346,563		0	12,463	187,296	(5,141)	151,280	665
Balance at Dec. 31, 2017	340,304		0	12,463	187,486	(5,121)	148,078	(2,602)
Cumulative effect of changes in accounting principles	0	[1]	0	0	0	0	57	(57)
Net income	22,727		0	0	0	0	22,727	0
Dividends paid on common stock	(7,153)		0	0	0	0	(7,153)	0
Stock options exercised	136		0	0	(68)	204	0	0
Release/lapse of restriction on RSUs	(85)		0	0	(609)	524	0	0
Repurchase of common stock	(1,081)					(1,081)
Stock compensation	772		0	0	772	0	0	0
Other comprehensive income (loss), net of tax	(6,431)		0	0	0	0	0	(6,431)
Balance at Sep. 30, 2018	$ 349,189		$ 0	$ 12,463	$ 187,581	$ (5,474)	$ 163,709	$ (9,090)
[1]

Consolidated Statement of Share

Consolidated Statement of Shareholders' Equity Parenthetical (Parentheticals) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017
Dividends paid on common stock (per share)	$ 0.585	$ 0.500
Common Stock
Repurchase of common stock (shares)	33,998	0
Common Stock
Issuance of common stock (shares)	0	750,000
Stock options exercised (shares)	9,700	8,250
Release/lapse of restriction on RSUs (shares)	28,525	26,875
Additional Paid-in Capital
Expenses incurred in issuance of common stock	$ 0	$ 1,328

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017
Cash flows from operating activities:
Net income	$ 22,727	$ 20,289
Adjustments to reconcile net income to net cash provided by operating activities:
Provision for loan losses	4,050	6,665
Depreciation, amortization and accretion	3,217	3,088
Amortization of other intangibles	1,793	2,412
Amortization of premiums and discounts on investment securities, net	(729)	(913)
(Gain) loss on sale of premises and equipment	616	(2)
Deferred income taxes	1,184	554
Excess tax benefit from share-based award activity	(14)	(91)
Stock-based compensation	772	660
Net losses on equity securities	34	0
Net gain on sale or call of debt securities available for sale	(201)	(196)
Net (gain) loss on sale or call of debt securities held to maturity	4	(43)
Net gain on sale of other real estate owned	(240)	(45)
Net gain on sale of loans held for sale	(1,214)	(1,337)
Writedown of other real estate owned	5	23
Origination of loans held for sale	49,091	65,078
Proceeds from sales of loans held for sale	50,037	70,044
Increase in interest receivable	(68)	0
Increase in cash surrender value of bank-owned life insurance	(1,229)	(990)
Increase in other assets	(4,554)	(2,224)
Increase (decrease) in deferred compensation liability	106	(22)
Increase in interest payable, accounts payable, accrued expenses, and other liabilities	4,692	445
Net cash provided by operating activities	30,987	33,957
Cash flows from investing activities:
Purchases of equity securities	(508)	(7)
Proceeds from sales of debt securities available for sale	16,494	22,546
Proceeds from maturities and calls of debt securities available for sale	51,338	53,171
Purchases of debt securities available for sale	(39,289)	(23,038)
Proceeds from sales of debt securities held to maturity	0	1,153
Proceeds from maturities and calls of debt securities held to maturity	4,220	12,370
Purchases of debt securities held to maturity	(553)	(28,546)
Net increase in loans	(92,320)	(100,880)
Purchases of premises and equipment	(5,196)	(3,035)
Proceeds from sale of other real estate owned	2,231	983
Proceeds from sale of premises and equipment	906	32
Proceeds of principal and earnings from bank-owned life insurance	452	0
Purchases of bank owned life insurance	0	11,211
Payments to acquire intangible assets	125	0
Net cash used in investing activities	(62,350)	(76,462)
Cash flows from financing activities:
Net increase in deposits	26,940	9,967
Increase (decrease) in federal funds purchased	18,056	(18,976)
Increase (decrease) in securities sold under agreements to repurchase	(27,307)	5,777
Proceeds from Federal Home Loan Bank borrowings	110,000	145,000
Repayment of Federal Home Loan Bank borrowings	(82,000)	(115,000)
Proceeds from stock options exercised	136	1
Excess tax benefit from share-based award activity	14	91
Taxes paid relating to net share settlement of equity awards	(85)	(108)
Payments on long-term debt	(3,750)	(3,750)
Dividends paid	(7,153)	(5,984)
Proceeds from issuance of common stock	0	25,688
Payments of stock issuance costs	0	(1,328)
Repurchase of common stock	(1,081)	0
Net cash provided by financing activities	33,770	41,378
Net increase (decrease) in cash and cash equivalents	2,407	(1,127)
Cash and cash equivalents at beginning of period	50,972	43,228
Cash and cash equivalents at end of period	53,379	42,101
Supplemental disclosures of cash flow information:
Cash paid during the period for interest	15,544	11,041
Cash paid during the period for income taxes	4,420	8,460
Supplemental schedule of non-cash investing activities:
Transfer of loans to other real estate owned	535	207
Accounting Standards Update 2016-01
Supplemental schedule of non-cash investing activities:
Transfer due to cumulative effective of change in accounting principles. See Note 2. “Effect of New Financial Accounting Standards” for additional information.	$ 57	$ 0

Derivatives and Hedging Activit

Derivatives and Hedging Activities Schedule of Other Derivatives Not Designated as Hedging Instruments - Other Gain (Loss) - Not Designated as Hedging Instrument - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Derivative Instruments, Gain (Loss) [Line Items]
Other gain (loss), net	$ 147	$ 0	$ 127	$ 0
Interest Rate Swap
Derivative Instruments, Gain (Loss) [Line Items]
Other gain (loss), net	0	0	(20)	0
Risk Participation Agreement
Derivative Instruments, Gain (Loss) [Line Items]
Other gain (loss), net	$ 147	$ 0	$ 147	$ 0

Derivatives and Hedging Activ_2

Derivatives and Hedging Activities Offsetting Derivative Assets and Liabilities - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Derivative Asset [Abstract]
Gross amount of recognized assets	$ 205	$ 0
Gross amount offset in the balance sheet	0	0
Net amount of assets presented in the balance sheet	205	0
Financial instruments	100	0
Cash collateral received	0	0
Net assets	105	0
Derivative Liability [Abstract]
Gross amount of recognized liabilities	(178)	0
Gross amount offset in the balance sheet	0	0
Net amount of liabilities presented in the balance sheet	178	0
Financial instruments	100	0
Cash collateral paid	0	0
Net liabilities	$ 78	$ 0

Principles of Consolidation and

Principles of Consolidation and Presentation	9 Months Ended
	Sep. 30, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization, Consolidation and Presentation of Financial Statements Disclosure [Text Block]	Principles of Consolidation and Presentation MidWest One Financial Group, Inc. (the “Company,” which is also referred to herein as “we,” “our” or “us”) is an Iowa corporation incorporated in 1983, a bank holding company under the Bank Holding Company Act of 1956, as amended, and a financial holding company under the Gramm-Leach-Bliley Act of 1999. Our principal executive offices are located at 102 South Clinton Street, Iowa City, Iowa 52240. On August 21, 2018, the Company entered into a merger agreement with ATBancorp, an Iowa corporation, pursuant to which ATBancorp will merge with and into the Company. In connection with the merger, American Trust & Savings Bank, an Iowa state chartered bank and wholly owned subsidiary of ATBancorp, and American Bank & Trust Wisconsin, a Wisconsin state chartered bank and wholly owned subsidiary of ATBancorp, will merge with and into MidWest One Bank, which will continue as the surviving bank. The merger agreement also provides that each of the outstanding shares of ATBancorp common stock will be converted into the right of ATBancorp shareholders to receive 117.5500 shares of Company common stock and $992.51 in cash. The corporate headquarters of the combined company will be in Iowa City, Iowa. The merger is anticipated to be completed in the first quarter of 2019. For further information, please refer to the Current Report on Form 8-K filed by the Company with the SEC on August 22, 2018. The Company owns all of the common stock of MidWest One Bank, an Iowa state non-member bank chartered in 1934 with its main office in Iowa City, Iowa (the “Bank”), and all of the common stock of MidWest One Insurance Services, Inc., Oskaloosa, Iowa. We operate primarily through MidWest One Bank, our bank subsidiary, and MidWest One Insurance Services, Inc., our wholly owned subsidiary that operates an insurance agency business through six offices located in central and east-central Iowa. The accompanying unaudited consolidated financial statements have been prepared in accordance with the instructions to Form 10-Q and, therefore, do not include all the information and notes necessary for complete financial statements in conformity with U.S. generally accepted accounting principles (“GAAP”). The information in this Quarterly Report on Form 10-Q is written with the presumption that the users of the interim financial statements have read or have access to the most recent Annual Report on Form 10-K of the Company, filed with the Securities and Exchange Commission (SEC) on March 1, 2018 , which contains the latest audited financial statements and notes thereto, together with Management’s Discussion and Analysis of Financial Condition and Results of Operations as of December 31, 2017 and for the year then ended. Management believes that the disclosures in this Form 10-Q are adequate to make the information presented not misleading. In the opinion of management, the accompanying consolidated financial statements contain all adjustments (consisting of only normal recurring accruals) necessary to present fairly the Company’s financial position as of September 30, 2018 and December 31, 2017 , and the results of operations and cash flows for the three and nine months ended September 30, 2018 and 2017 . All significant intercompany accounts and transactions have been eliminated in consolidation. The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect: (1) the reported amounts of assets and liabilities, (2) the disclosure of contingent assets and liabilities at the date of the financial statements, and (3) the reported amounts of revenues and expenses during the reporting period. These estimates are based on information available to management at the time the estimates are made. Actual results could differ from those estimates. The results for the three and nine months ended September 30, 2018 may not be indicative of results for the year ending December 31, 2018 , or for any other period. All significant accounting policies followed in the preparation of the quarterly financial statements are disclosed in the Annual Report on Form 10-K for the year ended December 31, 2017 . In the consolidated statements of cash flows, cash and cash equivalents include cash and due from banks, interest-bearing deposits in banks, and federal funds sold. Certain reclassifications have been made to prior periods’ consolidated financial statements to present them on a basis comparable with the current period’s consolidated financial statements.

Effect of New Financial Account

Effect of New Financial Accounting Standards	9 Months Ended
	Sep. 30, 2018
New Accounting Pronouncements and Changes in Accounting Principles [Abstract]
New Accounting Pronouncements and Changes in Accounting Principles [Text Block]	Effect of New Financial Accounting Standards Accounting Guidance Adopted in 2018 In May 2014, the Financial Accounting Standards Board (the “FASB”) issued Accounting Standards Update (“ASU”) No. 2014-09, Revenue from Contract with Customers (Topic 606). Subsequent to the issuance of ASU 2014-09, the FASB issued targeted updates to clarify specific implementation issues including ASU No. 2016-08, “ Principal versus Agent Considerations (Reporting Revenue Gross versus Net) ,” ASU No. 2016-10, “ Identifying Performance Obligations and Licensing, ” ASU No. 2016-12, “ Narrow-Scope Improvements and Practical Expedients, ” and ASU No. 2016-20 “ Technical Corrections and Improvements to Topic 606, Revenue from Contracts with Customers. ” For financial reporting purposes, the standard allows for either full retrospective adoption, meaning the standard is applied to all of the periods presented, or modified retrospective adoption, meaning the standard is applied only to the most current period presented in the financial statements with the cumulative effect of initially applying the standard recognized at the date of initial application. Since the guidance does not apply to revenue associated with financial instruments, including loans and securities that are accounted for under other sections of GAAP, the new guidance did not have a material impact on revenue most closely associated with financial instruments, including interest income and expense. The Company completed its overall assessment of revenue streams and review of related contracts potentially affected by the ASU, including trust and asset management fees, service charges on deposit accounts, sales of other real estate, and debit card interchange fees. Based on this assessment, the Company concluded that ASU 2014-09 did not materially change the method in which the Company currently recognizes revenue for these revenue streams. The Company also completed its evaluation of certain costs related to these revenue streams to determine whether such costs should be presented as expenses or contra-revenue (i.e., gross versus net). Based on its evaluation, the Company determined that ASU 2014-09 also did not materially change the method in which the Company currently recognizes costs for these revenue streams. The Company adopted this update on January 1, 2018, utilizing the modified retrospective transition method. Since there was no net income impact upon adoption of the new guidance, a cumulative effect adjustment to opening retained earnings was not deemed necessary. See Note 14 “Revenue Recognition” for more information. In January 2016, the FASB issued Accounting Standards Update No. 2016-01, Financial Instruments-Overall: Recognition and Measurement of Financial Assets and Financial Liabilities. The guidance in this update makes changes to the current GAAP model primarily affect the accounting for equity investments, financial liabilities under the fair value option, and the presentation and disclosure requirements for financial instruments. In addition, the FASB clarified guidance related to the valuation allowance assessment when recognizing deferred tax assets resulting from unrealized losses on available-for-sale debt securities. The accounting for other financial instruments, such as loans, investments in debt securities, and financial liabilities is largely unchanged. The treatment of gains and losses for all equity securities, including those without a readily determinable market value, is expected to result in additional volatility in the income statement, with the loss of mark to market via equity for these investments. Additionally, changes in the allowable method for determining the fair value of financial instruments in the financial statement footnotes (“exit price” only) require changes to current methodologies of determining these values, and how they are disclosed in the financial statement footnotes. The new standard applies to public business entities in fiscal years beginning after December 15, 2017, including interim periods within those fiscal years. The Company adopted this update on January 1, 2018. With the elimination of the classification of available for sale equity securities, the net unrealized gain or loss on these securities that had been included in accumulated other comprehensive income at December 31, 2017, in the amount of $57,000 , has been transferred to retained earnings, as shown in the consolidated statements of shareholders’ equity. Changes in the fair value of equity securities with readily determinable fair values are now reflected in the noninterest income portion of the consolidated statements of income, in the other gains (losses) line item. In accordance with the ASU requirements, the Company measured the fair value of its loan portfolio as of September 30, 2018 using an exit price notion. See Note 13. “Estimated Fair Value of Financial Instruments and Fair Value Measurements” to our consolidated financial statements. Accounting Guidance Pending Adoption at September 30, 2018 In February 2016, the FASB issued Accounting Standards Update No. 2016-02, Leases (Topic 842) . The guidance in this update is meant to increase transparency and comparability among organizations by recognizing lease assets and lease liabilities on the balance sheet and disclosing key information about leasing arrangements. The core principle of Topic 842 is that a lessee should recognize the assets and liabilities that arise from leases. All leases create an asset and a liability for the lessee in accordance with FASB Concepts Statement No. 6, Elements of Financial Statements , and, therefore, recognition of those lease assets and lease liabilities represents an improvement over previous GAAP, which did not require lease assets and lease liabilities to be recognized for most leases. Disclosures are required by lessees and lessors to meet the objective of enabling users of financial statements to assess the amount, timing, and uncertainty of cash flows arising from leases. To meet that objective, qualitative disclosures along with specific quantitative disclosures are required. The new standard applies to public business entities in fiscal years beginning after December 15, 2018, including interim periods within those fiscal years, with early adoption permitted. The Company has several lease agreements, such as branch locations, which are currently considered operating leases, and therefore not recognized on the Company’s consolidated balance sheets. The Company expects the new guidance will require these lease agreements to now be recognized on the consolidated balance sheets as right-of-use assets and a corresponding lease liability. Therefore, the Company’s preliminary evaluation indicates the provisions of ASU No. 2016-02 are expected to impact the Company’s consolidated statements of income, along with the Company’s regulatory capital ratios. However, the Company continues to evaluate the extent of potential impact the new guidance will have on the Company’s consolidated financial statements, and does not expect to early adopt the standard. In June 2016, the FASB issued Accounting Standards Update No. 2016-13, Financial Instruments-Credit Losses (Topic 326) - Measurement of Credit Losses on Financial Instruments . The new guidance introduces an approach based on expected losses to estimate credit losses on certain types of financial instruments. It also modifies the impairment model for available-for-sale debt securities and provides for a simplified accounting model for purchased financial assets with credit deterioration since their origination. The amendment requires the use of a new model covering current expected credit losses (CECL), which will apply to: (1) financial assets subject to credit losses and measured at amortized cost, and (2) certain off-balance sheet credit exposures. Upon initial recognition of the exposure, the CECL model requires an entity to estimate the credit losses expected over the life of an exposure (or pool of exposures). The estimate of expected credit losses (ECL) should consider historical information, current information, and reasonable and supportable forecasts, including estimates of prepayments. The new guidance also amends the current available for sale (AFS) security other-than-temporary impairment (OTTI) model for debt securities. The new model will require an estimate of ECL only when the fair value is below the amortized cost of the asset. The length of time the fair value of an AFS debt security has been below the amortized cost will no longer impact the determination of whether a credit loss exists. As such, it is no longer an other-than-temporary model. Finally, the purchased financial assets with credit deterioration (PCD) model applies to purchased financial assets (measured at amortized cost or AFS) that have experienced more than insignificant credit deterioration since origination. This represents a change from the scope of what are considered purchased credit-impaired assets under today’s model. Different than the accounting for originated or purchased assets that do not qualify as PCD, the initial estimate of expected credit losses for a PCD would be recognized through an allowance for loan and lease losses with an offset to the cost basis of the related financial asset at acquisition. The new standard applies to public business entities that are SEC filers in fiscal years beginning after December 15, 2019, including interim periods within those fiscal years, with early adoption permitted for fiscal years beginning after December 31, 2018, including interim periods within those fiscal years, and is expected to increase the allowance for loan losses upon adoption. The Company has formed a working group to evaluate the impact of the standard’s adoption on the Company’s consolidated financial statements, and has selected a software vendor to assist with implementation. The team meets periodically to discuss the latest developments, ensure progress is being made, and keep current on evolving interpretations and industry practices related to ASU 2016-13. The Company’s preliminary evaluation indicates the provisions of ASU No. 2016-13 are expected to impact the Company’s consolidated financial statements, in particular the level of the reserve for credit losses. The Company is continuing to evaluate the extent of the potential impact. In August 2018, the FASB issued Accounting Standards Update No. 2018-13, Fair Value Measurement (Topic 820): Disclosure Framework-Changes to the Disclosure Requirements for Fair Value Measurement. The amendments in this update modify the disclosure requirements on fair value measurements in Topic 820, Fair Value Measurement, including the consideration of costs and benefits. Four disclosure requirements were removed, three were modified, and two were added. In addition, the amendments eliminate “ at a minimum” from the phrase “ an entity shall disclose at a minimum”

Investment Securities

Investment Securities	9 Months Ended
	Sep. 30, 2018
Investments, Debt and Equity Securities [Abstract]
Investments in Debt and Marketable Equity Securities (and Certain Trading Assets) Disclosure [Text Block]	Investment Securities The amortized cost and fair value of debt securities available for sale, with gross unrealized gains and losses, were as follows: As of September 30, 2018 (in thousands) Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Estimated Fair Value U.S. Government agencies and corporations $ 5,561 $ — $ 42 $ 5,519 State and political subdivisions 115,251 716 831 115,136 Mortgage-backed securities 53,664 112 1,880 51,896 Collateralized mortgage obligations 179,748 3 8,874 170,877 Corporate debt securities 65,842 8 1,512 64,338 Total $ 420,066 $ 839 $ 13,139 $ 407,766 As of December 31, 2017 (in thousands) Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Estimated Fair Value U.S. Government agencies and corporations $ 15,716 $ — $ 90 $ 15,626 State and political subdivisions 139,561 2,475 197 141,839 Mortgage-backed securities 48,744 181 428 48,497 Collateralized mortgage obligations 173,339 29 5,172 168,196 Corporate debt securities 71,562 31 427 71,166 Total $ 448,922 $ 2,716 $ 6,314 $ 445,324 The amortized cost and fair value of debt securities held to maturity, with gross unrealized gains and losses, were as follows: As of September 30, 2018 (in thousands) Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Estimated Fair Value State and political subdivisions $ 125,783 $ 155 $ 3,743 $ 122,195 Mortgage-backed securities 11,467 1 564 10,904 Collateralized mortgage obligations 19,373 — 1,104 18,269 Corporate debt securities 35,110 98 519 34,689 Total $ 191,733 $ 254 $ 5,930 $ 186,057 As of December 31, 2017 (in thousands) Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Estimated Fair Value U.S. Government agencies and corporations $ 10,049 $ — $ — $ 10,049 State and political subdivisions 126,413 804 1,631 125,586 Mortgage-backed securities 1,906 4 13 1,897 Collateralized mortgage obligations 22,115 — 707 21,408 Corporate debt securities 35,136 548 281 35,403 Total $ 195,619 $ 1,356 $ 2,632 $ 194,343 Investment securities with a carrying value of $217.8 million and $237.4 million at September 30, 2018 and December 31, 2017 , respectively, were pledged on public deposits, securities sold under agreements to repurchase and for other purposes, as required or permitted by law. As of September 30, 2018 , the Company owned $0.4 million of equity securities in banks and financial service-related companies, and $2.4 million of mutual funds invested in debt securities and other debt instruments that will cause units of the fund to be deemed to be qualified under the Community Reinvestment Act. Prior to January 1, 2018, we accounted for our marketable equity securities at fair value with unrealized gains and losses recognized in accumulated other comprehensive income on the balance sheet. Realized gains and losses on marketable equity securities sold or impaired were recognized in noninterest income. Effective with the January 1, 2018 adoption of ASU 2016-01, both the realized and unrealized net gains and losses on equity securities are required to be recognized in the statement of income. A breakdown between net realized and unrealized gains and losses is provided later in this financial statement footnote. These net changes are included in the other gains line item in the noninterest income section of the Consolidated Statements of Income . The summary of investment securities shows that some of the securities in the available for sale and held to maturity investment portfolios had unrealized losses, or were temporarily impaired, as of September 30, 2018 and December 31, 2017 . This temporary impairment represents the estimated amount of loss that would be realized if the securities were sold on the valuation date. The following tables present information pertaining to securities with gross unrealized losses as of September 30, 2018 and December 31, 2017 , aggregated by investment category and length of time that individual securities have been in a continuous loss position: As of September 30, 2018 Number of Securities Less than 12 Months 12 Months or More Total Available for Sale Fair Value Unrealized Losses Fair Value Unrealized Losses Fair Value Unrealized Losses (in thousands, except number of securities) U.S. Government agencies and corporations 2 $ 539 $ 14 $ 4,980 $ 28 $ 5,519 $ 42 State and political subdivisions 115 46,374 697 5,350 134 51,724 831 Mortgage-backed securities 26 40,039 1,613 7,591 267 47,630 1,880 Collateralized mortgage obligations 41 44,912 1,269 116,814 7,605 161,726 8,874 Corporate debt securities 12 50,439 1,149 12,230 363 62,669 1,512 Total 196 $ 182,303 $ 4,742 $ 146,965 $ 8,397 $ 329,268 $ 13,139 As of December 31, 2017 Number of Securities Less than 12 Months 12 Months or More Total Fair Value Unrealized Losses Fair Value Unrealized Losses Fair Value Unrealized Losses (in thousands, except number of securities) U.S. Government agencies and corporations 3 $ 15,626 $ 90 $ — $ — $ 15,626 $ 90 State and political subdivisions 34 11,705 167 1,800 30 13,505 197 Mortgage-backed securities 20 37,964 359 3,961 69 41,925 428 Collateralized mortgage obligations 35 37,881 489 122,757 4,683 160,638 5,172 Corporate debt securities 12 55,340 298 8,778 129 64,118 427 Other equity securities 1 — — 1,944 56 1,944 56 Total 105 $ 158,516 $ 1,403 $ 139,240 $ 4,967 $ 297,756 $ 6,370 As of September 30, 2018 Number of Securities Less than 12 Months 12 Months or More Total Held to Maturity Fair Value Unrealized Losses Fair Value Unrealized Losses Fair Value Unrealized Losses (in thousands, except number of securities) State and political subdivisions 257 $ 54,969 $ 1,271 $ 33,512 $ 2,472 $ 88,481 $ 3,743 Mortgage-backed securities 6 10,016 524 820 40 10,836 564 Collateralized mortgage obligations 7 — — 18,259 1,104 18,259 1,104 Corporate debt securities 13 18,126 345 2,722 174 20,848 519 Total 283 $ 83,111 $ 2,140 $ 55,313 $ 3,790 $ 138,424 $ 5,930 As of December 31, 2017 Number of Securities Less than 12 Months 12 Months or More Total Fair Value Unrealized Losses Fair Value Unrealized Losses Fair Value Unrealized Losses (in thousands, except number of securities) State and political subdivisions 167 $ 33,237 $ 393 $ 25,843 $ 1,238 $ 59,080 $ 1,631 Mortgage-backed securities 4 349 2 887 11 1,236 13 Collateralized mortgage obligations 7 5,221 90 16,168 617 21,389 707 Corporate debt securities 3 3,093 4 2,617 277 5,710 281 Total 181 $ 41,900 $ 489 $ 45,515 $ 2,143 $ 87,415 $ 2,632 The Company's assessment of OTTI is based on its reasonable judgment of the specific facts and circumstances impacting each individual debt security at the time such assessments are made. The Company reviews and considers factual information, including expected cash flows, the structure of the debt security, the creditworthiness of the issuer, the type of underlying assets and the current and anticipated market conditions. At September 30, 2018 and December 31, 2017 , the Company’s mortgage-backed securities and collateralized mortgage obligations portfolios consisted of securities predominantly backed by one- to four-family mortgage loans and underwritten to the standards of and guaranteed by the following government-sponsored agencies: the Federal Home Loan Mortgage Corporation, the Federal National Mortgage Association, and the Government National Mortgage Association. The receipt of principal, at par, and interest on mortgage-backed securities is guaranteed by the respective government-sponsored agency guarantor, such that the Company believes that its mortgage-backed securities and collateralized mortgage obligations do not expose the Company to credit-related losses. At September 30, 2018 , approximately 53% of the municipal bonds held by the Company were Iowa-based, and approximately 24% were Minnesota-based. The Company does not intend to sell these municipal obligations, and it is more likely than not that the Company will not be required to sell them until the recovery of their cost. Due to the issuers’ continued satisfaction of their obligations under the securities in accordance with their contractual terms and the expectation that they will continue to do so, management’s intent and ability to hold these securities for a period of time sufficient to allow for any anticipated recovery in fair value, as well as the evaluation of the fundamentals of the issuers’ financial conditions and other objective evidence, the Company believed that the municipal obligations identified in the tables above were temporarily impaired as of September 30, 2018 and December 31, 2017 . At September 30, 2018 and December 31, 2017 , all but one of the Company’s corporate bonds held an investment grade rating from Moody’s, S&P or Kroll, or carried a guarantee from an agency of the US government. We have evaluated financial statements of the company issuing the non-investment grade bond and found the company’s earnings and equity position to be satisfactory and in line with industry norms. Therefore, we expect to receive all contractual payments. The internal evaluation of the non-investment grade bond along with the investment grade ratings on the remainder of the corporate portfolio lead us to conclude that all of the corporate bonds in our portfolio will continue to pay according to their contractual terms. Since the Company has the ability and intent to hold securities until price recovery, we believe that there is no other-than-temporary-impairment in the corporate bond portfolio. It is reasonably possible that the fair values of the Company’s investment securities could decline in the future if interest rates increase or the overall economy or the financial conditions of the issuers deteriorate. As a result, there is a risk that OTTI may be recognized in the future, and any such amounts could be material to the Company’s consolidated statements of income. Unless certain conditions are met, investment securities classified as held to maturity may not be sold without calling into question the Company’s intent to hold other debt securities so classified (“tainting”). One acceptable condition, outlined in Accounting Standards Codification 320-10-25-6(a), is the significant deterioration of an issuer’s creditworthiness. During the first quarter of 2017, $1.2 million of debt securities from a single issuer in the state and political subdivisions category were identified by the Company as having an elevated level of credit risk and were internally classified as “watch.” Given the significant deterioration of the issuer’s creditworthiness, the Company sold the debt securities in March 2017. The Company believes the sale was in accordance with applicable accounting guidance and did not taint the remainder of the held to maturity portfolio. The contractual maturity distribution of investment debt securities at September 30, 2018 , is summarized as follows: Available For Sale Held to Maturity (in thousands) Amortized Cost Fair Value Amortized Cost Fair Value Due in one year or less $ 27,913 $ 27,866 $ 734 $ 736 Due after one year through five years 99,630 98,105 24,275 23,867 Due after five years through ten years 55,757 55,700 97,511 95,353 Due after ten years 3,354 3,322 38,373 36,928 Debt securities without a single maturity date 233,412 222,773 30,840 29,173 Total $ 420,066 $ 407,766 $ 191,733 $ 186,057 Mortgage-backed securities and collateralized mortgage obligations are collateralized by mortgage loans and guaranteed by U.S. government agencies. Our experience has indicated that principal payments will be collected sooner than scheduled because of prepayments. Therefore, these securities are not scheduled in the maturity categories indicated above. Realized gains and losses on sales are determined on the basis of specific identification of investments based on the trade date. Realized gains (losses) on investments due to sale or call, including impairment losses for the three and nine months ended September 30, 2018 and 2017 , were as follows: Three Months Ended September 30, Nine Months Ended September 30, (in thousands) 2018 2017 2018 2017 Debt securities available for sale: Gross realized gains $ 194 $ 179 203 199 Gross realized losses (2 ) (3 ) (2 ) (3 ) Net realized gain $ 192 $ 176 $ 201 $ 196 Debt securities held to maturity: Gross realized gains $ — $ — $ — $ 43 Gross realized losses — — (4 ) — Net realized gain (loss) $ — $ — $ (4 ) $ 43 Total net realized gain on sale or call of debt securities $ 192 $ 176 $ 197 $ 239 The following tables present the net gains and losses on equity investments during the three and nine months ended September 30, 2018 , disaggregated into realized and unrealized gains and losses: Three Months Ended September 30, Nine Months Ended September 30, (in thousands) 2018 2017 2018 2017 Net losses recognized $ (10 ) $ — $ (34 ) $ — Less: Net gains and losses recognized due to sales — — — — Unrealized losses on securities still held at the reporting date $ (10 ) $ — $ (34 ) $ —

Loans Receivable and the Allowa

Loans Receivable and the Allowance for Loan Losses	9 Months Ended
	Sep. 30, 2018
Loans and Leases Receivable Disclosure [Abstract]
Loans, Notes, Trade and Other Receivables Disclosure [Text Block]	Loans Receivable and the Allowance for Loan Losses The composition of allowance for loan losses and loans by portfolio segment and based on impairment method are as follows: Allowance for Loan Losses and Recorded Investment in Loan Receivables As of September 30, 2018 and December 31, 2017 (in thousands) Agricultural Commercial and Industrial Commercial Real Estate Residential Real Estate Consumer Total September 30, 2018 Loans receivable Individually evaluated for impairment $ 6,711 $ 12,924 $ 17,375 $ 3,981 $ 8 $ 40,999 Collectively evaluated for impairment 96,496 510,357 1,223,311 450,246 38,788 2,319,198 Purchased credit impaired loans — 52 13,104 4,296 — 17,452 Total $ 103,207 $ 523,333 $ 1,253,790 $ 458,523 $ 38,796 $ 2,377,649 Allowance for loan losses: Individually evaluated for impairment $ 195 $ 3,059 $ 4,183 $ 143 $ — $ 7,580 Collectively evaluated for impairment 2,532 5,183 12,563 2,356 251 22,885 Purchased credit impaired loans — — 343 470 — 813 Total $ 2,727 $ 8,242 $ 17,089 $ 2,969 $ 251 $ 31,278 (in thousands) Agricultural Commercial and Industrial Commercial Real Estate Residential Real Estate Consumer Total December 31, 2017 Loans receivable Individually evaluated for impairment $ 2,969 $ 9,734 $ 10,386 $ 3,722 $ — $ 26,811 Collectively evaluated for impairment 102,543 493,844 1,147,133 460,475 36,158 2,240,153 Purchased credit impaired loans — 46 14,452 5,233 — 19,731 Total $ 105,512 $ 503,624 $ 1,171,971 $ 469,430 $ 36,158 $ 2,286,695 Allowance for loan losses: Individually evaluated for impairment $ 140 $ 1,126 $ 2,157 $ 226 $ — $ 3,649 Collectively evaluated for impairment 2,650 7,392 11,144 2,182 244 23,612 Purchased credit impaired loans — — 336 462 — 798 Total $ 2,790 $ 8,518 $ 13,637 $ 2,870 $ 244 $ 28,059 As of September 30, 2018 , the gross purchased credit impaired loans included above were $18.3 million , with a discount of $0.9 million . Loans with unpaid principal in the amount of $459.1 million and $477.6 million at September 30, 2018 and December 31, 2017 , respectively, were pledged to the Federal Home Loan Bank (the “FHLB”) as collateral for borrowings. The changes in the allowance for loan losses by portfolio segment were as follows: Allowance for Loan Loss Activity For the Three Months Ended September 30, 2018 and 2017 (in thousands) Agricultural Commercial and Industrial Commercial Real Estate Residential Real Estate Consumer Total 2018 Beginning balance $ 2,656 $ 8,557 $ 16,341 $ 2,990 $ 256 $ 30,800 Charge-offs (365 ) (108 ) (17 ) — (327 ) (817 ) Recoveries 41 78 77 131 18 345 Provision 395 (285 ) 688 (152 ) 304 950 Ending balance $ 2,727 $ 8,242 $ 17,089 $ 2,969 $ 251 $ 31,278 2017 Beginning balance $ 2,666 $ 7,959 $ 9,013 $ 2,650 $ 222 $ 22,510 Charge-offs (318 ) (534 ) — (75 ) (51 ) (978 ) Recoveries 150 113 201 126 4 594 Provision 67 2,157 1,166 915 79 4,384 Ending balance $ 2,565 $ 9,695 $ 10,380 $ 3,616 $ 254 $ 26,510 Allowance for Loan Loss Activity For the Nine Months Ended September 30, 2018 and 2017 (in thousands) Agricultural Commercial and Industrial Commercial Real Estate Residential Real Estate Consumer Total 2018 Beginning balance $ 2,790 $ 8,518 $ 13,637 $ 2,870 $ 244 $ 28,059 Charge-offs (633 ) (198 ) (281 ) (107 ) (365 ) (1,584 ) Recoveries 56 260 193 208 36 753 Provision 514 (338 ) 3,540 (2 ) 336 4,050 Ending balance $ 2,727 $ 8,242 $ 17,089 $ 2,969 $ 251 $ 31,278 2017 Beginning balance $ 2,003 $ 6,274 $ 9,860 $ 3,458 $ 255 $ 21,850 Charge-offs (1,202 ) (1,063 ) (106 ) (155 ) (211 ) (2,737 ) Recoveries 164 215 216 126 11 732 Provision 1,600 4,269 410 187 199 6,665 Ending balance $ 2,565 $ 9,695 $ 10,380 $ 3,616 $ 254 $ 26,510 Loan Portfolio Segment Risk Characteristics Agricultural - Agricultural loans, most of which are secured by crops, livestock, and machinery, are provided to finance capital improvements and farm operations as well as acquisitions of livestock and machinery. The ability of the borrower to repay may be affected by many factors outside of the borrower’s control including adverse weather conditions, loss of livestock due to disease or other factors, declines in market prices for agricultural products and the impact of government regulations. The ultimate repayment of agricultural loans is dependent upon the profitable operation or management of the agricultural entity. Collateral for these loans generally includes accounts receivable, inventory, equipment and real estate. However, depending on the overall financial condition of the borrower, some loans are made on an unsecured basis. The collateral securing these loans may depreciate over time, may be difficult to appraise and may fluctuate in value based on the success of the business. Commercial and Industrial - Commercial and industrial loans are primarily made based on the reported cash flow of the borrower and secondarily on the underlying collateral provided by the borrower. The collateral support provided by the borrower for most of these loans and the probability of repayment are based on the liquidation of the pledged collateral and enforcement of a personal guarantee, if any exists. The primary repayment risks of commercial and industrial loans are that the cash flows of the borrower may be unpredictable, and the collateral securing these loans may fluctuate in value. The size of the loans the Company can offer to commercial customers is less than the size of the loans that competitors with larger lending limits can offer. This may limit the Company’s ability to establish relationships with the largest businesses in the areas in which the Company operates. As a result, the Company may assume greater lending risks than financial institutions that have a lesser concentration of such loans and tend to make loans to larger businesses. Collateral for these loans generally includes accounts receivable, inventory, equipment and real estate. However, depending on the overall financial condition of the borrower, some loans are made on an unsecured basis. The collateral securing these loans may depreciate over time, may be difficult to appraise and may fluctuate in value based on the success of the business. In addition, a decline in the U.S. economy could harm or continue to harm the businesses of the Company’s commercial and industrial customers and reduce the value of the collateral securing these loans. Commercial Real Estate - The Company offers mortgage loans to commercial and agricultural customers for the acquisition of real estate used in their businesses, such as offices, warehouses and production facilities, and to real estate investors for the acquisition of apartment buildings, retail centers, office buildings and other commercial buildings. The market value of real estate securing commercial real estate loans can fluctuate significantly in a short period of time as a result of market conditions in the geographic area in which the real estate is located. Adverse developments affecting real estate values in one or more of the Company’s markets could increase the credit risk associated with its loan portfolio. Additionally, real estate lending typically involves higher loan principal amounts than other loans, and the repayment of the loans generally is dependent, in large part, on sufficient income from the properties securing the loans to cover operating expenses and debt service. Economic events or governmental regulations outside of the Company’s control or that of the borrower could negatively impact the future cash flow and market values of the affected properties. Residential Real Estate - The Company generally retains short-term residential mortgage loans that are originated for its own portfolio but sells most long-term loans to other parties while retaining servicing rights on the majority of those loans. The market value of real estate securing residential real estate loans can fluctuate as a result of market conditions in the geographic area in which the real estate is located. Adverse developments affecting real estate values in one or more of the Company’s markets could increase the credit risk associated with its loan portfolio. Additionally, real estate lending typically involves higher loan principal amounts than other loans, and the repayment of the loans generally is dependent, in large part, on the borrower’s continuing financial stability, and is therefore more likely to be affected by adverse personal circumstances. Consumer - Consumer loans typically have shorter terms, lower balances, higher yields and higher risks of default than real estate-related loans. Consumer loan collections are dependent on the borrower’s continuing financial stability, and are therefore more likely to be affected by adverse personal circumstances. Collateral for these loans generally includes automobiles, boats, recreational vehicles, mobile homes, and real estate. However, depending on the overall financial condition of the borrower, some loans are made on an unsecured basis. The collateral securing these loans may depreciate over time, may be difficult to recover and may fluctuate in value based on condition. In addition, a decline in the United States economy could result in reduced employment, impacting the ability of customers to repay their obligations. Purchased Loans Policy All purchased loans (nonimpaired and impaired) are initially measured at fair value as of the acquisition date in accordance with applicable authoritative accounting guidance. Credit discounts are included in the determination of fair value. An allowance for loan losses is not recorded at the acquisition date for loans purchased. Individual loans acquired through the completion of a transfer, including loans that have evidence of deterioration of credit quality since origination and for which it is probable, at acquisition, that the Company will be unable to collect all contractually required payments receivable, are referred to herein as “purchased credit impaired loans.” In determining the acquisition date fair value and estimated credit losses of purchased credit impaired loans, and in subsequent accounting, the Company accounts for loans individually. Contractually required payments for interest and principal that exceed the undiscounted cash flows expected at acquisition, or the “nonaccretable difference,” are not recognized as a yield adjustment or as a loss accrual or valuation allowance. Expected cash flows at the purchase date in excess of the fair value of loans, if any, are recorded as interest income over the expected life of the loans if the timing and amount of future cash flows are reasonably estimable. Subsequent to the purchase date, increases in cash flows over those expected at the purchase date are recognized as interest income prospectively. The present value of any decreases in expected cash flows after the purchase date is recognized by recording an allowance for loan losses and a provision for loan losses. If the Company does not have the information necessary to reasonably estimate cash flows to be expected, it may use the cost-recovery method or cash-basis method of income recognition. Charge-off Policy The Company requires a loan to be charged-off, in whole or in part, as soon as it becomes apparent that some loss will be incurred, or when its collectability is sufficiently questionable that it no longer is considered a bankable asset. The primary considerations when determining if and how much of a loan should be charged-off are as follows: (1) the potential for future cash flows; (2) the value of any collateral; and (3) the strength of any co-makers or guarantors. When it is determined that a loan requires a partial or full charge-off, a request for approval of a charge-off is submitted to the Company's President, Executive Vice President and Chief Credit Officer, and the Senior Regional Loan officer. The Bank's board of directors formally approves all loan charge-offs. Once a loan is charged-off, it cannot be restructured and returned to the Company's books. Allowance for Loan and Lease Losses The Company requires the maintenance of an adequate allowance for loan and lease losses (“ALLL”) in order to cover estimated probable losses without eroding the Company’s capital base. Calculations are done at each quarter end, or more frequently if warranted, to analyze the collectability of loans and to ensure the adequacy of the allowance. In line with FDIC directives, the ALLL calculation does not include consideration of loans held for sale or off-balance-sheet credit exposures (such as unfunded letters of credit). Determining the appropriate level for the ALLL relies on the informed judgment of management, and as such, is subject to inexactness. Given the inherently imprecise nature of calculating the necessary ALLL, the Company’s policy permits the actual ALLL to be between 20% above and 5% below the “indicated reserve.” Loans Reviewed Individually for Impairment The Company identifies loans to be reviewed and evaluated individually for impairment based on current information and events and the probability that the borrower will be unable to repay all amounts due according to the contractual terms of the loan agreement. Specific areas of consideration include: size of credit exposure, risk rating, delinquency, nonaccrual status, and loan classification. The level of individual impairment is measured using one of the following methods: (1) the fair value of the collateral less costs to sell; (2) the present value of expected future cash flows, discounted at the loan's effective interest rate; or (3) the loan's observable market price. Loans that are deemed fully collateralized or have been charged down to a level corresponding with any of the three measurements require no assignment of reserves from the ALLL. A loan modification is a change in an existing loan contract that has been agreed to by the borrower and the Bank, which may or may not be a troubled debt restructure or “TDR.” All loans deemed TDR are considered impaired. A loan is considered a TDR when, for economic or legal reasons related to a borrower’s financial difficulties, a concession is granted to the borrower that would not otherwise be considered. Both financial distress on the part of the borrower and the Bank’s granting of a concession, which are detailed further below, must be present in order for the loan to be considered a TDR. All of the following factors are indicators that the debtor is experiencing financial difficulties (one or more items may be present): • The debtor is currently in default on any of its debt. • The debtor has declared or is in the process of declaring bankruptcy. • There is significant doubt as to whether the debtor will continue to be a going concern. • Currently, the debtor has securities being held as collateral that have been delisted, are in the process of being delisted, or are under threat of being delisted from an exchange. • Based on estimates and projections that only encompass the current business capabilities, the debtor forecasts that its entity-specific cash flows will be insufficient to service the debt (both interest and principal) in accordance with the contractual terms of the existing agreement through maturity. • Absent the current modification, the debtor cannot obtain funds from sources other than the existing creditors at an effective interest rate equal to the current market interest rate for similar debt for a non-troubled debtor. The following factors are potential indicators that a concession has been granted (one or multiple items may be present): • The borrower receives a reduction of the stated interest rate for the remaining original life of the debt. • The borrower receives an extension of the maturity date or dates at a stated interest rate lower that the current market interest rate for new debt with similar risk characteristics. • The borrower receives a reduction of the face amount or maturity amount of the debt as stated in the instrument or other agreement. • The borrower receives a deferral of required payments (principal and/or interest). • The borrower receives a reduction of the accrued interest. The following table sets forth information on the Company’s TDRs by class of loan occurring during the stated periods: Three Months Ended September 30, 2018 2017 Number of Contracts Pre-Modification Outstanding Recorded Investment Post-Modification Outstanding Recorded Investment Number of Contracts Pre-Modification Outstanding Recorded Investment Post-Modification Outstanding Recorded Investment (dollars in thousands) Troubled Debt Restructurings (1) : Total — $ — $ — — $ — $ — Nine Months Ended September 30, 2018 2017 (dollars in thousands) Number of Contracts Pre-Modification Outstanding Recorded Investment Post-Modification Outstanding Recorded Investment Number of Contracts Pre-Modification Outstanding Recorded Investment Post-Modification Outstanding Recorded Investment Troubled Debt Restructurings (1) : Commercial and industrial Extended maturity date — $ — $ — 6 $ 2,037 $ 2,083 Commercial real estate: Farmland Extended maturity date 1 86 86 2 176 176 Commercial real estate-other Extended maturity date — — — 1 968 968 Other — — — 1 10,546 10,923 Total 1 $ 86 $ 86 10 $ 13,727 $ 14,150 (1) TDRs may include multiple concessions, and the disclosure classifications are based on the primary concession provided to the borrower. Loans by class modified as TDRs within 12 months of modification and for which there was a payment default during the stated periods were as follows: Three Months Ended September 30, Nine Months Ended September 30, 2018 2017 2018 2017 (dollars in thousands) Number of Contracts Recorded Investment Number of Contracts Recorded Investment Number of Contracts Recorded Investment Number of Contracts Recorded Investment Troubled Debt Restructurings (1) That Subsequently Defaulted: Commercial and industrial Extended maturity date — $ — — $ — — $ — 4 $ 1,504 Commercial real estate: Commercial real estate-other Extended maturity date — — — — — — 1 968 Total — $ — — $ — — $ — 5 $ 2,472 (1) TDRs may include multiple concessions, and the disclosure classifications are based on the primary concession provided to the borrower. Loans Reviewed Collectively for Impairment All loans not evaluated individually for impairment will be separated into homogeneous pools to be collectively evaluated. Loans will be first grouped into the various loan types (i.e. commercial, agricultural, consumer, etc.) and further segmented within each subset by risk classification (i.e. pass, special mention/watch, and substandard). Homogeneous loans past due 60-89 days and 90 days or more are classified special mention/watch and substandard, respectively, for allocation purposes. The Company’s historical loss experience for each group segmented by loan type is calculated for the prior 20 quarters as a starting point for estimating losses. In addition, other prevailing qualitative or environmental factors likely to cause probable losses to vary from historical data are incorporated in the form of adjustments to increase or decrease the loss rate applied to each group. These adjustments are documented and fully explain how the current information, events, circumstances, and conditions impact the historical loss measurement assumptions. Although not a comprehensive list, the following are considered key factors and are evaluated with each calculation of the ALLL to determine if adjustments to historical loss rates are warranted: • Changes in national and local economic and business conditions and developments that affect the collectability of the portfolio, including the condition of various market segments. • Changes in the quality and experience of lending staff and management. • Changes in lending policies and procedures, including changes in underwriting standards and collection, charge-off, and recovery practices not considered elsewhere in estimating credit losses. • Changes in the volume and severity of past due loans, classified loans and non-performing loans. • The existence and potential impact of any concentrations of credit. • Changes in the nature and terms of loans such as growth rates and utilization rates. • Changes in the value of underlying collateral for collateral-dependent loans, considering the Company’s disposition bias. • The effect of other external factors such as the legal and regulatory environment. The Company may also consider other qualitative factors for additional allowance allocations, including changes in the Company’s loan review process. Changes in the criteria used in this evaluation or the availability of new information could cause the allowance to be increased or decreased in future periods. In addition, bank regulatory agencies, as part of their examination process, may require adjustments to the allowance for loan losses based on their judgments and estimates. The items listed above are used to determine the pass percentage for loans evaluated under ASC 450, and as such, are applied to the loans risk rated pass. Due to the inherent risks associated with special mention/watch risk-rated loans (i.e. early stages of financial deterioration, technical exceptions, etc.), this subset is reserved at a level that will cover losses above a pass allocation for loans that had a loss in the last 20 quarters in which the loan was risk-rated special mention/watch at the time of the loss. Substandard loans carry greater risk than special mention/watch loans, and as such, this subset is reserved at a level that will cover losses above a pass allocation for loans that had a loss in the last 20 quarters in which the loan was risk-rated substandard at the time of the loss. Ongoing analysis is performed to support these factor multiples. The following tables set forth the risk category of loans by class of loans and credit quality indicator based on the most recent analysis performed, as of September 30, 2018 and December 31, 2017 : (in thousands) Pass Special Mention/ Watch Substandard Doubtful Loss Total September 30, 2018 Agricultural $ 78,007 $ 17,266 $ 7,934 $ — $ — $ 103,207 Commercial and industrial 482,136 21,166 20,027 4 — 523,333 Commercial real estate: Construction and development 221,114 1,078 1,132 — — 223,324 Farmland 69,824 6,970 8,941 — — 85,735 Multifamily 124,092 1,391 1,180 — — 126,663 Commercial real estate-other 748,837 44,603 24,628 — — 818,068 Total commercial real estate 1,163,867 54,042 35,881 — — 1,253,790 Residential real estate: One- to four- family first liens 333,974 2,289 6,492 — — 342,755 One- to four- family junior liens 113,526 687 1,555 — — 115,768 Total residential real estate 447,500 2,976 8,047 — — 458,523 Consumer 38,621 148 — 27 — 38,796 Total $ 2,210,131 $ 95,598 $ 71,889 $ 31 $ — $ 2,377,649 (in thousands) Pass Special Mention/ Watch Substandard Doubtful Loss Total December 31, 2017 Agricultural $ 80,377 $ 21,989 $ 3,146 $ — $ — $ 105,512 Commercial and industrial 453,363 23,153 27,102 6 — 503,624 Commercial real estate: Construction and development 162,968 1,061 1,247 — — 165,276 Farmland 76,740 10,357 771 — — 87,868 Multifamily 131,507 2,498 501 — — 134,506 Commercial real estate-other 731,231 34,056 19,034 — — 784,321 Total commercial real estate 1,102,446 47,972 21,553 — — 1,171,971 Residential real estate: One- to four- family first liens 340,446 2,776 9,004 — — 352,226 One- to four- family junior liens 114,763 952 1,489 — — 117,204 Total residential real estate 455,209 3,728 10,493 — — 469,430 Consumer 36,059 — 68 31 — 36,158 Total $ 2,127,454 $ 96,842 $ 62,362 $ 37 $ — $ 2,286,695 Included within the special mention/watch, substandard, and doubtful categories at September 30, 2018 and December 31, 2017 are purchased credit impaired loans totaling $11.1 million and $12.6 million , respectively. Below are descriptions of the risk classifications of our loan portfolio. Special Mention/Watch - A special mention/watch asset has potential weaknesses that deserve management’s close attention. If left uncorrected, these potential weaknesses may result in deterioration of the repayment prospects for the asset or in the Company’s credit position at some future date. Special mention/watch assets are not adversely classified and do not expose the Company to sufficient risk to warrant adverse classification. Substandard - Substandard loans are inadequately protected by the current net worth and paying capacity of the obligor or of the collateral pledged, if any. Loans so classified have a well-defined weakness or weaknesses that jeopardize the liquidation of the debt. They are characterized by the distinct possibility that the Company will sustain some loss if the deficiencies are not corrected. Doubtful - Loans classified as doubtful have all the weaknesses inherent in those classified as substandard with the added characteristic that the weaknesses make collection or liquidation in full, on the basis of currently known facts, conditions and values, highly questionable and improbable. Loss - Loans classified as loss are considered uncollectible and of such little value that their continuance as bankable assets is not warranted. This classification does not mean that the loan has absolutely no recovery or salvage value but rather it is not practical or desirable to defer writing off this basically worthless asset even though partial recovery may be effected in the future. The following table presents loans individually evaluated for impairment, excluding purchased credit impaired loans, by class of loan, as of September 30, 2018 and December 31, 2017 : September 30, 2018 December 31, 2017 (in thousands) Recorded Investment Unpaid Principal Balance Related Allowance Recorded Investment Unpaid Principal Balance Related Allowance With no related allowance recorded: Agricultural $ 5,161 $ 5,661 $ — $ 1,523 $ 2,023 $ — Commercial and industrial 3,796 3,990 — 7,588 7,963 — Commercial real estate: Construction and development 84 84 — 84 84 — Farmland 3,539 3,539 — 287 287 — Multifamily 821 821 — — — — Commercial real estate-other 6,290 6,800 — 5,746 6,251 — Total commercial real estate 10,734 11,244 — 6,117 6,622 — Residential real estate: One- to four- family first liens 2,677 2,737 — 2,449 2,482 — One- to four- family junior liens 344 345 — 26 26 — Total residential real estate 3,021 3,082 — 2,475 2,508 — Consumer 8 8 — — — — Total $ 22,720 $ 23,985 $ — $ 17,703 $ 19,116 $ — With an allowance recorded: Agricultural $ 1,550 $ 1,920 $ 195 $ 1,446 $ 1,446 $ 140 Commercial and industrial 9,128 9,258 3,059 2,146 2,177 1,126 Commercial real estate: Construction and development — — — — — — Farmland 2,123 2,123 662 — — — Multifamily — — — — — — Commercial real estate-other 4,518 12,184 3,521 4,269 11,536 2,157 Total commercial real estate 6,641 14,307 4,183 4,269 11,536 2,157 Residential real estate: One- to four- family first liens 960 960 143 979 979 185 One- to four- family junior liens — — — 268 268 41 Total residential real estate 960 960 143 1,247 1,247 226 Consumer — — — — — — Total $ 18,279 $ 26,445 $ 7,580 $ 9,108 $ 16,406 $ 3,649 Total: Agricultural $ 6,711 $ 7,581 $ 195 $ 2,969 $ 3,469 $ 140 Commercial and industrial 12,924 13,248 3,059 9,734 10,140 1,126 Commercial real estate: Construction and development 84 84 — 84 84 — Farmland 5,662 5,662 662 287 287 — Multifamily 821 821 — — — — Commercial real estate-other 10,808 18,984 3,521 10,015 17,787 2,157 Total commercial real estate 17,375 25,551 4,183 10,386 18,158 2,157 Residential real estate: One- to four- family first liens 3,637 3,697 143 3,428 3,461 185 One- to four- family junior liens 344 345 — 294 294 41 Total residential real estate 3,981 4,042 143 3,722 3,755 226 Consumer 8 8 — — — — Total $ 40,999 $ 50,430 $ 7,580 $ 26,811 $ 35,522 $ 3,649 The following table presents the average recorded investment and interest income recognized for loans individually evaluated for impairment, excluding purchased credit impaired loans, by class of loan, during the stated periods: Three Months Ended September 30, Nine Months Ended September 30, 2018 2017 2018 2017 (in thousands) Average Recorded Investment Interest Income Recognized Average Recorded Investment Interest Income Recognized Average Recorded Investment Interest Income Recognized Average Recorded Investment Interest Income Recognized With no related allowance recorded: Agricultural $ 4,864 $ 71 $ 881 $ 17 $ 3,480 $ 180 $ 674 $ 50 Commercial and industrial 3,961 36 2,878 77 3,563 150 2,899 124 Commercial real estate: Construction and development 84 — 423 — 84 — 434 2 Farmland 3,274 44 212 — 1,745 86 1,193 58 Multifamily 822 10 — — 618 30 — — Commercial real estate-other 6,326 77 2,148 18 5,428 201 1,894 63 Total commercial real estate 10,506 131 2,783 18 7,875 317 3,521 123 Residential real estate: One- to four- family first liens 2,578 34 2,183 23 1,942 53 2,197 69 One- to four- family junior liens 323 1 13 — 301 1 13 — Total residential real estate 2,901 35 2,196 23 2,243 54 2,210 69 Consumer 4 — — — 2 — — — Total $ 22,236 $ 273 $ 8,738 $ 135 $ 17,163 $ 701 $ 9,304 $ 366 With an allowance recorded: Agricultural $ 1,974 $ — $ 1,446 $ 11 $ 2,108 $ — $ 1,460 $ 33 Commercial and industrial 8,905 43 8,458 85 7,778 89 8,423 163 Commercial real estate: Construction and development — — 311 — — — 232 — Farmland 2,123 — — — 1,584 — — — Multifamily — — — — — — — — Commercial real estate-other 4,536 16 12,863 — 4,443 — 12,881 44 Total commercial real estate 6,659 16 13,174 — 6,027 — 13,113 44 Residential real estate: One- to four- family first liens 963 9 1,361 9 969 27 1,392 26 One- to four- family junior liens — — — — — — — — Total residential real estate 963 9 1,361 9 969 27 1,392 26 Consumer — — — — — — — — Total $ 18,501 $ 68 $ 24,439 $ 105 $ 16,882 $ 116 $ 24,388 $ 266 Total: Agricultural $ 6,838 $ 71 $ 2,327 $ 28 $ 5,588 $ 180 $ 2,134 $ 83 Commercial and industrial 12,866 79 11,336 162 11,341 239 11,322 287 Commercial real estate: Construction and development 84 — 734 — 84 — 666 2 Farmland 5,397 44 212 — 3,329 86 1,193 58 Multifamily 822 10 — — 618 30 — — Commercial real estate-other 10,862 93 15,011 18 9,871 201 14,775 107 Total commercial real estate 17,165 147 15,957 18 13,902 317 16,634 167 Residential real estate: One- to four- family first liens 3,541 43 3,544 32 2,911 80 3,589 95 One- to four- family junior liens 323 1 13 — 301 1 13 — Total residential real estate 3,864 44 3,557 32 3,212 81 3,602 95 Consumer 4 — — — 2 — — — Total $ 40,737 $ 341 $ 33,177 $ 240 $ 34,045 $ 817 $ 33,692 $ 632 The following table presents the contractual aging of the recorded investment in past due loans by class of loans at September 30, 2018 and December 31, 2017 : (in thousands) 30 - 59 Days Past Due 60 - 89 Days Past Due 90 Days or More Past Due Total Past Due Current Total Loans Receivable September 30, 2018 Agricultural $ 72 $ 100 $ 230 $ 402 $ 102,805 $ 103,207 Commercial and industrial 1,206 315 6,701 8,222 515,111 523,333 Commercial real estate: Construction and development — 10 83 93 223,231 223,324 Farmland — — 141 141 85,594 85,735 Multifamily — — — — 126,663 126,663 Commercial real estate-other 4,198 101 3,814 8,113 809,955 818,068 Total commercial real estate 4,198 111 4,038 8,347 1,245,443 1,253,790 Residential real estate: One- to four- family first liens 3,381 313 965 4,659 338,096 342,755 One- to four- family junior liens 225 94 377 696 115,072 115,768 Total residential real estate 3,606 407 1,342 5,355 453,168 458,523 Consumer 138 3 31 172 38,624 38,796 Total $ 9,220 $ 936 $ 12,342 $ 22,498 $ 2,355,151 $ 2,377,649 Included in the totals above are the following purchased credit impaired loans $ — $ — $ — $ — $ 17,452 $ 17,452 December 31, 2017 Agricultural $ 95 $ 118 $ 168 $ 381 $ 105,131 $ 105,512 Commercial and industrial 1,434 1,336 1,576 4,346 499,278 503,624 Commercial real estate: Construction and development 57 97 82 236 165,040 165,276 Farmland 217 — 373 590 87,278 87,868 Multifamily — 25 — 25 134,481 134,506 Commercial real estate-other 74 — 1,852 1,926 782,395 784,321 Total commercial real estate 348 122 2,307 2,777 1,169,194 1,171,971 Residential real estate: One- to four- family first liens 3,854 756 1,019 5,629 346,597 352,226 One- to four- family junior liens 325 770 271 1,366 115,838 117,204 Total residential real estate 4,179 1,526 1,290 6,995 462,435 469,430 Consumer 79 15 29 123 36,035 36,158 Total $ 6,135 $ 3,117 $ 5,370 $ 14,622 $ 2,272,073 $ 2,286,695 Included in the totals above are the following purchased credit impaired loans $ 164 $ 756 $ 553 $ 1,473 $ 18,258 $ 19,731 Non-accrual and Delinquent Loans Loans are placed on non-accrual when (1) payment in full of principal and interest is no longer e

Derivatives and Hedging Activ_3

Derivatives and Hedging Activities (Notes)	9 Months Ended
	Sep. 30, 2018
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivative Instruments and Hedging Activities Disclosure [Text Block]	Derivatives and Hedging Activities FASB ASC 815, Derivatives and Hedging (“ASC 815”), provides the disclosure requirements for derivatives and hedging activities with the intent to provide users of financial statements with an enhanced understanding of: (a) how and why an entity uses derivative instruments, (b) how the entity accounts for derivative instruments and related hedged items, and (c) how derivative instruments and related hedged items affect an entity’s financial position, financial performance, and cash flows. Further, qualitative disclosures are required that explain the Company’s objectives and strategies for using derivatives, as well as quantitative disclosures about the fair value of and gains and losses on derivative instruments, and disclosures about credit-risk-related contingent features in derivative instruments. As required by ASC 815, the Company records all derivatives on the balance sheet at fair value. The accounting for changes in the fair value of derivatives depends on the intended use of the derivative, whether the Company has elected to designate a derivative in a hedging relationship and apply hedge accounting and whether the hedging relationship has satisfied the criteria necessary to apply hedge accounting. Derivatives designated and qualifying as a hedge of the exposure to changes in the fair value of an asset, liability, or firm commitment attributable to a particular risk, such as interest rate risk, are considered fair value hedges. Derivatives designated and qualifying as a hedge of the exposure to variability in expected future cash flows, or other types of forecasted transactions, are considered cash flow hedges. Hedge accounting generally provides for the matching of the timing of gain or loss recognition on the hedging instrument with the recognition of the changes in the fair value of the hedged asset or liability that are attributable to the hedged risk in a fair value hedge or the earnings effect of the hedged forecasted transactions in a cash flow hedge. The Company may enter into derivative contracts that are intended to economically hedge certain of its risk, even though hedge accounting does not apply or the Company elects not to apply hedge accounting. The Company does not use derivatives for trading or speculative purposes. In accordance with the FASB’s fair value measurement guidance, the Company made an accounting policy election to measure the credit risk of its derivative financial instruments that are subject to master netting agreements on a net basis by counterparty portfolio. The Company is exposed to certain risks arising from both its business operations and economic conditions. The Company principally manages its exposures to a wide variety of business and operational risks through management of its core business activities. The Company manages economic risks, including interest rate, liquidity, and credit risk primarily by managing the amount, sources, and duration of its assets and liabilities and the use of derivative financial instruments. Specifically, the Company enters into derivative financial instruments to manage exposures that arise from business activities that result in the receipt or payment of future known and uncertain cash amounts, the value of which are determined by interest rates. The Company’s derivative financial instruments are used to manage differences in the amount, timing, and duration of the Company’s known or expected cash receipts and its known or expected cash payments principally related to the Company’s loans and borrowings. The following table presents the total notional and gross fair value of the Company’s derivatives as of September 30, 2018 and December 31, 2017 . The derivative asset and liability balances are presented on a gross basis, prior to the application of master netting agreements, as included in other assets and other liabilities, respectively, on the consolidated balance sheets. As of September 30, 2018 As of December 31, 2017 Fair Value Fair Value (in thousands) Notional Amount Derivative Assets Derivative Liabilities Notional Amount Derivative Assets Derivative Liabilities Derivatives designated as hedging instruments: Fair value hedges: Interest rate swaps $ 7,855 $ 100 $ — $ — $ — $ — Derivatives not designated as hedging instruments: Interest rate swaps $ 13,840 $ 105 $ 125 $ — $ — $ — Risk participation agreements (RPAs) 10,112 — 53 — — — Total derivatives not designated as hedging instruments $ 23,952 $ 105 $ 178 $ — $ — $ — Derivatives Designated as Hedging Instruments The Company is exposed to changes in the fair value of certain of its fixed-rate assets due to changes in benchmark interest rates. The Company uses interest rate swaps to manage its exposure to changes in fair value on these instruments attributable to changes in the designated benchmark interest rate, LIBOR. Interest rate swaps designated as fair value hedges involve the payment of fixed-rate amounts to a counterparty in exchange for the Company receiving variable-rate payments over the life of the agreements without the exchange of the underlying notional amount. For derivatives designated and that qualify as fair value hedges, the gain or loss on the derivative as well as the offsetting loss or gain on the hedged item attributable to the hedged risk are recognized in interest income. The table below presents the effect of the Company’s derivative financial instruments designated as hedging instruments on the consolidated statements of income for the three and nine months ended September 30, 2018 and September 30, 2017 : Location and Amount of Gain or Loss Recognized in Income on Fair Value Hedging Relationships For the Three Months Ended September 30, For the Nine Months Ended September 30, 2018 2017 2018 2017 (in thousands) Interest Income (Expense) Other Gain (Loss) Interest Income (Expense) Other Gain (Loss) Interest Income (Expense) Other Gain (Loss) Interest Income (Expense) Other Gain (Loss) Total amounts of income and expense line items presented in the Consolidated Statements of Income in which the effects of fair value hedges are recorded $ — $ — $ — $ — $ (1 ) $ — $ — $ — The effects of fair value hedging: Gain (Loss) on fair value hedging relationships in subtopic 815-20: Interest contracts: Hedged items (126 ) — — — (101 ) — — — Derivative designated as hedging instruments 126 — — — 100 — — — As of September 30, 2018 , the following amounts were recorded on the balance sheet related to cumulative basis adjustment for fair value hedges: Line Item in the Balance Sheet in Which the Hedged Item is Included Carrying Amount of the Hedged Assets Cumulative Amount of Fair Value Hedging Adjustment Included in the Carrying Amount of the Hedged Asset (in thousands) Loans $ 7,754 $ (101 ) Derivatives Not Designated as Hedging Instruments Interest Rate Swaps -The Company enters into interest rate derivatives, including interest rate swaps with its customers, to allow them to hedge against the risk of rising interest rates by providing fixed rate loans. To economically hedge against the interest rate risks in the products offered to its customers, the Company enters into mirrored interest rate contracts with institutional counterparties, with one designated as a central counterparty. The following table represents the notional amounts and the gross fair values of interest rate derivative contracts outstanding as of September 30, 2018 and December 31, 2017 respectively. September 30, 2018 Customer Counterparties Financial Counterparties Fair Value Fair Value (in thousands) Notional Amount Assets Liabilities Notional Amount Assets Liabilities Swaps $ 6,920 $ 105 $ — $ 6,920 $ — $ 125 December 31, 2017 Customer Counterparties Financial Counterparties Fair Value Fair Value (in thousands) Notional Amount Assets Liabilities Notional Amount Assets Liabilities Swaps $ — $ — $ — $ — $ — $ — Credit Risk Participation Agreements -The Company may periodically enter into RPAs to manage the credit exposure on interest rate contracts associated with a syndicated loan. The Company may enter into protection purchased RPAs with institutional counterparties to decrease or increase its exposure to a borrower. Under the RPA, the Company will receive or make payment if a borrower defaults on the related interest rate contract. The Company manages its credit risk on RPAs by monitoring the creditworthiness of the borrowers and institutional counterparties, which is based on the normal credit review process. The notional amount of the RPAs reflects the Company’s pro-rata share of the derivative instrument. The following table represents the notional amounts and the gross fair values of RPAs purchased and sold outstanding as of September 30, 2018 and December 31, 2017 respectively. September 30, 2018 December 31, 2017 Fair Value Fair Value (in thousands) Notional Amount Assets Liabilities Notional Amount Assets Liabilities RPAs - protection purchased $ 10,112 $ — $ 53 $ — $ — $ — The following table presents the net gains (losses) recognized on the consolidated statements of income related to the derivatives not designated as hedging instruments for the three and nine months ended September 30, 2018 and September 30, 2017 : Location in the Consolidated Statements of Income For the Three Months Ended September 30, For the Nine Months Ended September 30, (in thousands) 2018 2017 2018 2017 Interest rate swaps Other gain (loss) $ — $ — $ (20 ) $ — RPAs Other gain (loss) 147 — 147 — Total $ 147 $ — $ 127 $ — Offsetting of Derivatives The table below presents a gross presentation, the effects of offsetting, and a net presentation of the Company’s derivatives as of September 30, 2018 and December 31, 2017 . The net amounts of derivative assets or liabilities can be reconciled to the tabular disclosure of fair value. The tabular disclosure of fair value provides the location that derivative assets and liabilities are presented on the consolidated balance sheets. Gross Amounts Not Offset in the Balance Sheet (in thousands) Gross Amounts of Recognized Assets (Liabilities) Gross Amounts Offset in the Balance Sheet Net Amounts of Assets (Liabilities) presented in the Balance Sheet Financial Instruments Cash Collateral Received (Paid) Net Assets (Liabilities) As of September 30, 2018 Asset Derivatives $ 205 $ — $ 205 $ 100 $ — $ 105 Liability Derivatives (178 ) — (178 ) 100 — (78 ) As of December 31, 2017 Derivatives $ — $ — $ — $ — $ — $ — Liability Derivatives — — — — — — Credit-risk-related Contingent Features The Company has an unsecured federal funds line with its derivative counterparty.The Company has an agreement with its derivative counterparty that contains a provision under which if the Company defaults on any of its indebtedness, including default where repayment of the indebtedness has not been accelerated by the lender, then the Company could also be declared in default on its derivative obligations. The Company also has an agreement with its derivative counterparty that contains a provision under which the Company could be declared in default on its derivative obligations if repayment of the underlying indebtedness is accelerated by the lender due to the Company's default on the indebtedness. As of September 30, 2018 , the fair value of derivatives in a net liability position, which includes accrued interest but excludes any adjustment for nonperformance risk, related to these agreements was $179,000 . As of September 30, 2018 , the Company has minimum collateral posting thresholds with certain of its derivative counterparties, and has not posted any collateral related to these agreements. If the Company had breached any of these provisions at September 30, 2018 , it could have been required to settle its obligations under the agreements at their termination value of $179,000

Goodwill and Intangible Assets

Goodwill and Intangible Assets	9 Months Ended
	Sep. 30, 2018
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill and Intangible Assets Disclosure [Text Block]	Goodwill and Intangible Assets The excess of the cost of an acquisition over the fair value of the net assets acquired, including core deposit, trade name, and client relationship intangibles, consists of goodwill. Under ASC Topic 350, goodwill and the non-amortizing portion of the trade name intangible are subject to at least annual assessments for impairment by applying a fair value based test. The Company reviews goodwill and the non-amortizing portion of the trade name intangible at the reporting unit level to determine potential impairment annually on October 1, or more frequently if events or changes in circumstances indicate that the carrying value may not be recoverable, by comparing the carrying value of the reporting unit with the fair value of the reporting unit. No impairment was recorded on either the goodwill or the trade name intangible assets during the nine months ended September 30, 2018 . The carrying amount of goodwill was $64.7 million at September 30, 2018 , the same as at December 31, 2017 . During the second quarter of 2018, the Company recognized a $125,000 customer list intangible due to the purchase of a registered investment adviser in the Denver, Colorado area. The following table presents the changes in the carrying amount of intangibles (excluding goodwill), gross carrying amount, accumulated amortization, and net book value as of and for the nine months ended September 30, 2018 : (in thousands) Insurance Agency Intangible Core Deposit Intangible Indefinite-Lived Trade Name Intangible Finite-Lived Trade Name Intangible Customer List Intangible Total September 30, 2018 Balance, beginning of period $ 148 $ 4,011 $ 7,040 $ 744 $ 103 $ 12,046 Finite-lived intangible assets acquired — — — — 125 125 Amortization expense (28 ) (1,600 ) — (143 ) (22 ) (1,793 ) Balance at end of period $ 120 $ 2,411 $ 7,040 $ 601 $ 206 $ 10,378 Gross carrying amount $ 1,320 $ 18,206 $ 7,040 $ 1,380 $ 455 $ 28,401 Accumulated amortization (1,200 ) (15,795 ) — (779 ) (249 ) (18,023 ) Net book value $ 120 $ 2,411 $ 7,040 $ 601 $ 206 $ 10,378

Other Assets

Other Assets	9 Months Ended
	Sep. 30, 2018
Other Assets [Abstract]
Other Assets Disclosure [Text Block]	Other Assets The components of the Company’s other assets were as follows: (in thousands) September 30, 2018 December 31, 2017 Federal Home Loan Bank Stock $ 13,260 $ 11,324 Prepaid expenses 2,286 2,992 Mortgage servicing rights 2,711 2,316 Assets held for sale 895 — Federal & state income taxes receivable, current 322 3,120 Accounts receivable & other miscellaneous assets 7,841 3,009 $ 27,315 $ 22,761 The Bank is a member of the FHLB of Des Moines, and ownership of FHLB stock is a requirement for such membership. The amount of FHLB stock the Bank is required to hold is directly related to the amount of FHLB advances borrowed. Because this security is not readily marketable and there are no available market values, this security is carried at cost and evaluated for potential impairment each quarter. Redemption of this investment is at the option of the FHLB. Mortgage servicing rights are recorded at fair value based on assumptions provided by a third-party valuation service. The valuation model incorporates assumptions that market participants would use in estimating future net servicing income, such as the servicing cost per loan, the discount rate, the escrow float rate, an inflation rate, ancillary income, prepayment speeds and default rates and losses.

Short-Term Borrowings

Short-Term Borrowings	9 Months Ended
	Sep. 30, 2018
Short-term Debt [Abstract]
Short-term Debt [Text Block]	Short-Term Borrowings Short-term borrowings were as follows as of September 30, 2018 and December 31, 2017 : September 30, 2018 December 31, 2017 (in thousands) Weighted Average Cost Balance Weighted Average Cost Balance Federal funds purchased 2.39 % $ 19,056 1.77 % $ 1,000 Securities sold under agreements to repurchase 0.97 68,922 0.71 96,229 Total 1.28 % $ 87,978 0.73 % $ 97,229 At September 30, 2018 and December 31, 2017 , the Company had no borrowings through the Federal Reserve Discount Window, while the borrowing capacity was $11.4 million as of September 30, 2018 and December 31, 2017 . As of September 30, 2018 and December 31, 2017 , the Bank had municipal securities pledged with a market value of $12.6 million and $12.8 million , respectively, to the Federal Reserve to secure potential borrowings. The Company also has various other unsecured federal funds agreements with correspondent banks as well as the FHLB. As of September 30, 2018 and December 31, 2017 , there were $19.1 million and $1.0 million of borrowings through these correspondent bank federal funds agreements, respectively. Securities sold under agreements to repurchase are agreements in which the Company acquires funds by selling assets to another party under a simultaneous agreement to repurchase the same assets at a specified price and date. The Company enters into repurchase agreements and also offers a demand deposit account product to customers that sweeps their balances in excess of an agreed upon target amount into overnight repurchase agreements. All securities sold under agreements to repurchase are recorded on the face of the balance sheet. On April 30, 2015 , the Company entered into a $5.0 million unsecured line of credit with a correspondent bank. Interest is payable at a rate of one-month LIBOR plus 2.00% . The line was renewed in May 2018, and matures on April 30, 2019 . The Company had no balance outstanding under this agreement as of September 30, 2018

Junior Subordinated Notes Issue

Junior Subordinated Notes Issued to Capital Trusts	9 Months Ended
	Sep. 30, 2018
Junior Subordinated Notes [Abstract]
Subordinated Borrowings Disclosure [Text Block]	The Company has established three statutory business trusts under the laws of the state of Delaware: Central Bancshares Capital Trust II, Barron Investment Capital Trust I, and MidWestOne Statutory Trust II. The trusts exist for the exclusive purposes of (i) issuing trust securities representing undivided beneficial interests in the assets of the respective trust; (ii) investing the gross proceeds of the trust securities in junior subordinated deferrable interest debentures (junior subordinated notes issued by the Company); and (iii) engaging in only those activities necessary or incidental thereto. For regulatory capital purposes, these trust securities qualify as a component of Tier 1 capital. The table below summarizes the outstanding junior subordinated notes and the related trust preferred securities issued by each trust as of September 30, 2018 and December 31, 2017 : Face Value Book Value Interest Rate Interest Rate at Maturity Date Callable Date (in thousands) 9/30/2018 September 30, 2018 Central Bancshares Capital Trust II (1) (2) $ 7,217 $ 6,716 Three-month LIBOR + 3.50% 5.83 % 03/15/2038 03/15/2013 Barron Investment Capital Trust I (1) (2) 2,062 1,685 Three-month LIBOR + 2.15% 4.52 % 09/23/2036 09/23/2011 MidWestOne Statutory Trust II (1) 15,464 15,464 Three-month LIBOR + 1.59% 3.92 % 12/15/2037 12/15/2012 Total $ 24,743 $ 23,865 Face Value Book Value Interest Rate Interest Rate at Maturity Date Callable Date (in thousands) 12/31/2017 December 31, 2017 Central Bancshares Capital Trust II (1) (2) $ 7,217 $ 6,674 Three-month LIBOR + 3.50% 5.09 % 03/15/2038 03/15/2013 Barron Investment Capital Trust I (1) (2) 2,062 1,655 Three-month LIBOR + 2.15% 3.82 % 09/23/2036 09/23/2011 MidWestOne Statutory Trust II (1) 15,464 15,464 Three-month LIBOR + 1.59% 3.18 % 12/15/2037 12/15/2012 Total $ 24,743 $ 23,793 (1) All distributions are cumulative and paid in cash quarterly. (2) Central Bancshares Capital Trust II and Barron Investment Capital Trust I were established by Central prior to the Company’s merger with Central, and the junior subordinated notes issued by Central were assumed by the Company. The trust preferred securities are subject to mandatory redemption, in whole or in part, upon repayment of the junior subordinated notes at the stated maturity date or upon redemption of the junior subordinated notes. Each trust’s ability to pay amounts due on the trust preferred securities is solely dependent upon the Company making payment on the related junior subordinated notes. The Company’s obligation under the junior subordinated notes and other relevant trust agreements, in aggregate, constitutes a full and unconditional guarantee by the Company of each trust’s obligations under the trust preferred securities issued by each trust. The Company has the right to defer payment of interest on the junior subordinated notes and, therefore, distributions on the trust preferred securities, for up to five years , but not beyond the stated maturity date in the table above. During any such deferral period the Company may not pay cash dividends on its stock and generally may not repurchase its stock.

Federal Home Loan Bank Borrowin

Federal Home Loan Bank Borrowings and Long-Term Debt	9 Months Ended
	Sep. 30, 2018
Long-term Debt, by Type, Current and Noncurrent [Abstract]
Long-term Debt [Text Block]	Long-Term Debt Federal Home Loan Bank borrowings and long-term debt were as follows as of September 30, 2018 and December 31, 2017 : September 30, 2018 December 31, 2017 (in thousands) Weighted Average Cost Balance Weighted Average Cost Balance FHLB Borrowings 2.20 % $ 143,000 1.72 % $ 115,000 Note payable to unaffiliated bank 3.85 8,750 3.32 12,500 Total 2.30 % $ 151,750 1.88 % $ 127,500 The Company utilizes FHLB borrowings as a supplement to customer deposits to fund interest-earning assets and to assist in managing interest rate risk. As a member of the Federal Home Loan Bank of Des Moines, the Bank may borrow funds from the FHLB in amounts up to 35% of the Bank’s total assets, provided the Bank is able to pledge an adequate amount of qualified assets to secure the borrowings. Advances from the FHLB are collateralized primarily by one- to four-family residential, commercial and agricultural real estate first mortgages equal to various percentages of the total outstanding notes. See Note 4 “Loans Receivable and the Allowance for Loan Losses” of the notes to the consolidated financial statements. On April 30, 2015 , the Company entered into a $35.0 million unsecured note payable with a correspondent bank with a maturity date of June 30, 2020 . The Company drew $25.0 million on the note prior to June 30, 2015, at which time the ability to obtain additional advances ceased. Payments of principal and interest are payable quarterly , which began on September 30, 2015 . As of September 30, 2018 , $8.8 million

Income Taxes

Income Taxes	9 Months Ended
	Sep. 30, 2018
Income Tax Disclosure [Abstract]
Income Tax Disclosure [Text Block]	Income Taxes Income tax expense for the three and nine months ended September 30, 2018 and 2017 was equal to or less than the amount computed by applying the maximum effective federal income tax rate of 21% and 35% , respectively, to the income before income taxes, because of the following items: For the Three Months Ended September 30, For the Nine Months Ended September 30, 2018 2017 2018 2017 (in thousands) Amount % of Pretax Income Amount % of Pretax Income Amount % of Pretax Income Amount % of Pretax Income Income tax based on statutory rate $ 1,803 21.0 % $ 2,898 35.0 % $ 6,016 21.0 % $ 9,762 35.0 % Tax-exempt interest (468 ) (5.4 ) (808 ) (9.7 ) (1,459 ) (5.0 ) (2,389 ) (8.6 ) Bank-owned life insurance (84 ) (1.0 ) (121 ) (1.5 ) (257 ) (0.9 ) (346 ) (1.2 ) State income taxes, net of federal income tax benefit 445 5.2 366 4.4 1,540 5.4 1,214 4.4 Non-deductible acquisition expenses 124 1.4 — — 124 0.4 — — General business credits (22 ) (0.2 ) (405 ) (4.9 ) (62 ) (0.2 ) (445 ) (1.6 ) Other 8 — 8 0.1 19 — (193 ) (0.7 ) Total income tax expense $ 1,806 21.0 % $ 1,938 23.4 % $ 5,921 20.7 % $ 7,603 27.3 %

Earnings per Share

Earnings per Share	9 Months Ended
	Sep. 30, 2018
Earnings Per Share [Abstract]
Earnings Per Share Disclosure [Text Block]	Earnings per Share Basic per-share amounts are computed by dividing net income (the numerator) by the weighted-average number of common shares outstanding (the denominator). Diluted per-share amounts assume issuance of all common stock issuable upon conversion or exercise of other securities, unless the effect is to reduce the loss or increase the income per common share from continuing operations. The following table presents the computation of earnings per common share for the respective periods: Three Months Ended September 30, Nine Months Ended September 30, (dollars in thousands, except per share amounts) 2018 2017 2018 2017 Basic earnings per common share computation Numerator: Net income $ 6,778 $ 6,342 $ 22,727 $ 20,289 Denominator: Weighted average shares outstanding 12,221,107 12,218,528 12,220,673 11,977,579 Basic earnings per common share $ 0.55 $ 0.52 $ 1.86 $ 1.69 Diluted earnings per common share computation Numerator: Net income $ 6,778 $ 6,342 $ 22,727 $ 20,289 Denominator: Weighted average shares outstanding, including all dilutive potential shares 12,239,864 12,238,991 12,237,462 11,999,608 Diluted earnings per common share $ 0.55 $ 0.52 $ 1.86 $ 1.69

Estimated Fair Value of Financi

Estimated Fair Value of Financial Instruments and Fair Value Measurements	9 Months Ended
	Sep. 30, 2018
Fair Value Disclosures [Abstract]
Fair Value Disclosures [Text Block]	Estimated Fair Value of Financial Instruments and Fair Value Measurements Fair value is the exchange price that would be received for an asset or paid to transfer a liability (exit price) in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. Market participants are defined as buyers and sellers in the principal (or most advantageous) market for the asset or liability that have all of the following characteristics: 1) an unrelated party; 2) knowledgeable (having a reasonable understanding about the asset or liability and the transaction based on all available information; including information that might be obtained through due diligence efforts that are usual or customary); 3) able to transact; and 4) willing to transact (motivated but not forced or otherwise compelled to do so). The FASB states “valuation techniques that are appropriate in the circumstances and for which sufficient data are available shall be used to measure fair value.” The valuation techniques for measuring fair value are consistent with the three traditional approaches to value: the market approach, the income approach, and the cost or asset approach. In applying valuation techniques, the use of relevant inputs (both observable and unobservable) based on the facts and circumstances must be used. The FASB has defined a fair value hierarchy for these inputs which prioritizes the inputs into three broad levels: • Level 1 Inputs – Quoted prices (unadjusted) for identical assets or liabilities in active markets. A quoted price in an active market provides the most reliable evidence of fair value and is used to measure fair value whenever available. A contractually binding sales price also provides reliable evidence of fair value. • Level 2 Inputs – Inputs to the valuation methodology include quoted prices for similar assets or liabilities in active markets; inputs to the valuation methodology include quoted prices for identical or similar assets or liabilities in markets that are not active; or inputs to the valuation methodology that utilize model-based techniques for which all significant assumptions are observable in the market. • Level 3 Inputs – Inputs to the valuation methodology are unobservable and significant to the fair value measurement; inputs to the valuation methodology that utilize model-based techniques for which significant assumptions are not observable in the market; or inputs to the valuation methodology that require significant management judgment or estimation, some of which may be internally developed. Unobservable inputs should be used only to the extent that relevant observable inputs are not available; this allows for situations where there is little, if any, market activity for the asset or liability at the measurement date. Unobservable inputs should reflect the reporting entity’s own assumptions about the assumptions that market participants would use in pricing the asset or liability, including assumptions about risk. It is the Company’s policy to maximize the use of observable inputs and minimize the use of unobservable inputs when developing fair value measurements. The Company is required to use observable inputs, to the extent available, in the fair value estimation process unless that data results from forced liquidations or distressed sales. The Company used the following methods and significant assumptions to estimate fair value: Investment Securities - The fair value for investment securities are determined by quoted market prices, if available (Level 1). The Company utilizes an independent pricing service to obtain the fair value of debt securities. On a quarterly basis, the Company selects a sample of 30 securities from its primary pricing service and compares them to a secondary independent pricing service to validate value. In addition, the Company periodically reviews the pricing methodology utilized by the primary independent service for reasonableness. Debt securities issued by the U.S. Treasury and other U.S. Government agencies and corporations, mortgage-backed securities, and collateralized mortgage obligations are priced utilizing industry-standard models that consider various assumptions, including time value, yield curves, volatility factors, prepayment speeds, default rates, loss severity, current market and contractual prices for the underlying financial instruments, as well as other relevant economic measures. Substantially all of these assumptions are observable in the marketplace, can be derived from observable data, or are supported by observable levels at which transactions are executed in the marketplace (Level 2). Municipal securities are valued using a type of matrix, or grid, pricing in which securities are benchmarked against the treasury rate based on credit rating (Level 2). On an annual basis, a group of selected municipal securities have their credit rating evaluated by a securities dealer and that information is used to verify the primary independent service’s rating and pricing. Loans Held for Sale - Loans held for sale are carried at the lower of cost or fair value, with fair value being based on binding contracts from third party investors (Level 2). The portfolio has historically consisted primarily of residential real estate loans. Loans, Net - The estimated fair value of loans, net, was performed using the income approach, with the market approach used for certain nonperforming loans, resulting in a Level 3 fair value classification. The application of the income approach establishes value by methods that discount or capitalize earnings and/or cash flow, by a discount or capitalization rate that reflects market rate of return expectations, market conditions, and the relative risk of the investment. Generally, this can be accomplished by the discounted cash flow method. For loans that exhibited some characteristics of performance and where it appears that the borrower may have adequate cash flows to service the loan, a discounted cash flow analysis was used. The discounted cash flow analysis was based on the contractual maturity of the loan and market indications of rates, prepayment speeds, defaults and credit risk. For loans with balloon or interest only payment structures, the repayment was extended by assuming a renewal period beyond the current contractual maturity date. For loans analyzed using the asset approach, the fair value was determined based on the estimated values of the underlying collateral. For impaired loans, the estimated net sales proceeds was used to determine the fair value of the loans when deemed appropriate. The implied sales proceeds value provides a better indication of value than the income stream as these loans are not performing or exhibit strong signs indicative of nonperformance. Collateral Dependent Impaired Loans - From time to time, a loan is considered impaired and an allowance for credit losses is established. The specific reserves for collateral dependent impaired loans are based on the fair value of the collateral less estimated costs to sell, based on appraisals. These appraisals may utilize a single valuation approach or a combination of approaches including comparable sales and the income approach. Adjustments are routinely made in the appraisal process by the independent appraisers to adjust for differences between the comparable sales and income data available for similar loans and collateral underlying such loans, and resulted in a Level 3 classification for inputs for determining fair value. Non-real estate collateral may be valued using an appraisal, net book value per the borrower’s financial statements, or aging reports, adjusted or discounted based on management’s historical knowledge, changes in market conditions from the time of valuation, and management’s expertise and knowledge of the client and the client’s business, resulting in a Level 3 fair value classification. Impaired loans are evaluated on a quarterly basis for additional impairment and adjusted in accordance with the allowance policy. Other Real Estate Owned (“OREO”) - OREO represents property acquired through foreclosures and settlements of loans. Property acquired through or in lieu of foreclosure are initially recorded at fair value less estimated selling cost at the date of foreclosure, establishing a new cost basis. These assets are subsequently accounted for at the lower of cost or fair value less estimated costs to sell. Fair value is commonly based on recent real estate appraisals which are updated no less frequently than every 18 months. These appraisals may utilize a single valuation approach or a combination of approaches, including comparable sales and the income approach. Adjustments are routinely made in the appraisal process by the independent appraisers to adjust for differences between the comparable sales and income data available for similar loans and the collateral underlying such loans, resulting in a Level 3 classification for inputs for determining fair value. Real estate owned properties are evaluated on a quarterly basis for additional impairment and adjusted accordingly. Appraisals for both collateral dependent impaired loans and OREO are performed by certified general appraisers (for commercial properties) or certified residential appraisers (for residential properties) whose qualifications and licenses have been reviewed and verified by the Company. Once received, a member of the Special Assets Department reviews the assumptions and approaches utilized in the appraisal as well as the overall resulting fair value in comparison with independent data sources such as recent market data or industry-wide statistics. Interest Rate Swaps - Interest rate swaps are valued by the Company's swap dealers using cash flow valuation techniques with observable market data inputs. The fair values estimated by the Company's swap dealers use interest rates that are observable or that can be corroborated by observable market data and, therefore, are classified within Level 2 of the valuation hierarchy. The Company has entered into collateral agreements with its swap dealers which entitle it to receive collateral to cover market values on derivatives which are in asset position, thus a credit risk adjustment on interest rate swaps is not warranted. Credit Risk Participation Agreements — The Company enters into credit risk participation agreements (“RPAs”) with institutional counterparties, under which the Company assumes its pro-rata share of the credit exposure associated with a borrower’s performance related to interest rate derivative contracts. The fair value of RPAs is calculated by determining the total expected asset or liability exposure of the derivatives to the borrowers and applying the borrowers’ credit spread to that exposure. Total expected exposure incorporates both the current and potential future exposure of the derivatives, derived from using observable inputs, such as yield curves and volatilities. Accordingly, RPAs fall within Level 2. The following table summarizes assets and liabilities measured at fair value on a recurring basis as of September 30, 2018 and December 31, 2017 . The assets and liabilities are segregated by the level of valuation inputs within the fair value hierarchy utilized to measure fair value: Fair Value Measurement at September 30, 2018 Using (in thousands) Fair Value Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Assets: Available for sale debt securities: U.S. Government agencies and corporations $ 5,519 $ — $ 5,519 $ — State and political subdivisions 115,136 — 115,136 — Mortgage-backed securities 51,896 — 51,896 — Collateralized mortgage obligations 170,877 — 170,877 — Corporate debt securities 64,338 — 64,338 — Total available for sale debt securities $ 407,766 $ — $ 407,766 $ — Derivatives: Interest rate swaps $ 205 $ — $ 205 $ — RPAs — — — — Total derivative assets $ 205 $ — $ 205 $ — Liabilities: Derivatives: Interest rate swaps $ 125 $ — $ 125 $ — RPAs 53 — 53 — Total derivative liabilities $ 178 $ — $ 178 $ — Fair Value Measurement at December 31, 2017 Using (in thousands) Fair Value Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Assets: Available for sale debt securities: U.S. Government agencies and corporations $ 15,626 $ — $ 15,626 $ — State and political subdivisions 141,839 — 141,839 — Mortgage-backed securities 48,497 — 48,497 — Collateralized mortgage obligations 168,196 — 168,196 — Corporate debt securities 71,166 — 71,166 — Total available for sale debt securities $ 445,324 $ — $ 445,324 $ — There were no transfers of assets between Level 3 and other levels of the fair value hierarchy during the three and nine months ended September 30, 2018 or the year ended December 31, 2017 . Changes in the fair value of available for sale debt securities are included in other comprehensive income, and changes in the fair value of equity securities are included in noninterest income. The following table discloses the Company’s estimated fair value amounts of its assets recorded at fair value on a nonrecurring basis. It is management’s belief that the fair values presented below are reasonable based on the valuation techniques and data available to the Company as of September 30, 2018 and December 31, 2017 , as more fully described above. Fair Value Measurement at September 30, 2018 Using (in thousands) Fair Value Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Assets: Collateral dependent impaired loans $ 8,362 $ — $ — $ 8,362 Other real estate owned $ 549 $ — $ — $ 549 Fair Value Measurement at December 31, 2017 Using (in thousands) Fair Value Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Assets: Collateral dependent impaired loans $ 3,927 $ — $ — $ 3,927 Other real estate owned $ 2,010 $ — $ — $ 2,010 The following presents the valuation technique(s), unobservable inputs, and quantitative information about the unobservable inputs used for fair value measurements of the financial instruments held by the Company at September 30, 2018 , categorized within Level 3 of the fair value hierarchy: Quantitative Information About Level 3 Fair Value Measurements (dollars in thousands) Fair Value at September 30, 2018 Valuation Techniques(s) Unobservable Input Range of Inputs Weighted Average Collateral dependent impaired loans $ 8,362 Modified appraised value Third party appraisal NM * - NM * NM * Appraisal discount NM * - NM * NM * Other real estate owned $ 549 Modified appraised value Third party appraisal NM * - NM * NM * Appraisal discount NM * - NM * NM * * Not Meaningful. Third party appraisals are obtained as to the value of the underlying asset, but disclosure of this information would not provide meaningful information, as the range will vary widely from loan to loan. Types of discounts considered include age of the appraisal, local market conditions, current condition of the property, and estimated sales costs. These discounts will also vary from loan to loan, thus providing a range would not be meaningful. Due to the adoption of ASU 2016-01 as of January 1, 2018, the estimated fair value amounts shown for December 31, 2017 are not comparable to those for September 30, 2018 , due to a change in the required methodology (“exit price” only) for determining current estimated fair value. The carrying amount and estimated fair value of financial instruments not carried at fair value, at September 30, 2018 and December 31, 2017 are as follows: September 30, 2018 (in thousands) Carrying Amount Estimated Fair Value Quoted Significant Other Significant Financial assets: Cash and cash equivalents $ 53,379 $ 53,379 $ 53,379 $ — $ — Investment securities: Equity securities 2,797 2,797 2,797 — — Debt securities available for sale 407,766 407,766 — 407,766 — Debt securities held to maturity 191,733 186,057 — 186,057 — Total investment securities 602,296 596,620 2,797 593,823 — Loans held for sale 1,124 1,145 — 1,145 — Loans held for investment, net 2,346,371 2,283,363 — — 2,283,363 Interest receivable 14,800 14,800 14,800 — — Federal Home Loan Bank stock 13,260 13,260 — 13,260 — Derivative assets 205 205 — 205 — Financial liabilities: Deposits: Non-interest bearing demand 458,576 458,576 458,576 — — Interest-bearing checking 1,236,922 1,236,922 1,236,922 — — Savings 211,591 211,591 211,591 — — Certificates of deposit under $100,000 348,099 342,998 — 342,998 — Certificates of deposit $100,000 and over 377,071 373,313 — 373,313 — Total deposits 2,632,259 2,623,400 1,907,089 716,311 — Federal funds purchased and securities sold under agreements to repurchase 87,978 87,978 87,978 — — Federal Home Loan Bank borrowings 143,000 141,110 — 141,110 — Junior subordinated notes issued to capital trusts 23,865 21,058 — 21,058 — Long-term debt 8,750 8,750 — 8,750 — Derivative liabilities 178 178 — 178 — December 31, 2017 (in thousands) Carrying Amount Estimated Fair Value Quoted Prices in Markets for Significant Other Significant Financial assets: Cash and cash equivalents $ 50,972 $ 50,972 $ 50,972 $ — $ — Investment securities: Equity securities 2,336 2,336 2,336 — — Debt securities available for sale 445,324 445,324 — 445,324 — Debt securities held to maturity 195,619 194,343 — 194,343 — Total investment securities 643,279 642,003 2,336 639,667 — Loans held for sale 856 871 — — 871 Loans held for investment, net 2,258,636 2,256,726 — 2,256,726 — Interest receivable 14,732 14,732 14,732 — — Federal Home Loan Bank stock 11,324 11,324 — 11,324 — Financial liabilities: Deposits: Non-interest bearing demand 461,969 461,969 461,969 — — Interest-bearing checking 1,228,112 1,228,112 1,228,112 — — Savings 213,430 213,430 213,430 — — Certificates of deposit under $100,000 324,681 321,197 — 321,197 — Certificates of deposit $100,000 and over 377,127 374,685 — 374,685 — Total deposits 2,605,319 2,599,393 1,903,511 695,882 — Federal funds purchased and securities sold under agreements to repurchase 97,229 97,229 97,229 — — Federal Home Loan Bank borrowings 115,000 114,945 — 114,945 — Junior subordinated notes issued to capital trusts 23,793 19,702 — 19,702 — Long-term debt 12,500 12,500 — 12,500 —

Revenue Recognition (Notes)

Revenue Recognition (Notes)	9 Months Ended
	Sep. 30, 2018
Revenue from Contract with Customer [Abstract]
Revenue from Contract with Customer [Text Block]	Revenue Recognition On January 1, 2018, the Company adopted ASU No. 2014-09 “Revenue from Contracts with Customers” (Topic 606) and all subsequent ASUs that modified Topic 606. As stated in Note 2. “Effect of New Financial Accounting Standards,” the implementation of the new standard did not have a material impact on the measurement or recognition of revenue; as such, a cumulative effect adjustment to opening retained earnings was not deemed necessary. Results for reporting periods beginning after January 1, 2018 are presented under Topic 606, while prior period amounts were not adjusted and continue to be reported in accordance with our historic accounting under Topic 605. Topic 606 does not apply to revenue associated with financial instruments, including revenue from loans and securities. In addition, certain noninterest income streams such as fees associated with mortgage servicing rights, financial guarantees, derivatives, and certain credit card fees are also not in scope of the new guidance. Topic 606 is applicable to noninterest revenue streams such as trust and asset management fees, service charges on deposit accounts, sales of other real estate, and debit card interchange fees. However, the recognition of these revenue streams did not change significantly upon adoption of Topic 606. Substantially all of the Company’s revenue is generated from contracts with customers. Noninterest revenue streams in-scope of Topic 606 are discussed below. Trust and Asset Management Trust and asset management income is primarily comprised of fees earned from the management and administration of trusts and other customer assets. The Company’s performance obligation is generally satisfied over time, and the resulting fees are recognized monthly, based upon the month-end market value of the assets under management and the applicable fee rate. Payment is generally received a few days after month end through a direct charge to customers’ accounts. The Company does not earn performance-based incentives. Optional services such as real estate sales and tax return preparation services are also available to existing trust and asset management customers. The Company’s performance obligation for these transactional-based services is generally satisfied, and related revenue recognized, at a point in time (i.e., as incurred). Payment is received shortly after services are rendered. Service Charges on Deposit Accounts Service charges on deposit accounts consist of account analysis fees (i.e., net fees earned on analyzed business and public checking accounts), monthly service fees, check orders, and other deposit account related fees. The Company’s performance obligation for account analysis fees and monthly service fees is generally satisfied, and the related revenue recognized, over the period in which the service is provided. Check orders and other deposit account related fees are largely transactional based, and therefore, the Company’s performance obligation is satisfied, and related revenue recognized, at a point in time. Payment for service charges on deposit accounts is primarily received immediately or in the following month through a direct charge to customers’ accounts. Fees, Exchange, and Other Service Charges Fees, exchange, and other service charges are primarily comprised of debit and credit card income, ATM fees, merchant services income, and other service charges. Debit and credit card income is primarily comprised of interchange fees earned whenever the Company’s debit and credit cards are processed through card payment networks such as Visa. ATM fees are primarily generated when a Company cardholder uses a non-Company ATM or a non-Company cardholder uses a Company ATM. Merchant services income mainly represents fees charged to merchants to process their debit and credit card transactions, in addition to account management fees. Other service charges include revenue from processing wire transfers, bill pay service, cashier’s checks, and other services. The Company’s performance obligation for fees, exchange, and other service charges are largely satisfied, and related revenue recognized, when the services are rendered or upon completion. Payment is typically received immediately or in the following month. Gains/Losses on Sales of OREO Gain or loss from the sale of OREO occurs when control of the property transfers to the buyer, which generally occurs at the time of an executed deed. When the Company finances the sale of OREO to the buyer, the Company assesses whether the buyer is committed to perform their obligations under the contract and whether collectability of the transaction price is probable. Once these criteria are met, the OREO asset is derecognized and the gain or loss on sale is recorded upon the transfer of control of the property to the buyer. In determining the gain or loss on the sale, the Company adjusts the transaction price and related gain (loss) on sale if a significant financing component is present. OREO sales for the nine months ended September 30, 2018 and September 30, 2017 were not financed by the Bank. Other Other noninterest income consists of other recurring revenue streams such as safe deposit box rental fees, and other miscellaneous revenue streams. Safe deposit box rental fees are charged to the customer on an annual basis and recognized upon receipt of payment. The Company determined that since rentals and renewals occur fairly consistently over time, revenue is recognized on a basis consistent with the duration of the performance obligation. Contract Balances A contract asset balance occurs when an entity performs a service for a customer before the customer pays consideration (resulting in a contract receivable) or before payment is due (resulting in a contract asset). A contract liability balance is an entity’s obligation to transfer a service to a customer for which the entity has already received payment (or payment is due) from the customer. The Company’s noninterest revenue streams are largely based on transactional activity, or standard month-end revenue accruals such as asset management fees based on month-end market values. Consideration is often received immediately or shortly after the Company satisfies its performance obligation and revenue is recognized. The Company does not typically enter into long-term revenue contracts with customers, and therefore, does not experience significant contract balances. As of September 30, 2018 and December 31, 2017 , the Company did not have any significant contract balances. Contract Acquisition Costs

Operating Segments

Operating Segments	9 Months Ended
	Sep. 30, 2018
Segment Reporting [Abstract]
Segment Reporting Disclosure [Text Block]	Operating Segments The Company’s activities are considered to be a single industry segment for financial reporting purposes. The Company is engaged in the business of commercial and retail banking, investment management and insurance services with operations throughout central and eastern Iowa, the Twin Cities area of Minnesota and Wisconsin, Florida, and Denver,

Proposed Merger (Notes)

Proposed Merger (Notes)	9 Months Ended
	Sep. 30, 2018
Business Combinations [Abstract]
Mergers, Acquisitions and Dispositions Disclosures [Text Block]	Proposed Merger On August 21, 2018, the Company entered into a merger agreement with ATBancorp, an Iowa corporation, pursuant to which ATBancorp will merge with and into the Company. In connection with the merger, American Trust & Savings Bank, an Iowa state chartered bank and wholly owned subsidiary of ATBancorp, and American Bank & Trust Wisconsin, a Wisconsin state chartered bank and wholly owned subsidiary of ATBancorp, will merge with and into MidWest One Bank, which will continue as the surviving bank. The merger agreement also provides that each of the outstanding shares of ATBancorp common stock will be converted into the right of ATBancorp shareholders to receive 117.5500 shares of Company common stock and $992.51 in cash. The corporate headquarters of the combined company will be in Iowa City, Iowa. The merger is anticipated to be completed in the first quarter of 2019. For further information, please refer to the Current Report on Form 8-K

Subsequent Events

Subsequent Events	9 Months Ended
	Sep. 30, 2018
Subsequent Events [Abstract]
Subsequent Events [Text Block]	Subsequent Events Management evaluated subsequent events through the date the consolidated financial statements were issued. Events or transactions occurring after September 30, 2018 , but prior to the date the consolidated financial statements were issued, that provided additional evidence about conditions that existed at September 30, 2018 have been recognized in the consolidated financial statements for the three and nine months ended September 30, 2018 . Events or transactions that provided evidence about conditions that did not exist at September 30, 2018 , but arose before the consolidated financial statements were issued, have not been recognized in the consolidated financial statements for the three and nine months ended September 30, 2018 . On October 16, 2018 , the Board of Directors of the Company approved a new share repurchase program, allowing for the repurchase of up to $5.0 million of common stock through December 31, 2020 . The new repurchase program replaces the Company's prior repurchase program, pursuant to which the Company had repurchased 33,998 shares of common stock for approximately $1.1 million since the plan was announced in July 2016. The prior program had authorized the repurchase of $5.0 million of stock and was due to expire on December 31, 2018. On October 16, 2018 , the board of directors of the Company declared a cash dividend of $0.195 per share payable on December 15, 2018 to shareholders of record as of the close of business on December 1, 2018

Significant Accounting Policies

Significant Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 2018
Accounting Policies [Abstract]
Certain Loans and Debt Securities Acquired in Transfer, Recognizing Interest Income on Impaired Loans, Policy [Policy Text Block]	Purchased Loans Policy All purchased loans (nonimpaired and impaired) are initially measured at fair value as of the acquisition date in accordance with applicable authoritative accounting guidance. Credit discounts are included in the determination of fair value. An allowance for loan losses is not recorded at the acquisition date for loans purchased. Individual loans acquired through the completion of a transfer, including loans that have evidence of deterioration of credit quality since origination and for which it is probable, at acquisition, that the Company will be unable to collect all contractually required payments receivable, are referred to herein as “purchased credit impaired loans.” In determining the acquisition date fair value and estimated credit losses of purchased credit impaired loans, and in subsequent accounting, the Company accounts for loans individually. Contractually required payments for interest and principal that exceed the undiscounted cash flows expected at acquisition, or the “nonaccretable difference,” are not recognized as a yield adjustment or as a loss accrual or valuation allowance. Expected cash flows at the purchase date in excess of the fair value of loans, if any, are recorded as interest income over the expected life of the loans if the timing and amount of future cash flows are reasonably estimable. Subsequent to the purchase date, increases in cash flows over those expected at the purchase date are recognized as interest income prospectively. The present value of any decreases in expected cash flows after the purchase date is recognized by recording an allowance for loan losses and a provision for loan losses. If the Company does not have the information necessary to reasonably estimate cash flows to be expected, it may use the cost-recovery method or cash-basis method of income recognition.
Financing Receivable, Allowance for Credit Losses, Policy for Uncollectible Amounts [Policy Text Block]	Charge-off Policy The Company requires a loan to be charged-off, in whole or in part, as soon as it becomes apparent that some loss will be incurred, or when its collectability is sufficiently questionable that it no longer is considered a bankable asset. The primary considerations when determining if and how much of a loan should be charged-off are as follows: (1) the potential for future cash flows; (2) the value of any collateral; and (3) the strength of any co-makers or guarantors.
Loans and Leases Receivable, Allowance for Loan Losses Policy [Policy Text Block]	Allowance for Loan and Lease Losses The Company requires the maintenance of an adequate allowance for loan and lease losses (“ALLL”) in order to cover estimated probable losses without eroding the Company’s capital base. Calculations are done at each quarter end, or more frequently if warranted, to analyze the collectability of loans and to ensure the adequacy of the allowance. In line with FDIC directives, the ALLL calculation does not include consideration of loans held for sale or off-balance-sheet credit exposures (such as unfunded letters of credit). Determining the appropriate level for the ALLL relies on the informed judgment of management, and as such, is subject to inexactness. Given the inherently imprecise nature of calculating the necessary ALLL, the Company’s policy permits the actual ALLL to be between 20% above and 5% below the “indicated reserve.”
Loans and Leases Receivable, Troubled Debt Restructuring Policy [Policy Text Block]	Loans Reviewed Individually for Impairment The Company identifies loans to be reviewed and evaluated individually for impairment based on current information and events and the probability that the borrower will be unable to repay all amounts due according to the contractual terms of the loan agreement. Specific areas of consideration include: size of credit exposure, risk rating, delinquency, nonaccrual status, and loan classification. The level of individual impairment is measured using one of the following methods: (1) the fair value of the collateral less costs to sell; (2) the present value of expected future cash flows, discounted at the loan's effective interest rate; or (3) the loan's observable market price. Loans that are deemed fully collateralized or have been charged down to a level corresponding with any of the three measurements require no assignment of reserves from the ALLL. A loan modification is a change in an existing loan contract that has been agreed to by the borrower and the Bank, which may or may not be a troubled debt restructure or “TDR.” All loans deemed TDR are considered impaired. A loan is considered a TDR when, for economic or legal reasons related to a borrower’s financial difficulties, a concession is granted to the borrower that would not otherwise be considered. Both financial distress on the part of the borrower and the Bank’s granting of a concession, which are detailed further below, must be present in order for the loan to be considered a TDR. All of the following factors are indicators that the debtor is experiencing financial difficulties (one or more items may be present): • The debtor is currently in default on any of its debt. • The debtor has declared or is in the process of declaring bankruptcy. • There is significant doubt as to whether the debtor will continue to be a going concern. • Currently, the debtor has securities being held as collateral that have been delisted, are in the process of being delisted, or are under threat of being delisted from an exchange. • Based on estimates and projections that only encompass the current business capabilities, the debtor forecasts that its entity-specific cash flows will be insufficient to service the debt (both interest and principal) in accordance with the contractual terms of the existing agreement through maturity. • Absent the current modification, the debtor cannot obtain funds from sources other than the existing creditors at an effective interest rate equal to the current market interest rate for similar debt for a non-troubled debtor. The following factors are potential indicators that a concession has been granted (one or multiple items may be present): • The borrower receives a reduction of the stated interest rate for the remaining original life of the debt. • The borrower receives an extension of the maturity date or dates at a stated interest rate lower that the current market interest rate for new debt with similar risk characteristics. • The borrower receives a reduction of the face amount or maturity amount of the debt as stated in the instrument or other agreement. • The borrower receives a deferral of required payments (principal and/or interest). •
Loans and Leases Receivable, Past Due Status, Policy [Policy Text Block]	Non-accrual and Delinquent Loans Loans are placed on non-accrual when (1) payment in full of principal and interest is no longer expected or (2) principal or interest has been in default for 90 days or more (unless the loan is both well secured with marketable collateral and in the process of collection). All loans rated doubtful or worse, and certain loans rated substandard, are placed on non-accrual. A non-accrual asset may be restored to an accrual status when (1) all past due principal and interest has been paid (excluding renewals and modifications that involve the capitalizing of interest) or (2) the loan becomes well secured with marketable collateral and is in the process of collection. An established track record of performance is also considered when determining accrual status.
Derivatives, Methods of Accounting, Hedging Derivatives [Policy Text Block]	As required by ASC 815, the Company records all derivatives on the balance sheet at fair value. The accounting for changes in the fair value of derivatives depends on the intended use of the derivative, whether the Company has elected to designate a derivative in a hedging relationship and apply hedge accounting and whether the hedging relationship has satisfied the criteria necessary to apply hedge accounting. Derivatives designated and qualifying as a hedge of the exposure to changes in the fair value of an asset, liability, or firm commitment attributable to a particular risk, such as interest rate risk, are considered fair value hedges. Derivatives designated and qualifying as a hedge of the exposure to variability in expected future cash flows, or other types of forecasted transactions, are considered cash flow hedges. Hedge accounting generally provides for the matching of the timing of gain or loss recognition on the hedging instrument with the recognition of the changes in the fair value of the hedged asset or liability that are attributable to the hedged risk in a fair value hedge or the earnings effect of the hedged forecasted transactions in a cash flow hedge. The Company may enter into derivative contracts that are intended to economically hedge certain of its risk, even though hedge accounting does not apply or the Company elects not to apply hedge accounting. The Company does not use derivatives for trading or speculative purposes.
Fair Value of Financial Instruments, Policy [Policy Text Block]	Fair value is the exchange price that would be received for an asset or paid to transfer a liability (exit price) in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. Market participants are defined as buyers and sellers in the principal (or most advantageous) market for the asset or liability that have all of the following characteristics: 1) an unrelated party; 2) knowledgeable (having a reasonable understanding about the asset or liability and the transaction based on all available information; including information that might be obtained through due diligence efforts that are usual or customary); 3) able to transact; and 4) willing to transact (motivated but not forced or otherwise compelled to do so). The FASB states “valuation techniques that are appropriate in the circumstances and for which sufficient data are available shall be used to measure fair value.” The valuation techniques for measuring fair value are consistent with the three traditional approaches to value: the market approach, the income approach, and the cost or asset approach. In applying valuation techniques, the use of relevant inputs (both observable and unobservable) based on the facts and circumstances must be used. The FASB has defined a fair value hierarchy for these inputs which prioritizes the inputs into three broad levels: • Level 1 Inputs – Quoted prices (unadjusted) for identical assets or liabilities in active markets. A quoted price in an active market provides the most reliable evidence of fair value and is used to measure fair value whenever available. A contractually binding sales price also provides reliable evidence of fair value. • Level 2 Inputs – Inputs to the valuation methodology include quoted prices for similar assets or liabilities in active markets; inputs to the valuation methodology include quoted prices for identical or similar assets or liabilities in markets that are not active; or inputs to the valuation methodology that utilize model-based techniques for which all significant assumptions are observable in the market. • Level 3 Inputs – Inputs to the valuation methodology are unobservable and significant to the fair value measurement; inputs to the valuation methodology that utilize model-based techniques for which significant assumptions are not observable in the market; or inputs to the valuation methodology that require significant management judgment or estimation, some of which may be internally developed. Unobservable inputs should be used only to the extent that relevant observable inputs are not available; this allows for situations where there is little, if any, market activity for the asset or liability at the measurement date. Unobservable inputs should reflect the reporting entity’s own assumptions about the assumptions that market participants would use in pricing the asset or liability, including assumptions about risk.
Fair Value Measurement, Policy [Policy Text Block]	The Company used the following methods and significant assumptions to estimate fair value: Investment Securities - The fair value for investment securities are determined by quoted market prices, if available (Level 1). The Company utilizes an independent pricing service to obtain the fair value of debt securities. On a quarterly basis, the Company selects a sample of 30 securities from its primary pricing service and compares them to a secondary independent pricing service to validate value. In addition, the Company periodically reviews the pricing methodology utilized by the primary independent service for reasonableness. Debt securities issued by the U.S. Treasury and other U.S. Government agencies and corporations, mortgage-backed securities, and collateralized mortgage obligations are priced utilizing industry-standard models that consider various assumptions, including time value, yield curves, volatility factors, prepayment speeds, default rates, loss severity, current market and contractual prices for the underlying financial instruments, as well as other relevant economic measures. Substantially all of these assumptions are observable in the marketplace, can be derived from observable data, or are supported by observable levels at which transactions are executed in the marketplace (Level 2). Municipal securities are valued using a type of matrix, or grid, pricing in which securities are benchmarked against the treasury rate based on credit rating (Level 2). On an annual basis, a group of selected municipal securities have their credit rating evaluated by a securities dealer and that information is used to verify the primary independent service’s rating and pricing. Loans Held for Sale - Loans held for sale are carried at the lower of cost or fair value, with fair value being based on binding contracts from third party investors (Level 2). The portfolio has historically consisted primarily of residential real estate loans. Loans, Net - The estimated fair value of loans, net, was performed using the income approach, with the market approach used for certain nonperforming loans, resulting in a Level 3 fair value classification. The application of the income approach establishes value by methods that discount or capitalize earnings and/or cash flow, by a discount or capitalization rate that reflects market rate of return expectations, market conditions, and the relative risk of the investment. Generally, this can be accomplished by the discounted cash flow method. For loans that exhibited some characteristics of performance and where it appears that the borrower may have adequate cash flows to service the loan, a discounted cash flow analysis was used. The discounted cash flow analysis was based on the contractual maturity of the loan and market indications of rates, prepayment speeds, defaults and credit risk. For loans with balloon or interest only payment structures, the repayment was extended by assuming a renewal period beyond the current contractual maturity date. For loans analyzed using the asset approach, the fair value was determined based on the estimated values of the underlying collateral. For impaired loans, the estimated net sales proceeds was used to determine the fair value of the loans when deemed appropriate. The implied sales proceeds value provides a better indication of value than the income stream as these loans are not performing or exhibit strong signs indicative of nonperformance. Collateral Dependent Impaired Loans - From time to time, a loan is considered impaired and an allowance for credit losses is established. The specific reserves for collateral dependent impaired loans are based on the fair value of the collateral less estimated costs to sell, based on appraisals. These appraisals may utilize a single valuation approach or a combination of approaches including comparable sales and the income approach. Adjustments are routinely made in the appraisal process by the independent appraisers to adjust for differences between the comparable sales and income data available for similar loans and collateral underlying such loans, and resulted in a Level 3 classification for inputs for determining fair value. Non-real estate collateral may be valued using an appraisal, net book value per the borrower’s financial statements, or aging reports, adjusted or discounted based on management’s historical knowledge, changes in market conditions from the time of valuation, and management’s expertise and knowledge of the client and the client’s business, resulting in a Level 3 fair value classification. Impaired loans are evaluated on a quarterly basis for additional impairment and adjusted in accordance with the allowance policy. Other Real Estate Owned (“OREO”) - OREO represents property acquired through foreclosures and settlements of loans. Property acquired through or in lieu of foreclosure are initially recorded at fair value less estimated selling cost at the date of foreclosure, establishing a new cost basis. These assets are subsequently accounted for at the lower of cost or fair value less estimated costs to sell. Fair value is commonly based on recent real estate appraisals which are updated no less frequently than every 18 months. These appraisals may utilize a single valuation approach or a combination of approaches, including comparable sales and the income approach. Adjustments are routinely made in the appraisal process by the independent appraisers to adjust for differences between the comparable sales and income data available for similar loans and the collateral underlying such loans, resulting in a Level 3 classification for inputs for determining fair value. Real estate owned properties are evaluated on a quarterly basis for additional impairment and adjusted accordingly. Appraisals for both collateral dependent impaired loans and OREO are performed by certified general appraisers (for commercial properties) or certified residential appraisers (for residential properties) whose qualifications and licenses have been reviewed and verified by the Company. Once received, a member of the Special Assets Department reviews the assumptions and approaches utilized in the appraisal as well as the overall resulting fair value in comparison with independent data sources such as recent market data or industry-wide statistics. Interest Rate Swaps

Investment Securities (Tables)

Investment Securities (Tables)	9 Months Ended
	Sep. 30, 2018
Investments, Debt and Equity Securities [Abstract]
Schedule of Available-for-sale Securities Reconciliation [Table Text Block]	The amortized cost and fair value of debt securities available for sale, with gross unrealized gains and losses, were as follows: As of September 30, 2018 (in thousands) Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Estimated Fair Value U.S. Government agencies and corporations $ 5,561 $ — $ 42 $ 5,519 State and political subdivisions 115,251 716 831 115,136 Mortgage-backed securities 53,664 112 1,880 51,896 Collateralized mortgage obligations 179,748 3 8,874 170,877 Corporate debt securities 65,842 8 1,512 64,338 Total $ 420,066 $ 839 $ 13,139 $ 407,766 As of December 31, 2017 (in thousands) Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Estimated Fair Value U.S. Government agencies and corporations $ 15,716 $ — $ 90 $ 15,626 State and political subdivisions 139,561 2,475 197 141,839 Mortgage-backed securities 48,744 181 428 48,497 Collateralized mortgage obligations 173,339 29 5,172 168,196 Corporate debt securities 71,562 31 427 71,166 Total $ 448,922 $ 2,716 $ 6,314 $ 445,324
Debt Securities, Held-to-maturity [Table Text Block]	The amortized cost and fair value of debt securities held to maturity, with gross unrealized gains and losses, were as follows: As of September 30, 2018 (in thousands) Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Estimated Fair Value State and political subdivisions $ 125,783 $ 155 $ 3,743 $ 122,195 Mortgage-backed securities 11,467 1 564 10,904 Collateralized mortgage obligations 19,373 — 1,104 18,269 Corporate debt securities 35,110 98 519 34,689 Total $ 191,733 $ 254 $ 5,930 $ 186,057 As of December 31, 2017 (in thousands) Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Estimated Fair Value U.S. Government agencies and corporations $ 10,049 $ — $ — $ 10,049 State and political subdivisions 126,413 804 1,631 125,586 Mortgage-backed securities 1,906 4 13 1,897 Collateralized mortgage obligations 22,115 — 707 21,408 Corporate debt securities 35,136 548 281 35,403 Total $ 195,619 $ 1,356 $ 2,632 $ 194,343
Schedule of Temporary Impairment Losses, Investments [Table Text Block]	The following tables present information pertaining to securities with gross unrealized losses as of September 30, 2018 and December 31, 2017 , aggregated by investment category and length of time that individual securities have been in a continuous loss position: As of September 30, 2018 Number of Securities Less than 12 Months 12 Months or More Total Available for Sale Fair Value Unrealized Losses Fair Value Unrealized Losses Fair Value Unrealized Losses (in thousands, except number of securities) U.S. Government agencies and corporations 2 $ 539 $ 14 $ 4,980 $ 28 $ 5,519 $ 42 State and political subdivisions 115 46,374 697 5,350 134 51,724 831 Mortgage-backed securities 26 40,039 1,613 7,591 267 47,630 1,880 Collateralized mortgage obligations 41 44,912 1,269 116,814 7,605 161,726 8,874 Corporate debt securities 12 50,439 1,149 12,230 363 62,669 1,512 Total 196 $ 182,303 $ 4,742 $ 146,965 $ 8,397 $ 329,268 $ 13,139 As of December 31, 2017 Number of Securities Less than 12 Months 12 Months or More Total Fair Value Unrealized Losses Fair Value Unrealized Losses Fair Value Unrealized Losses (in thousands, except number of securities) U.S. Government agencies and corporations 3 $ 15,626 $ 90 $ — $ — $ 15,626 $ 90 State and political subdivisions 34 11,705 167 1,800 30 13,505 197 Mortgage-backed securities 20 37,964 359 3,961 69 41,925 428 Collateralized mortgage obligations 35 37,881 489 122,757 4,683 160,638 5,172 Corporate debt securities 12 55,340 298 8,778 129 64,118 427 Other equity securities 1 — — 1,944 56 1,944 56 Total 105 $ 158,516 $ 1,403 $ 139,240 $ 4,967 $ 297,756 $ 6,370 As of September 30, 2018 Number of Securities Less than 12 Months 12 Months or More Total Held to Maturity Fair Value Unrealized Losses Fair Value Unrealized Losses Fair Value Unrealized Losses (in thousands, except number of securities) State and political subdivisions 257 $ 54,969 $ 1,271 $ 33,512 $ 2,472 $ 88,481 $ 3,743 Mortgage-backed securities 6 10,016 524 820 40 10,836 564 Collateralized mortgage obligations 7 — — 18,259 1,104 18,259 1,104 Corporate debt securities 13 18,126 345 2,722 174 20,848 519 Total 283 $ 83,111 $ 2,140 $ 55,313 $ 3,790 $ 138,424 $ 5,930 As of December 31, 2017 Number of Securities Less than 12 Months 12 Months or More Total Fair Value Unrealized Losses Fair Value Unrealized Losses Fair Value Unrealized Losses (in thousands, except number of securities) State and political subdivisions 167 $ 33,237 $ 393 $ 25,843 $ 1,238 $ 59,080 $ 1,631 Mortgage-backed securities 4 349 2 887 11 1,236 13 Collateralized mortgage obligations 7 5,221 90 16,168 617 21,389 707 Corporate debt securities 3 3,093 4 2,617 277 5,710 281 Total 181 $ 41,900 $ 489 $ 45,515 $ 2,143 $ 87,415 $ 2,632
Investments Classified by Contractual Maturity Date [Table Text Block]	The contractual maturity distribution of investment debt securities at September 30, 2018 , is summarized as follows: Available For Sale Held to Maturity (in thousands) Amortized Cost Fair Value Amortized Cost Fair Value Due in one year or less $ 27,913 $ 27,866 $ 734 $ 736 Due after one year through five years 99,630 98,105 24,275 23,867 Due after five years through ten years 55,757 55,700 97,511 95,353 Due after ten years 3,354 3,322 38,373 36,928 Debt securities without a single maturity date 233,412 222,773 30,840 29,173 Total $ 420,066 $ 407,766 $ 191,733 $ 186,057
Realized Gain (Loss) on Investments [Table Text Block]	Realized gains and losses on sales are determined on the basis of specific identification of investments based on the trade date. Realized gains (losses) on investments due to sale or call, including impairment losses for the three and nine months ended September 30, 2018 and 2017 , were as follows: Three Months Ended September 30, Nine Months Ended September 30, (in thousands) 2018 2017 2018 2017 Debt securities available for sale: Gross realized gains $ 194 $ 179 203 199 Gross realized losses (2 ) (3 ) (2 ) (3 ) Net realized gain $ 192 $ 176 $ 201 $ 196 Debt securities held to maturity: Gross realized gains $ — $ — $ — $ 43 Gross realized losses — — (4 ) — Net realized gain (loss) $ — $ — $ (4 ) $ 43 Total net realized gain on sale or call of debt securities $ 192 $ 176 $ 197 $ 239 The following tables present the net gains and losses on equity investments during the three and nine months ended September 30, 2018 , disaggregated into realized and unrealized gains and losses: Three Months Ended September 30, Nine Months Ended September 30, (in thousands) 2018 2017 2018 2017 Net losses recognized $ (10 ) $ — $ (34 ) $ — Less: Net gains and losses recognized due to sales — — — — Unrealized losses on securities still held at the reporting date $ (10 ) $ — $ (34 ) $ —

Loans Receivable and the Allo_2

Loans Receivable and the Allowance for Loan Losses (Tables)	9 Months Ended
	Sep. 30, 2018
Loans and Leases Receivable Disclosure [Abstract]
Schedule of Accounts, Notes, Loans and Financing Receivable [Table Text Block]	The composition of allowance for loan losses and loans by portfolio segment and based on impairment method are as follows: Allowance for Loan Losses and Recorded Investment in Loan Receivables As of September 30, 2018 and December 31, 2017 (in thousands) Agricultural Commercial and Industrial Commercial Real Estate Residential Real Estate Consumer Total September 30, 2018 Loans receivable Individually evaluated for impairment $ 6,711 $ 12,924 $ 17,375 $ 3,981 $ 8 $ 40,999 Collectively evaluated for impairment 96,496 510,357 1,223,311 450,246 38,788 2,319,198 Purchased credit impaired loans — 52 13,104 4,296 — 17,452 Total $ 103,207 $ 523,333 $ 1,253,790 $ 458,523 $ 38,796 $ 2,377,649 Allowance for loan losses: Individually evaluated for impairment $ 195 $ 3,059 $ 4,183 $ 143 $ — $ 7,580 Collectively evaluated for impairment 2,532 5,183 12,563 2,356 251 22,885 Purchased credit impaired loans — — 343 470 — 813 Total $ 2,727 $ 8,242 $ 17,089 $ 2,969 $ 251 $ 31,278 (in thousands) Agricultural Commercial and Industrial Commercial Real Estate Residential Real Estate Consumer Total December 31, 2017 Loans receivable Individually evaluated for impairment $ 2,969 $ 9,734 $ 10,386 $ 3,722 $ — $ 26,811 Collectively evaluated for impairment 102,543 493,844 1,147,133 460,475 36,158 2,240,153 Purchased credit impaired loans — 46 14,452 5,233 — 19,731 Total $ 105,512 $ 503,624 $ 1,171,971 $ 469,430 $ 36,158 $ 2,286,695 Allowance for loan losses: Individually evaluated for impairment $ 140 $ 1,126 $ 2,157 $ 226 $ — $ 3,649 Collectively evaluated for impairment 2,650 7,392 11,144 2,182 244 23,612 Purchased credit impaired loans — — 336 462 — 798 Total $ 2,790 $ 8,518 $ 13,637 $ 2,870 $ 244 $ 28,059
Allowance for Credit Losses on Financing Receivables [Table Text Block]	The changes in the allowance for loan losses by portfolio segment were as follows: Allowance for Loan Loss Activity For the Three Months Ended September 30, 2018 and 2017 (in thousands) Agricultural Commercial and Industrial Commercial Real Estate Residential Real Estate Consumer Total 2018 Beginning balance $ 2,656 $ 8,557 $ 16,341 $ 2,990 $ 256 $ 30,800 Charge-offs (365 ) (108 ) (17 ) — (327 ) (817 ) Recoveries 41 78 77 131 18 345 Provision 395 (285 ) 688 (152 ) 304 950 Ending balance $ 2,727 $ 8,242 $ 17,089 $ 2,969 $ 251 $ 31,278 2017 Beginning balance $ 2,666 $ 7,959 $ 9,013 $ 2,650 $ 222 $ 22,510 Charge-offs (318 ) (534 ) — (75 ) (51 ) (978 ) Recoveries 150 113 201 126 4 594 Provision 67 2,157 1,166 915 79 4,384 Ending balance $ 2,565 $ 9,695 $ 10,380 $ 3,616 $ 254 $ 26,510 Allowance for Loan Loss Activity For the Nine Months Ended September 30, 2018 and 2017 (in thousands) Agricultural Commercial and Industrial Commercial Real Estate Residential Real Estate Consumer Total 2018 Beginning balance $ 2,790 $ 8,518 $ 13,637 $ 2,870 $ 244 $ 28,059 Charge-offs (633 ) (198 ) (281 ) (107 ) (365 ) (1,584 ) Recoveries 56 260 193 208 36 753 Provision 514 (338 ) 3,540 (2 ) 336 4,050 Ending balance $ 2,727 $ 8,242 $ 17,089 $ 2,969 $ 251 $ 31,278 2017 Beginning balance $ 2,003 $ 6,274 $ 9,860 $ 3,458 $ 255 $ 21,850 Charge-offs (1,202 ) (1,063 ) (106 ) (155 ) (211 ) (2,737 ) Recoveries 164 215 216 126 11 732 Provision 1,600 4,269 410 187 199 6,665 Ending balance $ 2,565 $ 9,695 $ 10,380 $ 3,616 $ 254 $ 26,510
Troubled Debt Restructurings on Financing Receivables [Table Text Block]	The following table sets forth information on the Company’s TDRs by class of loan occurring during the stated periods: Three Months Ended September 30, 2018 2017 Number of Contracts Pre-Modification Outstanding Recorded Investment Post-Modification Outstanding Recorded Investment Number of Contracts Pre-Modification Outstanding Recorded Investment Post-Modification Outstanding Recorded Investment (dollars in thousands) Troubled Debt Restructurings (1) : Total — $ — $ — — $ — $ — Nine Months Ended September 30, 2018 2017 (dollars in thousands) Number of Contracts Pre-Modification Outstanding Recorded Investment Post-Modification Outstanding Recorded Investment Number of Contracts Pre-Modification Outstanding Recorded Investment Post-Modification Outstanding Recorded Investment Troubled Debt Restructurings (1) : Commercial and industrial Extended maturity date — $ — $ — 6 $ 2,037 $ 2,083 Commercial real estate: Farmland Extended maturity date 1 86 86 2 176 176 Commercial real estate-other Extended maturity date — — — 1 968 968 Other — — — 1 10,546 10,923 Total 1 $ 86 $ 86 10 $ 13,727 $ 14,150 (1) TDRs may include multiple concessions, and the disclosure classifications are based on the primary concession provided to the borrower. Loans by class modified as TDRs within 12 months of modification and for which there was a payment default during the stated periods were as follows: Three Months Ended September 30, Nine Months Ended September 30, 2018 2017 2018 2017 (dollars in thousands) Number of Contracts Recorded Investment Number of Contracts Recorded Investment Number of Contracts Recorded Investment Number of Contracts Recorded Investment Troubled Debt Restructurings (1) That Subsequently Defaulted: Commercial and industrial Extended maturity date — $ — — $ — — $ — 4 $ 1,504 Commercial real estate: Commercial real estate-other Extended maturity date — — — — — — 1 968 Total — $ — — $ — — $ — 5 $ 2,472 (1) TDRs may include multiple concessions, and the disclosure classifications are based on the primary concession provided to the borrower.
Financing Receivable Credit Quality Indicators [Table Text Block]	The following tables set forth the risk category of loans by class of loans and credit quality indicator based on the most recent analysis performed, as of September 30, 2018 and December 31, 2017 : (in thousands) Pass Special Mention/ Watch Substandard Doubtful Loss Total September 30, 2018 Agricultural $ 78,007 $ 17,266 $ 7,934 $ — $ — $ 103,207 Commercial and industrial 482,136 21,166 20,027 4 — 523,333 Commercial real estate: Construction and development 221,114 1,078 1,132 — — 223,324 Farmland 69,824 6,970 8,941 — — 85,735 Multifamily 124,092 1,391 1,180 — — 126,663 Commercial real estate-other 748,837 44,603 24,628 — — 818,068 Total commercial real estate 1,163,867 54,042 35,881 — — 1,253,790 Residential real estate: One- to four- family first liens 333,974 2,289 6,492 — — 342,755 One- to four- family junior liens 113,526 687 1,555 — — 115,768 Total residential real estate 447,500 2,976 8,047 — — 458,523 Consumer 38,621 148 — 27 — 38,796 Total $ 2,210,131 $ 95,598 $ 71,889 $ 31 $ — $ 2,377,649 (in thousands) Pass Special Mention/ Watch Substandard Doubtful Loss Total December 31, 2017 Agricultural $ 80,377 $ 21,989 $ 3,146 $ — $ — $ 105,512 Commercial and industrial 453,363 23,153 27,102 6 — 503,624 Commercial real estate: Construction and development 162,968 1,061 1,247 — — 165,276 Farmland 76,740 10,357 771 — — 87,868 Multifamily 131,507 2,498 501 — — 134,506 Commercial real estate-other 731,231 34,056 19,034 — — 784,321 Total commercial real estate 1,102,446 47,972 21,553 — — 1,171,971 Residential real estate: One- to four- family first liens 340,446 2,776 9,004 — — 352,226 One- to four- family junior liens 114,763 952 1,489 — — 117,204 Total residential real estate 455,209 3,728 10,493 — — 469,430 Consumer 36,059 — 68 31 — 36,158 Total $ 2,127,454 $ 96,842 $ 62,362 $ 37 $ — $ 2,286,695
Impaired Financing Receivables [Table Text Block]	The following table presents loans individually evaluated for impairment, excluding purchased credit impaired loans, by class of loan, as of September 30, 2018 and December 31, 2017 : September 30, 2018 December 31, 2017 (in thousands) Recorded Investment Unpaid Principal Balance Related Allowance Recorded Investment Unpaid Principal Balance Related Allowance With no related allowance recorded: Agricultural $ 5,161 $ 5,661 $ — $ 1,523 $ 2,023 $ — Commercial and industrial 3,796 3,990 — 7,588 7,963 — Commercial real estate: Construction and development 84 84 — 84 84 — Farmland 3,539 3,539 — 287 287 — Multifamily 821 821 — — — — Commercial real estate-other 6,290 6,800 — 5,746 6,251 — Total commercial real estate 10,734 11,244 — 6,117 6,622 — Residential real estate: One- to four- family first liens 2,677 2,737 — 2,449 2,482 — One- to four- family junior liens 344 345 — 26 26 — Total residential real estate 3,021 3,082 — 2,475 2,508 — Consumer 8 8 — — — — Total $ 22,720 $ 23,985 $ — $ 17,703 $ 19,116 $ — With an allowance recorded: Agricultural $ 1,550 $ 1,920 $ 195 $ 1,446 $ 1,446 $ 140 Commercial and industrial 9,128 9,258 3,059 2,146 2,177 1,126 Commercial real estate: Construction and development — — — — — — Farmland 2,123 2,123 662 — — — Multifamily — — — — — — Commercial real estate-other 4,518 12,184 3,521 4,269 11,536 2,157 Total commercial real estate 6,641 14,307 4,183 4,269 11,536 2,157 Residential real estate: One- to four- family first liens 960 960 143 979 979 185 One- to four- family junior liens — — — 268 268 41 Total residential real estate 960 960 143 1,247 1,247 226 Consumer — — — — — — Total $ 18,279 $ 26,445 $ 7,580 $ 9,108 $ 16,406 $ 3,649 Total: Agricultural $ 6,711 $ 7,581 $ 195 $ 2,969 $ 3,469 $ 140 Commercial and industrial 12,924 13,248 3,059 9,734 10,140 1,126 Commercial real estate: Construction and development 84 84 — 84 84 — Farmland 5,662 5,662 662 287 287 — Multifamily 821 821 — — — — Commercial real estate-other 10,808 18,984 3,521 10,015 17,787 2,157 Total commercial real estate 17,375 25,551 4,183 10,386 18,158 2,157 Residential real estate: One- to four- family first liens 3,637 3,697 143 3,428 3,461 185 One- to four- family junior liens 344 345 — 294 294 41 Total residential real estate 3,981 4,042 143 3,722 3,755 226 Consumer 8 8 — — — — Total $ 40,999 $ 50,430 $ 7,580 $ 26,811 $ 35,522 $ 3,649 The following table presents the average recorded investment and interest income recognized for loans individually evaluated for impairment, excluding purchased credit impaired loans, by class of loan, during the stated periods: Three Months Ended September 30, Nine Months Ended September 30, 2018 2017 2018 2017 (in thousands) Average Recorded Investment Interest Income Recognized Average Recorded Investment Interest Income Recognized Average Recorded Investment Interest Income Recognized Average Recorded Investment Interest Income Recognized With no related allowance recorded: Agricultural $ 4,864 $ 71 $ 881 $ 17 $ 3,480 $ 180 $ 674 $ 50 Commercial and industrial 3,961 36 2,878 77 3,563 150 2,899 124 Commercial real estate: Construction and development 84 — 423 — 84 — 434 2 Farmland 3,274 44 212 — 1,745 86 1,193 58 Multifamily 822 10 — — 618 30 — — Commercial real estate-other 6,326 77 2,148 18 5,428 201 1,894 63 Total commercial real estate 10,506 131 2,783 18 7,875 317 3,521 123 Residential real estate: One- to four- family first liens 2,578 34 2,183 23 1,942 53 2,197 69 One- to four- family junior liens 323 1 13 — 301 1 13 — Total residential real estate 2,901 35 2,196 23 2,243 54 2,210 69 Consumer 4 — — — 2 — — — Total $ 22,236 $ 273 $ 8,738 $ 135 $ 17,163 $ 701 $ 9,304 $ 366 With an allowance recorded: Agricultural $ 1,974 $ — $ 1,446 $ 11 $ 2,108 $ — $ 1,460 $ 33 Commercial and industrial 8,905 43 8,458 85 7,778 89 8,423 163 Commercial real estate: Construction and development — — 311 — — — 232 — Farmland 2,123 — — — 1,584 — — — Multifamily — — — — — — — — Commercial real estate-other 4,536 16 12,863 — 4,443 — 12,881 44 Total commercial real estate 6,659 16 13,174 — 6,027 — 13,113 44 Residential real estate: One- to four- family first liens 963 9 1,361 9 969 27 1,392 26 One- to four- family junior liens — — — — — — — — Total residential real estate 963 9 1,361 9 969 27 1,392 26 Consumer — — — — — — — — Total $ 18,501 $ 68 $ 24,439 $ 105 $ 16,882 $ 116 $ 24,388 $ 266 Total: Agricultural $ 6,838 $ 71 $ 2,327 $ 28 $ 5,588 $ 180 $ 2,134 $ 83 Commercial and industrial 12,866 79 11,336 162 11,341 239 11,322 287 Commercial real estate: Construction and development 84 — 734 — 84 — 666 2 Farmland 5,397 44 212 — 3,329 86 1,193 58 Multifamily 822 10 — — 618 30 — — Commercial real estate-other 10,862 93 15,011 18 9,871 201 14,775 107 Total commercial real estate 17,165 147 15,957 18 13,902 317 16,634 167 Residential real estate: One- to four- family first liens 3,541 43 3,544 32 2,911 80 3,589 95 One- to four- family junior liens 323 1 13 — 301 1 13 — Total residential real estate 3,864 44 3,557 32 3,212 81 3,602 95 Consumer 4 — — — 2 — — — Total $ 40,737 $ 341 $ 33,177 $ 240 $ 34,045 $ 817 $ 33,692 $ 632
Past Due Financing Receivables [Table Text Block]	The following table presents the contractual aging of the recorded investment in past due loans by class of loans at September 30, 2018 and December 31, 2017 : (in thousands) 30 - 59 Days Past Due 60 - 89 Days Past Due 90 Days or More Past Due Total Past Due Current Total Loans Receivable September 30, 2018 Agricultural $ 72 $ 100 $ 230 $ 402 $ 102,805 $ 103,207 Commercial and industrial 1,206 315 6,701 8,222 515,111 523,333 Commercial real estate: Construction and development — 10 83 93 223,231 223,324 Farmland — — 141 141 85,594 85,735 Multifamily — — — — 126,663 126,663 Commercial real estate-other 4,198 101 3,814 8,113 809,955 818,068 Total commercial real estate 4,198 111 4,038 8,347 1,245,443 1,253,790 Residential real estate: One- to four- family first liens 3,381 313 965 4,659 338,096 342,755 One- to four- family junior liens 225 94 377 696 115,072 115,768 Total residential real estate 3,606 407 1,342 5,355 453,168 458,523 Consumer 138 3 31 172 38,624 38,796 Total $ 9,220 $ 936 $ 12,342 $ 22,498 $ 2,355,151 $ 2,377,649 Included in the totals above are the following purchased credit impaired loans $ — $ — $ — $ — $ 17,452 $ 17,452 December 31, 2017 Agricultural $ 95 $ 118 $ 168 $ 381 $ 105,131 $ 105,512 Commercial and industrial 1,434 1,336 1,576 4,346 499,278 503,624 Commercial real estate: Construction and development 57 97 82 236 165,040 165,276 Farmland 217 — 373 590 87,278 87,868 Multifamily — 25 — 25 134,481 134,506 Commercial real estate-other 74 — 1,852 1,926 782,395 784,321 Total commercial real estate 348 122 2,307 2,777 1,169,194 1,171,971 Residential real estate: One- to four- family first liens 3,854 756 1,019 5,629 346,597 352,226 One- to four- family junior liens 325 770 271 1,366 115,838 117,204 Total residential real estate 4,179 1,526 1,290 6,995 462,435 469,430 Consumer 79 15 29 123 36,035 36,158 Total $ 6,135 $ 3,117 $ 5,370 $ 14,622 $ 2,272,073 $ 2,286,695 Included in the totals above are the following purchased credit impaired loans $ 164 $ 756 $ 553 $ 1,473 $ 18,258 $ 19,731
Schedule of Financing Receivables, Non Accrual Status [Table Text Block]	The following table sets forth the composition of the Company’s recorded investment in loans on nonaccrual status and past due 90 days or more and still accruing by class of loans, excluding purchased credit impaired loans, as of September 30, 2018 and December 31, 2017 : September 30, 2018 December 31, 2017 (in thousands) Non-Accrual Loans Past Due 90 Days or More and Still Accruing Non-Accrual Loans Past Due 90 Days or More and Still Accruing Agricultural $ 662 $ — $ 168 $ — Commercial and industrial 11,208 — 7,124 — Commercial real estate: Construction and development 100 — 188 — Farmland 2,367 — 386 — Multifamily — — — — Commercial real estate-other 4,816 — 5,279 — Total commercial real estate 7,283 — 5,853 — Residential real estate: One- to four- family first liens 1,277 171 1,228 205 One- to four- family junior liens 413 — 346 2 Total residential real estate 1,690 171 1,574 207 Consumer 86 — 65 — Total $ 20,929 $ 171 $ 14,784 $ 207
Schedule of Changes in Accretable Yield for Purchased Credit Impaired Loans [Table Text Block]	Changes in the accretable yield for loans acquired and accounted for under ASC 310-30 were as follows for the three and nine months ended September 30, 2018 and 2017 : Three Months Ended September 30, Nine Months Ended September 30, (in thousands) 2018 2017 2018 2017 Balance at beginning of period $ 311 $ 1,371 $ 840 $ 1,961 Accretion (223 ) (350 ) (873 ) (1,241 ) Reclassification (to) from nonaccretable difference (7 ) 63 114 364 Balance at end of period $ 81 $ 1,084 $ 81 $ 1,084

Derivatives and Hedging Activ_4

Derivatives and Hedging Activities (Tables)	9 Months Ended
	Sep. 30, 2018
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Schedule of Derivative Instruments [Table Text Block]	The following table presents the total notional and gross fair value of the Company’s derivatives as of September 30, 2018 and December 31, 2017 . The derivative asset and liability balances are presented on a gross basis, prior to the application of master netting agreements, as included in other assets and other liabilities, respectively, on the consolidated balance sheets. As of September 30, 2018 As of December 31, 2017 Fair Value Fair Value (in thousands) Notional Amount Derivative Assets Derivative Liabilities Notional Amount Derivative Assets Derivative Liabilities Derivatives designated as hedging instruments: Fair value hedges: Interest rate swaps $ 7,855 $ 100 $ — $ — $ — $ — Derivatives not designated as hedging instruments: Interest rate swaps $ 13,840 $ 105 $ 125 $ — $ — $ — Risk participation agreements (RPAs) 10,112 — 53 — — — Total derivatives not designated as hedging instruments $ 23,952 $ 105 $ 178 $ — $ — $ —
Schedule of Derivatives Instruments Statements of Financial Performance and Financial Position, Location [Table Text Block]	The table below presents the effect of the Company’s derivative financial instruments designated as hedging instruments on the consolidated statements of income for the three and nine months ended September 30, 2018 and September 30, 2017 : Location and Amount of Gain or Loss Recognized in Income on Fair Value Hedging Relationships For the Three Months Ended September 30, For the Nine Months Ended September 30, 2018 2017 2018 2017 (in thousands) Interest Income (Expense) Other Gain (Loss) Interest Income (Expense) Other Gain (Loss) Interest Income (Expense) Other Gain (Loss) Interest Income (Expense) Other Gain (Loss) Total amounts of income and expense line items presented in the Consolidated Statements of Income in which the effects of fair value hedges are recorded $ — $ — $ — $ — $ (1 ) $ — $ — $ — The effects of fair value hedging: Gain (Loss) on fair value hedging relationships in subtopic 815-20: Interest contracts: Hedged items (126 ) — — — (101 ) — — — Derivative designated as hedging instruments 126 — — — 100 — — —
Hedged Items In Fair Value Hedging Relationship [Table Text Block]	As of September 30, 2018 , the following amounts were recorded on the balance sheet related to cumulative basis adjustment for fair value hedges: Line Item in the Balance Sheet in Which the Hedged Item is Included Carrying Amount of the Hedged Assets Cumulative Amount of Fair Value Hedging Adjustment Included in the Carrying Amount of the Hedged Asset (in thousands) Loans $ 7,754 $ (101 )
Derivatives Not Designated as Hedging Instruments [Table Text Block]	Derivatives Not Designated as Hedging Instruments Interest Rate Swaps -The Company enters into interest rate derivatives, including interest rate swaps with its customers, to allow them to hedge against the risk of rising interest rates by providing fixed rate loans. To economically hedge against the interest rate risks in the products offered to its customers, the Company enters into mirrored interest rate contracts with institutional counterparties, with one designated as a central counterparty. The following table represents the notional amounts and the gross fair values of interest rate derivative contracts outstanding as of September 30, 2018 and December 31, 2017 respectively. September 30, 2018 Customer Counterparties Financial Counterparties Fair Value Fair Value (in thousands) Notional Amount Assets Liabilities Notional Amount Assets Liabilities Swaps $ 6,920 $ 105 $ — $ 6,920 $ — $ 125 December 31, 2017 Customer Counterparties Financial Counterparties Fair Value Fair Value (in thousands) Notional Amount Assets Liabilities Notional Amount Assets Liabilities Swaps $ — $ — $ — $ — $ — $ — Credit Risk Participation Agreements -The Company may periodically enter into RPAs to manage the credit exposure on interest rate contracts associated with a syndicated loan. The Company may enter into protection purchased RPAs with institutional counterparties to decrease or increase its exposure to a borrower. Under the RPA, the Company will receive or make payment if a borrower defaults on the related interest rate contract. The Company manages its credit risk on RPAs by monitoring the creditworthiness of the borrowers and institutional counterparties, which is based on the normal credit review process. The notional amount of the RPAs reflects the Company’s pro-rata share of the derivative instrument. The following table represents the notional amounts and the gross fair values of RPAs purchased and sold outstanding as of September 30, 2018 and December 31, 2017 respectively. September 30, 2018 December 31, 2017 Fair Value Fair Value (in thousands) Notional Amount Assets Liabilities Notional Amount Assets Liabilities RPAs - protection purchased $ 10,112 $ — $ 53 $ — $ — $ — The following table presents the net gains (losses) recognized on the consolidated statements of income related to the derivatives not designated as hedging instruments for the three and nine months ended September 30, 2018 and September 30, 2017 : Location in the Consolidated Statements of Income For the Three Months Ended September 30, For the Nine Months Ended September 30, (in thousands) 2018 2017 2018 2017 Interest rate swaps Other gain (loss) $ — $ — $ (20 ) $ — RPAs Other gain (loss) 147 — 147 — Total $ 147 $ — $ 127 $ —
Offsetting Derivative Assets And Liabilities [Table Text Block]	The table below presents a gross presentation, the effects of offsetting, and a net presentation of the Company’s derivatives as of September 30, 2018 and December 31, 2017 . The net amounts of derivative assets or liabilities can be reconciled to the tabular disclosure of fair value. The tabular disclosure of fair value provides the location that derivative assets and liabilities are presented on the consolidated balance sheets. Gross Amounts Not Offset in the Balance Sheet (in thousands) Gross Amounts of Recognized Assets (Liabilities) Gross Amounts Offset in the Balance Sheet Net Amounts of Assets (Liabilities) presented in the Balance Sheet Financial Instruments Cash Collateral Received (Paid) Net Assets (Liabilities) As of September 30, 2018 Asset Derivatives $ 205 $ — $ 205 $ 100 $ — $ 105 Liability Derivatives (178 ) — (178 ) 100 — (78 ) As of December 31, 2017 Derivatives $ — $ — $ — $ — $ — $ — Liability Derivatives — — — — — —

Goodwill and Intangible Assets

Goodwill and Intangible Assets (Tables)	9 Months Ended
	Sep. 30, 2018
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of Intangible Assets and Goodwill [Table Text Block]	The following table presents the changes in the carrying amount of intangibles (excluding goodwill), gross carrying amount, accumulated amortization, and net book value as of and for the nine months ended September 30, 2018 : (in thousands) Insurance Agency Intangible Core Deposit Intangible Indefinite-Lived Trade Name Intangible Finite-Lived Trade Name Intangible Customer List Intangible Total September 30, 2018 Balance, beginning of period $ 148 $ 4,011 $ 7,040 $ 744 $ 103 $ 12,046 Finite-lived intangible assets acquired — — — — 125 125 Amortization expense (28 ) (1,600 ) — (143 ) (22 ) (1,793 ) Balance at end of period $ 120 $ 2,411 $ 7,040 $ 601 $ 206 $ 10,378 Gross carrying amount $ 1,320 $ 18,206 $ 7,040 $ 1,380 $ 455 $ 28,401 Accumulated amortization (1,200 ) (15,795 ) — (779 ) (249 ) (18,023 ) Net book value $ 120 $ 2,411 $ 7,040 $ 601 $ 206 $ 10,378

Other Assets (Tables)

Other Assets (Tables)	9 Months Ended
	Sep. 30, 2018
Other Assets [Abstract]
Schedule of Other Assets [Table Text Block]	The components of the Company’s other assets were as follows: (in thousands) September 30, 2018 December 31, 2017 Federal Home Loan Bank Stock $ 13,260 $ 11,324 Prepaid expenses 2,286 2,992 Mortgage servicing rights 2,711 2,316 Assets held for sale 895 — Federal & state income taxes receivable, current 322 3,120 Accounts receivable & other miscellaneous assets 7,841 3,009 $ 27,315 $ 22,761

Short-Term Borrowings (Tables)

Short-Term Borrowings (Tables)	9 Months Ended
	Sep. 30, 2018
Short-term Debt [Abstract]
Schedule of Short-term Debt [Table Text Block]	Short-term borrowings were as follows as of September 30, 2018 and December 31, 2017 : September 30, 2018 December 31, 2017 (in thousands) Weighted Average Cost Balance Weighted Average Cost Balance Federal funds purchased 2.39 % $ 19,056 1.77 % $ 1,000 Securities sold under agreements to repurchase 0.97 68,922 0.71 96,229 Total 1.28 % $ 87,978 0.73 % $ 97,229

Junior Subordinated Notes Iss_2

Junior Subordinated Notes Issued to Capital Trusts (Tables)	9 Months Ended
	Sep. 30, 2018
Junior Subordinated Notes [Abstract]
Schedule of Subordinated Borrowing [Table Text Block]	The table below summarizes the outstanding junior subordinated notes and the related trust preferred securities issued by each trust as of September 30, 2018 and December 31, 2017 : Face Value Book Value Interest Rate Interest Rate at Maturity Date Callable Date (in thousands) 9/30/2018 September 30, 2018 Central Bancshares Capital Trust II (1) (2) $ 7,217 $ 6,716 Three-month LIBOR + 3.50% 5.83 % 03/15/2038 03/15/2013 Barron Investment Capital Trust I (1) (2) 2,062 1,685 Three-month LIBOR + 2.15% 4.52 % 09/23/2036 09/23/2011 MidWestOne Statutory Trust II (1) 15,464 15,464 Three-month LIBOR + 1.59% 3.92 % 12/15/2037 12/15/2012 Total $ 24,743 $ 23,865 Face Value Book Value Interest Rate Interest Rate at Maturity Date Callable Date (in thousands) 12/31/2017 December 31, 2017 Central Bancshares Capital Trust II (1) (2) $ 7,217 $ 6,674 Three-month LIBOR + 3.50% 5.09 % 03/15/2038 03/15/2013 Barron Investment Capital Trust I (1) (2) 2,062 1,655 Three-month LIBOR + 2.15% 3.82 % 09/23/2036 09/23/2011 MidWestOne Statutory Trust II (1) 15,464 15,464 Three-month LIBOR + 1.59% 3.18 % 12/15/2037 12/15/2012 Total $ 24,743 $ 23,793 (1) All distributions are cumulative and paid in cash quarterly.

Federal Home Loan Bank Borrow_2

Federal Home Loan Bank Borrowings and Long-Term Debt (Tables)	9 Months Ended
	Sep. 30, 2018
Long-term Debt, by Type, Current and Noncurrent [Abstract]
Schedule of Long-term Debt Instruments [Table Text Block]	ong-term debt were as follows as of September 30, 2018 and December 31, 2017 : September 30, 2018 December 31, 2017 (in thousands) Weighted Average Cost Balance Weighted Average Cost Balance FHLB Borrowings 2.20 % $ 143,000 1.72 % $ 115,000 Note payable to unaffiliated bank 3.85 8,750 3.32 12,500 Total 2.30 % $ 151,750 1.88 % $ 127,500

Income Taxes (Tables)

Income Taxes (Tables)	9 Months Ended
	Sep. 30, 2018
Income Tax Disclosure [Abstract]
Schedule of Effective Income Tax Rate Reconciliation [Table Text Block]	ncome tax expense for the three and nine months ended September 30, 2018 and 2017 was equal to or less than the amount computed by applying the maximum effective federal income tax rate of 21% and 35% , respectively, to the income before income taxes, because of the following items: For the Three Months Ended September 30, For the Nine Months Ended September 30, 2018 2017 2018 2017 (in thousands) Amount % of Pretax Income Amount % of Pretax Income Amount % of Pretax Income Amount % of Pretax Income Income tax based on statutory rate $ 1,803 21.0 % $ 2,898 35.0 % $ 6,016 21.0 % $ 9,762 35.0 % Tax-exempt interest (468 ) (5.4 ) (808 ) (9.7 ) (1,459 ) (5.0 ) (2,389 ) (8.6 ) Bank-owned life insurance (84 ) (1.0 ) (121 ) (1.5 ) (257 ) (0.9 ) (346 ) (1.2 ) State income taxes, net of federal income tax benefit 445 5.2 366 4.4 1,540 5.4 1,214 4.4 Non-deductible acquisition expenses 124 1.4 — — 124 0.4 — — General business credits (22 ) (0.2 ) (405 ) (4.9 ) (62 ) (0.2 ) (445 ) (1.6 ) Other 8 — 8 0.1 19 — (193 ) (0.7 ) Total income tax expense $ 1,806 21.0 % $ 1,938 23.4 % $ 5,921 20.7 % $ 7,603 27.3 %

Earnings per Share (Tables)

Earnings per Share (Tables)	9 Months Ended
	Sep. 30, 2018
Earnings Per Share [Abstract]
Schedule of Earnings Per Share, Basic, by Common Class, Including Two Class Method [Table Text Block]	The following table presents the computation of earnings per common share for the respective periods: Three Months Ended September 30, Nine Months Ended September 30, (dollars in thousands, except per share amounts) 2018 2017 2018 2017 Basic earnings per common share computation Numerator: Net income $ 6,778 $ 6,342 $ 22,727 $ 20,289 Denominator: Weighted average shares outstanding 12,221,107 12,218,528 12,220,673 11,977,579 Basic earnings per common share $ 0.55 $ 0.52 $ 1.86 $ 1.69 Diluted earnings per common share computation Numerator: Net income $ 6,778 $ 6,342 $ 22,727 $ 20,289 Denominator: Weighted average shares outstanding, including all dilutive potential shares 12,239,864 12,238,991 12,237,462 11,999,608 Diluted earnings per common share $ 0.55 $ 0.52 $ 1.86 $ 1.69

Estimated Fair Value of Finan_2

Estimated Fair Value of Financial Instruments and Fair Value Measurements (Tables)	9 Months Ended
	Sep. 30, 2018
Fair Value Disclosures [Abstract]
Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis [Table Text Block]	The following table summarizes assets and liabilities measured at fair value on a recurring basis as of September 30, 2018 and December 31, 2017 . The assets and liabilities are segregated by the level of valuation inputs within the fair value hierarchy utilized to measure fair value: Fair Value Measurement at September 30, 2018 Using (in thousands) Fair Value Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Assets: Available for sale debt securities: U.S. Government agencies and corporations $ 5,519 $ — $ 5,519 $ — State and political subdivisions 115,136 — 115,136 — Mortgage-backed securities 51,896 — 51,896 — Collateralized mortgage obligations 170,877 — 170,877 — Corporate debt securities 64,338 — 64,338 — Total available for sale debt securities $ 407,766 $ — $ 407,766 $ — Derivatives: Interest rate swaps $ 205 $ — $ 205 $ — RPAs — — — — Total derivative assets $ 205 $ — $ 205 $ — Liabilities: Derivatives: Interest rate swaps $ 125 $ — $ 125 $ — RPAs 53 — 53 — Total derivative liabilities $ 178 $ — $ 178 $ — Fair Value Measurement at December 31, 2017 Using (in thousands) Fair Value Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Assets: Available for sale debt securities: U.S. Government agencies and corporations $ 15,626 $ — $ 15,626 $ — State and political subdivisions 141,839 — 141,839 — Mortgage-backed securities 48,497 — 48,497 — Collateralized mortgage obligations 168,196 — 168,196 — Corporate debt securities 71,166 — 71,166 — Total available for sale debt securities $ 445,324 $ — $ 445,324 $ —
Fair Value, Assets and Liabilities Measured on Nonrecurring Basis [Table Text Block]	The following table discloses the Company’s estimated fair value amounts of its assets recorded at fair value on a nonrecurring basis. It is management’s belief that the fair values presented below are reasonable based on the valuation techniques and data available to the Company as of September 30, 2018 and December 31, 2017 , as more fully described above. Fair Value Measurement at September 30, 2018 Using (in thousands) Fair Value Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Assets: Collateral dependent impaired loans $ 8,362 $ — $ — $ 8,362 Other real estate owned $ 549 $ — $ — $ 549 Fair Value Measurement at December 31, 2017 Using (in thousands) Fair Value Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Assets: Collateral dependent impaired loans $ 3,927 $ — $ — $ 3,927 Other real estate owned $ 2,010 $ — $ — $ 2,010
Fair Value, by Balance Sheet Grouping [Table Text Block]	Due to the adoption of ASU 2016-01 as of January 1, 2018, the estimated fair value amounts shown for December 31, 2017 are not comparable to those for September 30, 2018 , due to a change in the required methodology (“exit price” only) for determining current estimated fair value. The carrying amount and estimated fair value of financial instruments not carried at fair value, at September 30, 2018 and December 31, 2017 are as follows: September 30, 2018 (in thousands) Carrying Amount Estimated Fair Value Quoted Significant Other Significant Financial assets: Cash and cash equivalents $ 53,379 $ 53,379 $ 53,379 $ — $ — Investment securities: Equity securities 2,797 2,797 2,797 — — Debt securities available for sale 407,766 407,766 — 407,766 — Debt securities held to maturity 191,733 186,057 — 186,057 — Total investment securities 602,296 596,620 2,797 593,823 — Loans held for sale 1,124 1,145 — 1,145 — Loans held for investment, net 2,346,371 2,283,363 — — 2,283,363 Interest receivable 14,800 14,800 14,800 — — Federal Home Loan Bank stock 13,260 13,260 — 13,260 — Derivative assets 205 205 — 205 — Financial liabilities: Deposits: Non-interest bearing demand 458,576 458,576 458,576 — — Interest-bearing checking 1,236,922 1,236,922 1,236,922 — — Savings 211,591 211,591 211,591 — — Certificates of deposit under $100,000 348,099 342,998 — 342,998 — Certificates of deposit $100,000 and over 377,071 373,313 — 373,313 — Total deposits 2,632,259 2,623,400 1,907,089 716,311 — Federal funds purchased and securities sold under agreements to repurchase 87,978 87,978 87,978 — — Federal Home Loan Bank borrowings 143,000 141,110 — 141,110 — Junior subordinated notes issued to capital trusts 23,865 21,058 — 21,058 — Long-term debt 8,750 8,750 — 8,750 — Derivative liabilities 178 178 — 178 — December 31, 2017 (in thousands) Carrying Amount Estimated Fair Value Quoted Prices in Markets for Significant Other Significant Financial assets: Cash and cash equivalents $ 50,972 $ 50,972 $ 50,972 $ — $ — Investment securities: Equity securities 2,336 2,336 2,336 — — Debt securities available for sale 445,324 445,324 — 445,324 — Debt securities held to maturity 195,619 194,343 — 194,343 — Total investment securities 643,279 642,003 2,336 639,667 — Loans held for sale 856 871 — — 871 Loans held for investment, net 2,258,636 2,256,726 — 2,256,726 — Interest receivable 14,732 14,732 14,732 — — Federal Home Loan Bank stock 11,324 11,324 — 11,324 — Financial liabilities: Deposits: Non-interest bearing demand 461,969 461,969 461,969 — — Interest-bearing checking 1,228,112 1,228,112 1,228,112 — — Savings 213,430 213,430 213,430 — — Certificates of deposit under $100,000 324,681 321,197 — 321,197 — Certificates of deposit $100,000 and over 377,127 374,685 — 374,685 — Total deposits 2,605,319 2,599,393 1,903,511 695,882 — Federal funds purchased and securities sold under agreements to repurchase 97,229 97,229 97,229 — — Federal Home Loan Bank borrowings 115,000 114,945 — 114,945 — Junior subordinated notes issued to capital trusts 23,793 19,702 — 19,702 — Long-term debt 12,500 12,500 — 12,500 —
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis, Valuation Techniques [Table Text Block]	The following presents the valuation technique(s), unobservable inputs, and quantitative information about the unobservable inputs used for fair value measurements of the financial instruments held by the Company at September 30, 2018 , categorized within Level 3 of the fair value hierarchy: Quantitative Information About Level 3 Fair Value Measurements (dollars in thousands) Fair Value at September 30, 2018 Valuation Techniques(s) Unobservable Input Range of Inputs Weighted Average Collateral dependent impaired loans $ 8,362 Modified appraised value Third party appraisal NM * - NM * NM * Appraisal discount NM * - NM * NM * Other real estate owned $ 549 Modified appraised value Third party appraisal NM * - NM * NM * Appraisal discount NM * - NM * NM *

Principles of Consolidation a_2

Principles of Consolidation and Presentation Textual References (Details) - ATBancorp [Member]	9 Months Ended
	Sep. 30, 2018USD ($)shares
Business Acquisition, Equity Interests Issued or Issuable [Line Items]
Cash to be paid per share | $	$ 992.51
Common Stock
Business Acquisition, Equity Interests Issued or Issuable [Line Items]
Stock to be issued, exchange ratio | shares	117.5500

Investment Securities Schedule

Investment Securities Schedule of Available for Sale Securities (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Schedule of Available-for-sale Securities
Amortized cost basis	$ 420,066	$ 448,922
Gross unrealized gains	839	2,716
Gross unrealized losses	13,139	6,314
Estimated fair value	407,766	445,324
U.S. Government agencies and corporations
Schedule of Available-for-sale Securities
Amortized cost basis	5,561	15,716
Gross unrealized gains	0	0
Gross unrealized losses	42	90
Estimated fair value	5,519	15,626
State and political subdivisions
Schedule of Available-for-sale Securities
Amortized cost basis	115,251	139,561
Gross unrealized gains	716	2,475
Gross unrealized losses	831	197
Estimated fair value	115,136	141,839
Mortgage-backed securities
Schedule of Available-for-sale Securities
Amortized cost basis	53,664	48,744
Gross unrealized gains	112	181
Gross unrealized losses	1,880	428
Estimated fair value	51,896	48,497
Collateralized mortgage obligations
Schedule of Available-for-sale Securities
Amortized cost basis	179,748	173,339
Gross unrealized gains	3	29
Gross unrealized losses	8,874	5,172
Estimated fair value	170,877	168,196
Corporate debt securities
Schedule of Available-for-sale Securities
Amortized cost basis	65,842	71,562
Gross unrealized gains	8	31
Gross unrealized losses	1,512	427
Estimated fair value	$ 64,338	$ 71,166

Investment Securities Schedul_2

Investment Securities Schedule of Held to Maturity Securities (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Schedule of Held-to-maturity Securities
Held to maturity securities, amortized cost	$ 191,733	$ 195,619
Gross unrealized gains	254	1,356
Gross unrealized losses	5,930	2,632
Estimated fair value	186,057	194,343
U.S. Government agencies and corporations
Schedule of Held-to-maturity Securities
Held to maturity securities, amortized cost		10,049
Estimated fair value		10,049
State and political subdivisions
Schedule of Held-to-maturity Securities
Held to maturity securities, amortized cost	125,783	126,413
Gross unrealized gains	155	804
Gross unrealized losses	3,743	1,631
Estimated fair value	122,195	125,586
Mortgage-backed securities
Schedule of Held-to-maturity Securities
Held to maturity securities, amortized cost	11,467	1,906
Gross unrealized gains	1	4
Gross unrealized losses	564	13
Estimated fair value	10,904	1,897
Collateralized mortgage obligations
Schedule of Held-to-maturity Securities
Held to maturity securities, amortized cost	19,373	22,115
Gross unrealized losses	1,104	707
Estimated fair value	18,269	21,408
Corporate debt securities
Schedule of Held-to-maturity Securities
Held to maturity securities, amortized cost	35,110	35,136
Gross unrealized gains	98	548
Gross unrealized losses	519	281
Estimated fair value	$ 34,689	$ 35,403

Investment Securities Available

Investment Securities Available for Sale Securities in Continuous Loss Position (Details) $ in Thousands	Sep. 30, 2018USD ($)count	Dec. 31, 2017USD ($)count
Schedule of Available-for-sale Securities
Available for sale securities in unrealized loss positions, number of positions | count	196	105
Available for sale securities, continuous unrealized loss position, less than twelve months, estimated fair value	$ 182,303	$ 158,516
Available for sale securities, continuous unrealized loss position, less than 12 months, Accumulated Loss	4,742	1,403
Available for sale securities, continuous unrealized loss position, twelve months or longer, estimated fair value	146,965	139,240
Available for sale securities, continuous unrealized loss position, 12 months or longer, accumulated loss	8,397	4,967
Available for sale securities, continuous unrealized loss position, fair value	329,268	297,756
Available for sale securities, continuous unrealized loss position, accumulated loss	$ 13,139	$ 6,370
U.S. Government agencies and corporations
Schedule of Available-for-sale Securities
Available for sale securities in unrealized loss positions, number of positions | count	2	3
Available for sale securities, continuous unrealized loss position, less than twelve months, estimated fair value	$ 539	$ 15,626
Available for sale securities, continuous unrealized loss position, less than 12 months, Accumulated Loss	14	90
Available for sale securities, continuous unrealized loss position, twelve months or longer, estimated fair value	4,980
Available for sale securities, continuous unrealized loss position, 12 months or longer, accumulated loss	28
Available for sale securities, continuous unrealized loss position, fair value	5,519	15,626
Available for sale securities, continuous unrealized loss position, accumulated loss	$ 42	$ 90
State and political subdivisions
Schedule of Available-for-sale Securities
Available for sale securities in unrealized loss positions, number of positions | count	115	34
Available for sale securities, continuous unrealized loss position, less than twelve months, estimated fair value	$ 46,374	$ 11,705
Available for sale securities, continuous unrealized loss position, less than 12 months, Accumulated Loss	697	167
Available for sale securities, continuous unrealized loss position, twelve months or longer, estimated fair value	5,350	1,800
Available for sale securities, continuous unrealized loss position, 12 months or longer, accumulated loss	134	30
Available for sale securities, continuous unrealized loss position, fair value	51,724	13,505
Available for sale securities, continuous unrealized loss position, accumulated loss	$ 831	$ 197
Mortgage-backed securities
Schedule of Available-for-sale Securities
Available for sale securities in unrealized loss positions, number of positions | count	26	20
Available for sale securities, continuous unrealized loss position, less than twelve months, estimated fair value	$ 40,039	$ 37,964
Available for sale securities, continuous unrealized loss position, less than 12 months, Accumulated Loss	1,613	359
Available for sale securities, continuous unrealized loss position, twelve months or longer, estimated fair value	7,591	3,961
Available for sale securities, continuous unrealized loss position, 12 months or longer, accumulated loss	267	69
Available for sale securities, continuous unrealized loss position, fair value	47,630	41,925
Available for sale securities, continuous unrealized loss position, accumulated loss	$ 1,880	$ 428
Collateralized mortgage obligations
Schedule of Available-for-sale Securities
Available for sale securities in unrealized loss positions, number of positions | count	41	35
Available for sale securities, continuous unrealized loss position, less than twelve months, estimated fair value	$ 44,912	$ 37,881
Available for sale securities, continuous unrealized loss position, less than 12 months, Accumulated Loss	1,269	489
Available for sale securities, continuous unrealized loss position, twelve months or longer, estimated fair value	116,814	122,757
Available for sale securities, continuous unrealized loss position, 12 months or longer, accumulated loss	7,605	4,683
Available for sale securities, continuous unrealized loss position, fair value	161,726	160,638
Available for sale securities, continuous unrealized loss position, accumulated loss	$ 8,874	$ 5,172
Corporate debt securities
Schedule of Available-for-sale Securities
Available for sale securities in unrealized loss positions, number of positions | count	12	12
Available for sale securities, continuous unrealized loss position, less than twelve months, estimated fair value	$ 50,439	$ 55,340
Available for sale securities, continuous unrealized loss position, less than 12 months, Accumulated Loss	1,149	298
Available for sale securities, continuous unrealized loss position, twelve months or longer, estimated fair value	12,230	8,778
Available for sale securities, continuous unrealized loss position, 12 months or longer, accumulated loss	363	129
Available for sale securities, continuous unrealized loss position, fair value	62,669	64,118
Available for sale securities, continuous unrealized loss position, accumulated loss	$ 1,512	$ 427
Equity securities
Schedule of Available-for-sale Securities
Available for sale securities in unrealized loss positions, number of positions | count		1
Available for sale securities, continuous unrealized loss position, twelve months or longer, estimated fair value		$ 1,944
Available for sale securities, continuous unrealized loss position, 12 months or longer, accumulated loss		56
Available for sale securities, continuous unrealized loss position, fair value		1,944
Available for sale securities, continuous unrealized loss position, accumulated loss		$ 56

Investment Securities Held to M

Investment Securities Held to Maturity Securities in Continuous Loss Position (Details) $ in Thousands	Sep. 30, 2018USD ($)count	Dec. 31, 2017USD ($)count
Schedule of Held-to-maturity Securities
Held to maturity securities in unrealized loss positions, number of positions | count	283	181
Held to maturity securities, continuous unrealized loss position, less than twelve months, estimated fair value	$ 83,111	$ 41,900
Held to maturity securities, continuous unrealized loss position, less than 12 months, accumulated loss	2,140	489
Held to maturity securities, continuous unrealized loss position, twelve months or longer, fair value	55,313	45,515
Held to maturity securities, continuous unrealized loss position, 12 months or longer, accumulated loss	3,790	2,143
Held to maturity securities, continuous urealized loss position, fair value	138,424	87,415
Held to maturity securities, continuous unrealized loss position, accumulated loss	$ 5,930	$ 2,632
State and political subdivisions
Schedule of Held-to-maturity Securities
Held to maturity securities in unrealized loss positions, number of positions | count	257	167
Held to maturity securities, continuous unrealized loss position, less than twelve months, estimated fair value	$ 54,969	$ 33,237
Held to maturity securities, continuous unrealized loss position, less than 12 months, accumulated loss	1,271	393
Held to maturity securities, continuous unrealized loss position, twelve months or longer, fair value	33,512	25,843
Held to maturity securities, continuous unrealized loss position, 12 months or longer, accumulated loss	2,472	1,238
Held to maturity securities, continuous urealized loss position, fair value	88,481	59,080
Held to maturity securities, continuous unrealized loss position, accumulated loss	$ 3,743	$ 1,631
Mortgage-backed securities
Schedule of Held-to-maturity Securities
Held to maturity securities in unrealized loss positions, number of positions | count	6	4
Held to maturity securities, continuous unrealized loss position, less than twelve months, estimated fair value	$ 10,016	$ 349
Held to maturity securities, continuous unrealized loss position, less than 12 months, accumulated loss	524	2
Held to maturity securities, continuous unrealized loss position, twelve months or longer, fair value	820	887
Held to maturity securities, continuous unrealized loss position, 12 months or longer, accumulated loss	40	11
Held to maturity securities, continuous urealized loss position, fair value	10,836	1,236
Held to maturity securities, continuous unrealized loss position, accumulated loss	$ 564	$ 13
Collateralized mortgage obligations
Schedule of Held-to-maturity Securities
Held to maturity securities in unrealized loss positions, number of positions | count	7	7
Held to maturity securities, continuous unrealized loss position, less than twelve months, estimated fair value		$ 5,221
Held to maturity securities, continuous unrealized loss position, less than 12 months, accumulated loss		90
Held to maturity securities, continuous unrealized loss position, twelve months or longer, fair value	$ 18,259	16,168
Held to maturity securities, continuous unrealized loss position, 12 months or longer, accumulated loss	1,104	617
Held to maturity securities, continuous urealized loss position, fair value	18,259	21,389
Held to maturity securities, continuous unrealized loss position, accumulated loss	$ 1,104	$ 707
Corporate debt securities
Schedule of Held-to-maturity Securities
Held to maturity securities in unrealized loss positions, number of positions | count	13	3
Held to maturity securities, continuous unrealized loss position, less than twelve months, estimated fair value	$ 18,126	$ 3,093
Held to maturity securities, continuous unrealized loss position, less than 12 months, accumulated loss	345	4
Held to maturity securities, continuous unrealized loss position, twelve months or longer, fair value	2,722	2,617
Held to maturity securities, continuous unrealized loss position, 12 months or longer, accumulated loss	174	277
Held to maturity securities, continuous urealized loss position, fair value	20,848	5,710
Held to maturity securities, continuous unrealized loss position, accumulated loss	$ 519	$ 281

Investment Securities Investmen

Investment Securities Investments Classified by Contractual Maturity (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Debt Securities, Available-for-sale, Maturity, Amortized Cost, Rolling Maturity [Abstract]
Due in one year or less, amortized cost	$ 27,913
Due after one year through five years, amortized cost	99,630
Due after five years through ten years, amortized cost	55,757
Due after ten years, amortized cost	3,354
Debt securities without a single maturity date, amortized cost	233,412
Total available for sale securities, debt securities, amortized cost	420,066
Debt Securities, Available-for-sale, Maturity, Fair Value, Rolling Maturity [Abstract]
Due in one year or less, estimated fair value	27,866
Due after one year through five years, estimated fair value	98,105
Due after five years through ten years, estimated fair value	55,700
Due after ten years, estimated fair value	3,322
Debt securities without a single maturity date, estimated fair value	222,773
Total debt securities available for sale, estimated fair value	407,766	$ 445,324
Debt Securities, Held-to-maturity, Maturity, Amortized Cost, Rolling Maturity [Abstract]
Due in one year or less, amortized cost	734
Due after one year through five years, amortized cost	24,275
Due after five years through ten years, amortized cost	97,511
Due after ten years, amortized cost	38,373
Debt securities without a single maturity date, amortized cost	30,840
Held to maturity securities, amortized cost	191,733	195,619
Debt Securities, Held-to-maturity, Maturity, Fair Value, Rolling Maturity [Abstract]
Due in one year or less, estimated fair value	736
Due after one year through five years, estimated fair value	23,867
Due after five years through ten years, estimated fair value	95,353
Due after ten years, estimated fair value	36,928
Debt securities without a single maturity date, estimated fair value	29,173
Fair value of debt securities held to maturity	$ 186,057	$ 194,343

Investment Securities Realized

Investment Securities Realized Gains and Losses (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Debt Securities, Held-to-maturity, Fair Value to Amortized Cost [Abstract]
Debt Securities, Realized Gain (Loss)	$ 192	$ 176	$ 197	$ 239
Equity Securities, FV-NI, Gain (Loss) [Abstract]
Equity Securities, FV-NI, Realized Gain (Loss)	(10)		(34)
Gain (Loss) on Sale of Equity Investments	0		0
Equity Securities, FV-NI, Unrealized Gain (Loss)	(10)		(34)
Debt securities
Debt Securities, Available-for-sale [Abstract]
Gross realized gains	194	179	203	199
Gross realized losses	(2)	(3)	(2)	(3)
Available for sale securities, gross realized gain (loss)	192	176	201	196
Debt Securities, Held-to-maturity, Fair Value to Amortized Cost [Abstract]
Gross realized gains	0	0	0	43
Gross realized losses	0	0	(4)	0
Held to maturity securities, gross realized gain (loss)	$ 0	$ 0	$ (4)	$ 43

Investment Securities Textual R

Investment Securities Textual References (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
	Mar. 31, 2017	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017
Schedule of Available-for-sale Securities
Pledged securities		$ 217,800		$ 237,400
Equity securities		2,797		$ 2,336
Proceeds from sales of debt securities held to maturity	$ 1,200	0	$ 1,153
Other equity securities | Banks and Financial Service-Related Companies
Schedule of Available-for-sale Securities
Equity securities		400
Community Reinvestment Act qualified investment
Schedule of Available-for-sale Securities
Equity securities		$ 2,400
Geographic Concentration Risk | Total Obligations of State and Political Subdivisions | State and political subdivisions | IOWA
Schedule of Available-for-sale Securities
Concentration risk, percentage		53.00%
Geographic Concentration Risk | Total Obligations of State and Political Subdivisions | State and political subdivisions | MINNESOTA
Schedule of Available-for-sale Securities
Concentration risk, percentage		24.00%

Loans Receivable and the Allo_3

Loans Receivable and the Allowance for Loan Losses Allowance for Loan Losses and Recorded Investment in Loan Receivables (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Jun. 30, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Dec. 31, 2016
Financing Receivable, Allowance for Credit Losses [Line Items]
Loans receivable, allowance for credit losses, individually evaluated for impairment	$ 7,580		$ 3,649
Loans receivable, allowance for credit losses, collectively evaluated for impairment	22,885		23,612
Allowance for loan losses	31,278	$ 30,800	28,059	$ 26,510	$ 22,510	$ 21,850
Financing Receivable [Abstract]
Loans receivable, individually evaluated for impairment	40,999		26,811
Loans receivable, collectively evaluated for impairment	2,319,198		2,240,153
Loans receivable,purchased credit impaired			19,731
Loans and leases receivable, gross	2,377,649		2,286,695
Receivables Acquired with Deteriorated Credit Quality
Financing Receivable, Allowance for Credit Losses [Line Items]
Certain loans acquired in transfer not accounted for as debt securities, allowance for loan losses	813		798
Financing Receivable [Abstract]
Loans receivable,purchased credit impaired	17,452
Agricultural Portfolio Segment
Financing Receivable, Allowance for Credit Losses [Line Items]
Loans receivable, allowance for credit losses, individually evaluated for impairment	195		140
Loans receivable, allowance for credit losses, collectively evaluated for impairment	2,532		2,650
Allowance for loan losses	2,727	2,656	2,790	2,565	2,666	2,003
Financing Receivable [Abstract]
Loans receivable, individually evaluated for impairment	6,711		2,969
Loans receivable, collectively evaluated for impairment	96,496		102,543
Loans and leases receivable, gross	103,207		105,512
Commercial Portfolio Segment
Financing Receivable, Allowance for Credit Losses [Line Items]
Loans receivable, allowance for credit losses, individually evaluated for impairment	3,059		1,126
Loans receivable, allowance for credit losses, collectively evaluated for impairment	5,183		7,392
Allowance for loan losses	8,242	8,557	8,518	9,695	7,959	6,274
Financing Receivable [Abstract]
Loans receivable, individually evaluated for impairment	12,924		9,734
Loans receivable, collectively evaluated for impairment	510,357		493,844
Loans and leases receivable, gross	523,333		503,624
Commercial Portfolio Segment | Receivables Acquired with Deteriorated Credit Quality
Financing Receivable [Abstract]
Loans receivable,purchased credit impaired	52		46
Commercial Real Estate Portfolio Segment
Financing Receivable, Allowance for Credit Losses [Line Items]
Loans receivable, allowance for credit losses, individually evaluated for impairment	4,183		2,157
Loans receivable, allowance for credit losses, collectively evaluated for impairment	12,563		11,144
Allowance for loan losses	17,089	16,341	13,637	10,380	9,013	9,860
Financing Receivable [Abstract]
Loans receivable, individually evaluated for impairment	17,375		10,386
Loans receivable, collectively evaluated for impairment	1,223,311		1,147,133
Loans and leases receivable, gross	1,253,790		1,171,971
Commercial Real Estate Portfolio Segment | Receivables Acquired with Deteriorated Credit Quality
Financing Receivable, Allowance for Credit Losses [Line Items]
Certain loans acquired in transfer not accounted for as debt securities, allowance for loan losses	343		336
Financing Receivable [Abstract]
Loans receivable,purchased credit impaired	13,104		14,452
Residential Portfolio Segment
Financing Receivable, Allowance for Credit Losses [Line Items]
Loans receivable, allowance for credit losses, individually evaluated for impairment	143		226
Loans receivable, allowance for credit losses, collectively evaluated for impairment	2,356		2,182
Allowance for loan losses	2,969	2,990	2,870	3,616	2,650	3,458
Financing Receivable [Abstract]
Loans receivable, individually evaluated for impairment	3,981		3,722
Loans receivable, collectively evaluated for impairment	450,246		460,475
Loans and leases receivable, gross	458,523		469,430
Residential Portfolio Segment | Receivables Acquired with Deteriorated Credit Quality
Financing Receivable, Allowance for Credit Losses [Line Items]
Certain loans acquired in transfer not accounted for as debt securities, allowance for loan losses	470		462
Financing Receivable [Abstract]
Loans receivable,purchased credit impaired	4,296		5,233
Consumer Portfolio Segment
Financing Receivable, Allowance for Credit Losses [Line Items]
Loans receivable, allowance for credit losses, collectively evaluated for impairment	251		244
Allowance for loan losses	251	$ 256	244	$ 254	$ 222	$ 255
Financing Receivable [Abstract]
Loans receivable, individually evaluated for impairment	8
Loans receivable, collectively evaluated for impairment	38,788		36,158
Loans and leases receivable, gross	$ 38,796		$ 36,158

Loans Receivable and the Allo_4

Loans Receivable and the Allowance for Loan Losses Allowance for Loan Loss Activity (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Beginning balance	$ 30,800	$ 22,510	$ 28,059	$ 21,850
Charge-offs	(817)	(978)	(1,584)	(2,737)
Recoveries	345	594	753	732
Provision	950	4,384	4,050	6,665
Ending balance	31,278	26,510	31,278	26,510
Agricultural Portfolio Segment
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Beginning balance	2,656	2,666	2,790	2,003
Charge-offs	(365)	(318)	(633)	(1,202)
Recoveries	41	150	56	164
Provision	395	67	514	1,600
Ending balance	2,727	2,565	2,727	2,565
Commercial Portfolio Segment
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Beginning balance	8,557	7,959	8,518	6,274
Charge-offs	(108)	(534)	(198)	(1,063)
Recoveries	78	113	260	215
Provision	(285)	2,157	(338)	4,269
Ending balance	8,242	9,695	8,242	9,695
Commercial Real Estate Portfolio Segment
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Beginning balance	16,341	9,013	13,637	9,860
Charge-offs	(17)		(281)	(106)
Recoveries	77	201	193	216
Provision	688	1,166	3,540	410
Ending balance	17,089	10,380	17,089	10,380
Residential Portfolio Segment
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Beginning balance	2,990	2,650	2,870	3,458
Charge-offs		(75)	(107)	(155)
Recoveries	131	126	208	126
Provision	(152)	915	(2)	187
Ending balance	2,969	3,616	2,969	3,616
Consumer Portfolio Segment
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Beginning balance	256	222	244	255
Charge-offs	(327)	(51)	(365)	(211)
Recoveries	18	4	36	11
Provision	304	79	336	199
Ending balance	$ 251	$ 254	$ 251	$ 254

Loans Receivable and the Allo_5

Loans Receivable and the Allowance for Loan Losses New Troubled Debt Restructurings During Period (Details) $ in Thousands		9 Months Ended
		Sep. 30, 2018USD ($)count	Sep. 30, 2017USD ($)count
Financing Receivable, Modifications
Financing Receivable, Modifications, Number of Contracts | count		1	10
Financing Receivable, Modifications, Pre-Modification Recorded Investment		$ 86	$ 13,727
Financing Receivable, Modifications, Post-Modification Recorded Investment		$ 86	$ 14,150
Commercial and Industrial Loan Financing Receivable | Extended Maturity
Financing Receivable, Modifications
Financing Receivable, Modifications, Number of Contracts | count	[1]		6
Financing Receivable, Modifications, Pre-Modification Recorded Investment	[1]		$ 2,037
Financing Receivable, Modifications, Post-Modification Recorded Investment	[1]		$ 2,083
Commercial Real Estate Portfolio Segment | Farmland Loan Financing Receivable | Extended Maturity
Financing Receivable, Modifications
Financing Receivable, Modifications, Number of Contracts | count	[1]	1	2
Financing Receivable, Modifications, Pre-Modification Recorded Investment	[1]	$ 86	$ 176
Financing Receivable, Modifications, Post-Modification Recorded Investment	[1]	$ 86	$ 176
Commercial Real Estate Portfolio Segment | Commercial Real Estate Loan Other Financing Receivable | Extended Maturity
Financing Receivable, Modifications
Financing Receivable, Modifications, Number of Contracts | count	[1]		1
Financing Receivable, Modifications, Pre-Modification Recorded Investment	[1]		$ 968
Financing Receivable, Modifications, Post-Modification Recorded Investment	[1]		$ 968
Commercial Real Estate Portfolio Segment | Commercial Real Estate Loan Other Financing Receivable | Other Concession
Financing Receivable, Modifications
Financing Receivable, Modifications, Number of Contracts | count	[1]		1
Financing Receivable, Modifications, Pre-Modification Recorded Investment	[1]		$ 10,546
Financing Receivable, Modifications, Post-Modification Recorded Investment	[1]		$ 10,923
[1]	TDRs may include multiple concessions, and the disclosure classifications are based on the primary concession provided to the borrower.

Loans Receivable and the Allo_6

Loans Receivable and the Allowance for Loan Losses New Troubled Debt Restructurings During Past Twelve Months That Defaulted During the Period (Details) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2018USD ($)count	Sep. 30, 2017USD ($)count	Sep. 30, 2018USD ($)count	Sep. 30, 2017USD ($)count
Financing Receivable, Modifications
Financing receivable, modifications, subsequent default, number of contracts | count		0	0	0	5
Financing receivable, modifications, subsequent default, recorded investment | $		$ 0	$ 0	$ 0	$ 2,472
Commercial Portfolio Segment | Commercial and Industrial Loan Financing Receivable | Extended Maturity
Financing Receivable, Modifications
Financing receivable, modifications, subsequent default, number of contracts | count	[1]				4
Financing receivable, modifications, subsequent default, recorded investment | $	[1]				$ 1,504
Commercial Real Estate Portfolio Segment | Commercial Real Estate Loan Other Financing Receivable | Extended Maturity
Financing Receivable, Modifications
Financing receivable, modifications, subsequent default, number of contracts | count	[1]				1
Financing receivable, modifications, subsequent default, recorded investment | $	[1]				$ 968
[1]	TDRs may include multiple concessions, and the disclosure classifications are based on the primary concession provided to the borrower.

Loans Receivable and the Allo_7

Loans Receivable and the Allowance for Loan Losses Loans by Internally Assigned Credit Quality Indicators (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Financing Receivable, Recorded Investment
Loans receivable, net	$ 2,377,649	$ 2,286,695
Purchased credit-impaired loans, internally classified as other than pass	11,100	12,600
Internally Assigned Grade Pass
Financing Receivable, Recorded Investment
Loans receivable, net	2,210,131	2,127,454
Internally Assigned Grade Special Mention Watch
Financing Receivable, Recorded Investment
Loans receivable, net	95,598	96,842
Internally Assigned Grade Substandard
Financing Receivable, Recorded Investment
Loans receivable, net	71,889	62,362
Internally Assigned Grade Doubtful
Financing Receivable, Recorded Investment
Loans receivable, net	31	37
Agricultural Portfolio Segment | Agricultural Loan Financing Receivable
Financing Receivable, Recorded Investment
Loans receivable, net	103,207	105,512
Agricultural Portfolio Segment | Agricultural Loan Financing Receivable | Internally Assigned Grade Pass
Financing Receivable, Recorded Investment
Loans receivable, net	78,007	80,377
Agricultural Portfolio Segment | Agricultural Loan Financing Receivable | Internally Assigned Grade Special Mention Watch
Financing Receivable, Recorded Investment
Loans receivable, net	17,266	21,989
Agricultural Portfolio Segment | Agricultural Loan Financing Receivable | Internally Assigned Grade Substandard
Financing Receivable, Recorded Investment
Loans receivable, net	7,934	3,146
Commercial Portfolio Segment | Commercial and Industrial Loan Financing Receivable
Financing Receivable, Recorded Investment
Loans receivable, net	523,333	503,624
Commercial Portfolio Segment | Commercial and Industrial Loan Financing Receivable | Internally Assigned Grade Pass
Financing Receivable, Recorded Investment
Loans receivable, net	482,136	453,363
Commercial Portfolio Segment | Commercial and Industrial Loan Financing Receivable | Internally Assigned Grade Special Mention Watch
Financing Receivable, Recorded Investment
Loans receivable, net	21,166	23,153
Commercial Portfolio Segment | Commercial and Industrial Loan Financing Receivable | Internally Assigned Grade Substandard
Financing Receivable, Recorded Investment
Loans receivable, net	20,027	27,102
Commercial Portfolio Segment | Commercial and Industrial Loan Financing Receivable | Internally Assigned Grade Doubtful
Financing Receivable, Recorded Investment
Loans receivable, net	4	6
Commercial Real Estate Portfolio Segment
Financing Receivable, Recorded Investment
Loans receivable, net	1,253,790	1,171,971
Commercial Real Estate Portfolio Segment | Internally Assigned Grade Pass
Financing Receivable, Recorded Investment
Loans receivable, net	1,163,867	1,102,446
Commercial Real Estate Portfolio Segment | Internally Assigned Grade Special Mention Watch
Financing Receivable, Recorded Investment
Loans receivable, net	54,042	47,972
Commercial Real Estate Portfolio Segment | Internally Assigned Grade Substandard
Financing Receivable, Recorded Investment
Loans receivable, net	35,881	21,553
Commercial Real Estate Portfolio Segment | Commercial Real Estate Construction and Development Loan Financing Receivable
Financing Receivable, Recorded Investment
Loans receivable, net	223,324	165,276
Commercial Real Estate Portfolio Segment | Commercial Real Estate Construction and Development Loan Financing Receivable | Internally Assigned Grade Pass
Financing Receivable, Recorded Investment
Loans receivable, net	221,114	162,968
Commercial Real Estate Portfolio Segment | Commercial Real Estate Construction and Development Loan Financing Receivable | Internally Assigned Grade Special Mention Watch
Financing Receivable, Recorded Investment
Loans receivable, net	1,078	1,061
Commercial Real Estate Portfolio Segment | Commercial Real Estate Construction and Development Loan Financing Receivable | Internally Assigned Grade Substandard
Financing Receivable, Recorded Investment
Loans receivable, net	1,132	1,247
Commercial Real Estate Portfolio Segment | Farmland Loan Financing Receivable
Financing Receivable, Recorded Investment
Loans receivable, net	85,735	87,868
Commercial Real Estate Portfolio Segment | Farmland Loan Financing Receivable | Internally Assigned Grade Pass
Financing Receivable, Recorded Investment
Loans receivable, net	69,824	76,740
Commercial Real Estate Portfolio Segment | Farmland Loan Financing Receivable | Internally Assigned Grade Special Mention Watch
Financing Receivable, Recorded Investment
Loans receivable, net	6,970	10,357
Commercial Real Estate Portfolio Segment | Farmland Loan Financing Receivable | Internally Assigned Grade Substandard
Financing Receivable, Recorded Investment
Loans receivable, net	8,941	771
Commercial Real Estate Portfolio Segment | Multifamily Real Estate Loan Financing Receivable
Financing Receivable, Recorded Investment
Loans receivable, net	126,663	134,506
Commercial Real Estate Portfolio Segment | Multifamily Real Estate Loan Financing Receivable | Internally Assigned Grade Pass
Financing Receivable, Recorded Investment
Loans receivable, net	124,092	131,507
Commercial Real Estate Portfolio Segment | Multifamily Real Estate Loan Financing Receivable | Internally Assigned Grade Special Mention Watch
Financing Receivable, Recorded Investment
Loans receivable, net	1,391	2,498
Commercial Real Estate Portfolio Segment | Multifamily Real Estate Loan Financing Receivable | Internally Assigned Grade Substandard
Financing Receivable, Recorded Investment
Loans receivable, net	1,180	501
Commercial Real Estate Portfolio Segment | Commercial Real Estate Loan Other Financing Receivable
Financing Receivable, Recorded Investment
Loans receivable, net	818,068	784,321
Commercial Real Estate Portfolio Segment | Commercial Real Estate Loan Other Financing Receivable | Internally Assigned Grade Pass
Financing Receivable, Recorded Investment
Loans receivable, net	748,837	731,231
Commercial Real Estate Portfolio Segment | Commercial Real Estate Loan Other Financing Receivable | Internally Assigned Grade Special Mention Watch
Financing Receivable, Recorded Investment
Loans receivable, net	44,603	34,056
Commercial Real Estate Portfolio Segment | Commercial Real Estate Loan Other Financing Receivable | Internally Assigned Grade Substandard
Financing Receivable, Recorded Investment
Loans receivable, net	24,628	19,034
Residential Portfolio Segment
Financing Receivable, Recorded Investment
Loans receivable, net	458,523	469,430
Residential Portfolio Segment | Internally Assigned Grade Pass
Financing Receivable, Recorded Investment
Loans receivable, net	447,500	455,209
Residential Portfolio Segment | Internally Assigned Grade Special Mention Watch
Financing Receivable, Recorded Investment
Loans receivable, net	2,976	3,728
Residential Portfolio Segment | Internally Assigned Grade Substandard
Financing Receivable, Recorded Investment
Loans receivable, net	8,047	10,493
Residential Portfolio Segment | Residential Real Estate First Lien Loan Financing Receivable
Financing Receivable, Recorded Investment
Loans receivable, net	342,755	352,226
Residential Portfolio Segment | Residential Real Estate First Lien Loan Financing Receivable | Internally Assigned Grade Pass
Financing Receivable, Recorded Investment
Loans receivable, net	333,974	340,446
Residential Portfolio Segment | Residential Real Estate First Lien Loan Financing Receivable | Internally Assigned Grade Special Mention Watch
Financing Receivable, Recorded Investment
Loans receivable, net	2,289	2,776
Residential Portfolio Segment | Residential Real Estate First Lien Loan Financing Receivable | Internally Assigned Grade Substandard
Financing Receivable, Recorded Investment
Loans receivable, net	6,492	9,004
Residential Portfolio Segment | Residential Real Estate Junior Lien Loan Financing Receivable
Financing Receivable, Recorded Investment
Loans receivable, net	115,768	117,204
Residential Portfolio Segment | Residential Real Estate Junior Lien Loan Financing Receivable | Internally Assigned Grade Pass
Financing Receivable, Recorded Investment
Loans receivable, net	113,526	114,763
Residential Portfolio Segment | Residential Real Estate Junior Lien Loan Financing Receivable | Internally Assigned Grade Special Mention Watch
Financing Receivable, Recorded Investment
Loans receivable, net	687	952
Residential Portfolio Segment | Residential Real Estate Junior Lien Loan Financing Receivable | Internally Assigned Grade Substandard
Financing Receivable, Recorded Investment
Loans receivable, net	1,555	1,489
Consumer Portfolio Segment | Consumer Loan Financing Receivable
Financing Receivable, Recorded Investment
Loans receivable, net	38,796	36,158
Consumer Portfolio Segment | Consumer Loan Financing Receivable | Internally Assigned Grade Pass
Financing Receivable, Recorded Investment
Loans receivable, net	38,621	36,059
Consumer Portfolio Segment | Consumer Loan Financing Receivable | Internally Assigned Grade Special Mention Watch
Financing Receivable, Recorded Investment
Loans receivable, net	148
Consumer Portfolio Segment | Consumer Loan Financing Receivable | Internally Assigned Grade Substandard
Financing Receivable, Recorded Investment
Loans receivable, net		68
Consumer Portfolio Segment | Consumer Loan Financing Receivable | Internally Assigned Grade Doubtful
Financing Receivable, Recorded Investment
Loans receivable, net	$ 27	$ 31

Loans Receivable and the Allo_8

Loans Receivable and the Allowance for Loan Losses Amounts and Categories of Impaired Loans (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017
Financing Receivable, Impaired
Impaired financing receivable, with no related allowance, recorded investment	$ 22,720		$ 22,720		$ 17,703
Impaired financing receivable, with no related allowance, unpaid principal balance	23,985		23,985		19,116
Impaired financing receivable, with related allowance, recorded investment	18,279		18,279		9,108
Impaired financing receivable, with related allowance, unpaid principal balance	26,445		26,445		16,406
Impaired financing receivable, related allowance	7,580		7,580		3,649
Impaired financing receivable, recorded investment	40,999		40,999		26,811
Impaired financing receivable, unpaid principal balance	50,430		50,430		35,522
Impaired financing receivable, with no related allowance, average recorded investment	22,236	$ 8,738	17,163	$ 9,304
Impaired financing receivable, with no related allowance, interest income, accrual method	273	135	701	366
Impaired financing receivable, with related allowance, average recorded investment	18,501	24,439	16,882	24,388
Impaired financing receivable, with related allowance, interest income, accrual method	68	105	116	266
Impaired financing receivable, average recorded investment	40,737	33,177	34,045	33,692
Impaired financing receivable, interest income, accrual method	341	240	817	632
Agricultural Portfolio Segment | Agricultural Loan Financing Receivable
Financing Receivable, Impaired
Impaired financing receivable, with no related allowance, recorded investment	5,161		5,161		1,523
Impaired financing receivable, with no related allowance, unpaid principal balance	5,661		5,661		2,023
Impaired financing receivable, with related allowance, recorded investment	1,550		1,550		1,446
Impaired financing receivable, with related allowance, unpaid principal balance	1,920		1,920		1,446
Impaired financing receivable, related allowance	195		195		140
Impaired financing receivable, recorded investment	6,711		6,711		2,969
Impaired financing receivable, unpaid principal balance	7,581		7,581		3,469
Impaired financing receivable, with no related allowance, average recorded investment	4,864	881	3,480	674
Impaired financing receivable, with no related allowance, interest income, accrual method	71	17	180	50
Impaired financing receivable, with related allowance, average recorded investment	1,974	1,446	2,108	1,460
Impaired financing receivable, with related allowance, interest income, accrual method		11		33
Impaired financing receivable, average recorded investment	6,838	2,327	5,588	2,134
Impaired financing receivable, interest income, accrual method	71	28	180	83
Commercial Portfolio Segment | Commercial and Industrial Loan Financing Receivable
Financing Receivable, Impaired
Impaired financing receivable, with no related allowance, recorded investment	3,796		3,796		7,588
Impaired financing receivable, with no related allowance, unpaid principal balance	3,990		3,990		7,963
Impaired financing receivable, with related allowance, recorded investment	9,128		9,128		2,146
Impaired financing receivable, with related allowance, unpaid principal balance	9,258		9,258		2,177
Impaired financing receivable, related allowance	3,059		3,059		1,126
Impaired financing receivable, recorded investment	12,924		12,924		9,734
Impaired financing receivable, unpaid principal balance	13,248		13,248		10,140
Impaired financing receivable, with no related allowance, average recorded investment	3,961	2,878	3,563	2,899
Impaired financing receivable, with no related allowance, interest income, accrual method	36	77	150	124
Impaired financing receivable, with related allowance, average recorded investment	8,905	8,458	7,778	8,423
Impaired financing receivable, with related allowance, interest income, accrual method	43	85	89	163
Impaired financing receivable, average recorded investment	12,866	11,336	11,341	11,322
Impaired financing receivable, interest income, accrual method	79	162	239	287
Commercial Real Estate Portfolio Segment
Financing Receivable, Impaired
Impaired financing receivable, with no related allowance, recorded investment	10,734		10,734		6,117
Impaired financing receivable, with no related allowance, unpaid principal balance	11,244		11,244		6,622
Impaired financing receivable, with related allowance, recorded investment	6,641		6,641		4,269
Impaired financing receivable, with related allowance, unpaid principal balance	14,307		14,307		11,536
Impaired financing receivable, related allowance	4,183		4,183		2,157
Impaired financing receivable, recorded investment	17,375		17,375		10,386
Impaired financing receivable, unpaid principal balance	25,551		25,551		18,158
Impaired financing receivable, with no related allowance, average recorded investment	10,506	2,783	7,875	3,521
Impaired financing receivable, with no related allowance, interest income, accrual method	131	18	317	123
Impaired financing receivable, with related allowance, average recorded investment	6,659	13,174	6,027	13,113
Impaired financing receivable, with related allowance, interest income, accrual method	16			44
Impaired financing receivable, average recorded investment	17,165	15,957	13,902	16,634
Impaired financing receivable, interest income, accrual method	147	18	317	167
Commercial Real Estate Portfolio Segment | Commercial Real Estate Construction and Development Loan Financing Receivable
Financing Receivable, Impaired
Impaired financing receivable, with no related allowance, recorded investment	84		84		84
Impaired financing receivable, with no related allowance, unpaid principal balance	84		84		84
Impaired financing receivable, recorded investment	84		84		84
Impaired financing receivable, unpaid principal balance	84		84		84
Impaired financing receivable, with no related allowance, average recorded investment	84	423	84	434
Impaired financing receivable, with no related allowance, interest income, accrual method				2
Impaired financing receivable, with related allowance, average recorded investment		311		232
Impaired financing receivable, average recorded investment	84	734	84	666
Impaired financing receivable, interest income, accrual method				2
Commercial Real Estate Portfolio Segment | Farmland Loan Financing Receivable
Financing Receivable, Impaired
Impaired financing receivable, with no related allowance, recorded investment	3,539		3,539		287
Impaired financing receivable, with no related allowance, unpaid principal balance	3,539		3,539		287
Impaired financing receivable, with related allowance, recorded investment	2,123		2,123
Impaired financing receivable, with related allowance, unpaid principal balance	2,123		2,123
Impaired financing receivable, related allowance	662		662
Impaired financing receivable, recorded investment	5,662		5,662		287
Impaired financing receivable, unpaid principal balance	5,662		5,662		287
Impaired financing receivable, with no related allowance, average recorded investment	3,274	212	1,745	1,193
Impaired financing receivable, with no related allowance, interest income, accrual method	44		86	58
Impaired financing receivable, with related allowance, average recorded investment	2,123		1,584
Impaired financing receivable, average recorded investment	5,397	212	3,329	1,193
Impaired financing receivable, interest income, accrual method	44		86	58
Commercial Real Estate Portfolio Segment | Multifamily Real Estate Loan Financing Receivable
Financing Receivable, Impaired
Impaired financing receivable, with no related allowance, recorded investment	821		821
Impaired financing receivable, with no related allowance, unpaid principal balance	821		821
Impaired financing receivable, recorded investment	821		821
Impaired financing receivable, unpaid principal balance	821		821
Impaired financing receivable, with no related allowance, average recorded investment	822		618
Impaired financing receivable, with no related allowance, interest income, accrual method	10		30
Impaired financing receivable, average recorded investment	822		618
Impaired financing receivable, interest income, accrual method	10		30
Commercial Real Estate Portfolio Segment | Commercial Real Estate Loan Other Financing Receivable
Financing Receivable, Impaired
Impaired financing receivable, with no related allowance, recorded investment	6,290		6,290		5,746
Impaired financing receivable, with no related allowance, unpaid principal balance	6,800		6,800		6,251
Impaired financing receivable, with related allowance, recorded investment	4,518		4,518		4,269
Impaired financing receivable, with related allowance, unpaid principal balance	12,184		12,184		11,536
Impaired financing receivable, related allowance	3,521		3,521		2,157
Impaired financing receivable, recorded investment	10,808		10,808		10,015
Impaired financing receivable, unpaid principal balance	18,984		18,984		17,787
Impaired financing receivable, with no related allowance, average recorded investment	6,326	2,148	5,428	1,894
Impaired financing receivable, with no related allowance, interest income, accrual method	77	18	201	63
Impaired financing receivable, with related allowance, average recorded investment	4,536	12,863	4,443	12,881
Impaired financing receivable, with related allowance, interest income, accrual method	16			44
Impaired financing receivable, average recorded investment	10,862	15,011	9,871	14,775
Impaired financing receivable, interest income, accrual method	93	18	201	107
Residential Portfolio Segment
Financing Receivable, Impaired
Impaired financing receivable, with no related allowance, recorded investment	3,021		3,021		2,475
Impaired financing receivable, with no related allowance, unpaid principal balance	3,082		3,082		2,508
Impaired financing receivable, with related allowance, recorded investment	960		960		1,247
Impaired financing receivable, with related allowance, unpaid principal balance	960		960		1,247
Impaired financing receivable, related allowance	143		143		226
Impaired financing receivable, recorded investment	3,981		3,981		3,722
Impaired financing receivable, unpaid principal balance	4,042		4,042		3,755
Impaired financing receivable, with no related allowance, average recorded investment	2,901	2,196	2,243	2,210
Impaired financing receivable, with no related allowance, interest income, accrual method	35	23	54	69
Impaired financing receivable, with related allowance, average recorded investment	963	1,361	969	1,392
Impaired financing receivable, with related allowance, interest income, accrual method	9	9	27	26
Impaired financing receivable, average recorded investment	3,864	3,557	3,212	3,602
Impaired financing receivable, interest income, accrual method	44	32	81	95
Residential Portfolio Segment | Residential Real Estate First Lien Loan Financing Receivable
Financing Receivable, Impaired
Impaired financing receivable, with no related allowance, recorded investment	2,677		2,677		2,449
Impaired financing receivable, with no related allowance, unpaid principal balance	2,737		2,737		2,482
Impaired financing receivable, with related allowance, recorded investment	960		960		979
Impaired financing receivable, with related allowance, unpaid principal balance	960		960		979
Impaired financing receivable, related allowance	143		143		185
Impaired financing receivable, recorded investment	3,637		3,637		3,428
Impaired financing receivable, unpaid principal balance	3,697		3,697		3,461
Impaired financing receivable, with no related allowance, average recorded investment	2,578	2,183	1,942	2,197
Impaired financing receivable, with no related allowance, interest income, accrual method	34	23	53	69
Impaired financing receivable, with related allowance, average recorded investment	963	1,361	969	1,392
Impaired financing receivable, with related allowance, interest income, accrual method	9	9	27	26
Impaired financing receivable, average recorded investment	3,541	3,544	2,911	3,589
Impaired financing receivable, interest income, accrual method	43	32	80	95
Residential Portfolio Segment | Residential Real Estate Junior Lien Loan Financing Receivable
Financing Receivable, Impaired
Impaired financing receivable, with no related allowance, recorded investment	344		344		26
Impaired financing receivable, with no related allowance, unpaid principal balance	345		345		26
Impaired financing receivable, with related allowance, recorded investment					268
Impaired financing receivable, with related allowance, unpaid principal balance					268
Impaired financing receivable, related allowance					41
Impaired financing receivable, recorded investment	344		344		294
Impaired financing receivable, unpaid principal balance	345		345		$ 294
Impaired financing receivable, with no related allowance, average recorded investment	323	13	301	13
Impaired financing receivable, with no related allowance, interest income, accrual method	1		1
Impaired financing receivable, average recorded investment	323	$ 13	301	$ 13
Impaired financing receivable, interest income, accrual method	1		1
Consumer Portfolio Segment | Consumer Loan Financing Receivable
Financing Receivable, Impaired
Impaired financing receivable, with no related allowance, recorded investment	8		8
Impaired financing receivable, with no related allowance, unpaid principal balance	8		8
Impaired financing receivable, recorded investment	8		8
Impaired financing receivable, unpaid principal balance	8		8
Impaired financing receivable, with no related allowance, average recorded investment	4		2
Impaired financing receivable, average recorded investment	$ 4		$ 2

Loans Receivable and the Allo_9

Loans Receivable and the Allowance for Loan Losses Past Due Loan Aging (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Financing Receivable, Recorded Investment, Past Due
Loans past due	$ 22,498	$ 14,622
Loans current	2,355,151	2,272,073
Total Loans Receivable	2,377,649	2,286,695
Purchased Credit Impaired Loans Receivable
Financing Receivable, Recorded Investment, Past Due
Loans past due		1,473
Loans current	17,452	18,258
Total Loans Receivable	17,452	19,731
Financing Receivables, 30 to 59 Days Past Due
Financing Receivable, Recorded Investment, Past Due
Loans past due	9,220	6,135
Financing Receivables, 30 to 59 Days Past Due | Purchased Credit Impaired Loans Receivable
Financing Receivable, Recorded Investment, Past Due
Loans past due		164
Financing Receivables, 60 to 89 Days Past Due
Financing Receivable, Recorded Investment, Past Due
Loans past due	936	3,117
Financing Receivables, 60 to 89 Days Past Due | Purchased Credit Impaired Loans Receivable
Financing Receivable, Recorded Investment, Past Due
Loans past due		756
Financing Receivables, Equal to Greater than 90 Days Past Due
Financing Receivable, Recorded Investment, Past Due
Loans past due	12,342	5,370
Financing Receivables, Equal to Greater than 90 Days Past Due | Purchased Credit Impaired Loans Receivable
Financing Receivable, Recorded Investment, Past Due
Loans past due		553
Agricultural Portfolio Segment | Agricultural Loan Financing Receivable
Financing Receivable, Recorded Investment, Past Due
Loans past due	402	381
Loans current	102,805	105,131
Total Loans Receivable	103,207	105,512
Agricultural Portfolio Segment | Financing Receivables, 30 to 59 Days Past Due | Agricultural Loan Financing Receivable
Financing Receivable, Recorded Investment, Past Due
Loans past due	72	95
Agricultural Portfolio Segment | Financing Receivables, 60 to 89 Days Past Due | Agricultural Loan Financing Receivable
Financing Receivable, Recorded Investment, Past Due
Loans past due	100	118
Agricultural Portfolio Segment | Financing Receivables, Equal to Greater than 90 Days Past Due | Agricultural Loan Financing Receivable
Financing Receivable, Recorded Investment, Past Due
Loans past due	230	168
Commercial Portfolio Segment | Commercial and Industrial Loan Financing Receivable
Financing Receivable, Recorded Investment, Past Due
Loans past due	8,222	4,346
Loans current	515,111	499,278
Total Loans Receivable	523,333	503,624
Commercial Portfolio Segment | Financing Receivables, 30 to 59 Days Past Due | Commercial and Industrial Loan Financing Receivable
Financing Receivable, Recorded Investment, Past Due
Loans past due	1,206	1,434
Commercial Portfolio Segment | Financing Receivables, 60 to 89 Days Past Due | Commercial and Industrial Loan Financing Receivable
Financing Receivable, Recorded Investment, Past Due
Loans past due	315	1,336
Commercial Portfolio Segment | Financing Receivables, Equal to Greater than 90 Days Past Due | Commercial and Industrial Loan Financing Receivable
Financing Receivable, Recorded Investment, Past Due
Loans past due	6,701	1,576
Commercial Real Estate Portfolio Segment
Financing Receivable, Recorded Investment, Past Due
Loans past due	8,347	2,777
Loans current	1,245,443	1,169,194
Total Loans Receivable	1,253,790	1,171,971
Commercial Real Estate Portfolio Segment | Commercial Real Estate Construction and Development Loan Financing Receivable
Financing Receivable, Recorded Investment, Past Due
Loans past due	93	236
Loans current	223,231	165,040
Total Loans Receivable	223,324	165,276
Commercial Real Estate Portfolio Segment | Farmland Loan Financing Receivable
Financing Receivable, Recorded Investment, Past Due
Loans past due	141	590
Loans current	85,594	87,278
Total Loans Receivable	85,735	87,868
Commercial Real Estate Portfolio Segment | Multifamily Real Estate Loan Financing Receivable
Financing Receivable, Recorded Investment, Past Due
Loans past due		25
Loans current	126,663	134,481
Total Loans Receivable	126,663	134,506
Commercial Real Estate Portfolio Segment | Commercial Real Estate Loan Other Financing Receivable
Financing Receivable, Recorded Investment, Past Due
Loans past due	8,113	1,926
Loans current	809,955	782,395
Total Loans Receivable	818,068	784,321
Commercial Real Estate Portfolio Segment | Financing Receivables, 30 to 59 Days Past Due
Financing Receivable, Recorded Investment, Past Due
Loans past due	4,198	348
Commercial Real Estate Portfolio Segment | Financing Receivables, 30 to 59 Days Past Due | Commercial Real Estate Construction and Development Loan Financing Receivable
Financing Receivable, Recorded Investment, Past Due
Loans past due		57
Commercial Real Estate Portfolio Segment | Financing Receivables, 30 to 59 Days Past Due | Farmland Loan Financing Receivable
Financing Receivable, Recorded Investment, Past Due
Loans past due		217
Commercial Real Estate Portfolio Segment | Financing Receivables, 30 to 59 Days Past Due | Commercial Real Estate Loan Other Financing Receivable
Financing Receivable, Recorded Investment, Past Due
Loans past due	4,198	74
Commercial Real Estate Portfolio Segment | Financing Receivables, 60 to 89 Days Past Due
Financing Receivable, Recorded Investment, Past Due
Loans past due	111	122
Commercial Real Estate Portfolio Segment | Financing Receivables, 60 to 89 Days Past Due | Commercial Real Estate Construction and Development Loan Financing Receivable
Financing Receivable, Recorded Investment, Past Due
Loans past due	10	97
Commercial Real Estate Portfolio Segment | Financing Receivables, 60 to 89 Days Past Due | Multifamily Real Estate Loan Financing Receivable
Financing Receivable, Recorded Investment, Past Due
Loans past due		25
Commercial Real Estate Portfolio Segment | Financing Receivables, 60 to 89 Days Past Due | Commercial Real Estate Loan Other Financing Receivable
Financing Receivable, Recorded Investment, Past Due
Loans past due	101
Commercial Real Estate Portfolio Segment | Financing Receivables, Equal to Greater than 90 Days Past Due
Financing Receivable, Recorded Investment, Past Due
Loans past due	4,038	2,307
Commercial Real Estate Portfolio Segment | Financing Receivables, Equal to Greater than 90 Days Past Due | Commercial Real Estate Construction and Development Loan Financing Receivable
Financing Receivable, Recorded Investment, Past Due
Loans past due	83	82
Commercial Real Estate Portfolio Segment | Financing Receivables, Equal to Greater than 90 Days Past Due | Farmland Loan Financing Receivable
Financing Receivable, Recorded Investment, Past Due
Loans past due	141	373
Commercial Real Estate Portfolio Segment | Financing Receivables, Equal to Greater than 90 Days Past Due | Commercial Real Estate Loan Other Financing Receivable
Financing Receivable, Recorded Investment, Past Due
Loans past due	3,814	1,852
Residential Portfolio Segment
Financing Receivable, Recorded Investment, Past Due
Loans past due	5,355	6,995
Loans current	453,168	462,435
Total Loans Receivable	458,523	469,430
Residential Portfolio Segment | Residential Real Estate First Lien Loan Financing Receivable
Financing Receivable, Recorded Investment, Past Due
Loans past due	4,659	5,629
Loans current	338,096	346,597
Total Loans Receivable	342,755	352,226
Residential Portfolio Segment | Residential Real Estate Junior Lien Loan Financing Receivable
Financing Receivable, Recorded Investment, Past Due
Loans past due	696	1,366
Loans current	115,072	115,838
Total Loans Receivable	115,768	117,204
Residential Portfolio Segment | Financing Receivables, 30 to 59 Days Past Due
Financing Receivable, Recorded Investment, Past Due
Loans past due	3,606	4,179
Residential Portfolio Segment | Financing Receivables, 30 to 59 Days Past Due | Residential Real Estate First Lien Loan Financing Receivable
Financing Receivable, Recorded Investment, Past Due
Loans past due	3,381	3,854
Residential Portfolio Segment | Financing Receivables, 30 to 59 Days Past Due | Residential Real Estate Junior Lien Loan Financing Receivable
Financing Receivable, Recorded Investment, Past Due
Loans past due	225	325
Residential Portfolio Segment | Financing Receivables, 60 to 89 Days Past Due
Financing Receivable, Recorded Investment, Past Due
Loans past due	407	1,526
Residential Portfolio Segment | Financing Receivables, 60 to 89 Days Past Due | Residential Real Estate First Lien Loan Financing Receivable
Financing Receivable, Recorded Investment, Past Due
Loans past due	313	756
Residential Portfolio Segment | Financing Receivables, 60 to 89 Days Past Due | Residential Real Estate Junior Lien Loan Financing Receivable
Financing Receivable, Recorded Investment, Past Due
Loans past due	94	770
Residential Portfolio Segment | Financing Receivables, Equal to Greater than 90 Days Past Due
Financing Receivable, Recorded Investment, Past Due
Loans past due	1,342	1,290
Residential Portfolio Segment | Financing Receivables, Equal to Greater than 90 Days Past Due | Residential Real Estate First Lien Loan Financing Receivable
Financing Receivable, Recorded Investment, Past Due
Loans past due	965	1,019
Residential Portfolio Segment | Financing Receivables, Equal to Greater than 90 Days Past Due | Residential Real Estate Junior Lien Loan Financing Receivable
Financing Receivable, Recorded Investment, Past Due
Loans past due	377	271
Consumer Portfolio Segment | Consumer Loan Financing Receivable
Financing Receivable, Recorded Investment, Past Due
Loans past due	172	123
Loans current	38,624	36,035
Total Loans Receivable	38,796	36,158
Consumer Portfolio Segment | Financing Receivables, 30 to 59 Days Past Due | Consumer Loan Financing Receivable
Financing Receivable, Recorded Investment, Past Due
Loans past due	138	79
Consumer Portfolio Segment | Financing Receivables, 60 to 89 Days Past Due | Consumer Loan Financing Receivable
Financing Receivable, Recorded Investment, Past Due
Loans past due	3	15
Consumer Portfolio Segment | Financing Receivables, Equal to Greater than 90 Days Past Due | Consumer Loan Financing Receivable
Financing Receivable, Recorded Investment, Past Due
Loans past due	$ 31	$ 29

Loans Receivable and the All_10

Loans Receivable and the Allowance for Loan Losses Nonaccrual and 90+ Days Past Due and Still Accruing Loans (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Financing Receivable, Recorded Investment, Past Due
Loans in nonaccrual status	$ 20,929	$ 14,784
Loans 90 days past due and still accruing	171	207
Purchased Credit Impaired Loans Receivable
Financing Receivable, Recorded Investment, Past Due
Loans, nonaccrual or 90 days past due and still accruing	300	700
Loans, discount, nonaccrual or 90 days past due and still accruing	0	100
Agricultural Portfolio Segment | Agricultural Loan Financing Receivable
Financing Receivable, Recorded Investment, Past Due
Loans in nonaccrual status	662	168
Commercial Portfolio Segment | Commercial and Industrial Loan Financing Receivable
Financing Receivable, Recorded Investment, Past Due
Loans in nonaccrual status	11,208	7,124
Commercial Real Estate Portfolio Segment
Financing Receivable, Recorded Investment, Past Due
Loans in nonaccrual status	7,283	5,853
Loans 90 days past due and still accruing		0
Commercial Real Estate Portfolio Segment | Commercial Real Estate Construction and Development Loan Financing Receivable [Member]
Financing Receivable, Recorded Investment, Past Due
Loans in nonaccrual status	100	188
Commercial Real Estate Portfolio Segment | Farmland Loan Financing Receivable
Financing Receivable, Recorded Investment, Past Due
Loans in nonaccrual status	2,367	386
Commercial Real Estate Portfolio Segment | Commercial Real Estate Loan Other Financing Receivable
Financing Receivable, Recorded Investment, Past Due
Loans in nonaccrual status	4,816	5,279
Residential Portfolio Segment
Financing Receivable, Recorded Investment, Past Due
Loans in nonaccrual status	1,690	1,574
Loans 90 days past due and still accruing	171	207
Residential Portfolio Segment | Residential Real Estate First Lien Loan Financing Receivable
Financing Receivable, Recorded Investment, Past Due
Loans in nonaccrual status	1,277	1,228
Loans 90 days past due and still accruing	171	205
Residential Portfolio Segment | Residential Real Estate Junior Lien Loan Financing Receivable
Financing Receivable, Recorded Investment, Past Due
Loans in nonaccrual status	413	346
Loans 90 days past due and still accruing		2
Consumer Portfolio Segment | Consumer Loan Financing Receivable
Financing Receivable, Recorded Investment, Past Due
Loans in nonaccrual status	$ 86	$ 65

Loans Receivable and the All_11

Loans Receivable and the Allowance for Loan Losses Accretable Yield for Loans Acquired and Accounted for Under ASC 310-30 (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Loans and Leases Receivable Disclosure [Abstract]
Balance at beginning of period	$ 311	$ 1,371	$ 840	$ 1,961
Accretion	(223)	(350)	(873)	(1,241)
Reclassifications from nonaccretable difference	(7)	63	114	364
Balance at end of period	$ 81	$ 1,084	$ 81	$ 1,084

Loans Receivable and the All_12

Loans Receivable and the Allowance for Loan Losses Textual References (Details) $ in Millions	Sep. 30, 2018USD ($)quarters	Dec. 31, 2017USD ($)
Financing Receivable, Allowance for Credit Losses [Line Items]
Loans pledged for Federal Home Loan Bank debt	$ 459.1	$ 477.6
Allowance for loan losses, maximum overage percentage	20.00%
Allowance for loan losses, maximum shortage percentage	5.00%
Loans reviewed collectively for impairment, historical loss lookback, number of quarters | quarters	20
Loans and leases receivable, impaired, commitment to lend	$ 0.1
Receivables Acquired with Deteriorated Credit Quality
Financing Receivable, Allowance for Credit Losses [Line Items]
Purchased credit-impaired loans, outstanding balance	18.3
Purchased credit-impaired loans, discount	$ 0.9

Derivatives and Hedging Activ_5

Derivatives and Hedging Activities Derivatives and Hedging Activities (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Not Designated as Hedging Instrument
Derivatives, Fair Value [Line Items]
Notional amount	$ 23,952	$ 0
Not Designated as Hedging Instrument | Derivative Financial Instruments, Assets
Derivatives, Fair Value [Line Items]
Derivative assets, fair value	105	0
Not Designated as Hedging Instrument | Derivative Financial Instruments, Liabilities
Derivatives, Fair Value [Line Items]
Derivative liabilities, fair value	178	0
Interest Rate Swap | Designated as Hedging Instrument
Derivatives, Fair Value [Line Items]
Notional amount	7,855	0
Interest Rate Swap | Designated as Hedging Instrument | Derivative Financial Instruments, Assets
Derivatives, Fair Value [Line Items]
Derivative assets, fair value	100	0
Interest Rate Swap | Designated as Hedging Instrument | Derivative Financial Instruments, Liabilities
Derivatives, Fair Value [Line Items]
Derivative liabilities, fair value	0	0
Interest Rate Swap | Not Designated as Hedging Instrument
Derivatives, Fair Value [Line Items]
Notional amount	13,840	0
Interest Rate Swap | Not Designated as Hedging Instrument | Derivative Financial Instruments, Assets
Derivatives, Fair Value [Line Items]
Derivative assets, fair value	105	0
Interest Rate Swap | Not Designated as Hedging Instrument | Derivative Financial Instruments, Liabilities
Derivatives, Fair Value [Line Items]
Derivative liabilities, fair value	125	0
Risk Participation Agreement | Not Designated as Hedging Instrument
Derivatives, Fair Value [Line Items]
Notional amount	10,112	0
Derivative assets, fair value	0	0
Derivative liabilities, fair value	53	0
Risk Participation Agreement | Not Designated as Hedging Instrument | Derivative Financial Instruments, Assets
Derivatives, Fair Value [Line Items]
Derivative assets, fair value	0	0
Risk Participation Agreement | Not Designated as Hedging Instrument | Derivative Financial Instruments, Liabilities
Derivatives, Fair Value [Line Items]
Derivative liabilities, fair value	$ 53	$ 0

Derivatives and Hedging Activ_6

Derivatives and Hedging Activities Schedule of Derivatives Instruments Statements of Financial Performance and Financial Position, Location (Details) - Designated as Hedging Instrument - Interest Rate Swap - Fair Value Hedging - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Interest Income
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) on fair value hedge ineffectiveness, net	$ 0	$ 0	$ (1)	$ 0
Hedged items	(126)	0	(101)	0
Change in Unrealized Gain (Loss) on Fair Value Hedging Instruments	126		100	0
Other Gain (Loss)
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) on fair value hedge ineffectiveness, net	0	0	0	0
Hedged items	0	0	0
Change in Unrealized Gain (Loss) on Fair Value Hedging Instruments	$ 0	$ 0	$ 0	$ 0

Derivatives and Hedging Activ_7

Derivatives and Hedging Activities Hedged Items in Fair Value Hedging Relationship (Details) - Hedged Item, Loans - Interest Rate Swap - Designated as Hedging Instrument - Fair Value Hedging $ in Thousands	Sep. 30, 2018USD ($)
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Carrying amount of hedged assets	$ 7,754
Cumulative amount of fair value hedging adjustment included in the carrying amount of the hedged asset	$ (101)

Derivatives and Hedging Activ_8

Derivatives and Hedging Activities Interest Rate Swaps (Details) - Not Designated as Hedging Instrument - Interest Rate Swap - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Customer Counterparties
Derivative [Line Items]
Derivative Asset, Notional Amount	$ 6,920	$ 0
Derivative assets, fair value	105	0
Derivative liabilities, fair value	0	0
Financial Counterparties
Derivative [Line Items]
Derivative Asset, Notional Amount	6,920	0
Derivative assets, fair value	0	0
Derivative liabilities, fair value	$ 125	$ 0

Derivatives and Hedging Activ_9

Derivatives and Hedging Activities Credit Risk Participation Agreements (Details) - Not Designated as Hedging Instrument - Risk Participation Agreement - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Derivative [Line Items]
Derivative Asset, Notional Amount	$ 10,112	$ 0
Derivative assets, fair value	0	0
Derivative liabilities, fair value	$ 53	$ 0

Derivatives and Hedging Acti_10

Derivatives and Hedging Activities Textual References (Details)	Sep. 30, 2018USD ($)
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Fair value of derivatives in a net liability position, including accrued interest	$ 179,000
Assets needed for immediate settlement, aggregate fair value	$ 179,000

Goodwill and Intangible Asset_2

Goodwill and Intangible Assets Changes in Carrying Amount of Non-Goodwill Intangibles (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018
Schedule of Intangible Assets [Line Items]
Balance, beginning of period			$ 12,046
Finite-lived intangible assets acquired			125
Amortization expense	$ (547)	$ (759)	(1,793)	$ (2,412)
Balance at end of period	10,378		10,378
Gross carrying amount					$ 28,401
Accumulated amortizations					(18,023)
Net book value	10,378		10,378		10,378
Trade names intangible
Schedule of Intangible Assets [Line Items]
Balance, beginning of period			7,040
Amortization expense			0
Balance at end of period	7,040		7,040
Gross carrying amount					7,040
Net book value	7,040		7,040		7,040
Insurance agency intangible
Schedule of Intangible Assets [Line Items]
Balance, beginning of period			148
Finite-lived intangible assets acquired			0
Amortization expense			(28)
Balance at end of period	120		120
Gross carrying amount					1,320
Accumulated amortizations					(1,200)
Net book value	120		148		120
Core deposit intangible
Schedule of Intangible Assets [Line Items]
Balance, beginning of period			4,011
Finite-lived intangible assets acquired			0
Amortization expense			(1,600)
Balance at end of period	2,411		2,411
Gross carrying amount					18,206
Accumulated amortizations					(15,795)
Net book value	2,411		4,011		2,411
Trade names intangible
Schedule of Intangible Assets [Line Items]
Balance, beginning of period			744
Finite-lived intangible assets acquired			0
Amortization expense			(143)
Balance at end of period	601		601
Gross carrying amount					1,380
Accumulated amortizations					(779)
Net book value	601		744		601
Customer list intangible
Schedule of Intangible Assets [Line Items]
Balance, beginning of period			103
Finite-lived intangible assets acquired			125
Amortization expense			(22)
Balance at end of period	206		206
Gross carrying amount					455
Accumulated amortizations					(249)
Net book value	$ 206		$ 103		$ 206

Goodwill and Intangible Asset_3

Goodwill and Intangible Assets Textual References (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2018	Dec. 31, 2017
Schedule of Intangible Assets [Line Items]
Goodwill, impairment loss	$ 0
Goodwill	64,654	$ 64,654
Trade names intangible
Schedule of Intangible Assets [Line Items]
Impairment of indefinite-lived trade name intangible	$ 0

Other Assets (Details)

Other Assets (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Other Assets [Abstract]
Federal Home Loan Bank stock	$ 13,260	$ 11,324
Prepaid expense	2,286	2,992
Mortgage servicing rights	2,711	2,316
Assets held for sale	895	0
Federal & state income taxes receivable, current	322	3,120
Accounts receivable & other miscellaneous assets	7,841	3,009
Other assets	$ 27,315	$ 22,761

Short-Term Borrowings (Details)

Short-Term Borrowings (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2018	Dec. 31, 2017
Short-term Debt [Line Items]
Weighted Average Cost	1.28%	0.73%
Short-term debt	$ 87,978	$ 97,229
Pledged securities	217,800	237,400
Federal Reserve Bank advances
Short-term Debt [Line Items]
Short-term debt	0	0
Unsercured line of credit, maximum borrowing capacity	11,400	11,536
Pledged securities	$ 12,600	$ 12,800
Federal funds purchased
Short-term Debt [Line Items]
Weighted Average Cost	2.39%	1.77%
Short-term debt	$ 19,056	$ 1,000
Securities sold under agreements to repurchase
Short-term Debt [Line Items]
Weighted Average Cost	0.97%	0.71%
Short-term debt	$ 68,922	$ 96,229
Line of credit
Short-term Debt [Line Items]
Short-term debt	0
Unsercured line of credit, maximum borrowing capacity	$ 5,000
Debt instrument, issuance date	Apr. 30, 2015
Debt instrument, maturity date	Apr. 30, 2019
London Interbank Offered Rate (LIBOR) | Line of credit
Short-term Debt [Line Items]
Description of variable interest rate basis	one-month LIBOR
Debt instrument, basis spread on variable rate	2.00%

Junior Subordinated Notes Iss_3

Junior Subordinated Notes Issued to Capital Trusts (Details) - USD ($) $ in Thousands		9 Months Ended	12 Months Ended
		Sep. 30, 2018	Dec. 31, 2017
Debt Instrument [Line Items]
Junior subordinated notes issued to capital trusts, book value		$ 23,865	$ 23,793
Junior subordinated notes
Debt Instrument [Line Items]
Junior subordinated debenture owed to unconsolidated subsidiary trust, face value	[1]	24,743	24,743
Junior subordinated notes issued to capital trusts, book value		23,865	23,793
Junior subordinated notes | CBI Capital Trust II
Debt Instrument [Line Items]
Junior subordinated debenture owed to unconsolidated subsidiary trust, face value	[1],[2]	7,217	7,217
Junior subordinated notes issued to capital trusts, book value	[1],[2]	$ 6,716	$ 6,674
Interest rate	[1],[2]	5.83%	5.09%
Debt instrument, maturity date	[1],[2]	Mar. 15, 2038	Mar. 15, 2038
Debt instrument, earliest call date	[1],[2]	Mar. 15, 2013	Mar. 15, 2013
Junior subordinated notes | CBI Capital Trust II | London Interbank Offered Rate (LIBOR)
Debt Instrument [Line Items]
Description of variable interest rate basis	[1],[2]	Three-month LIBOR
Debt instrument, basis spread on variable rate	[1],[2]	3.50%
Junior subordinated notes | Barron Investment Capital Trust I
Debt Instrument [Line Items]
Junior subordinated debenture owed to unconsolidated subsidiary trust, face value	[1],[2]	$ 2,062	$ 2,062
Junior subordinated notes issued to capital trusts, book value	[1],[2]	$ 1,685	$ 1,655
Interest rate	[1],[2]	4.52%	3.82%
Debt instrument, maturity date	[1],[2]	Sep. 23, 2036	Sep. 23, 2036
Debt instrument, earliest call date	[1],[2]	Sep. 23, 2011	Sep. 23, 2011
Junior subordinated notes | Barron Investment Capital Trust I | London Interbank Offered Rate (LIBOR)
Debt Instrument [Line Items]
Description of variable interest rate basis	[1],[2]	Three-month LIBOR
Debt instrument, basis spread on variable rate	[1],[2]	2.15%
Junior subordinated notes | MidWestOne Statutory Trust II
Debt Instrument [Line Items]
Junior subordinated debenture owed to unconsolidated subsidiary trust, face value	[1]	$ 15,464	$ 15,464
Junior subordinated notes issued to capital trusts, book value	[1]	$ 15,464	$ 15,464
Interest rate	[1]	3.92%	3.18%
Debt instrument, maturity date	[1]	Dec. 15, 2037	Dec. 15, 2037
Debt instrument, earliest call date	[1]	Dec. 15, 2012	Dec. 15, 2012
Junior subordinated notes | MidWestOne Statutory Trust II | London Interbank Offered Rate (LIBOR)
Debt Instrument [Line Items]
Description of variable interest rate basis	[1]	Three-month LIBOR
Debt instrument, basis spread on variable rate	[1]	1.59%
Maximum
Debt Instrument [Line Items]
Junior subordinated debenture owed to unconsolidated subsidiary, deferral period		5 years
[1]	(1) All distributions are cumulative and paid in cash quarterly.
[2]	(2) Central Bancshares Capital Trust II and Barron Investment Capital Trust I were established by Central prior to the Company’s merger with Central, and the junior subordinated notes issued by Central were assumed by the Company.

Federal Home Loan Bank Borrow_3

Federal Home Loan Bank Borrowings and Long-Term Debt (Details) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2018	Dec. 31, 2017	Jun. 30, 2015	Apr. 30, 2015
Debt Instrument [Line Items]
Long-term debt, excluding subordinated debt, weighted average interest rate	2.30%	1.88%
Long-term debt, gross	$ 151,750	$ 127,500
Federal Home Loan Bank Borrowings
Debt Instrument [Line Items]
Weighted average cost	2.20%	1.72%
Long-term debt, gross	$ 143,000	$ 115,000
Federal Home Loan, Bank advances general debt obligations, disclosures maximum borrowing capacity as percentage of total assets	35.00%
Note payable to unaffiliated bank
Debt Instrument [Line Items]
Weighted average cost	3.85%	3.32%
Long-term debt, gross	$ 8,750	$ 12,500
Debt instrument, issuance date		Apr. 30, 2015
Original note face amount				$ 35,000
Debt instrument, maturity date	Jun. 30, 2020
Long-term debt, amount advanced			$ 25,000
Debt instrument, frequency of periodic payment	quarterly
Debt Instrument, Date of First Required Payment	Sep. 30, 2015

Income Taxes (Details)

Income Taxes (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Effective Income Tax Rate Reconciliation, Amount [Abstract]
Income tax based on statutory rate, amount	$ 1,803	$ 2,898	$ 6,016	$ 9,762
Tax-exempt interest, amount	(468)	(808)	(1,459)	(2,389)
Bank-owned life insurance, amount	(84)	(121)	(257)	(346)
State income taxes, net of federal income tax benefit, amount	445	366	1,540	1,214
Non-deductible acquisition expenses	124	0	124	0
General business credits, amount	(22)	(405)	(62)	(445)
Other, amount	8	8	19	(193)
Total income tax expense, amount	$ 1,806	$ 1,938	$ 5,921	$ 7,603
Effective Income Tax Rate Reconciliation, Percent [Abstract]
Income tax based on statutory amount, percent	21.00%	35.00%	21.00%	35.00%
Tax-exempt interest, percent	(5.40%)	(9.70%)	(5.00%)	(8.60%)
Bank-owned life insurance, percent	(1.00%)	(1.50%)	(0.90%)	(1.20%)
State income taxes, net of federal income tax benefit, percent	5.20%	4.40%	5.40%	4.40%
Non-deductible acquisition expenses, percent	1.40%	0.00%	0.40%	0.00%
General business credits, percent	(0.20%)	(4.90%)	(0.20%)	(1.60%)
Other, percent	0.00%	0.10%	0.00%	(0.70%)
Total income tax provision, percent	21.00%	23.40%	20.70%	27.30%

Earnings per Share (Details)

Earnings per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Earnings Per Share [Abstract]
Net income	$ 6,778	$ 6,342	$ 22,727	$ 20,289
Average number of shares outstanding	12,221,107	12,218,528	12,220,673	11,977,579
Earnings per common share - basic	$ 0.55	$ 0.52	$ 1.86	$ 1.69
Diluted average number of shares	12,239,864	12,238,991	12,237,462	11,999,608
Earnings per common share - diluted	$ 0.55	$ 0.52	$ 1.86	$ 1.69

Estimated Fair Value of Finan_3

Estimated Fair Value of Financial Instruments and Fair Value Measurements Fair Value Financial Assets and Liabilities Measured on a Recurring Basis (Details) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2018USD ($)count	Dec. 31, 2017USD ($)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Available for sale securities	$ 407,766	$ 445,324
Transfer of assets, fair value, to (from) Level 3, amount	0	0
Fair Value, Inputs, Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Derivative assets, fair value	0
Derivative liabilities, fair value	0
Fair Value, Inputs, Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Derivative assets, fair value	205
Derivative liabilities, fair value	178
Fair Value, Inputs, Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Derivative assets, fair value	0
Derivative liabilities, fair value	0
Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Derivative assets, fair value	205
Derivative liabilities, fair value	178
Recurring | Fair Value, Inputs, Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Derivative assets, fair value	0
Derivative liabilities, fair value	0
Recurring | Fair Value, Inputs, Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Derivative assets, fair value	205
Derivative liabilities, fair value	178
Recurring | Fair Value, Inputs, Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Derivative assets, fair value	0
Derivative liabilities, fair value	0
U.S. Government agencies and corporations
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Available for sale securities	5,519	15,626
U.S. Government agencies and corporations | Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Available for sale securities	5,519	15,626
U.S. Government agencies and corporations | Recurring | Fair Value, Inputs, Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Available for sale securities	5,519	15,626
State and political subdivisions
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Available for sale securities	115,136	141,839
State and political subdivisions | Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Available for sale securities	115,136	141,839
State and political subdivisions | Recurring | Fair Value, Inputs, Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Available for sale securities	115,136	141,839
Mortgage-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Available for sale securities	51,896	48,497
Mortgage-backed securities | Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Available for sale securities	51,896	48,497
Mortgage-backed securities | Recurring | Fair Value, Inputs, Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Available for sale securities	51,896	48,497
Collateralized mortgage obligations | Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Available for sale securities	170,877	168,196
Collateralized mortgage obligations | Recurring | Fair Value, Inputs, Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Available for sale securities	170,877	168,196
Corporate debt securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Available for sale securities	64,338	71,166
Corporate debt securities | Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Available for sale securities	64,338	71,166
Corporate debt securities | Recurring | Fair Value, Inputs, Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Available for sale securities	$ 64,338	71,166
Debt securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Sample size used to validate pricing service results | count	30
Debt securities | Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Available for sale securities	$ 407,766	445,324
Debt securities | Recurring | Fair Value, Inputs, Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Available for sale securities	407,766	$ 445,324
Interest Rate Swap | Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Derivative assets, fair value	205
Derivative liabilities, fair value	125
Interest Rate Swap | Recurring | Fair Value, Inputs, Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Derivative assets, fair value	0
Derivative liabilities, fair value	0
Interest Rate Swap | Recurring | Fair Value, Inputs, Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Derivative assets, fair value	205
Derivative liabilities, fair value	125
Interest Rate Swap | Recurring | Fair Value, Inputs, Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Derivative assets, fair value	0
Derivative liabilities, fair value	0
Risk Participation Agreement | Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Derivative assets, fair value	0
Derivative liabilities, fair value	53
Risk Participation Agreement | Recurring | Fair Value, Inputs, Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Derivative assets, fair value	0
Derivative liabilities, fair value	0
Risk Participation Agreement | Recurring | Fair Value, Inputs, Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Derivative assets, fair value	0
Derivative liabilities, fair value	53
Risk Participation Agreement | Recurring | Fair Value, Inputs, Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Derivative assets, fair value	0
Derivative liabilities, fair value	$ 0

Estimated Fair Value of Finan_4

Estimated Fair Value of Financial Instruments and Fair Value Measurements Fair Value Assets and Liabilities Measured on a Nonrecurring Basis (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Other real estate owned	$ 549	$ 2,010
Nonrecurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Collateral dependent impaired loans	8,362	3,927
Other real estate owned	549	2,010
Nonrecurring | Fair Value, Inputs, Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Collateral dependent impaired loans	8,362	3,927
Other real estate owned	$ 549	$ 2,010

Estimated Fair Value of Finan_5

Estimated Fair Value of Financial Instruments and Fair Value Measurements Fair Value of Financial Instruments (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Investment securities:
Equity securities	$ 2,797	$ 2,336
Debt securities available for sale	407,766	445,324
Debt securities held to maturity securities	191,733	195,619
Debt securities held to maturity, estimated fair value	186,057	194,343
Interest receivable	14,800	14,732
Federal Home Loan Bank stock	13,260	11,324
Deposits:
Non-interest-bearing demand	458,576	461,969
Interest-bearing checking	1,236,922	1,228,112
Savings	211,591	213,430
Reported Value Measurement
Financial Assets
Cash and cash equivalents	53,379	50,972
Investment securities:
Equity securities	2,797	2,336
Debt securities available for sale	407,766	445,324
Debt securities held to maturity securities	191,733	195,619
Total investment securities	602,296	643,279
Loans held for sale	1,124	856
Loans held for investment, net	2,346,371	2,258,636
Interest receivable	14,800	14,732
Derivative assets, fair value	205
Deposits:
Non-interest-bearing demand	458,576	461,969
Interest-bearing checking	1,236,922	1,228,112
Savings	211,591	213,430
Certificates of deposit under $100,000	348,099	324,681
Certificates of deposit $100,000 and over	377,071	377,127
Total deposits	2,632,259	2,605,319
Federal funds purchased and securities sold under agreements to repurchase	87,978	97,229
Federal Home Loan Bank borrowings	143,000	115,000
Junior subordinated notes issued to capital trusts	23,865	23,793
Long-term debt	8,750	12,500
Derivative liabilities, fair value	178
Estimate of Fair Value Measurement
Financial Assets
Cash and cash equivalents	53,379	50,972
Investment securities:
Equity securities	2,797	2,336
Debt securities available for sale	407,766	445,324
Debt securities held to maturity, estimated fair value	186,057	194,343
Total investment securities	596,620	642,003
Loans held for sale	1,145	871
Loans held for investment, net	2,283,363	2,256,726
Interest receivable	14,800	14,732
Federal Home Loan Bank stock	13,260	11,324
Derivative assets, fair value	205
Deposits:
Non-interest-bearing demand	458,576	461,969
Interest-bearing checking	1,236,922	1,228,112
Savings	211,591	213,430
Certificates of deposit under $100,000	342,998	321,197
Certificates of deposit $100,000 and over	373,313	374,685
Total deposits	2,623,400	2,599,393
Federal funds purchased and securities sold under agreements to repurchase	87,978	97,229
Federal Home Loan Bank borrowings	141,110	114,945
Junior subordinated notes issued to capital trusts	21,058	19,702
Long-term debt	8,750	12,500
Derivative liabilities, fair value	178
Fair Value, Inputs, Level 1
Financial Assets
Cash and cash equivalents	53,379	50,972
Investment securities:
Equity securities	2,797	2,336
Total investment securities	2,797	2,336
Interest receivable	14,800	14,732
Derivative assets, fair value	0
Deposits:
Non-interest-bearing demand	458,576	461,969
Interest-bearing checking	1,236,922	1,228,112
Savings	211,591	213,430
Total deposits	1,907,089	1,903,511
Federal funds purchased and securities sold under agreements to repurchase	87,978	97,229
Derivative liabilities, fair value	0
Fair Value, Inputs, Level 2
Investment securities:
Equity securities	0	0
Debt securities available for sale	407,766	445,324
Debt securities held to maturity, estimated fair value	186,057	194,343
Total investment securities	593,823	639,667
Loans held for sale	1,145
Loans held for investment, net		2,256,726
Federal Home Loan Bank stock	13,260	11,324
Derivative assets, fair value	205
Deposits:
Certificates of deposit under $100,000	342,998	321,197
Certificates of deposit $100,000 and over	373,313	374,685
Total deposits	716,311	695,882
Federal Home Loan Bank borrowings	141,110	114,945
Junior subordinated notes issued to capital trusts	21,058	19,702
Long-term debt	8,750	12,500
Derivative liabilities, fair value	178
Fair Value, Inputs, Level 3
Investment securities:
Equity securities	0	0
Loans held for sale		$ 871
Loans held for investment, net	2,283,363
Derivative assets, fair value	0
Deposits:
Derivative liabilities, fair value	$ 0

Proposed Merger (Details)

Proposed Merger (Details) - ATBancorp [Member]	9 Months Ended
	Sep. 30, 2018USD ($)shares
Business Acquisition [Line Items]
Cash to be paid per share | $	$ 992.51
Common Stock
Business Acquisition [Line Items]
Stock to be issued, exchange ratio | shares	117.5500

Subsequent Events (Details)

Subsequent Events (Details) - Subsequent Event $ / shares in Units, $ in Millions	Oct. 16, 2018USD ($)$ / shares
October 16, 2018 Share Repurchase Program [Member] | Common Stock
Subsequent Event
Stock Repurchase Program, Authorized Amount | $	$ 5
Common Stock
Subsequent Event
Dividends payable, amount per share | $ / shares	$ 0.195
Dividends payable, date to be paid	Dec. 15, 2018
Dividends payable, date of record	Dec. 1, 2018