Hills Bancorporation (HBIA) 10-Q 7 Nov 17 2017 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2017	Oct. 31, 2017
Document and Entity Information [Abstract]
Entity Registrant Name	HILLS BANCORPORATION
Entity Central Index Key	732,417
Current Fiscal Year End Date	--12-31
Entity Well-known Season Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Filer Category	Accelerated Filer
Entity Common Stock, Shares Outstanding (in shares)		9,339,712
Document Fiscal Year Focus	2,017
Document Fiscal Period Focus	Q3
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Sep. 30, 2017

CONSOLIDATED BALANCE SHEETS

CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
ASSETS
Cash and cash equivalents	$ 36,792	$ 38,197
Investment securities available for sale at fair value (amortized cost September 30, 2017 $253,689; December 31, 2016 $269,039)	254,984	267,537
Stock of Federal Home Loan Bank	16,126	12,413
Loans held for sale	6,717	9,806
Loans, net of allowance for loan losses (September 30, 2017 $29,350; December 31, 2016 $26,530)	2,391,430	2,251,445
Property and equipment, net	37,799	37,859
Tax credit real estate investment	10,016	10,563
Accrued interest receivable	11,484	9,121
Deferred income taxes, net	12,871	12,611
Other real estate	144	237
Goodwill	2,500	2,500
Other assets	2,906	3,481
Total Assets	2,783,769	2,655,770
Liabilities
Noninterest-bearing deposits	349,883	348,505
Interest-bearing deposits	1,723,159	1,687,807
Total deposits	2,073,042	2,036,312
Other borrowings	13,761	33,489
Federal Home Loan Bank borrowings	323,000	235,000
Accrued interest payable	1,079	984
Other liabilities	20,850	19,934
Total Liabilities	2,431,732	2,325,719
Redeemable Common Stock Held by Employee Stock Ownership Plan (ESOP)	42,471	40,781
STOCKHOLDERS' EQUITY
Common stock, no par value; authorized 20,000,000 shares; issued September 30, 2017 10,318,906 shares; December 31, 2016 10,227,178 shares	0	0
Paid in capital	49,194	44,606
Retained earnings	337,380	319,982
Accumulated other comprehensive loss	(1,339)	(3,359)
Treasury stock at cost (September 30, 2017 1,000,774 shares; December 31, 2016 962,951 shares)	(33,198)	(31,178)
Total Stockholders' Equity	352,037	330,051
Less maximum cash obligation related to ESOP shares	42,471	40,781
Total Stockholders' Equity Less Maximum Cash Obligations Related to ESOP Shares	309,566	289,270
Total Liabilities & Stockholders' Equity	$ 2,783,769	$ 2,655,770

CONSOLIDATED BALANCE SHEETS (Pa

CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
ASSETS
Investment securities available for sale, amortized cost	$ 253,689	$ 269,039
Loans, allowance for loan losses	$ 29,350	$ 26,530
STOCKHOLDERS' EQUITY
Common stock, no par value (in dollars per share)	$ 0	$ 0
Common stock, authorized (in shares)	20,000,000	20,000,000
Common stock, issued (in shares)	10,318,906	10,227,178
Treasury stock at cost (in shares)	1,000,774	962,951

CONSOLIDATED STATEMENTS OF INCO

CONSOLIDATED STATEMENTS OF INCOME (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Interest income:
Loans, including fees	$ 25,643	$ 23,626	$ 74,378	$ 68,974
Investment securities:
Taxable	437	362	1,237	1,080
Nontaxable	783	786	2,425	2,414
Federal funds sold	9	6	145	124
Total interest income	26,872	24,780	78,185	72,592
Interest expense:
Deposits	2,319	1,917	6,730	5,742
Short-term borrowings	100	70	149	127
FHLB borrowings	2,233	1,935	5,938	6,224
Total interest expense	4,652	3,922	12,817	12,093
Net interest income	22,220	20,858	65,368	60,499
Provision for loan losses	130	(1,832)	1,827	(2,004)
Net interest income after provision for loan losses	22,090	22,690	63,541	62,503
Noninterest income:
Net gain on sale of loans	423	602	1,119	1,437
Trust fees	1,980	1,731	5,883	5,185
Service charges and fees	2,197	2,243	6,557	6,516
Net gain on sale of other real estate owned and other repossessed assets	33	342	89	376
Other noninterest income	372	396	1,599	1,541
Noninterest income	5,005	5,314	15,247	15,055
Noninterest expenses:
Salaries and employee benefits	8,134	8,158	24,707	22,617
Occupancy	1,087	1,017	3,148	3,001
Furniture and equipment	1,491	1,350	4,356	4,111
Office supplies and postage	516	436	1,487	1,282
Advertising and business development	628	800	2,123	2,426
Outside services	2,077	1,845	5,943	5,386
FDIC insurance assessment	217	315	636	938
Other noninterest expense	671	510	2,033	1,585
Noninterest expenses	14,821	14,431	44,433	41,346
Income before income taxes	12,274	13,573	34,355	36,212
Income taxes	3,722	4,397	10,472	11,369
Net income	$ 8,552	$ 9,176	$ 23,883	$ 24,843
Earnings per share:
Basic (in dollars per share)	$ 0.92	$ 0.99	$ 2.56	$ 2.67
Diluted (in dollars per share)	$ 0.92	$ 0.99	$ 2.56	$ 2.67

CONSOLIDATED STATEMENTS OF COMP

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Statement of Comprehensive Income [Abstract]
Net income	$ 8,552	$ 9,176	$ 23,883	$ 24,843
Securities:
Net change in unrealized (loss) gain on securities available for sale	(302)	(1,090)	2,797	1,104
Reclassification adjustment for net gains realized in net income	0	0	0	0
Income taxes	116	417	(1,070)	(423)
Other comprehensive (loss) income on securities available for sale	(186)	(673)	1,727	681
Derivatives used in cash flow hedging relationships:
Net change in unrealized gain (loss) on derivatives	259	500	474	(1,931)
Income taxes	(99)	(192)	(181)	738
Other comprehensive income (loss) on cash flow hedges	160	308	293	(1,193)
Other comprehensive (loss) income, net of tax	(26)	(365)	2,020	(512)
Comprehensive income	$ 8,526	$ 8,811	$ 25,903	$ 24,331

CONSOLIDATED STATEMENTS OF STOC

CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY (Unaudited) - USD ($) $ in Thousands	Total	Paid In Capital [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Treasury Stock [Member]	Maximum Cash Obligation Related To ESOP Shares [Member]
Beginning Balance at Dec. 31, 2015	$ 272,175	$ 43,697	$ 294,487	$ (1,195)	$ (27,252)	$ (37,562)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of 7,646 and 92,621 shares of common stock for 9 months ended September 30, 2016 and 2017, respectively	348	348
Issuance 3,482 and 4,483 shares of common stock under the employee stock purchase plan for 9 months ended September 30, 2016 and 2017, respectively	154	154
Unearned restricted stock compensation	112	112
Forfeiture of 1,264 and 2,934 shares of common stock for 9 months ended September 30, 2016 and 2017, respectively	(52)	(52)
Share-based compensation	22	22
Income tax benefit related to share-based compensation	64	64
Change related to ESOP shares	(2,220)					(2,220)
Net income	24,843		24,843
Cash dividends ($0.65 and $0.70 per share for 9 months ended September 30, 2016 and 2017, respectively)	(6,060)		(6,060)
Purchase of 62,266 and 40,265 shares of common stock for 9 months ended September 30, 2016 and 2017, respectively	(2,819)				(2,819)
Other comprehensive income (loss)	(512)			(512)
Ending Balance at Sep. 30, 2016	286,055	44,345	313,270	(1,707)	(30,071)	(39,782)
Beginning Balance at Dec. 31, 2016	289,270	44,606	319,982	(3,359)	(31,178)	(40,781)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of 7,646 and 92,621 shares of common stock for 9 months ended September 30, 2016 and 2017, respectively	4,263	4,208			55
Issuance 3,482 and 4,483 shares of common stock under the employee stock purchase plan for 9 months ended September 30, 2016 and 2017, respectively	210	210
Unearned restricted stock compensation	277	277
Forfeiture of 1,264 and 2,934 shares of common stock for 9 months ended September 30, 2016 and 2017, respectively	(118)	(118)
Share-based compensation	11	11
Change related to ESOP shares	(1,690)					(1,690)
Net income	23,883		23,883
Cash dividends ($0.65 and $0.70 per share for 9 months ended September 30, 2016 and 2017, respectively)	(6,485)		(6,485)
Purchase of 62,266 and 40,265 shares of common stock for 9 months ended September 30, 2016 and 2017, respectively	(2,075)				(2,075)
Other comprehensive income (loss)	2,020			2,020
Ending Balance at Sep. 30, 2017	$ 309,566	$ 49,194	$ 337,380	$ (1,339)	$ (33,198)	$ (42,471)

CONSOLIDATED STATEMENTS OF STO7

CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY (Unaudited) (Parenthetical) - $ / shares	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016
Statement of Stockholders' Equity [Abstract]
Issuance of common stock (in shares)	92,621	7,646
Issuance of common stock purchased under the employee stock purchase plan (in shares)	4,483	3,482
Forfeiture of common stock (in shares)	2,934	1,264
Cash dividends (in dollars per share)	$ 0.70	$ 0.65
Purchase of common stock (in shares)	40,265	62,266

CONSOLIDATED STATEMENTS OF CASH

CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016
Cash Flows from Operating Activities
Net income	$ 23,883	$ 24,843
Adjustments to reconcile net income to net cash and cash equivalents provided by operating activities:
Depreciation	2,270	2,182
Provision for loan losses	1,827	(2,004)
Share-based compensation	11	22
Forfeiture of common stock	(118)	(52)
Compensation expensed through issuance of common stock	208	348
Excess tax benefits from share-based compensation	0	(64)
Provision for deferred income taxes	(1,513)	54
Net gain on sale of other real estate owned and other repossessed assets	(89)	(376)
Increase in accrued interest receivable	(2,363)	(1,867)
Amortization of premium on investment securities, net	437	452
Decrease in other assets	1,049	650
Increase (decrease) in accrued interest payable and other liabilities	1,288	(92)
Loans originated for sale	(109,522)	(151,545)
Proceeds on sales of loans	113,730	150,047
Net gain on sales of loans	(1,119)	(1,437)
Net cash and cash equivalents provided by operating activities	29,979	21,161
Cash Flows from Investing Activities
Proceeds from maturities of investment securities available for sale	48,937	46,148
Purchases of investment securities available for sale	(37,735)	(31,456)
Loans made to customers, net of collections	(141,994)	(97,285)
Proceeds on sale of other real estate owned and other repossessed assets	364	764
Purchases of property and equipment	(2,210)	(4,180)
Income from tax credit real estate, net	547	545
Net cash and cash equivalents used in investing activities	(132,091)	(85,464)
Cash Flows from Financing Activities
Net increase in deposits	36,730	105,710
Net decrease in other borrowings	(19,728)	(4,148)
Net increase in FHLB borrowings	88,000
Net decrease in FHLB borrowings		(15,000)
Issuance of common stock, net of costs	3,762	0
Stock options exercised	238	0
Excess tax benefits related to share-based compensation	0	64
Issuance of treasury stock	55	0
Purchase of treasury stock	(2,075)	(2,819)
Proceeds from the issuance of common stock through the employee stock purchase plan	210	154
Dividends paid	(6,485)	(6,060)
Net cash and cash equivalents provided by financing activities	100,707	77,901
(Decrease) increase in cash and cash equivalents	(1,405)	13,598
Cash and cash equivalents:
Beginning of period	38,197	35,427
End of period	36,792	49,025
Cash payments for:
Interest paid to depositors	6,635	5,776
Interest paid on other obligations	6,087	6,351
Income taxes paid	10,530	10,201
Noncash activities:
Increase in maximum cash obligation related to ESOP shares	1,690	2,220
Transfers to other real estate owned	182	310
Sale and financing of other real estate owned	$ 262	$ 135

Summary of Significant Accounti

Summary of Significant Accounting Policies	9 Months Ended
	Sep. 30, 2017
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	Summary of Significant Accounting Policies Basis of Presentation: The accompanying unaudited consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America for interim financial reporting and with instructions for Form 10-Q and Regulation S-X. These financial statements include all adjustments (consisting of normal recurring accruals) which in the opinion of management are considered necessary for the fair presentation of the financial position and results of operations for the periods shown. Certain prior year amounts have been reclassified to conform to the current year presentation. The Company considers that it operates as one business segment, a commercial bank. Operating results for the nine month period ended September 30, 2017 are not necessarily indicative of the results that may be expected for the fiscal year ending December 31, 2017. For further information, refer to the consolidated financial statements and footnotes thereto included in the Form 10-K Annual Report of Hills Bancorporation and subsidiary (the “Company”) for the year ended December 31, 2016 filed with the Securities Exchange Commission on March 3, 2017 . The consolidated balance sheet as of December 31, 2016 , has been derived from the audited consolidated financial statements for that period. The Company evaluated subsequent events through the filing date of its quarterly report on Form 10-Q with the SEC. Effect of New Financial Accounting Standards: In May 2014, The FASB and International Accounting Standards Board (IASB) issued ASU No. 2014-09, Revenue from Contracts with Customers (Topic 606). The core principle of ASU 2014-09 is that a company should recognize revenue to depict the transfer of promised good or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods and services. For financial institutions, significant changes are not expected given that most financial instruments are not in the scope of the accounting standard update. ASU 2014-09 is effective for annual periods and interim periods within those annual periods beginning after December 15, 2016. In August 2015, FASB issued ASU 2015-14 deferring the effective date for annual periods and interim periods within those annual periods after December 15, 2017. Earlier application is permitted only as of annual reporting periods beginning after December 15, 2016, including interim reporting periods within that reporting period. The Company has evaluated all of its noninterest income streams and contracts to determine potential impact. The adoption of ASU 2014-09 by the Company will not have a material impact. In January 2016, the FASB issued ASU No. 2016-01, Financial Instruments - Overall (Subtopic 825-10), Recognition and Measurement of Financial Assets and Financial Liabilities. ASU 2016-01 created Subtopic 321-10, Investments-Equity Securities which is applicable to all entities except those in industries that account for substantially all investments at fair value through earnings or the change in net assets. Under this new subtopic, equity securities are generally required to be measured at fair value with unrealized holding gains and losses reflected in net income. ASU 2016-01 is effective for annual periods and interim periods within those annual periods beginning after December 15, 2017. The adoption of ASU 2016-01 by the Company is not expected to have a material impact. In February 2016, the FASB issued ASU No. 2016-02 (Topic 842), Leases . The ASU provides guidance requiring lessees to recognize right-of-use assets and lease liabilities for all leases other than those that meet the definition of short-term leases. For short-term leases, lessees may elect an accounting policy by class of underlying asset under which these assets and liabilities are not recognized and lease payments are generally recognized over the lease term on a straight-line basis. Under this new ASU, lessees will recognize right-of use assets and lease liabilities for most leases currently accounted for as operating leases under generally accepted accounting principles. For public companies, ASU 2016-02 is effective for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2018. The Company is in the process of analyzing a comprehensive list of lease agreements. The adoption of ASU 2016-02 by the Company is not expected to have a material impact. In March 2016, the FASB issued ASU No. 2016-04, Liabilities - Extinguishments of Liabilities (Subtopic 405-20), Recognition of Breakage for Certain Prepaid Stored-Value Products . ASU 2016-04 applies to all entities that offer certain prepaid stored - value products. The ASU provides guidance for the derecognition of financial liabilities related to the issuance of these products and aligns the recognition of breakage to current authoritative guidance. For public companies, ASU 2016-04 is effective for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2017. The adoption of ASU 2016-04 by the Company is not expected to have a material impact. In March 2016, the FASB issued ASU No. 2016-09, Compensation - Stock Compensation (Topic 718), Improvements to Employee Share-Based Payment Accounting . The ASU simplifies several aspects of the accounting for share-based payment transaction, including the income tax consequences, classification of awards as either equity or liabilities, and classification on the statement of cash flows. For public companies, ASU 2016-09 is effective for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2016. The Company adopted ASU 2016-09 for the period ending March 31, 2017. There was no material impact on the financial statements. In June 2016, the FASB issued ASU No. 2016-13, Financial Instruments - Credit Losses (Topic 326), Measurement of Credit Losses on Financial Instruments (CECL). The ASU changes the way entities recognize impairment of financial assets by requiring immediate recognition of estimated credit losses expected to occur over the remaining life of many financial assets. Under the CECL model, we will be required to present certain financial assets carried at amortized cost, such as loans held for investment and held-to-maturity debt securities, at the net amount expected to be collected. The measurement of expected credit losses is to be based on information about past events, including historical experience, current conditions, and reasonable and supportable forecasts that affect the collectability of the reported amount. This measurement will take place at the time the financial asset is first added to the balance sheet and periodically thereafter. This differs significantly from the "incurred loss" model required under current GAAP, which delays recognition until it is probable a loss has been incurred. Accordingly, we expect that the adoption of the CECL model will materially affect how we determine our allowance for loan losses and could require us to significantly increase our allowance. For public companies, ASU 2016-13 is effective for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2019, early adoption is permitted for the fiscal year beginning after December 15, 2018. The Company is in the process of implementing a software solution to assist in the analysis of historical loan data to determine the CECL model that will be implemented. We expect to recognize a one-time cumulative-effect adjustment to our allowance for loan losses as of the beginning of the first reporting period in which the new standard is adopted. The amount of the one-time cumulative-effect adjustment has not yet been determined. In January 2017, the FASB issued ASU No. 2017-03, Accounting Changes and Error Corrections (Topic 250) and Investments - Equity Method and Joint Ventures (Topic 323), Amendments to SEC Paragraphs Pursuant to Staff Announcements at the September 22, 2016 and November 17, 2016 EITF Meetings. This ASU adds an SEC paragraph and amends other Topics pursuant to an SEC staff Announcement made at the September 22, 2016 Emerging Issues Task Force (EITF) meeting. The SEC paragraph applies to ASU No. 2014-09, Revenue from Contracts with Customers (Topic 606); ASU No. 2016-02, Leases (Topic 842); and ASU No. 2016-13, Financial Instruments - Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments. The ASU provides that a company should evaluate ASUs that have not yet been adopted to determine the appropriate financial statement disclosures about the potential material effects of those ASUs on the financial statements when adopted. If the company does not know or cannot reasonably estimate the impact that adoption of the ASUs referenced in this announcement is expected to have on the financial statements, then in addition to making a statement to that effect, the company should consider additional qualitative financial statement disclosures to assist the reader in assessing the significance of the impact that the standard will have on the financial statements of the company when adopted. Additional qualitative disclosures should include a description of the effect of the accounting policies that the company expects to apply and a comparison to the company's current accounting policies. Also, the company should describe the status of its process to implement the new standards and the significant implementation matters yet to be addressed. In January 2017, the FASB issued ASU No. 2017-04, Intangibles - Goodwill and Other (Topic 250), Simplifying the Test for Goodwill Impairment. The ASU simplifies the goodwill impairment test by requiring a company to perform its annual or interim, goodwill impairment test by comparing the fair value of a reporting unit with its carrying amount. An impairment charge should be recognized when the carrying amount exceeds fair value. For public companies, ASU 2017-04 is effective for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2019. The adoption of ASU No. 2017-04 by the Company is not expected to have a material impact. In March 2017, the FASB issued ASU No. 2017-08, Receivable - Nonrefundable Fees and Other Costs (Subtopic 310-20), Premium Amortization on Purchased Callable Debt Securities. This ASU shortens the amortization period for certain callable debt securities held at a premium. The premium will be amortized to the earliest call date. For public companies, ASU 2017-08 is effective for fiscal years, and interim periods within those fiscal years beginning after December 15, 2018. The Company adopted ASU 2017-08 for the period ending March 31, 2017. There was no material impact on the financial statements. In August 2017, the FASB issued ASU No. 2017-12, Derivatives and Hedging (Topic 815), Targeted Improvements to Accounting for Hedging Activities. This ASU requires companies to change the recognition and presentation of the effects of hedge accounting by eliminating the requirement to separately measure and report hedge ineffectiveness and requiring companies to present all of the elements of hedge accounting that affect earnings in the same income statement line as the hedged item. Furthermore, the standard eases the requirements for effectiveness testing, hedge documentation and applying the critical terms match method and introduces new alternatives that will permit companies to reduce the risk of material error corrections if they misapply the shortcut method. For public companies, ASU 2017-12 is effective for fiscal years, and interim periods within those fiscal years beginning after December 15, 2018. The adoption of ASU 2017-12 by the Company is not expected to have a material impact.

Earnings Per Share

Earnings Per Share	9 Months Ended
	Sep. 30, 2017
Earnings Per Share [Abstract]
Earnings Per Share	Earnings Per Share Basic earnings per share is computed using the weighted average number of actual common shares outstanding during the period. Diluted earnings per share reflects the potential dilution that would occur from the exercise of common stock options outstanding. ESOP shares are considered outstanding for this calculation unless unearned. The computation of basic and diluted earnings per share for the periods presented is as follows: Three Months Ended September 30, Nine Months Ended September 30, 2017 2016 2017 2016 Common shares outstanding at the beginning of the period 9,329,514 9,283,341 9,264,227 9,322,054 Weighted average number of net shares (redeemed) issued (4,596 ) (7,633 ) 64,144 (31,950 ) Weighted average shares outstanding (basic) 9,324,918 9,275,708 9,328,371 9,290,104 Weighted average of potential dilutive shares attributable to stock options granted, computed under the treasury stock method 3,559 6,584 4,874 6,357 Weighted average number of shares (diluted) 9,328,477 9,282,292 9,333,245 9,296,461 Net income (In thousands) $ 8,552 $ 9,176 $ 23,883 $ 24,843 Earnings per share: Basic $ 0.92 $ 0.99 $ 2.56 $ 2.67 Diluted $ 0.92 $ 0.99 $ 2.56 $ 2.67

Other Comprehensive Income (Los

Other Comprehensive Income (Loss)	9 Months Ended
	Sep. 30, 2017
Equity [Abstract]
Other Comprehensive Income (Loss)	Other Comprehensive Income (Loss) The following table summarizes the balances of each component of accumulated other comprehensive income (AOCI), included in stockholders’ equity, at September 30, 2017 and December 31, 2016 : September 30, December 31, 2016 (amounts in thousands) Net unrealized gain (loss) on available-for-sale securities $ 1,295 $ (1,502 ) Net unrealized loss on derivatives used for cash flow hedges (3,464 ) (3,938 ) Tax effect $ 830 $ 2,081 Net-of-tax amount $ (1,339 ) $ (3,359 )

Securities

Securities	9 Months Ended
	Sep. 30, 2017
Investments, Debt and Equity Securities [Abstract]
Securities	Securities The carrying values of investment securities at September 30, 2017 and December 31, 2016 are summarized in the following table (dollars in thousands): September 30, 2017 December 31, 2016 Amount Percent Amount Percent Securities available for sale U.S. Treasury $ 39,894 15.65 % $ 27,482 10.27 % Other securities (FHLB, FHLMC and FNMA) 48,759 19.12 61,660 23.05 State and political subdivisions 166,331 65.23 178,395 66.68 Total securities available for sale $ 254,984 100.00 % $ 267,537 100.00 % Investment securities have been classified in the consolidated balance sheets according to management’s intent. Available-for-sale securities consist of debt securities not classified as trading or held to maturity. Available-for-sale securities are stated at fair value, and unrealized holding gains and losses, net of the related deferred tax effect, are reported as a separate component of stockholders' equity. There were no trading or held to maturity securities as of September 30, 2017 or December 31, 2016 . The carrying amount of available-for-sale securities and their approximate fair values were as follows as of September 30, 2017 and December 31, 2016 (in thousands): Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Estimated Fair Value September 30, 2017: U.S. Treasury $ 39,823 $ 90 $ (19 ) $ 39,894 Other securities (FHLB, FHLMC and FNMA) 48,992 11 (244 ) 48,759 State and political subdivisions 164,874 1,721 (264 ) 166,331 Total $ 253,689 $ 1,822 $ (527 ) $ 254,984 December 31, 2016: U.S. Treasury $ 27,418 $ 82 $ (18 ) $ 27,482 Other securities (FHLB, FHLMC and FNMA) 62,047 65 (452 ) 61,660 State and political subdivisions 179,574 626 (1,805 ) 178,395 Total $ 269,039 $ 773 $ (2,275 ) $ 267,537 The amortized cost and estimated fair value of available-for-sale securities classified according to their contractual maturities at September 30, 2017 , were as follows (in thousands): Amortized Cost Fair Value Due in one year or less $ 42,320 $ 42,423 Due after one year through five years 138,727 139,316 Due after five years through ten years 72,022 72,625 Due over ten years 620 620 Total $ 253,689 $ 254,984 As of September 30, 2017 investment securities with a carrying value of $30.46 million were pledged to collateralize repurchase agreements, derivative financial instruments, and other borrowings. The following table shows the fair value, gross unrealized losses and the percentage of fair value represented by gross unrealized losses of applicable investment securities owned by the Company, aggregated by investment category and length of time that individual securities have been in a continuous unrealized loss position at September 30, 2017 and December 31, 2016 (in thousands): Less than 12 months 12 months or more Total September 30, 2017 # Fair Value Unrealized Loss % # Fair Value Unrealized Loss % # Fair Value Unrealized Loss % U.S. Treasury 4 $ 10,006 $ (19 ) 0.19 % — $ — $ — — % 4 $ 10,006 $ (19 ) 0.19 % Other securities (FHLB, FHLMC and FNMA) 11 26,539 (81 ) 0.31 4 10,208 (163 ) 1.60 15 36,747 (244 ) 0.66 State and political subdivisions 45 11,566 (66 ) 0.57 65 15,212 (198 ) 1.30 110 26,778 (264 ) 0.99 Total temporarily impaired securities 60 $ 48,111 $ (166 ) 0.35 % 69 $ 25,420 $ (361 ) 1.42 % 129 $ 73,531 $ (527 ) 0.72 % Less than 12 months 12 months or more Total December 31, 2016 # Fair Value Unrealized Loss % # Fair Value Unrealized Loss % # Fair Value Unrealized Loss % U.S. Treasury 2 $ 4,957 $ (18 ) 0.36 % — $ — $ — — % 2 $ 4,957 $ (18 ) 0.36 % Other securities (FHLB, FHLMC and FNMA) 14 34,648 (452 ) 1.30 — — — — 14 34,648 (452 ) 1.30 State and political subdivisions 365 87,841 (1,762 ) 2.01 11 1,486 (43 ) 2.89 376 89,327 (1,805 ) 2.02 Total temporarily impaired securities 381 $ 127,446 $ (2,232 ) 1.75 % 11 $ 1,486 $ (43 ) 2.89 % 392 $ 128,932 $ (2,275 ) 1.76 % The Company considered the following information in reaching the conclusion that the impairments disclosed in the table above are temporary and not other-than-temporary impairments. None of the unrealized losses in the above table was due to the deterioration in the credit quality of any of the issues that might result in the non-collection of contractual principal and interest. The unrealized losses are due to changes in interest rates. The Company has not recognized any unrealized loss in income because management does not have the intent to sell the securities included in the previous table. Management has concluded that it is more likely than not that the Company will not be required to sell these securities prior to recovery of the amortized cost basis.

Loans

Loans	9 Months Ended
	Sep. 30, 2017
Receivables [Abstract]
Loans	Loans Classes of loans are as follows: September 30, December 31, (Amounts In Thousands) Agricultural $ 76,484 $ 92,871 Commercial and financial 214,199 192,995 Real estate: Construction, 1 to 4 family residential 73,404 57,864 Construction, land development and commercial 107,170 121,561 Mortgage, farmland 208,982 202,340 Mortgage, 1 to 4 family first liens 823,529 767,469 Mortgage, 1 to 4 family junior liens 137,271 125,400 Mortgage, multi-family 335,439 302,831 Mortgage, commercial 359,332 334,198 Loans to individuals 26,223 25,157 Obligations of state and political subdivisions 57,861 54,462 $ 2,419,894 $ 2,277,148 Net unamortized fees and costs 886 827 $ 2,420,780 $ 2,277,975 Less allowance for loan losses 29,350 26,530 $ 2,391,430 $ 2,251,445 Changes in the allowance for loan losses, the allowance for loan losses applicable to impaired loans and the related loan balance of impaired loans for the three and nine months ended September 30, 2017 were as follows: Three Months Ended September 30, 2017 Agricultural Commercial and Real Estate: Real Estate: Real Estate: Real Estate: Other Total (Amounts In Thousands) Allowance for loan losses: Beginning balance $ 2,341 $ 4,586 $ 3,165 $ 4,009 $ 8,340 $ 5,414 $ 1,095 $ 28,950 Charge-offs (27 ) (21 ) — (3 ) (55 ) (86 ) (113 ) (305 ) Recoveries 56 219 33 — 203 7 57 575 Provision 92 (43 ) (182 ) 2 98 107 56 130 Ending balance $ 2,462 $ 4,741 $ 3,016 $ 4,008 $ 8,586 $ 5,442 $ 1,095 $ 29,350 Nine Months Ended September 30, 2017 Agricultural Commercial and Real Estate: Real Estate: Real Estate: Real Estate: Other Total (Amounts In Thousands) Allowance for loan losses: Beginning balance $ 2,947 $ 4,531 $ 2,890 $ 3,417 $ 7,677 $ 4,045 $ 1,023 $ 26,530 Charge-offs (66 ) (478 ) (114 ) (3 ) (263 ) (130 ) (410 ) (1,464 ) Recoveries 123 882 443 — 570 236 203 2,457 Provision (542 ) (194 ) (203 ) 594 602 1,291 279 1,827 Ending balance $ 2,462 $ 4,741 $ 3,016 $ 4,008 $ 8,586 $ 5,442 $ 1,095 $ 29,350 Ending balance, individually evaluated for impairment $ 653 $ 913 $ 46 $ 784 $ 110 $ 409 $ 85 $ 3,000 Ending balance, collectively evaluated for impairment $ 1,809 $ 3,828 $ 2,970 $ 3,224 $ 8,476 $ 5,033 $ 1,010 $ 26,350 Loans: Ending balance $ 76,484 $ 214,199 $ 180,574 $ 208,982 $ 960,800 $ 694,771 $ 84,084 $ 2,419,894 Ending balance, individually evaluated for impairment $ 6,181 $ 2,985 $ 1,161 $ 8,179 $ 7,097 $ 8,097 $ 85 $ 33,785 Ending balance, collectively evaluated for impairment $ 70,303 $ 211,214 $ 179,413 $ 200,803 $ 953,703 $ 686,674 $ 83,999 $ 2,386,109 Changes in the allowance for loan losses for the three and nine months ended September 30, 2016 were as follows: Three Months Ended September 30, 2016 Agricultural Commercial and Real Estate: Real Estate: Real Estate: Real Estate: Other Total (Amounts In Thousands) Allowance for loan losses: Beginning balance $ 2,997 $ 4,011 $ 2,898 $ 3,927 $ 8,226 $ 4,201 $ 1,030 $ 27,290 Charge-offs (19 ) (38 ) — (105 ) (176 ) — (140 ) (478 ) Recoveries — 289 186 — 276 358 51 1,160 Provision 201 (252 ) (75 ) (204 ) (425 ) (589 ) (86 ) (1,832 ) Ending balance $ 2,777 $ 4,010 $ 3,009 $ 3,618 $ 7,901 $ 3,970 $ 855 $ 26,140 Nine Months Ended September 30, 2016 Agricultural Commercial and Real Estate: Real Estate: Real Estate: Real Estate: Other Total (Amounts In Thousands) Allowance for loan losses: Beginning balance $ 3,082 $ 4,517 $ 2,280 $ 3,342 $ 8,172 $ 4,223 $ 894 $ 26,510 Charge-offs (44 ) (172 ) — (116 ) (704 ) (66 ) (416 ) (1,518 ) Recoveries 173 910 792 — 767 379 132 3,153 Provision (434 ) (1,245 ) (63 ) 392 (334 ) (566 ) 246 (2,004 ) Ending balance $ 2,777 $ 4,010 $ 3,009 $ 3,618 $ 7,901 $ 3,970 $ 855 $ 26,140 Ending balance, individually evaluated for impairment $ 746 $ 221 $ 223 $ 549 $ 283 $ 62 $ 29 $ 2,113 Ending balance, collectively evaluated for impairment $ 2,031 $ 3,789 $ 2,786 $ 3,069 $ 7,618 $ 3,908 $ 826 $ 24,027 Loans: Ending balance $ 88,104 $ 188,365 $ 178,820 $ 193,819 $ 883,693 $ 619,214 $ 74,917 $ 2,226,932 Ending balance, individually evaluated for impairment $ 12,276 $ 2,529 $ 2,877 $ 8,371 $ 6,497 $ 3,356 $ 29 $ 35,935 Ending balance, collectively evaluated for impairment $ 75,828 $ 185,836 $ 175,943 $ 185,448 $ 877,196 $ 615,858 $ 74,888 $ 2,190,997 The following table presents the credit quality indicators by type of loans in each category as of September 30, 2017 and December 31, 2016 , respectively (amounts in thousands): Agricultural Commercial and Financial Real Estate: Construction, 1 to 4 family residential Real Estate: Construction, land development and commercial September 30, 2017 Grade: Excellent $ 2,502 $ 10,234 $ 548 $ 2,950 Good 12,073 47,103 6,773 26,216 Satisfactory 37,109 117,612 49,639 41,317 Monitor 14,622 28,619 15,248 33,226 Special Mention 4,653 5,410 897 2,607 Substandard 5,525 5,221 299 854 Total $ 76,484 $ 214,199 $ 73,404 $ 107,170 Real Estate: Mortgage, farmland Real Estate: Mortgage, 1 to 4 family first liens Real Estate: Mortgage, 1 to 4 family junior liens Real Estate: Mortgage, multi- family September 30, 2017 Grade: Excellent $ 5,102 $ 2,064 $ 494 $ 5,712 Good 52,634 29,490 3,569 82,368 Satisfactory 105,155 681,699 124,625 188,549 Monitor 34,985 77,461 4,869 52,341 Special Mention 2,434 11,136 1,328 — Substandard 8,672 21,679 2,386 6,469 Total $ 208,982 $ 823,529 $ 137,271 $ 335,439 Real Estate: Mortgage, commercial Loans to individuals Obligations of state and political subdivisions Total September 30, 2017 Grade: Excellent $ 18,735 $ — $ 8,961 $ 57,302 Good 103,662 476 29,137 393,501 Satisfactory 183,140 24,962 16,186 1,569,993 Monitor 44,316 349 3,577 309,613 Special Mention 7,037 216 — 35,718 Substandard 2,442 220 — 53,767 Total $ 359,332 $ 26,223 $ 57,861 $ 2,419,894 Agricultural Commercial and Financial Real Estate: Construction, 1 to 4 family residential Real Estate: Construction, land development and commercial December 31, 2016 Grade: Excellent $ 4,205 $ 4,241 $ — $ 244 Good 13,611 43,472 1,701 25,337 Satisfactory 40,008 108,800 44,138 46,758 Monitor 12,699 20,023 8,896 44,487 Special Mention 8,381 11,177 972 4,250 Substandard 13,967 5,282 2,157 485 Total $ 92,871 $ 192,995 $ 57,864 $ 121,561 Real Estate: Mortgage, farmland Real Estate: Mortgage, 1 to 4 family first liens Real Estate: Mortgage, 1 to 4 family junior liens Real Estate: Mortgage, multi- family December 31, 2016 Grade: Excellent $ 2,916 $ 1,196 $ 65 $ 5,970 Good 47,569 15,725 3,002 71,822 Satisfactory 105,971 647,191 113,433 180,651 Monitor 29,778 66,164 4,877 40,444 Special Mention 7,004 12,914 1,566 3,636 Substandard 9,102 24,279 2,457 308 Total $ 202,340 $ 767,469 $ 125,400 $ 302,831 Real Estate: Mortgage, commercial Loans to individuals Obligations of state and political subdivisions Total December 31, 2016 Grade: Excellent $ 15,873 $ — $ — $ 34,710 Good 89,801 65 37,539 349,644 Satisfactory 185,650 24,446 16,417 1,513,463 Monitor 34,979 293 506 263,146 Special Mention 3,797 195 — 53,892 Substandard 4,098 158 — 62,293 Total $ 334,198 $ 25,157 $ 54,462 $ 2,277,148 The below are descriptions of the credit quality indicators: Excellent – Excellent rated loans are prime quality loans covered by highly liquid collateral with generous margins or supported by superior current financial conditions reflecting substantial net worth, relative to total credit extended, and based on assets of a stable and non-speculative nature whose values can be readily verified. Identified repayment source or cash flow is abundant and assured. Good – Good rated loans are adequately secured by readily marketable collateral or good financial condition characterized by liquidity, flexibility and sound net worth. Loans are supported by sound primary and secondary payment sources and timely and accurate financial information. Satisfactory – Satisfactory rated loans are loans to borrowers of average financial means not especially vulnerable to changes in economic or other circumstances, where the major support for the extension is sufficient collateral of a marketable nature, and the primary source of repayment is seen to be clear and adequate. Monitor – Monitor rated loans are identified by management as warranting special attention for a variety of reasons that may bear on ultimate collectability. This may be due to adverse trends, a particular industry, loan structure, or repayment that is dependent on projections, or a one-time occurrence. Special Mention – Special mention rated loans are supported by a marginal payment capacity and are marginally protected by collateral. There are identified weaknesses that if not monitored and corrected may adversely affect the Company’s credit position. A special mention credit would typically have a weakness in one of the general categories (cash flow, collateral position or payment history) but not in all categories. Substandard – Substandard loans are not adequately supported by the paying capacity of the borrower and may be inadequately collateralized. These loans have a well-defined weakness or weaknesses. For these loans, it is more probable than not that the Company could sustain some loss if the deficiency(ies) is not corrected. Past due loans as of September 30, 2017 and December 31, 2016 were as follows: 30 - 59 Days Past Due 60 - 89 Days Past Due 90 Days or More Past Due Total Past Due Current Total Loans Receivable Accruing Loans Past Due 90 Days or More (Amounts In Thousands) September 30, 2017 Agricultural $ 3 $ 23 $ 1,367 $ 1,393 $ 75,091 $ 76,484 $ 1,121 Commercial and financial 380 262 264 906 213,293 214,199 200 Real estate: Construction, 1 to 4 family residential — 22 — 22 73,382 73,404 — Construction, land development and commercial 3,320 — — 3,320 103,850 107,170 — Mortgage, farmland — 1,355 83 1,438 207,544 208,982 — Mortgage, 1 to 4 family first liens 733 1,578 2,235 4,546 818,983 823,529 412 Mortgage, 1 to 4 family junior liens 201 137 62 400 136,871 137,271 58 Mortgage, multi-family — — — — 335,439 335,439 — Mortgage, commercial 142 — 16 158 359,174 359,332 — Loans to individuals 38 67 — 105 26,118 26,223 — Obligations of state and political subdivisions — — — — 57,861 57,861 — $ 4,817 $ 3,444 $ 4,027 $ 12,288 $ 2,407,606 $ 2,419,894 $ 1,791 December 31, 2016 Agricultural $ 56 $ — $ 302 $ 358 $ 92,513 $ 92,871 $ — Commercial and financial 24 121 718 863 192,132 192,995 — Real estate: Construction, 1 to 4 family residential — — — — 57,864 57,864 — Construction, land development and commercial — 231 85 316 $ 121,245 121,561 — Mortgage, farmland 319 — — 319 202,021 202,340 — Mortgage, 1 to 4 family first liens 5,649 978 1,943 8,570 $ 758,899 767,469 192 Mortgage, 1 to 4 family junior liens 330 51 579 960 124,440 125,400 443 Mortgage, multi-family — — 40 40 $ 302,791 302,831 — Mortgage, commercial 371 — 207 578 333,620 334,198 — Loans to individuals 203 32 — 235 $ 24,922 25,157 — Obligations of state and political subdivisions — — — — 54,462 54,462 — $ 6,952 $ 1,413 $ 3,874 $ 12,239 $ 2,264,909 $ 2,277,148 $ 635 The Company does not have a material amount of loans that are past due less than 90 days where there are serious doubts as to the ability of the borrowers to comply with the loan repayment terms. Certain impaired loan information by loan type at September 30, 2017 and December 31, 2016 , was as follows: September 30, 2017 December 31, 2016 Non-accrual loans (1) Accruing loans past due 90 days or more TDR loans Non- accrual loans (1) Accruing loans past due 90 days or more TDR loans (Amounts In Thousands) (Amounts In Thousands) Agricultural $ 1,656 $ 1,121 $ 2,446 $ 1,741 $ — $ 91 Commercial and financial 947 200 1,839 1,354 — 1,057 Real estate: Construction, 1 to 4 family residential — — — — — 265 Construction, land development and commercial — — 341 85 — 118 Mortgage, farmland 1,454 — 1,462 1,205 — 1,389 Mortgage, 1 to 4 family first liens 4,415 412 1,399 4,097 192 1,375 Mortgage, 1 to 4 family junior liens 12 58 26 136 443 26 Mortgage, multi-family 223 — — 243 — — Mortgage, commercial 630 — 1,057 1,077 — 1,087 $ 9,337 $ 1,791 $ 8,570 $ 9,938 $ 635 $ 5,408 (1) There were $3.76 million and $4.23 million of TDR loans included within nonaccrual loans as of September 30, 2017 and December 31, 2016 , respectively. Loans 90 days or more past due that are still accruing interest increased $1.16 million from December 31, 2016 to September 30, 2017 due to an increase in the number of loans past due greater than 90 days including a $1.12 agricultural relationship. As of September 30, 2017 there were 10 accruing loans past due 90 days or more. The average balance of accruing loans past due as of September 30, 2017 are $0.18 million . There were 6 accruing loans past due 90 days or more as of December 31, 2016 and the average loan balance was $0.11 million . The accruing loans past due 90 days or more balances are believed to be adequately collateralized and the Company expects to collect all principal and interest as contractually due under these loans. The Company may modify the terms of a loan to maximize the collection of amounts due. Such a modification is considered a troubled debt restructuring (“TDR”). In most cases, the modification is either a reduction in interest rate, conversion to interest only payments or an extension of the maturity date. The borrower is experiencing financial difficulties or is expected to experience difficulties in the near-term, so a concessionary modification is granted to the borrower that would otherwise not be considered. TDR loans accrue interest as long as the borrower complies with the revised terms and conditions and has demonstrated repayment performance at a level commensurate with the modified terms over several payment cycles. Below is a summary of information for TDR loans as of September 30, 2017 and December 31, 2016 : September 30, 2017 December 31, 2016 Number of contracts Recorded investment Commitments outstanding Number of contracts Recorded investment Commitments outstanding (Amounts In Thousands) (Amounts In Thousands) Agricultural 9 $ 3,762 $ 267 4 $ 1,460 $ 167 Commercial and financial 15 2,526 157 14 2,053 117 Real estate: Construction, 1 to 4 family residential — — 193 3 265 1,225 Construction, land development and commercial 2 341 721 1 118 107 Mortgage, farmland 7 2,834 — 7 2,594 — Mortgage, 1 to 4 family first liens 13 1,486 — 12 1,471 — Mortgage, 1 to 4 family junior liens 1 26 54 1 26 65 Mortgage, multi-family — — — — — — Mortgage, commercial 8 1,355 — 10 1,650 — Loans to individuals — — — — — — 55 $ 12,330 $ 1,392 52 $ 9,637 $ 1,681 The following is a summary of TDR loans that were modified during the three and nine months ended September 30, 2017 : Three Months Ended September 30, 2017 Nine Months Ended September 30, 2017 Number of contracts Pre-modification recorded investment Post-modification recorded investment Number Pre-modification Post-modification (Amounts In Thousands) (Amounts In Thousands) Agricultural — $ — $ — 6 $ 10,890 $ 10,890 Commercial and financial 3 1,451 1,451 4 1,546 1,546 Real estate: Construction, 1 to 4 family residential — — — — — — Construction, land development and commercial — — — 1 231 231 Mortgage, farmland — — — 2 598 598 Mortgage, 1 to 4 family first lien 1 106 106 1 106 106 Mortgage, 1 to 4 family junior liens — — — — — — Mortgage, multi-family — — — 1 249 249 Mortgage, commercial — — — — — — 4 $ 1,557 $ 1,557 15 $ 13,620 $ 13,620 The Company had commitments to lend $1.39 million in additional borrowings to restructured loan customers as of September 30, 2017 . The Company had commitments to lend $1.68 million in additional borrowings to restructured loan customers as of December 31, 2016 . These commitments were in the normal course of business. The additional borrowings were not used to facilitate payments on these loans. There were no TDR loans that were in payment default (defined as past due 90 days or more) during the period ended September 30, 2017 and year ended December 31, 2016 . Information regarding impaired loans as of and for the three and nine months ended September 30, 2017 is as follows: September 30, 2017 Three Months Ended Nine Months Ended Recorded Investment Unpaid Principal Balance Related Allowance Average Recorded Interest Income Average Recorded Interest Income With no related allowance recorded: (Amounts In Thousands) Agricultural $ 1,739 $ 1,981 $ — $ 1,778 $ 3 $ 1,767 $ 1 Commercial and financial 1,333 2,047 — 1,598 17 1,375 5 Real estate: Construction, 1 to 4 family residential 116 151 — 116 4 116 1 Construction, land development and commercial 341 374 — 345 10 342 3 Mortgage, farmland 2,598 2,925 — 2,513 42 2,603 14 Mortgage, 1 to 4 family first liens 5,268 6,640 — 5,434 37 5,336 13 Mortgage, 1 to 4 family junior liens 12 485 — 25 — 13 — Mortgage, multi-family 223 357 — 233 — 226 — Mortgage, commercial 1,607 2,300 — 1,727 34 1,670 11 Loans to individuals — 14 — — — — — $ 13,237 $ 17,274 $ — $ 13,769 $ 147 $ 13,448 $ 48 With an allowance recorded: Agricultural $ 4,442 $ 4,503 $ 653 $ 4,897 $ 169 $ 4,491 $ 53 Commercial and financial 1,652 1,698 913 1,732 62 1,743 21 Real estate: Construction, 1 to 4 family residential 199 199 13 136 5 180 2 Construction, land development and commercial 505 505 33 321 11 354 4 Mortgage, farmland 5,581 5,581 784 5,667 183 5,584 61 Mortgage, 1 to 4 family first liens 1,734 1,861 106 1,761 54 1,743 17 Mortgage, 1 to 4 family junior liens 83 83 4 86 3 83 1 Mortgage, multi-family 6,187 6,187 407 6,251 210 6,228 71 Mortgage, commercial 80 80 2 81 3 80 1 Loans to individuals 85 85 85 88 7 90 3 $ 20,548 $ 20,782 $ 3,000 $ 21,020 $ 707 $ 20,576 $ 234 Total: Agricultural $ 6,181 $ 6,484 $ 653 $ 6,675 $ 172 $ 6,258 $ 54 Commercial and financial 2,985 3,745 913 3,330 79 3,118 26 Real estate: Construction, 1 to 4 family residential 315 350 13 252 9 296 3 Construction, land development and commercial 846 879 33 666 21 696 7 Mortgage, farmland 8,179 8,506 784 8,180 225 8,187 75 Mortgage, 1 to 4 family first liens 7,002 8,501 106 7,195 91 7,079 30 Mortgage, 1 to 4 family junior liens 95 568 4 111 3 96 1 Mortgage, multi-family 6,410 6,544 407 6,484 210 6,454 71 Mortgage, commercial 1,687 2,380 2 1,808 37 1,750 12 Loans to individuals 85 99 85 88 7 90 3 $ 33,785 $ 38,056 $ 3,000 $ 34,789 $ 854 $ 34,024 $ 282 Information regarding impaired loans as of December 31, 2016 is as follows: Recorded Investment Unpaid Principal Balance Related Allowance With no related allowance recorded: (Amounts In Thousands) Agricultural $ 800 $ 971 $ — Commercial and financial 1,540 2,175 — Real estate: Construction, 1 to 4 family residential 117 151 — Construction, land development and commercial 204 290 — Mortgage, farmland 2,594 2,887 — Mortgage, 1 to 4 family first liens 5,011 6,137 — Mortgage, 1 to 4 family junior liens 153 646 — Mortgage, multi-family 243 362 — Mortgage, commercial 1,901 2,727 — Loans to individuals — 19 — $ 12,563 $ 16,365 $ — With an allowance recorded: Agricultural $ 10,920 $ 10,978 $ 856 Commercial and financial 937 955 718 Real estate: Construction, 1 to 4 family residential 815 815 105 Construction, land development and commercial — — — Mortgage, farmland 5,434 5,434 390 Mortgage, 1 to 4 family first liens 1,266 1,374 79 Mortgage, 1 to 4 family junior liens 612 667 11 Mortgage, multi-family — — — Mortgage, commercial 967 1,004 34 Loans to individuals 150 150 150 $ 21,101 $ 21,377 $ 2,343 Total: Agricultural $ 11,720 $ 11,949 $ 856 Commercial and financial 2,477 3,130 718 Real estate: Construction, 1 to 4 family residential 932 966 105 Construction, land development and commercial 204 290 — Mortgage, farmland 8,028 8,321 390 Mortgage, 1 to 4 family first liens 6,277 7,511 79 Mortgage, 1 to 4 family junior liens 765 1,313 11 Mortgage, multi-family 243 362 — Mortgage, commercial 2,868 3,731 34 Loans to individuals 150 169 150 $ 33,664 $ 37,742 $ 2,343 Impaired loans increased $0.12 million from December 31, 2016 to September 30, 2017 . Impaired loans include any loan that has been placed on nonaccrual status, accruing loans past due 90 days or more and TDR loans. Impaired loans also include loans that, based on management’s evaluation of current information and events, the Company expects to be unable to collect in full according to the contractual terms of the original loan agreement. Impaired loans were 1.40% of loans held for investment as of September 30, 2017 and 1.48% as of December 31, 2016 . The increase in impaired loans is due mainly to an increase in TDR loans of $3.16 million and an increase in accruing loans past due 90 days or more of $1.16 million from December 31, 2016 to September 30, 2017 , and is offset by a decrease in nonaccrual loans of $0.60 million , and a decrease of $3.60 million in relationships with a specific allowance for losses. The Company regularly reviews a substantial portion of the loans in the portfolio and assesses whether the loans are impaired in accordance with ASC 310. If the loans are impaired, the Company determines if a specific allowance is appropriate. In addition, the Company's management also reviews and, where determined necessary, provides allowances for particular loans based upon (1) reviews of specific borrowers and (2) management’s assessment of areas that management considers are of higher credit risk, including loans that have been restructured. Loans that are determined not to be impaired and for which there are no specific allowances are classified into one or more risk categories. Based upon the risk category assigned, the Company allocates a percentage, as determined by management, for a required allowance needed. The determination of the appropriate percentage begins with historical loss experience factors, which are then adjusted for levels and trends in past due loans, levels and trends in charged-off and recovered loans, trends in volume growth, trends in problem and watch loans, trends in restructured loans, local economic trends and conditions, industry and other conditions, and effects of changing interest rates. Specific allowances for losses on impaired loans are established if the loan balances exceed the net present value of the relevant future cash flows or the fair value of the relevant collateral based on updated appraisals and/or updated collateral analysis for the properties if the loan is collateral dependent. The Company may recognize a charge off or record a specific allowance related to an impaired loan if there is a collateral shortfall or it is unlikely the borrower can make all principal and interest payments as contractually due. For loans that are collateral dependent, losses are evaluated based on the portion of a loan that exceeds the fair market value of the collateral. In general, this is the amount that the carrying value of the loan exceeds the related appraised value less estimated costs to sell the collateral. Generally, it is the Company’s policy not to rely on appraisals that are older than one year prior to the date the impairment is being measured. The most recent appraisal values may be adjusted if, in the Company’s judgment, experience and other market data indicate that the property’s value, use, condition, exit market or other variable affecting its value may have changed since the appraisal was performed, consistent with the December 2006 joint interagency guidance on the allowance for loan losses. The charge off or loss adjustment supported by an appraisal is considered the minimum charge off. Any adjustments made to the appraised value are to provide an additional charge off or specific reserve based on the applicable facts and circumstances. In instances where there is an estimated decline in value, a specific reserve may be provided or a charge off taken pending confirmation of the amount of the loss from an updated appraisal. Upon receipt of the new appraisals, an additional specific reserve may be provided or charge off taken based on the appraised value of the collateral. On average, appraisals are obtained within one month of order.

Fair Value Measurements

Fair Value Measurements	9 Months Ended
	Sep. 30, 2017
Fair Value Disclosures [Abstract]
Fair Value Measurements	Fair Value Measurements The carrying value and estimated fair values of the Company's financial instruments as of September 30, 2017 are as follows: September 30, 2017 Carrying Amount Estimated Fair Value Readily Available Market Prices(1) Observable Market Prices(2) Company Determined Market Prices(3) (Amounts In Thousands) Financial instrument assets: Cash and cash equivalents $ 36,792 $ 36,792 $ 36,792 $ — $ — Investment securities 271,110 271,110 — 271,110 — Loans held for sale 6,717 6,717 — 6,717 — Loans Agricultural 74,022 73,954 — — 73,954 Commercial and financial 209,458 209,387 — — 209,387 Real estate: Construction, 1 to 4 family residential 72,141 72,151 — — 72,151 Construction, land development and commercial 105,417 105,340 — — 105,340 Mortgage, farmland 204,974 205,401 — — 205,401 Mortgage, 1 to 4 family first liens 817,072 813,125 — — 813,125 Mortgage, 1 to 4 family junior liens 136,028 140,222 — — 140,222 Mortgage, multi-family 332,893 330,677 — — 330,677 Mortgage, commercial 356,436 354,673 — — 354,673 Loans to individuals 25,591 25,575 — — 25,575 Obligations of state and political subdivisions 57,398 56,681 — — 56,681 Accrued interest receivable 11,484 11,484 — 11,484 — Total financial instrument assets $ 2,717,533 $ 2,713,289 $ 36,792 $ 289,311 $ 2,387,186 Financial instrument liabilities Deposits Noninterest-bearing deposits $ 349,883 $ 349,883 $ — $ 349,883 $ — Interest-bearing deposits 1,723,159 1,727,433 — 1,727,433 — Other borrowings 13,761 13,761 — 13,761 — Federal Home Loan Bank borrowings 323,000 312,026 — 312,026 — Interest rate swaps 3,464 3,464 — 3,464 — Accrued interest payable 1,079 1,079 — 1,079 — Total financial instrument liabilities $ 2,414,346 $ 2,407,646 $ — $ 2,407,646 $ — Face Amount Financial instrument with off-balance sheet risk: Loan commitments $ 413,805 $ — $ — $ — $ — Letters of credit 11,398 — — — — Total financial instrument liabilities with off-balance-sheet risk $ 425,203 $ — $ — $ — $ — (1) Considered Level 1 under Accounting Standards Codification (“ASC”) Topic 820, Fair Value Measurements and Disclosures (“ASC 820”). (2) Considered Level 2 under ASC 820. (3) Considered Level 3 under ASC 820 and are based on valuation models that use significant assumptions that are not observable in an active market. The carrying value and estimated fair values of the Company's financial instruments as of December 31, 2016 are as follows: December 31, 2016 Carrying Amount Estimated Fair Value Readily Available Market Prices(1) Observable Market Prices(2) Company Determined Market Prices(3) (Amounts In Thousands) Financial instrument assets: Cash and cash equivalents $ 38,197 $ 38,197 $ 38,197 $ — $ — Investment securities 279,950 279,950 — 279,950 — Loans held for sale 9,806 9,806 — 9,806 — Loans Agricultural 89,924 89,862 — — 89,862 Commercial and financial 188,464 188,292 — — 188,292 Real estate: Construction, 1 to 4 family residential 56,841 56,715 — — 56,715 Construction, land development and commercial 119,694 119,716 — — 119,716 Mortgage, farmland 198,923 199,043 — — 199,043 Mortgage, 1 to 4 family first liens 760,909 764,174 — — 764,174 Mortgage, 1 to 4 family junior liens 124,283 129,339 — — 129,339 Mortgage, multi-family 301,162 297,646 — — 297,646 Mortgage, commercial 331,822 328,948 — — 328,948 Loans to individuals 24,515 24,499 — — 24,499 Obligations of state and political subdivisions 54,081 52,860 — — 52,860 Accrued interest receivable 9,121 9,121 — 9,121 — Total financial instrument assets $ 2,587,692 $ 2,588,168 $ 38,197 $ 298,877 $ 2,251,094 Financial instrument liabilities: Deposits Noninterest-bearing deposits $ 348,505 $ 348,505 $ — $ 348,505 $ — Interest-bearing deposits 1,687,807 1,691,679 — 1,691,679 — Other borrowings 33,489 33,489 — 33,489 — Federal Home Loan Bank borrowings 235,000 231,232 — 231,232 — Interest rate swaps 3,938 3,938 3,938 Accrued interest payable 984 984 — 984 — Total financial instrument liabilities $ 2,309,723 $ 2,309,827 $ — $ 2,309,827 $ — Face Amount Financial instrument with off-balance sheet risk: Loan commitments $ 388,666 $ — $ — $ — $ — Letters of credit 9,024 — — — — Total financial instrument liabilities with off-balance-sheet risk $ 397,690 $ — $ — $ — $ — (1) Considered Level 1 under ASC 820. (2) Considered Level 2 under ASC 820. (3) Considered Level 3 under ASC 820 and are based on valuation models that use significant assumptions that are not observable in an active market. Fair value of financial instruments : FASB ASC 820, Fair Value Measurements and Disclosures (“ASC 820”) provides a single definition for fair value, a framework for measuring fair value and expanded disclosures concerning fair value. Fair value is defined under ASC 820 as the exchange price that would be received for an asset or paid to transfer a liability (an 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. The Company determines the fair market value of its financial instruments based on the fair value hierarchy established in ASC 820. There are three levels of inputs that may be used to measure fair value as follows: Level 1 Quoted prices in active markets for identical assets or liabilities. Level 2 Observable inputs other than quoted prices included within Level 1. Observable inputs include the quoted prices for similar assets or liabilities in markets that are not active and inputs other than quoted prices that are observable for the asset or liability. Level 3 Unobservable inputs supported by little or no market activity for financial instruments. Level 3 assets and liabilities include financial instruments whose value is determined using pricing models, discounted cash flow methodologies, or similar techniques, as well as instruments for which the determination of fair value requires significant management judgment or estimation. 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 following is a description of valuation methodologies used for assets and liabilities recorded at fair value and for estimating fair value for assets or liabilities not recorded at fair value. ASSETS Cash and cash equivalents : The carrying amounts reported in the consolidated balance sheets for cash and short-term instruments approximate their fair values (Level 1). Investment securities available for sale : Investment securities available for sale are recorded at fair value on a recurring basis. Fair value measurement is based upon quoted prices, if available. If a quoted price is not available, the fair value is obtained from benchmarking the security against similar securities. All of the Company’s securities are considered Level 2. The pricing for investment securities is obtained from an independent source. There are no level 1 or level 3 investment securities owned by the Company. The Company obtains an understanding of the independent source’s valuation methodologies used to determine fair value by level of security. The Company validates assigned fair values on a sample basis using an additional third-party provider pricing service to determine if the fair value measurement is reasonable. Due to the nature of our investment portfolio, we do not expect significant and unusual fluctuations as fair value changes primarily relate to interest rate changes. No unusual fluctuations were identified during the nine months ended September 30, 2017 . If a fluctuation requiring investigation was identified, the Company would research the change with the independent source or other available information. Loans held for sale : Loans held for sale are carried at historical cost. The carrying amount is a reasonable estimate of fair value because of the short time between origination of the loan and its sale on the secondary market (Level 2). The market is active for these loans and as a result prices for similar assets are available. Loans : The Company does not record loans at fair value on a recurring basis. For variable-rate loans that reprice frequently and with no significant change in credit risk, fair values are based on carrying values (Level 3). The fair values for other loans are determined using estimated future cash flows, discounted at the interest rates currently being offered for loans with similar terms to borrowers with similar credit quality utilizing an entrance price concept (Level 3). The Company does record nonrecurring fair value adjustments to loans to reflect (1) partial write-downs that are based on the observable market price or appraised value of the collateral or (2) the full charge-off of the loan carrying value (Level 3). These loans are considered Level 3 as the instruments used to determine fair market value require significant management judgment and estimation. Foreclosed assets : The Company does not record foreclosed assets at fair value on a recurring basis. Foreclosed assets consist mainly of other real estate owned but may include other types of assets repossessed by the Company. Foreclosed assets are adjusted to the lower of carrying value or fair value less the cost of disposal. Fair value is generally based upon independent market prices or appraised values of the collateral, and may include a marketability discount as deemed necessary by management based on its experience with similar types of real estate. The value of foreclosed assets is evaluated periodically as a nonrecurring fair value adjustment. Foreclosed assets are classified as Level 3. Off-balance sheet instruments : Fair values for outstanding letters of credit are based on fees currently charged to enter into similar agreements, taking into account the remaining terms of the agreements and the counterparties' credit standing. The fair value of the outstanding letters of credit is not significant. Unfunded loan commitments are not valued since the loans are generally priced at market at the time of funding (Level 2). Accrued interest receivable : The fair value of accrued interest receivable equals the amount receivable due to the current nature of the amounts receivable (Level 2). Non-marketable equity investments : Non-marketable equity investments are recorded under the cost or equity method of accounting. There are generally restrictions on the sale and/or liquidation of these investments, including stock of the Federal Home Loan Bank. The carrying value of stock of the Federal Home Loan Bank approximates fair value (Level 2). LIABILITIES Deposit liabilities : Deposit liabilities are carried at historical cost. The fair value of demand deposits, savings accounts and certain money market account deposits is the amount payable on demand at the reporting date. The fair value of fixed maturity certificates of deposit is estimated using the rates currently offered for deposits of similar remaining maturities. If the fair value of the fixed maturity certificates of deposit is calculated at less than the carrying amount, the carrying value of these deposits is reported as the fair value (Level 2). Deposit liabilities are classified as Level 2 due to available prices for similar liabilities in the market. Other borrowings : Other borrowings are carried at historical cost and include federal funds purchased and securities sold under agreements to repurchase. The carrying amount is a reasonable estimate of fair value because of the relatively short time between the origination of the liability and its expected realization (Level 2). Other borrowings are classified as Level 2 due to available prices for similar liabilities in the market. Federal Home Loan Bank borrowings : Federal Home Loan Bank borrowings are recorded at historical cost. The fair values of the Company’s Federal Home Loan Bank borrowings are estimated using discounted cash flow analysis, based on the Company’s current incremental borrowing rates for similar types of borrowing arrangements (Level 2). Federal Home Loan Bank borrowings are classified as Level 2 due to available prices for similar liabilities in the market. Interest Rate Swap Agreements : The fair value is estimated using forward-looking interest rate curves and is calculated using discounted cash flows that are observable or that can be corroborated by observable market data (Level 2). Accrued interest payable : The fair value of accrued interest payable equals the amount payable due to the current nature of the amounts payable (Level 2). Assets and Liabilities Recorded at Fair Value on a Recurring Basis The table below represents the balances of assets and liabilities measured at fair value on a recurring basis: September 30, 2017 Readily Available Market Prices(1) Observable Market Prices(2) Company Determined Market Prices(3) Total at Fair Value Securities available for sale (Amounts In Thousands) U.S. Treasury $ — $ 39,894 $ — $ 39,894 State and political subdivisions — 166,331 — 166,331 Other securities (FHLB, FHLMC and FNMA) — 48,759 — 48,759 Derivative Financial Instruments Interest rate swaps $ — (3,464 ) $ — (3,464 ) Total $ — $ 251,520 $ — $ 251,520 December 31, 2016 Readily Available Market Prices(1) Observable Market Prices(2) Company Determined Market Prices(3) Total at Fair Value Securities available for sale (Amounts In Thousands) U.S. Treasury $ — $ 27,482 $ — $ 27,482 State and political subdivisions — 178,395 — 178,395 Other securities (FHLB, FHLMC and FNMA) — 61,660 — 61,660 Derivative Financial Instruments Interest rate swaps — (3,938 ) — (3,938 ) Total $ — $ 263,599 $ — $ 263,599 (1) Considered Level 1 under ASC 820. (2) Considered Level 2 under ASC 820. (3) Considered Level 3 under ASC 820 and are based on valuation models that use significant assumptions that are not observable in an active market. There were no transfers between Levels 1, 2 or 3 during the nine months ended September 30, 2017 and the year ended December 31, 2016 . Assets and Liabilities Recorded at Fair Value on a Nonrecurring Basis The Company is required to measure certain assets at fair value on a nonrecurring basis in accordance with GAAP. These adjustments to fair value usually result from application of lower-of-cost-or-market accounting or write-downs of individual assets. The valuation methodologies used to measure these fair value adjustments are described above. The following tables present the Company’s assets that are measured at fair value on a nonrecurring basis. September 30, 2017 Three Months Ended September 30, 2017 Nine Months Ended September 30, 2017 Readily Available Market Prices(1) Observable Market Prices(2) Company Determined Market Prices(3) Total at Fair Value Total Losses Total Losses (Amounts in Thousands) Loans (4) Agricultural $ — $ — $ 4,350 $ 4,350 $ — $ 23 Commercial and financial — — 1,667 1,667 8 135 Real Estate: Construction, 1 to 4 family residential — — 186 186 — — Construction, land development and commercial — — 697 697 — — Mortgage, farmland — — 6,862 6,862 — — Mortgage, 1 to 4 family first liens — — 6,214 6,214 31 150 Mortgage, 1 to 4 family junior liens — — 34 34 71 88 Mortgage, multi-family — — 6,003 6,003 — — Mortgage, commercial — — 1,101 1,101 86 111 Loans to individuals — — — — 10 20 Foreclosed assets (5) — — — — — — Total $ — $ — $ 27,114 $ 27,114 $ 206 $ 527 (1) Considered Level 1 under ASC 820. (2) Considered Level 2 under ASC 820. (3) Considered Level 3 under ASC 820 and are based on valuation models that use significant assumptions that are not observable in an active market. (4) Represents carrying value and related write-downs of loans for which adjustments are based on the value of the collateral. The carrying value of loans fully-charged off is zero . (5) Represents the fair value and related losses of foreclosed real estate and other collateral owned that were measured at fair value subsequent to their initial classification as foreclosed assets. Assets and Liabilities Recorded at Fair Value on a Nonrecurring Basis (continued) December 31, 2016 Year Ended December 31, 2016 Readily Available Market Prices(1) Observable Market Prices(2) Company Determined Market Prices(3) Total at Fair Value Total Losses (Amounts in Thousands) Loans (4) Agricultural $ — $ — $ 10,773 $ 10,773 $ — Commercial and financial — — 1,397 1,397 143 Real Estate: Construction, 1 to 4 family residential — — 827 827 — Construction, land development and commercial — — 85 85 — Mortgage, farmland — — 7,077 7,077 — Mortgage, 1 to 4 family first liens — — 5,424 5,424 756 Mortgage, 1 to 4 family junior liens — — 194 194 — Mortgage, multi-family — — 244 244 — Mortgage, commercial — — 1,541 1,541 65 Loans to individuals — — — — — Foreclosed assets (5) — — 75 75 20 Total $ — $ — $ 27,637 $ 27,637 $ 984 (1) Considered Level 1 under ASC 820. (2) Considered Level 2 under ASC 820. (3) Considered Level 3 under ASC 820 and are based on valuation models that use significant assumptions that are not observable in an active market. (4) Represents carrying value and related write-downs of loans for which adjustments are based on the value of the collateral. The carrying value of loans fully-charged off is zero. (5) Represents the fair value and related losses of foreclosed real estate and other collateral owned that were measured at fair value subsequent to their initial classification as foreclosed assets.

Stock Repurchase Program

Stock Repurchase Program	9 Months Ended
	Sep. 30, 2017
Equity [Abstract]
Stock Repurchase Program	Stock Repurchase Program On July 26, 2005, the Company’s Board of Directors authorized a program to repurchase up to a total of 1,500,000 shares of the Company’s common stock (the “2005 Stock Repurchase Program”). The Company’s Board of Directors has authorized the 2005 Stock Repurchase Program through December 31, 2018. The Company expects the purchases pursuant to the 2005 Stock Repurchase Program to be made from time to time in private transactions at a price equal to the most recent quarterly independent appraisal of the shares of the Company’s common stock and with the Board reviewing the overall results of the 2005 Stock Repurchase Program on a quarterly basis. All purchases made pursuant to the 2005 Stock Repurchase Program since its inception have been made on that basis. The amount and timing of stock repurchases will be based on various factors, such as the Board’s assessment of the Company’s capital structure and liquidity, the amount of interest shown by shareholders in selling shares of stock to the Company at their appraised value, and applicable regulatory, legal and accounting factors. The Company has purchased 1,003,216 shares of its common stock in privately negotiated transactions from August 1, 2005 through September 30, 2017 . Of these 1,003,216 shares, 14,538 shares were purchased during the quarter ended September 30, 2017 , at an average price per share of $52.80 .

Commitments and Contingencies

Commitments and Contingencies	9 Months Ended
	Sep. 30, 2017
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies Concentrations of credit risk : The Bank’s loans, commitments to extend credit, unused lines of credit and outstanding letters of credit have been granted to customers within the Bank's market area. Investments in securities issued by state and political subdivisions within the state of Iowa totaled approximately $68.95 million . The concentrations of credit by type of loan are set forth in Note 5 to the Consolidated Financial Statements. Outstanding letters of credit were granted primarily to commercial borrowers. Although the Bank has a diversified loan portfolio, a substantial portion of its debtors' ability to honor their contracts is dependent upon the economic conditions in Johnson, Linn and Washington Counties, Iowa. Contingencies : In the normal course of business, the Company and Bank are involved in various legal proceedings. While the ultimate outcome of such legal proceedings cannot be predicted with certainty, after reviewing pending and threatened litigation with counsel, management believes at this time that the outcome of such litigation will not have a material adverse effect on the Company's business, financial condition or results of operations. Financial instruments with off-balance sheet risk : The Bank is a party to financial instruments with off-balance sheet risk in the normal course of business to meet the financing needs of its customers. These financial instruments include commitments to extend credit, credit card participations and standby letters of credit. These instruments involve, to varying degrees, elements of credit risk in excess of the amount recognized in the consolidated balance sheets. The Bank’s exposure to credit loss in the event of nonperformance by the other party to the financial instrument for commitments to extend credit, credit card participations and standby letters of credit is represented by the contractual amount of those instruments. The Bank uses the same credit policies in making commitments and conditional obligations as it does for on-balance sheet instruments. A summary of the Bank’s commitments at September 30, 2017 and December 31, 2016 is as follows: September 30, 2017 December 31, 2016 (Amounts In Thousands) Firm loan commitments and unused portion of lines of credit: Home equity loans $ 54,200 $ 48,785 Credit cards 49,107 45,738 Commercial, real estate and home construction 138,982 113,251 Commercial lines and real estate purchase loans 171,516 180,892 Outstanding letters of credit 11,398 9,024

Income Taxes

Income Taxes	9 Months Ended
	Sep. 30, 2017
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes Federal income tax expense for the nine months ended September 30, 2017 and 2016 was computed using the consolidated effective federal tax rate. The Company also recognized income tax expense pertaining to state franchise taxes payable individually by the subsidiary bank. The Company files a consolidated tax return for federal purposes and separate tax returns for State of Iowa purposes. The tax years ended December 31, 2016 , 2015 , and 2014 remain subject to examination by the Internal Revenue Service. For state tax purposes, the tax years ended December 31, 2016 , 2015 , and 2014 remain open for examination. There were no material unrecognized tax benefits at September 30, 2017 and December 31, 2016 and therefore no interest or penalties on unrecognized tax benefits has been recorded. As of September 30, 2017 , the Company does not anticipate any significant increase in unrecognized tax benefits during the twelve-month period ending September 30, 2018. Income taxes as a percentage of income before taxes were 30.48% for the nine months ended September 30, 2017 and 31.40% for the same period in 2016 .

Derivative Financial Instrument

Derivative Financial Instruments	9 Months Ended
	Sep. 30, 2017
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivative Financial Instruments	Derivative Financial Instruments In the normal course of business, the Bank may use derivative financial instruments to manage its interest rate risk. These instruments carry varying degrees of credit, interest rate and market or liquidity risks. Derivative instruments are recognized as either assets or liabilities in the accompanying financial statement and are measured at fair value. The Bank’s objectives are to add stability to its net interest margin and to manage its exposure to movements in interest rates. The contract or notional amount of a derivative is used to determine, along with the other terms of the derivative, the amount to be exchanged between the counterparties. The Bank is exposed to credit risk in the event of nonperformance by counterparties to financial instruments. The Bank minimizes this risk by entering into derivative contracts with large, stable financial institutions. The Bank has not experienced any losses from nonperformance by counterparties. The Bank monitors counterparty risk in accordance with the provisions of ASC 815. In addition, the Bank’s interest rate-related derivative instruments contain language outlining collateral pledging requirements for each counterparty. Collateral must be posted when the market value exceeds certain threshold limits which are determined by credit ratings of each counterparty. The Bank was required to pledge $3.46 million of collateral as of September 30, 2017 . Cash Flow Hedges: The Bank executed two forward-starting interest rate swap transactions on November 7, 2013. One of the interest rate swap transactions had an effective date of November 9, 2015, and an expiration date of November 9, 2020, effectively converting $25.00 million of variable rate debt to fixed rate debt. The other interest rate swap transaction had an effective date of November 7, 2016 and an expiration date of November 7, 2023, effectively converting $25.00 million of variable rate debt to fixed rate debt. For accounting purposes, these swap transactions are designated as a cash flow hedge of the changes in cash flows attributable to changes in three-month LIBOR, the benchmark interest rate being hedged, associated with the interest payments made on an amount of the Bank’s debt principal equal to the then-outstanding swap notional amount. At inception, the Bank asserted that the underlying principal balance would remain outstanding throughout the hedge transaction making it probable that sufficient LIBOR-based interest payments would exist through the maturity date of the swaps. The table below identifies the balance sheet category and fair values of the Bank’s derivative instruments designated as cash flow hedges as of September 30, 2017 and December 31, 2016 : Notional Amount Fair Value Balance Sheet Category Maturity (Amounts in Thousands) September 30, 2017 Interest rate swap $ 25,000 $ (853 ) Other Liabilities 11/9/2020 Interest rate swap 25,000 (2,611 ) Other Liabilities 11/7/2023 December 31, 2016 Interest rate swap $ 25,000 $ (1,097 ) Other Liabilities 11/9/2020 Interest rate swap 25,000 (2,841 ) Other Liabilities 11/7/2023 The table below identifies the gains and losses recognized on the Bank’s derivative instruments designated as cash flow hedges for the nine months ended September 30, 2017 and the year ended December 31, 2016 : Effective Portion Ineffective Portion Recognized in OCI Reclassifed from AOCI into Income Recognized in Income on Derivatives Amount of Gain (Loss) Category Amount of Gain (Loss) Category Amount of Gain (Loss) (Amounts in Thousands) September 30, 2017 Interest rate swap $ 151 Interest Expense $ — Other Income $ — Interest rate swap 142 Interest Expense — Other Income — December 31, 2016 Interest rate swap $ 250 Interest Expense $ — Other Income $ — Interest rate swap (101 ) Interest Expense — Other Income —

Summary of Significant Accoun19

Summary of Significant Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 2017
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation: The accompanying unaudited consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America for interim financial reporting and with instructions for Form 10-Q and Regulation S-X. These financial statements include all adjustments (consisting of normal recurring accruals) which in the opinion of management are considered necessary for the fair presentation of the financial position and results of operations for the periods shown. Certain prior year amounts have been reclassified to conform to the current year presentation. The Company considers that it operates as one business segment, a commercial bank.
Effect of New Financial Accounting Standards	Effect of New Financial Accounting Standards: In May 2014, The FASB and International Accounting Standards Board (IASB) issued ASU No. 2014-09, Revenue from Contracts with Customers (Topic 606). The core principle of ASU 2014-09 is that a company should recognize revenue to depict the transfer of promised good or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods and services. For financial institutions, significant changes are not expected given that most financial instruments are not in the scope of the accounting standard update. ASU 2014-09 is effective for annual periods and interim periods within those annual periods beginning after December 15, 2016. In August 2015, FASB issued ASU 2015-14 deferring the effective date for annual periods and interim periods within those annual periods after December 15, 2017. Earlier application is permitted only as of annual reporting periods beginning after December 15, 2016, including interim reporting periods within that reporting period. The Company has evaluated all of its noninterest income streams and contracts to determine potential impact. The adoption of ASU 2014-09 by the Company will not have a material impact. In January 2016, the FASB issued ASU No. 2016-01, Financial Instruments - Overall (Subtopic 825-10), Recognition and Measurement of Financial Assets and Financial Liabilities. ASU 2016-01 created Subtopic 321-10, Investments-Equity Securities which is applicable to all entities except those in industries that account for substantially all investments at fair value through earnings or the change in net assets. Under this new subtopic, equity securities are generally required to be measured at fair value with unrealized holding gains and losses reflected in net income. ASU 2016-01 is effective for annual periods and interim periods within those annual periods beginning after December 15, 2017. The adoption of ASU 2016-01 by the Company is not expected to have a material impact. In February 2016, the FASB issued ASU No. 2016-02 (Topic 842), Leases . The ASU provides guidance requiring lessees to recognize right-of-use assets and lease liabilities for all leases other than those that meet the definition of short-term leases. For short-term leases, lessees may elect an accounting policy by class of underlying asset under which these assets and liabilities are not recognized and lease payments are generally recognized over the lease term on a straight-line basis. Under this new ASU, lessees will recognize right-of use assets and lease liabilities for most leases currently accounted for as operating leases under generally accepted accounting principles. For public companies, ASU 2016-02 is effective for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2018. The Company is in the process of analyzing a comprehensive list of lease agreements. The adoption of ASU 2016-02 by the Company is not expected to have a material impact. In March 2016, the FASB issued ASU No. 2016-04, Liabilities - Extinguishments of Liabilities (Subtopic 405-20), Recognition of Breakage for Certain Prepaid Stored-Value Products . ASU 2016-04 applies to all entities that offer certain prepaid stored - value products. The ASU provides guidance for the derecognition of financial liabilities related to the issuance of these products and aligns the recognition of breakage to current authoritative guidance. For public companies, ASU 2016-04 is effective for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2017. The adoption of ASU 2016-04 by the Company is not expected to have a material impact. In March 2016, the FASB issued ASU No. 2016-09, Compensation - Stock Compensation (Topic 718), Improvements to Employee Share-Based Payment Accounting . The ASU simplifies several aspects of the accounting for share-based payment transaction, including the income tax consequences, classification of awards as either equity or liabilities, and classification on the statement of cash flows. For public companies, ASU 2016-09 is effective for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2016. The Company adopted ASU 2016-09 for the period ending March 31, 2017. There was no material impact on the financial statements. In June 2016, the FASB issued ASU No. 2016-13, Financial Instruments - Credit Losses (Topic 326), Measurement of Credit Losses on Financial Instruments (CECL). The ASU changes the way entities recognize impairment of financial assets by requiring immediate recognition of estimated credit losses expected to occur over the remaining life of many financial assets. Under the CECL model, we will be required to present certain financial assets carried at amortized cost, such as loans held for investment and held-to-maturity debt securities, at the net amount expected to be collected. The measurement of expected credit losses is to be based on information about past events, including historical experience, current conditions, and reasonable and supportable forecasts that affect the collectability of the reported amount. This measurement will take place at the time the financial asset is first added to the balance sheet and periodically thereafter. This differs significantly from the "incurred loss" model required under current GAAP, which delays recognition until it is probable a loss has been incurred. Accordingly, we expect that the adoption of the CECL model will materially affect how we determine our allowance for loan losses and could require us to significantly increase our allowance. For public companies, ASU 2016-13 is effective for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2019, early adoption is permitted for the fiscal year beginning after December 15, 2018. The Company is in the process of implementing a software solution to assist in the analysis of historical loan data to determine the CECL model that will be implemented. We expect to recognize a one-time cumulative-effect adjustment to our allowance for loan losses as of the beginning of the first reporting period in which the new standard is adopted. The amount of the one-time cumulative-effect adjustment has not yet been determined. In January 2017, the FASB issued ASU No. 2017-03, Accounting Changes and Error Corrections (Topic 250) and Investments - Equity Method and Joint Ventures (Topic 323), Amendments to SEC Paragraphs Pursuant to Staff Announcements at the September 22, 2016 and November 17, 2016 EITF Meetings. This ASU adds an SEC paragraph and amends other Topics pursuant to an SEC staff Announcement made at the September 22, 2016 Emerging Issues Task Force (EITF) meeting. The SEC paragraph applies to ASU No. 2014-09, Revenue from Contracts with Customers (Topic 606); ASU No. 2016-02, Leases (Topic 842); and ASU No. 2016-13, Financial Instruments - Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments. The ASU provides that a company should evaluate ASUs that have not yet been adopted to determine the appropriate financial statement disclosures about the potential material effects of those ASUs on the financial statements when adopted. If the company does not know or cannot reasonably estimate the impact that adoption of the ASUs referenced in this announcement is expected to have on the financial statements, then in addition to making a statement to that effect, the company should consider additional qualitative financial statement disclosures to assist the reader in assessing the significance of the impact that the standard will have on the financial statements of the company when adopted. Additional qualitative disclosures should include a description of the effect of the accounting policies that the company expects to apply and a comparison to the company's current accounting policies. Also, the company should describe the status of its process to implement the new standards and the significant implementation matters yet to be addressed. In January 2017, the FASB issued ASU No. 2017-04, Intangibles - Goodwill and Other (Topic 250), Simplifying the Test for Goodwill Impairment. The ASU simplifies the goodwill impairment test by requiring a company to perform its annual or interim, goodwill impairment test by comparing the fair value of a reporting unit with its carrying amount. An impairment charge should be recognized when the carrying amount exceeds fair value. For public companies, ASU 2017-04 is effective for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2019. The adoption of ASU No. 2017-04 by the Company is not expected to have a material impact. In March 2017, the FASB issued ASU No. 2017-08, Receivable - Nonrefundable Fees and Other Costs (Subtopic 310-20), Premium Amortization on Purchased Callable Debt Securities. This ASU shortens the amortization period for certain callable debt securities held at a premium. The premium will be amortized to the earliest call date. For public companies, ASU 2017-08 is effective for fiscal years, and interim periods within those fiscal years beginning after December 15, 2018. The Company adopted ASU 2017-08 for the period ending March 31, 2017. There was no material impact on the financial statements. In August 2017, the FASB issued ASU No. 2017-12, Derivatives and Hedging (Topic 815), Targeted Improvements to Accounting for Hedging Activities. This ASU requires companies to change the recognition and presentation of the effects of hedge accounting by eliminating the requirement to separately measure and report hedge ineffectiveness and requiring companies to present all of the elements of hedge accounting that affect earnings in the same income statement line as the hedged item. Furthermore, the standard eases the requirements for effectiveness testing, hedge documentation and applying the critical terms match method and introduces new alternatives that will permit companies to reduce the risk of material error corrections if they misapply the shortcut method. For public companies, ASU 2017-12 is effective for fiscal years, and interim periods within those fiscal years beginning after December 15, 2018. The adoption of ASU 2017-12 by the Company is not expected to have a material impact.
Earnings Per Share	Earnings Per Share Basic earnings per share is computed using the weighted average number of actual common shares outstanding during the period. Diluted earnings per share reflects the potential dilution that would occur from the exercise of common stock options outstanding. ESOP shares are considered outstanding for this calculation unless unearned.

Earnings Per Share (Tables)

Earnings Per Share (Tables)	9 Months Ended
	Sep. 30, 2017
Earnings Per Share [Abstract]
Schedule of computation of basic and diluted earnings per share	The computation of basic and diluted earnings per share for the periods presented is as follows: Three Months Ended September 30, Nine Months Ended September 30, 2017 2016 2017 2016 Common shares outstanding at the beginning of the period 9,329,514 9,283,341 9,264,227 9,322,054 Weighted average number of net shares (redeemed) issued (4,596 ) (7,633 ) 64,144 (31,950 ) Weighted average shares outstanding (basic) 9,324,918 9,275,708 9,328,371 9,290,104 Weighted average of potential dilutive shares attributable to stock options granted, computed under the treasury stock method 3,559 6,584 4,874 6,357 Weighted average number of shares (diluted) 9,328,477 9,282,292 9,333,245 9,296,461 Net income (In thousands) $ 8,552 $ 9,176 $ 23,883 $ 24,843 Earnings per share: Basic $ 0.92 $ 0.99 $ 2.56 $ 2.67 Diluted $ 0.92 $ 0.99 $ 2.56 $ 2.67

Other Comprehensive Income (L21

Other Comprehensive Income (Loss) (Tables)	9 Months Ended
	Sep. 30, 2017
Equity [Abstract]
Components of accumulated other comprehensive income (AOCI)	The following table summarizes the balances of each component of accumulated other comprehensive income (AOCI), included in stockholders’ equity, at September 30, 2017 and December 31, 2016 : September 30, December 31, 2016 (amounts in thousands) Net unrealized gain (loss) on available-for-sale securities $ 1,295 $ (1,502 ) Net unrealized loss on derivatives used for cash flow hedges (3,464 ) (3,938 ) Tax effect $ 830 $ 2,081 Net-of-tax amount $ (1,339 ) $ (3,359 )

Securities (Tables)

Securities (Tables)	9 Months Ended
	Sep. 30, 2017
Investments, Debt and Equity Securities [Abstract]
Carrying values of investment securities	The carrying values of investment securities at September 30, 2017 and December 31, 2016 are summarized in the following table (dollars in thousands): September 30, 2017 December 31, 2016 Amount Percent Amount Percent Securities available for sale U.S. Treasury $ 39,894 15.65 % $ 27,482 10.27 % Other securities (FHLB, FHLMC and FNMA) 48,759 19.12 61,660 23.05 State and political subdivisions 166,331 65.23 178,395 66.68 Total securities available for sale $ 254,984 100.00 % $ 267,537 100.00 %
Carrying amount of available-for-sale securities and approximate fair values	The carrying amount of available-for-sale securities and their approximate fair values were as follows as of September 30, 2017 and December 31, 2016 (in thousands): Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Estimated Fair Value September 30, 2017: U.S. Treasury $ 39,823 $ 90 $ (19 ) $ 39,894 Other securities (FHLB, FHLMC and FNMA) 48,992 11 (244 ) 48,759 State and political subdivisions 164,874 1,721 (264 ) 166,331 Total $ 253,689 $ 1,822 $ (527 ) $ 254,984 December 31, 2016: U.S. Treasury $ 27,418 $ 82 $ (18 ) $ 27,482 Other securities (FHLB, FHLMC and FNMA) 62,047 65 (452 ) 61,660 State and political subdivisions 179,574 626 (1,805 ) 178,395 Total $ 269,039 $ 773 $ (2,275 ) $ 267,537
Available-for-sale securities classified as per contractual maturities	The amortized cost and estimated fair value of available-for-sale securities classified according to their contractual maturities at September 30, 2017 , were as follows (in thousands): Amortized Cost Fair Value Due in one year or less $ 42,320 $ 42,423 Due after one year through five years 138,727 139,316 Due after five years through ten years 72,022 72,625 Due over ten years 620 620 Total $ 253,689 $ 254,984
Available-for-sale securities, continuous unrealized loss position, fair value	The following table shows the fair value, gross unrealized losses and the percentage of fair value represented by gross unrealized losses of applicable investment securities owned by the Company, aggregated by investment category and length of time that individual securities have been in a continuous unrealized loss position at September 30, 2017 and December 31, 2016 (in thousands): Less than 12 months 12 months or more Total September 30, 2017 # Fair Value Unrealized Loss % # Fair Value Unrealized Loss % # Fair Value Unrealized Loss % U.S. Treasury 4 $ 10,006 $ (19 ) 0.19 % — $ — $ — — % 4 $ 10,006 $ (19 ) 0.19 % Other securities (FHLB, FHLMC and FNMA) 11 26,539 (81 ) 0.31 4 10,208 (163 ) 1.60 15 36,747 (244 ) 0.66 State and political subdivisions 45 11,566 (66 ) 0.57 65 15,212 (198 ) 1.30 110 26,778 (264 ) 0.99 Total temporarily impaired securities 60 $ 48,111 $ (166 ) 0.35 % 69 $ 25,420 $ (361 ) 1.42 % 129 $ 73,531 $ (527 ) 0.72 % Less than 12 months 12 months or more Total December 31, 2016 # Fair Value Unrealized Loss % # Fair Value Unrealized Loss % # Fair Value Unrealized Loss % U.S. Treasury 2 $ 4,957 $ (18 ) 0.36 % — $ — $ — — % 2 $ 4,957 $ (18 ) 0.36 % Other securities (FHLB, FHLMC and FNMA) 14 34,648 (452 ) 1.30 — — — — 14 34,648 (452 ) 1.30 State and political subdivisions 365 87,841 (1,762 ) 2.01 11 1,486 (43 ) 2.89 376 89,327 (1,805 ) 2.02 Total temporarily impaired securities 381 $ 127,446 $ (2,232 ) 1.75 % 11 $ 1,486 $ (43 ) 2.89 % 392 $ 128,932 $ (2,275 ) 1.76 %

Loans (Tables)

Loans (Tables)	9 Months Ended
	Sep. 30, 2017
Receivables [Abstract]
Schedule of classes of loans	Classes of loans are as follows: September 30, December 31, (Amounts In Thousands) Agricultural $ 76,484 $ 92,871 Commercial and financial 214,199 192,995 Real estate: Construction, 1 to 4 family residential 73,404 57,864 Construction, land development and commercial 107,170 121,561 Mortgage, farmland 208,982 202,340 Mortgage, 1 to 4 family first liens 823,529 767,469 Mortgage, 1 to 4 family junior liens 137,271 125,400 Mortgage, multi-family 335,439 302,831 Mortgage, commercial 359,332 334,198 Loans to individuals 26,223 25,157 Obligations of state and political subdivisions 57,861 54,462 $ 2,419,894 $ 2,277,148 Net unamortized fees and costs 886 827 $ 2,420,780 $ 2,277,975 Less allowance for loan losses 29,350 26,530 $ 2,391,430 $ 2,251,445
Schedule of changes in allowance for loan losses	Changes in the allowance for loan losses, the allowance for loan losses applicable to impaired loans and the related loan balance of impaired loans for the three and nine months ended September 30, 2017 were as follows: Three Months Ended September 30, 2017 Agricultural Commercial and Real Estate: Real Estate: Real Estate: Real Estate: Other Total (Amounts In Thousands) Allowance for loan losses: Beginning balance $ 2,341 $ 4,586 $ 3,165 $ 4,009 $ 8,340 $ 5,414 $ 1,095 $ 28,950 Charge-offs (27 ) (21 ) — (3 ) (55 ) (86 ) (113 ) (305 ) Recoveries 56 219 33 — 203 7 57 575 Provision 92 (43 ) (182 ) 2 98 107 56 130 Ending balance $ 2,462 $ 4,741 $ 3,016 $ 4,008 $ 8,586 $ 5,442 $ 1,095 $ 29,350 Nine Months Ended September 30, 2017 Agricultural Commercial and Real Estate: Real Estate: Real Estate: Real Estate: Other Total (Amounts In Thousands) Allowance for loan losses: Beginning balance $ 2,947 $ 4,531 $ 2,890 $ 3,417 $ 7,677 $ 4,045 $ 1,023 $ 26,530 Charge-offs (66 ) (478 ) (114 ) (3 ) (263 ) (130 ) (410 ) (1,464 ) Recoveries 123 882 443 — 570 236 203 2,457 Provision (542 ) (194 ) (203 ) 594 602 1,291 279 1,827 Ending balance $ 2,462 $ 4,741 $ 3,016 $ 4,008 $ 8,586 $ 5,442 $ 1,095 $ 29,350 Ending balance, individually evaluated for impairment $ 653 $ 913 $ 46 $ 784 $ 110 $ 409 $ 85 $ 3,000 Ending balance, collectively evaluated for impairment $ 1,809 $ 3,828 $ 2,970 $ 3,224 $ 8,476 $ 5,033 $ 1,010 $ 26,350 Loans: Ending balance $ 76,484 $ 214,199 $ 180,574 $ 208,982 $ 960,800 $ 694,771 $ 84,084 $ 2,419,894 Ending balance, individually evaluated for impairment $ 6,181 $ 2,985 $ 1,161 $ 8,179 $ 7,097 $ 8,097 $ 85 $ 33,785 Ending balance, collectively evaluated for impairment $ 70,303 $ 211,214 $ 179,413 $ 200,803 $ 953,703 $ 686,674 $ 83,999 $ 2,386,109 Changes in the allowance for loan losses for the three and nine months ended September 30, 2016 were as follows: Three Months Ended September 30, 2016 Agricultural Commercial and Real Estate: Real Estate: Real Estate: Real Estate: Other Total (Amounts In Thousands) Allowance for loan losses: Beginning balance $ 2,997 $ 4,011 $ 2,898 $ 3,927 $ 8,226 $ 4,201 $ 1,030 $ 27,290 Charge-offs (19 ) (38 ) — (105 ) (176 ) — (140 ) (478 ) Recoveries — 289 186 — 276 358 51 1,160 Provision 201 (252 ) (75 ) (204 ) (425 ) (589 ) (86 ) (1,832 ) Ending balance $ 2,777 $ 4,010 $ 3,009 $ 3,618 $ 7,901 $ 3,970 $ 855 $ 26,140 Nine Months Ended September 30, 2016 Agricultural Commercial and Real Estate: Real Estate: Real Estate: Real Estate: Other Total (Amounts In Thousands) Allowance for loan losses: Beginning balance $ 3,082 $ 4,517 $ 2,280 $ 3,342 $ 8,172 $ 4,223 $ 894 $ 26,510 Charge-offs (44 ) (172 ) — (116 ) (704 ) (66 ) (416 ) (1,518 ) Recoveries 173 910 792 — 767 379 132 3,153 Provision (434 ) (1,245 ) (63 ) 392 (334 ) (566 ) 246 (2,004 ) Ending balance $ 2,777 $ 4,010 $ 3,009 $ 3,618 $ 7,901 $ 3,970 $ 855 $ 26,140 Ending balance, individually evaluated for impairment $ 746 $ 221 $ 223 $ 549 $ 283 $ 62 $ 29 $ 2,113 Ending balance, collectively evaluated for impairment $ 2,031 $ 3,789 $ 2,786 $ 3,069 $ 7,618 $ 3,908 $ 826 $ 24,027 Loans: Ending balance $ 88,104 $ 188,365 $ 178,820 $ 193,819 $ 883,693 $ 619,214 $ 74,917 $ 2,226,932 Ending balance, individually evaluated for impairment $ 12,276 $ 2,529 $ 2,877 $ 8,371 $ 6,497 $ 3,356 $ 29 $ 35,935 Ending balance, collectively evaluated for impairment $ 75,828 $ 185,836 $ 175,943 $ 185,448 $ 877,196 $ 615,858 $ 74,888 $ 2,190,997
Schedule of credit quality indicators by type of loans	The following table presents the credit quality indicators by type of loans in each category as of September 30, 2017 and December 31, 2016 , respectively (amounts in thousands): Agricultural Commercial and Financial Real Estate: Construction, 1 to 4 family residential Real Estate: Construction, land development and commercial September 30, 2017 Grade: Excellent $ 2,502 $ 10,234 $ 548 $ 2,950 Good 12,073 47,103 6,773 26,216 Satisfactory 37,109 117,612 49,639 41,317 Monitor 14,622 28,619 15,248 33,226 Special Mention 4,653 5,410 897 2,607 Substandard 5,525 5,221 299 854 Total $ 76,484 $ 214,199 $ 73,404 $ 107,170 Real Estate: Mortgage, farmland Real Estate: Mortgage, 1 to 4 family first liens Real Estate: Mortgage, 1 to 4 family junior liens Real Estate: Mortgage, multi- family September 30, 2017 Grade: Excellent $ 5,102 $ 2,064 $ 494 $ 5,712 Good 52,634 29,490 3,569 82,368 Satisfactory 105,155 681,699 124,625 188,549 Monitor 34,985 77,461 4,869 52,341 Special Mention 2,434 11,136 1,328 — Substandard 8,672 21,679 2,386 6,469 Total $ 208,982 $ 823,529 $ 137,271 $ 335,439 Real Estate: Mortgage, commercial Loans to individuals Obligations of state and political subdivisions Total September 30, 2017 Grade: Excellent $ 18,735 $ — $ 8,961 $ 57,302 Good 103,662 476 29,137 393,501 Satisfactory 183,140 24,962 16,186 1,569,993 Monitor 44,316 349 3,577 309,613 Special Mention 7,037 216 — 35,718 Substandard 2,442 220 — 53,767 Total $ 359,332 $ 26,223 $ 57,861 $ 2,419,894 Agricultural Commercial and Financial Real Estate: Construction, 1 to 4 family residential Real Estate: Construction, land development and commercial December 31, 2016 Grade: Excellent $ 4,205 $ 4,241 $ — $ 244 Good 13,611 43,472 1,701 25,337 Satisfactory 40,008 108,800 44,138 46,758 Monitor 12,699 20,023 8,896 44,487 Special Mention 8,381 11,177 972 4,250 Substandard 13,967 5,282 2,157 485 Total $ 92,871 $ 192,995 $ 57,864 $ 121,561 Real Estate: Mortgage, farmland Real Estate: Mortgage, 1 to 4 family first liens Real Estate: Mortgage, 1 to 4 family junior liens Real Estate: Mortgage, multi- family December 31, 2016 Grade: Excellent $ 2,916 $ 1,196 $ 65 $ 5,970 Good 47,569 15,725 3,002 71,822 Satisfactory 105,971 647,191 113,433 180,651 Monitor 29,778 66,164 4,877 40,444 Special Mention 7,004 12,914 1,566 3,636 Substandard 9,102 24,279 2,457 308 Total $ 202,340 $ 767,469 $ 125,400 $ 302,831 Real Estate: Mortgage, commercial Loans to individuals Obligations of state and political subdivisions Total December 31, 2016 Grade: Excellent $ 15,873 $ — $ — $ 34,710 Good 89,801 65 37,539 349,644 Satisfactory 185,650 24,446 16,417 1,513,463 Monitor 34,979 293 506 263,146 Special Mention 3,797 195 — 53,892 Substandard 4,098 158 — 62,293 Total $ 334,198 $ 25,157 $ 54,462 $ 2,277,148
Schedule of past due loans	Past due loans as of September 30, 2017 and December 31, 2016 were as follows: 30 - 59 Days Past Due 60 - 89 Days Past Due 90 Days or More Past Due Total Past Due Current Total Loans Receivable Accruing Loans Past Due 90 Days or More (Amounts In Thousands) September 30, 2017 Agricultural $ 3 $ 23 $ 1,367 $ 1,393 $ 75,091 $ 76,484 $ 1,121 Commercial and financial 380 262 264 906 213,293 214,199 200 Real estate: Construction, 1 to 4 family residential — 22 — 22 73,382 73,404 — Construction, land development and commercial 3,320 — — 3,320 103,850 107,170 — Mortgage, farmland — 1,355 83 1,438 207,544 208,982 — Mortgage, 1 to 4 family first liens 733 1,578 2,235 4,546 818,983 823,529 412 Mortgage, 1 to 4 family junior liens 201 137 62 400 136,871 137,271 58 Mortgage, multi-family — — — — 335,439 335,439 — Mortgage, commercial 142 — 16 158 359,174 359,332 — Loans to individuals 38 67 — 105 26,118 26,223 — Obligations of state and political subdivisions — — — — 57,861 57,861 — $ 4,817 $ 3,444 $ 4,027 $ 12,288 $ 2,407,606 $ 2,419,894 $ 1,791 December 31, 2016 Agricultural $ 56 $ — $ 302 $ 358 $ 92,513 $ 92,871 $ — Commercial and financial 24 121 718 863 192,132 192,995 — Real estate: Construction, 1 to 4 family residential — — — — 57,864 57,864 — Construction, land development and commercial — 231 85 316 $ 121,245 121,561 — Mortgage, farmland 319 — — 319 202,021 202,340 — Mortgage, 1 to 4 family first liens 5,649 978 1,943 8,570 $ 758,899 767,469 192 Mortgage, 1 to 4 family junior liens 330 51 579 960 124,440 125,400 443 Mortgage, multi-family — — 40 40 $ 302,791 302,831 — Mortgage, commercial 371 — 207 578 333,620 334,198 — Loans to individuals 203 32 — 235 $ 24,922 25,157 — Obligations of state and political subdivisions — — — — 54,462 54,462 — $ 6,952 $ 1,413 $ 3,874 $ 12,239 $ 2,264,909 $ 2,277,148 $ 635
Schedule of impaired loan information	Certain impaired loan information by loan type at September 30, 2017 and December 31, 2016 , was as follows: September 30, 2017 December 31, 2016 Non-accrual loans (1) Accruing loans past due 90 days or more TDR loans Non- accrual loans (1) Accruing loans past due 90 days or more TDR loans (Amounts In Thousands) (Amounts In Thousands) Agricultural $ 1,656 $ 1,121 $ 2,446 $ 1,741 $ — $ 91 Commercial and financial 947 200 1,839 1,354 — 1,057 Real estate: Construction, 1 to 4 family residential — — — — — 265 Construction, land development and commercial — — 341 85 — 118 Mortgage, farmland 1,454 — 1,462 1,205 — 1,389 Mortgage, 1 to 4 family first liens 4,415 412 1,399 4,097 192 1,375 Mortgage, 1 to 4 family junior liens 12 58 26 136 443 26 Mortgage, multi-family 223 — — 243 — — Mortgage, commercial 630 — 1,057 1,077 — 1,087 $ 9,337 $ 1,791 $ 8,570 $ 9,938 $ 635 $ 5,408 (1) There were $3.76 million and $4.23 million of TDR loans included within nonaccrual loans as of September 30, 2017 and December 31, 2016 , respectively.
Schedule of information for TDR loans	Below is a summary of information for TDR loans as of September 30, 2017 and December 31, 2016 : September 30, 2017 December 31, 2016 Number of contracts Recorded investment Commitments outstanding Number of contracts Recorded investment Commitments outstanding (Amounts In Thousands) (Amounts In Thousands) Agricultural 9 $ 3,762 $ 267 4 $ 1,460 $ 167 Commercial and financial 15 2,526 157 14 2,053 117 Real estate: Construction, 1 to 4 family residential — — 193 3 265 1,225 Construction, land development and commercial 2 341 721 1 118 107 Mortgage, farmland 7 2,834 — 7 2,594 — Mortgage, 1 to 4 family first liens 13 1,486 — 12 1,471 — Mortgage, 1 to 4 family junior liens 1 26 54 1 26 65 Mortgage, multi-family — — — — — — Mortgage, commercial 8 1,355 — 10 1,650 — Loans to individuals — — — — — — 55 $ 12,330 $ 1,392 52 $ 9,637 $ 1,681 The following is a summary of TDR loans that were modified during the three and nine months ended September 30, 2017 : Three Months Ended September 30, 2017 Nine Months Ended September 30, 2017 Number of contracts Pre-modification recorded investment Post-modification recorded investment Number Pre-modification Post-modification (Amounts In Thousands) (Amounts In Thousands) Agricultural — $ — $ — 6 $ 10,890 $ 10,890 Commercial and financial 3 1,451 1,451 4 1,546 1,546 Real estate: Construction, 1 to 4 family residential — — — — — — Construction, land development and commercial — — — 1 231 231 Mortgage, farmland — — — 2 598 598 Mortgage, 1 to 4 family first lien 1 106 106 1 106 106 Mortgage, 1 to 4 family junior liens — — — — — — Mortgage, multi-family — — — 1 249 249 Mortgage, commercial — — — — — — 4 $ 1,557 $ 1,557 15 $ 13,620 $ 13,620
Schedule of impaired loans	Information regarding impaired loans as of and for the three and nine months ended September 30, 2017 is as follows: September 30, 2017 Three Months Ended Nine Months Ended Recorded Investment Unpaid Principal Balance Related Allowance Average Recorded Interest Income Average Recorded Interest Income With no related allowance recorded: (Amounts In Thousands) Agricultural $ 1,739 $ 1,981 $ — $ 1,778 $ 3 $ 1,767 $ 1 Commercial and financial 1,333 2,047 — 1,598 17 1,375 5 Real estate: Construction, 1 to 4 family residential 116 151 — 116 4 116 1 Construction, land development and commercial 341 374 — 345 10 342 3 Mortgage, farmland 2,598 2,925 — 2,513 42 2,603 14 Mortgage, 1 to 4 family first liens 5,268 6,640 — 5,434 37 5,336 13 Mortgage, 1 to 4 family junior liens 12 485 — 25 — 13 — Mortgage, multi-family 223 357 — 233 — 226 — Mortgage, commercial 1,607 2,300 — 1,727 34 1,670 11 Loans to individuals — 14 — — — — — $ 13,237 $ 17,274 $ — $ 13,769 $ 147 $ 13,448 $ 48 With an allowance recorded: Agricultural $ 4,442 $ 4,503 $ 653 $ 4,897 $ 169 $ 4,491 $ 53 Commercial and financial 1,652 1,698 913 1,732 62 1,743 21 Real estate: Construction, 1 to 4 family residential 199 199 13 136 5 180 2 Construction, land development and commercial 505 505 33 321 11 354 4 Mortgage, farmland 5,581 5,581 784 5,667 183 5,584 61 Mortgage, 1 to 4 family first liens 1,734 1,861 106 1,761 54 1,743 17 Mortgage, 1 to 4 family junior liens 83 83 4 86 3 83 1 Mortgage, multi-family 6,187 6,187 407 6,251 210 6,228 71 Mortgage, commercial 80 80 2 81 3 80 1 Loans to individuals 85 85 85 88 7 90 3 $ 20,548 $ 20,782 $ 3,000 $ 21,020 $ 707 $ 20,576 $ 234 Total: Agricultural $ 6,181 $ 6,484 $ 653 $ 6,675 $ 172 $ 6,258 $ 54 Commercial and financial 2,985 3,745 913 3,330 79 3,118 26 Real estate: Construction, 1 to 4 family residential 315 350 13 252 9 296 3 Construction, land development and commercial 846 879 33 666 21 696 7 Mortgage, farmland 8,179 8,506 784 8,180 225 8,187 75 Mortgage, 1 to 4 family first liens 7,002 8,501 106 7,195 91 7,079 30 Mortgage, 1 to 4 family junior liens 95 568 4 111 3 96 1 Mortgage, multi-family 6,410 6,544 407 6,484 210 6,454 71 Mortgage, commercial 1,687 2,380 2 1,808 37 1,750 12 Loans to individuals 85 99 85 88 7 90 3 $ 33,785 $ 38,056 $ 3,000 $ 34,789 $ 854 $ 34,024 $ 282 Information regarding impaired loans as of December 31, 2016 is as follows: Recorded Investment Unpaid Principal Balance Related Allowance With no related allowance recorded: (Amounts In Thousands) Agricultural $ 800 $ 971 $ — Commercial and financial 1,540 2,175 — Real estate: Construction, 1 to 4 family residential 117 151 — Construction, land development and commercial 204 290 — Mortgage, farmland 2,594 2,887 — Mortgage, 1 to 4 family first liens 5,011 6,137 — Mortgage, 1 to 4 family junior liens 153 646 — Mortgage, multi-family 243 362 — Mortgage, commercial 1,901 2,727 — Loans to individuals — 19 — $ 12,563 $ 16,365 $ — With an allowance recorded: Agricultural $ 10,920 $ 10,978 $ 856 Commercial and financial 937 955 718 Real estate: Construction, 1 to 4 family residential 815 815 105 Construction, land development and commercial — — — Mortgage, farmland 5,434 5,434 390 Mortgage, 1 to 4 family first liens 1,266 1,374 79 Mortgage, 1 to 4 family junior liens 612 667 11 Mortgage, multi-family — — — Mortgage, commercial 967 1,004 34 Loans to individuals 150 150 150 $ 21,101 $ 21,377 $ 2,343 Total: Agricultural $ 11,720 $ 11,949 $ 856 Commercial and financial 2,477 3,130 718 Real estate: Construction, 1 to 4 family residential 932 966 105 Construction, land development and commercial 204 290 — Mortgage, farmland 8,028 8,321 390 Mortgage, 1 to 4 family first liens 6,277 7,511 79 Mortgage, 1 to 4 family junior liens 765 1,313 11 Mortgage, multi-family 243 362 — Mortgage, commercial 2,868 3,731 34 Loans to individuals 150 169 150 $ 33,664 $ 37,742 $ 2,343

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	9 Months Ended
	Sep. 30, 2017
Fair Value Disclosures [Abstract]
Carrying value and estimated fair values of entity's financial instruments	The carrying value and estimated fair values of the Company's financial instruments as of September 30, 2017 are as follows: September 30, 2017 Carrying Amount Estimated Fair Value Readily Available Market Prices(1) Observable Market Prices(2) Company Determined Market Prices(3) (Amounts In Thousands) Financial instrument assets: Cash and cash equivalents $ 36,792 $ 36,792 $ 36,792 $ — $ — Investment securities 271,110 271,110 — 271,110 — Loans held for sale 6,717 6,717 — 6,717 — Loans Agricultural 74,022 73,954 — — 73,954 Commercial and financial 209,458 209,387 — — 209,387 Real estate: Construction, 1 to 4 family residential 72,141 72,151 — — 72,151 Construction, land development and commercial 105,417 105,340 — — 105,340 Mortgage, farmland 204,974 205,401 — — 205,401 Mortgage, 1 to 4 family first liens 817,072 813,125 — — 813,125 Mortgage, 1 to 4 family junior liens 136,028 140,222 — — 140,222 Mortgage, multi-family 332,893 330,677 — — 330,677 Mortgage, commercial 356,436 354,673 — — 354,673 Loans to individuals 25,591 25,575 — — 25,575 Obligations of state and political subdivisions 57,398 56,681 — — 56,681 Accrued interest receivable 11,484 11,484 — 11,484 — Total financial instrument assets $ 2,717,533 $ 2,713,289 $ 36,792 $ 289,311 $ 2,387,186 Financial instrument liabilities Deposits Noninterest-bearing deposits $ 349,883 $ 349,883 $ — $ 349,883 $ — Interest-bearing deposits 1,723,159 1,727,433 — 1,727,433 — Other borrowings 13,761 13,761 — 13,761 — Federal Home Loan Bank borrowings 323,000 312,026 — 312,026 — Interest rate swaps 3,464 3,464 — 3,464 — Accrued interest payable 1,079 1,079 — 1,079 — Total financial instrument liabilities $ 2,414,346 $ 2,407,646 $ — $ 2,407,646 $ — Face Amount Financial instrument with off-balance sheet risk: Loan commitments $ 413,805 $ — $ — $ — $ — Letters of credit 11,398 — — — — Total financial instrument liabilities with off-balance-sheet risk $ 425,203 $ — $ — $ — $ — (1) Considered Level 1 under Accounting Standards Codification (“ASC”) Topic 820, Fair Value Measurements and Disclosures (“ASC 820”). (2) Considered Level 2 under ASC 820. (3) Considered Level 3 under ASC 820 and are based on valuation models that use significant assumptions that are not observable in an active market. The carrying value and estimated fair values of the Company's financial instruments as of December 31, 2016 are as follows: December 31, 2016 Carrying Amount Estimated Fair Value Readily Available Market Prices(1) Observable Market Prices(2) Company Determined Market Prices(3) (Amounts In Thousands) Financial instrument assets: Cash and cash equivalents $ 38,197 $ 38,197 $ 38,197 $ — $ — Investment securities 279,950 279,950 — 279,950 — Loans held for sale 9,806 9,806 — 9,806 — Loans Agricultural 89,924 89,862 — — 89,862 Commercial and financial 188,464 188,292 — — 188,292 Real estate: Construction, 1 to 4 family residential 56,841 56,715 — — 56,715 Construction, land development and commercial 119,694 119,716 — — 119,716 Mortgage, farmland 198,923 199,043 — — 199,043 Mortgage, 1 to 4 family first liens 760,909 764,174 — — 764,174 Mortgage, 1 to 4 family junior liens 124,283 129,339 — — 129,339 Mortgage, multi-family 301,162 297,646 — — 297,646 Mortgage, commercial 331,822 328,948 — — 328,948 Loans to individuals 24,515 24,499 — — 24,499 Obligations of state and political subdivisions 54,081 52,860 — — 52,860 Accrued interest receivable 9,121 9,121 — 9,121 — Total financial instrument assets $ 2,587,692 $ 2,588,168 $ 38,197 $ 298,877 $ 2,251,094 Financial instrument liabilities: Deposits Noninterest-bearing deposits $ 348,505 $ 348,505 $ — $ 348,505 $ — Interest-bearing deposits 1,687,807 1,691,679 — 1,691,679 — Other borrowings 33,489 33,489 — 33,489 — Federal Home Loan Bank borrowings 235,000 231,232 — 231,232 — Interest rate swaps 3,938 3,938 3,938 Accrued interest payable 984 984 — 984 — Total financial instrument liabilities $ 2,309,723 $ 2,309,827 $ — $ 2,309,827 $ — Face Amount Financial instrument with off-balance sheet risk: Loan commitments $ 388,666 $ — $ — $ — $ — Letters of credit 9,024 — — — — Total financial instrument liabilities with off-balance-sheet risk $ 397,690 $ — $ — $ — $ — (1) Considered Level 1 under ASC 820. (2) Considered Level 2 under ASC 820. (3) Considered Level 3 under ASC 820 and are based on valuation models that use significant assumptions that are not observable in an active market.
Schedule of assets and liabilities measured at fair value on a recurring basis	The table below represents the balances of assets and liabilities measured at fair value on a recurring basis: September 30, 2017 Readily Available Market Prices(1) Observable Market Prices(2) Company Determined Market Prices(3) Total at Fair Value Securities available for sale (Amounts In Thousands) U.S. Treasury $ — $ 39,894 $ — $ 39,894 State and political subdivisions — 166,331 — 166,331 Other securities (FHLB, FHLMC and FNMA) — 48,759 — 48,759 Derivative Financial Instruments Interest rate swaps $ — (3,464 ) $ — (3,464 ) Total $ — $ 251,520 $ — $ 251,520 December 31, 2016 Readily Available Market Prices(1) Observable Market Prices(2) Company Determined Market Prices(3) Total at Fair Value Securities available for sale (Amounts In Thousands) U.S. Treasury $ — $ 27,482 $ — $ 27,482 State and political subdivisions — 178,395 — 178,395 Other securities (FHLB, FHLMC and FNMA) — 61,660 — 61,660 Derivative Financial Instruments Interest rate swaps — (3,938 ) — (3,938 ) Total $ — $ 263,599 $ — $ 263,599 (1) Considered Level 1 under ASC 820. (2) Considered Level 2 under ASC 820. (3) Considered Level 3 under ASC 820 and are based on valuation models that use significant assumptions that are not observable in an active market.
Schedule of assets measured at fair value on a nonrecurring basis	The following tables present the Company’s assets that are measured at fair value on a nonrecurring basis. September 30, 2017 Three Months Ended September 30, 2017 Nine Months Ended September 30, 2017 Readily Available Market Prices(1) Observable Market Prices(2) Company Determined Market Prices(3) Total at Fair Value Total Losses Total Losses (Amounts in Thousands) Loans (4) Agricultural $ — $ — $ 4,350 $ 4,350 $ — $ 23 Commercial and financial — — 1,667 1,667 8 135 Real Estate: Construction, 1 to 4 family residential — — 186 186 — — Construction, land development and commercial — — 697 697 — — Mortgage, farmland — — 6,862 6,862 — — Mortgage, 1 to 4 family first liens — — 6,214 6,214 31 150 Mortgage, 1 to 4 family junior liens — — 34 34 71 88 Mortgage, multi-family — — 6,003 6,003 — — Mortgage, commercial — — 1,101 1,101 86 111 Loans to individuals — — — — 10 20 Foreclosed assets (5) — — — — — — Total $ — $ — $ 27,114 $ 27,114 $ 206 $ 527 (1) Considered Level 1 under ASC 820. (2) Considered Level 2 under ASC 820. (3) Considered Level 3 under ASC 820 and are based on valuation models that use significant assumptions that are not observable in an active market. (4) Represents carrying value and related write-downs of loans for which adjustments are based on the value of the collateral. The carrying value of loans fully-charged off is zero . (5) Represents the fair value and related losses of foreclosed real estate and other collateral owned that were measured at fair value subsequent to their initial classification as foreclosed assets. Assets and Liabilities Recorded at Fair Value on a Nonrecurring Basis (continued) December 31, 2016 Year Ended December 31, 2016 Readily Available Market Prices(1) Observable Market Prices(2) Company Determined Market Prices(3) Total at Fair Value Total Losses (Amounts in Thousands) Loans (4) Agricultural $ — $ — $ 10,773 $ 10,773 $ — Commercial and financial — — 1,397 1,397 143 Real Estate: Construction, 1 to 4 family residential — — 827 827 — Construction, land development and commercial — — 85 85 — Mortgage, farmland — — 7,077 7,077 — Mortgage, 1 to 4 family first liens — — 5,424 5,424 756 Mortgage, 1 to 4 family junior liens — — 194 194 — Mortgage, multi-family — — 244 244 — Mortgage, commercial — — 1,541 1,541 65 Loans to individuals — — — — — Foreclosed assets (5) — — 75 75 20 Total $ — $ — $ 27,637 $ 27,637 $ 984 (1) Considered Level 1 under ASC 820. (2) Considered Level 2 under ASC 820. (3) Considered Level 3 under ASC 820 and are based on valuation models that use significant assumptions that are not observable in an active market. (4) Represents carrying value and related write-downs of loans for which adjustments are based on the value of the collateral. The carrying value of loans fully-charged off is zero. (5) Represents the fair value and related losses of foreclosed real estate and other collateral owned that were measured at fair value subsequent to their initial classification as foreclosed assets.

Commitments and Contingencies (

Commitments and Contingencies (Tables)	9 Months Ended
	Sep. 30, 2017
Commitments and Contingencies Disclosure [Abstract]
Schedule of banks commitments	A summary of the Bank’s commitments at September 30, 2017 and December 31, 2016 is as follows: September 30, 2017 December 31, 2016 (Amounts In Thousands) Firm loan commitments and unused portion of lines of credit: Home equity loans $ 54,200 $ 48,785 Credit cards 49,107 45,738 Commercial, real estate and home construction 138,982 113,251 Commercial lines and real estate purchase loans 171,516 180,892 Outstanding letters of credit 11,398 9,024

Derivative Financial Instrume26

Derivative Financial Instruments (Tables)	9 Months Ended
	Sep. 30, 2017
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Identification of the balance sheet category and fair values of the derivative instruments designated as cash flow hedges	The table below identifies the balance sheet category and fair values of the Bank’s derivative instruments designated as cash flow hedges as of September 30, 2017 and December 31, 2016 : Notional Amount Fair Value Balance Sheet Category Maturity (Amounts in Thousands) September 30, 2017 Interest rate swap $ 25,000 $ (853 ) Other Liabilities 11/9/2020 Interest rate swap 25,000 (2,611 ) Other Liabilities 11/7/2023 December 31, 2016 Interest rate swap $ 25,000 $ (1,097 ) Other Liabilities 11/9/2020 Interest rate swap 25,000 (2,841 ) Other Liabilities 11/7/2023
Identification of the gains and losses recognized on the derivative instruments designated as cash flow hedges	The table below identifies the gains and losses recognized on the Bank’s derivative instruments designated as cash flow hedges for the nine months ended September 30, 2017 and the year ended December 31, 2016 : Effective Portion Ineffective Portion Recognized in OCI Reclassifed from AOCI into Income Recognized in Income on Derivatives Amount of Gain (Loss) Category Amount of Gain (Loss) Category Amount of Gain (Loss) (Amounts in Thousands) September 30, 2017 Interest rate swap $ 151 Interest Expense $ — Other Income $ — Interest rate swap 142 Interest Expense — Other Income — December 31, 2016 Interest rate swap $ 250 Interest Expense $ — Other Income $ — Interest rate swap (101 ) Interest Expense — Other Income —

Summary of Significant Accoun27

Summary of Significant Accounting Policies (Details)	9 Months Ended
	Sep. 30, 2017segment
Accounting Policies [Abstract]
Number of operating segments	1

Earnings Per Share (Details)

Earnings Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016	Jun. 30, 2017	Dec. 31, 2016	Jun. 30, 2016	Dec. 31, 2015
Summary of computation of basic and diluted earnings per share [Abstract]
Common shares outstanding at the beginning of the period (shares)					9,329,514	9,264,227	9,283,341	9,322,054
Weighted average number of net shares (redeemed) issued (shares)	(4,596)	(7,633)	64,144	(31,950)
Weighted average shares outstanding (basic) (shares)	9,324,918	9,275,708	9,328,371	9,290,104
Weighted average of potential dilutive shares attributable to stock options granted, computed under the treasury stock method (shares)	3,559	6,584	4,874	6,357
Weighted average number of shares (diluted) (shares)	9,328,477	9,282,292	9,333,245	9,296,461
Net income (In thousands)	$ 8,552	$ 9,176	$ 23,883	$ 24,843
Earnings per share:
Basic (in dollars per share)	$ 0.92	$ 0.99	$ 2.56	$ 2.67
Diluted (in dollars per share)	$ 0.92	$ 0.99	$ 2.56	$ 2.67

Other Comprehensive Income (L29

Other Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2017	Dec. 31, 2016
Accumulated Other Comprehensive Income Loss [Line Items]
Tax effect	$ 830	$ 2,081
Net-of-tax amount	(1,339)	(3,359)
Net unrealized loss on available-for-sale securities [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Net unrealized gain (loss)	1,295	(1,502)
Net unrealized loss on derivatives used for cash flow hedges [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Net unrealized gain (loss)	$ (3,464)	$ (3,938)

Securities (Details)

Securities (Details) $ in Thousands	Sep. 30, 2017USD ($)security	Dec. 31, 2016USD ($)security
Securities available for sale
Securities available for sale	$ 254,984	$ 267,537
Securities available for sale, Percent	100.00%	100.00%
Available-for-sale Securities Reconciliation [Abstract]
Amortized Cost	$ 253,689	$ 269,039
Gross Unrealized Gains	1,822	773
Gross Unrealized Losses	(527)	(2,275)
Estimated Fair Value	254,984	267,537
Amortized Cost
Due in one year or less	42,320
Due after one year through five years	138,727
Due after five years through ten years	72,022
Due over ten years	620
Amortized Cost	253,689
Fair Value
Due in one year or less	42,423
Due after one year through five years	139,316
Due after five years through ten years	72,625
Due over ten years	620
Fair Value	254,984	$ 267,537
Carrying value of investment securities pledged to collateralize short-term borrowings	$ 30,460
Less than 12 months
Number of securities | security	60	381
Fair Value	$ 48,111	$ 127,446
Unrealized Loss	$ (166)	$ (2,232)
Percentage	0.35%	1.75%
12 months or more
Number of securities | security	69	11
Fair Value	$ 25,420	$ 1,486
Unrealized Loss	$ (361)	$ (43)
Percentage	1.42%	2.89%
Total
Number of securities | security	129	392
Fair Value	$ 73,531	$ 128,932
Unrealized Loss	$ (527)	$ (2,275)
Percentage	0.72%	1.76%
U.S. Treasury [Member]
Securities available for sale
Securities available for sale	$ 39,894	$ 27,482
Securities available for sale, Percent	15.65%	10.27%
Available-for-sale Securities Reconciliation [Abstract]
Amortized Cost	$ 39,823	$ 27,418
Gross Unrealized Gains	90	82
Gross Unrealized Losses	(19)	(18)
Estimated Fair Value	39,894	27,482
Fair Value
Fair Value	$ 39,894	$ 27,482
Less than 12 months
Number of securities | security	4	2
Fair Value	$ 10,006	$ 4,957
Unrealized Loss	$ (19)	$ (18)
Percentage	0.19%	0.36%
12 months or more
Number of securities | security	0	0
Fair Value	$ 0	$ 0
Unrealized Loss	$ 0	$ 0
Percentage	0.00%	0.00%
Total
Number of securities | security	4	2
Fair Value	$ 10,006	$ 4,957
Unrealized Loss	$ (19)	$ (18)
Percentage	0.19%	0.36%
Other securities (FHLB, FHLMC and FNMA) [Member]
Securities available for sale
Securities available for sale	$ 48,759	$ 61,660
Securities available for sale, Percent	19.12%	23.05%
Available-for-sale Securities Reconciliation [Abstract]
Amortized Cost	$ 48,992	$ 62,047
Gross Unrealized Gains	11	65
Gross Unrealized Losses	(244)	(452)
Estimated Fair Value	48,759	61,660
Fair Value
Fair Value	$ 48,759	$ 61,660
Less than 12 months
Number of securities | security	11	14
Fair Value	$ 26,539	$ 34,648
Unrealized Loss	$ (81)	$ (452)
Percentage	0.31%	1.30%
12 months or more
Number of securities | security	4	0
Fair Value	$ 10,208	$ 0
Unrealized Loss	$ (163)	$ 0
Percentage	1.60%	0.00%
Total
Number of securities | security	15	14
Fair Value	$ 36,747	$ 34,648
Unrealized Loss	$ (244)	$ (452)
Percentage	0.66%	1.30%
State and political subdivisions [Member]
Securities available for sale
Securities available for sale	$ 166,331	$ 178,395
Securities available for sale, Percent	65.23%	66.68%
Available-for-sale Securities Reconciliation [Abstract]
Amortized Cost	$ 164,874	$ 179,574
Gross Unrealized Gains	1,721	626
Gross Unrealized Losses	(264)	(1,805)
Estimated Fair Value	166,331	178,395
Fair Value
Fair Value	$ 166,331	$ 178,395
Less than 12 months
Number of securities | security	45	365
Fair Value	$ 11,566	$ 87,841
Unrealized Loss	$ (66)	$ (1,762)
Percentage	0.57%	2.01%
12 months or more
Number of securities | security	65	11
Fair Value	$ 15,212	$ 1,486
Unrealized Loss	$ (198)	$ (43)
Percentage	1.30%	2.89%
Total
Number of securities | security	110	376
Fair Value	$ 26,778	$ 89,327
Unrealized Loss	$ (264)	$ (1,805)
Percentage	0.99%	2.02%

Loans (Details)

Loans (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016	Sep. 30, 2016
Summary of classes of loans (abstract)
Loans and receivable	$ 2,419,894	$ 2,277,148	$ 2,226,932
Net unamortized fees and costs	886	827
Loans and receivable, gross	2,420,780	2,277,975
Less allowance for loan losses	29,350	26,530
Loans and receivable, net	2,391,430	2,251,445
Agricultural [Member]
Summary of classes of loans (abstract)
Loans and receivable	76,484	92,871	88,104
Commercial and financial [Member]
Summary of classes of loans (abstract)
Loans and receivable	214,199	192,995	188,365
Real Estate: Construction, 1 to 4 family residential [Member]
Summary of classes of loans (abstract)
Loans and receivable	73,404	57,864
Real Estate: Construction, land development and commercial [Member]
Summary of classes of loans (abstract)
Loans and receivable	107,170	121,561
Real Estate: Mortgage, farmland [Member]
Summary of classes of loans (abstract)
Loans and receivable	208,982	202,340	$ 193,819
Real Estate: Mortgage, 1 to 4 family first liens [Member]
Summary of classes of loans (abstract)
Loans and receivable	823,529	767,469
Real Estate: Mortgage, 1 to 4 family junior liens [Member]
Summary of classes of loans (abstract)
Loans and receivable	137,271	125,400
Real Estate: Mortgage, multi-family [Member]
Summary of classes of loans (abstract)
Loans and receivable	335,439	302,831
Real Estate: Mortgage, commercial [Member]
Summary of classes of loans (abstract)
Loans and receivable	359,332	334,198
Loans to individuals [Member]
Summary of classes of loans (abstract)
Loans and receivable	26,223	25,157
Obligations of state and political subdivisions [Member]
Summary of classes of loans (abstract)
Loans and receivable	$ 57,861	$ 54,462

Loans, Allowance For Credit Los

Loans, Allowance For Credit Losses (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2016
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Beginning balance	$ 28,950	$ 27,290	$ 26,530	$ 26,510
Charge-offs	(305)	(478)	(1,464)	(1,518)
Recoveries	575	1,160	2,457	3,153
Provision	130	(1,832)	1,827	(2,004)
Ending balance	29,350	26,140	29,350	26,140
Ending balance, individually evaluated for impairment	3,000	2,113	3,000	2,113
Ending balance, collectively evaluated for impairment	26,350	24,027	26,350	24,027
Loan [Abstract]
Total Loans Receivable	2,419,894	2,226,932	2,419,894	2,226,932	$ 2,277,148
Ending balance, individually evaluated for impairment	33,785	35,935	33,785	35,935
Ending balance, collectively evaluated for impairment	2,386,109	2,190,997	2,386,109	2,190,997
Agricultural [Member]
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Beginning balance	2,341	2,997	2,947	3,082
Charge-offs	(27)	(19)	(66)	(44)
Recoveries	56	0	123	173
Provision	92	201	(542)	(434)
Ending balance	2,462	2,777	2,462	2,777
Ending balance, individually evaluated for impairment	653	746	653	746
Ending balance, collectively evaluated for impairment	1,809	2,031	1,809	2,031
Loan [Abstract]
Total Loans Receivable	76,484	88,104	76,484	88,104	92,871
Ending balance, individually evaluated for impairment	6,181	12,276	6,181	12,276
Ending balance, collectively evaluated for impairment	70,303	75,828	70,303	75,828
Commercial and Financial [Member]
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Beginning balance	4,586	4,011	4,531	4,517
Charge-offs	(21)	(38)	(478)	(172)
Recoveries	219	289	882	910
Provision	(43)	(252)	(194)	(1,245)
Ending balance	4,741	4,010	4,741	4,010
Ending balance, individually evaluated for impairment	913	221	913	221
Ending balance, collectively evaluated for impairment	3,828	3,789	3,828	3,789
Loan [Abstract]
Total Loans Receivable	214,199	188,365	214,199	188,365	192,995
Ending balance, individually evaluated for impairment	2,985	2,529	2,985	2,529
Ending balance, collectively evaluated for impairment	211,214	185,836	211,214	185,836
Real Estate: Construction and land development [Member]
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Beginning balance	3,165	2,898	2,890	2,280
Charge-offs	0	0	(114)	0
Recoveries	33	186	443	792
Provision	(182)	(75)	(203)	(63)
Ending balance	3,016	3,009	3,016	3,009
Ending balance, individually evaluated for impairment	46	223	46	223
Ending balance, collectively evaluated for impairment	2,970	2,786	2,970	2,786
Loan [Abstract]
Total Loans Receivable	180,574	178,820	180,574	178,820
Ending balance, individually evaluated for impairment	1,161	2,877	1,161	2,877
Ending balance, collectively evaluated for impairment	179,413	175,943	179,413	175,943
Real Estate: Mortgage, farmland [Member]
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Beginning balance	4,009	3,927	3,417	3,342
Charge-offs	(3)	(105)	(3)	(116)
Recoveries	0	0	0	0
Provision	2	(204)	594	392
Ending balance	4,008	3,618	4,008	3,618
Ending balance, individually evaluated for impairment	784	549	784	549
Ending balance, collectively evaluated for impairment	3,224	3,069	3,224	3,069
Loan [Abstract]
Total Loans Receivable	208,982	193,819	208,982	193,819	$ 202,340
Ending balance, individually evaluated for impairment	8,179	8,371	8,179	8,371
Ending balance, collectively evaluated for impairment	200,803	185,448	200,803	185,448
Real Estate: Mortgage, 1 to 4 family [Member]
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Beginning balance	8,340	8,226	7,677	8,172
Charge-offs	(55)	(176)	(263)	(704)
Recoveries	203	276	570	767
Provision	98	(425)	602	(334)
Ending balance	8,586	7,901	8,586	7,901
Ending balance, individually evaluated for impairment	110	283	110	283
Ending balance, collectively evaluated for impairment	8,476	7,618	8,476	7,618
Loan [Abstract]
Total Loans Receivable	960,800	883,693	960,800	883,693
Ending balance, individually evaluated for impairment	7,097	6,497	7,097	6,497
Ending balance, collectively evaluated for impairment	953,703	877,196	953,703	877,196
Real Estate: Mortgage, multi-family and commercial [Member]
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Beginning balance	5,414	4,201	4,045	4,223
Charge-offs	(86)	0	(130)	(66)
Recoveries	7	358	236	379
Provision	107	(589)	1,291	(566)
Ending balance	5,442	3,970	5,442	3,970
Ending balance, individually evaluated for impairment	409	62	409	62
Ending balance, collectively evaluated for impairment	5,033	3,908	5,033	3,908
Loan [Abstract]
Total Loans Receivable	694,771	619,214	694,771	619,214
Ending balance, individually evaluated for impairment	8,097	3,356	8,097	3,356
Ending balance, collectively evaluated for impairment	686,674	615,858	686,674	615,858
Others [Member]
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Beginning balance	1,095	1,030	1,023	894
Charge-offs	(113)	(140)	(410)	(416)
Recoveries	57	51	203	132
Provision	56	(86)	279	246
Ending balance	1,095	855	1,095	855
Ending balance, individually evaluated for impairment	85	29	85	29
Ending balance, collectively evaluated for impairment	1,010	826	1,010	826
Loan [Abstract]
Total Loans Receivable	84,084	74,917	84,084	74,917
Ending balance, individually evaluated for impairment	85	29	85	29
Ending balance, collectively evaluated for impairment	$ 83,999	$ 74,888	$ 83,999	$ 74,888

Loans, Credit Quality Indicator

Loans, Credit Quality Indicators (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016	Sep. 30, 2016
Summary of credit quality indicators by type of loans [Abstract]
Loans and receivable	$ 2,419,894	$ 2,277,148	$ 2,226,932
Excellent [Member]
Summary of credit quality indicators by type of loans [Abstract]
Loans and receivable	57,302	34,710
Good [Member]
Summary of credit quality indicators by type of loans [Abstract]
Loans and receivable	393,501	349,644
Satisfactory [Member]
Summary of credit quality indicators by type of loans [Abstract]
Loans and receivable	1,569,993	1,513,463
Monitor [Member]
Summary of credit quality indicators by type of loans [Abstract]
Loans and receivable	309,613	263,146
Special Mention [Member]
Summary of credit quality indicators by type of loans [Abstract]
Loans and receivable	35,718	53,892
Substandard [Member]
Summary of credit quality indicators by type of loans [Abstract]
Loans and receivable	53,767	62,293
Agricultural [Member]
Summary of credit quality indicators by type of loans [Abstract]
Loans and receivable	76,484	92,871	88,104
Agricultural [Member] | Excellent [Member]
Summary of credit quality indicators by type of loans [Abstract]
Loans and receivable	2,502	4,205
Agricultural [Member] | Good [Member]
Summary of credit quality indicators by type of loans [Abstract]
Loans and receivable	12,073	13,611
Agricultural [Member] | Satisfactory [Member]
Summary of credit quality indicators by type of loans [Abstract]
Loans and receivable	37,109	40,008
Agricultural [Member] | Monitor [Member]
Summary of credit quality indicators by type of loans [Abstract]
Loans and receivable	14,622	12,699
Agricultural [Member] | Special Mention [Member]
Summary of credit quality indicators by type of loans [Abstract]
Loans and receivable	4,653	8,381
Agricultural [Member] | Substandard [Member]
Summary of credit quality indicators by type of loans [Abstract]
Loans and receivable	5,525	13,967
Commercial and Financial [Member]
Summary of credit quality indicators by type of loans [Abstract]
Loans and receivable	214,199	192,995	188,365
Commercial and Financial [Member] | Excellent [Member]
Summary of credit quality indicators by type of loans [Abstract]
Loans and receivable	10,234	4,241
Commercial and Financial [Member] | Good [Member]
Summary of credit quality indicators by type of loans [Abstract]
Loans and receivable	47,103	43,472
Commercial and Financial [Member] | Satisfactory [Member]
Summary of credit quality indicators by type of loans [Abstract]
Loans and receivable	117,612	108,800
Commercial and Financial [Member] | Monitor [Member]
Summary of credit quality indicators by type of loans [Abstract]
Loans and receivable	28,619	20,023
Commercial and Financial [Member] | Special Mention [Member]
Summary of credit quality indicators by type of loans [Abstract]
Loans and receivable	5,410	11,177
Commercial and Financial [Member] | Substandard [Member]
Summary of credit quality indicators by type of loans [Abstract]
Loans and receivable	5,221	5,282
Real Estate: Construction, 1 to 4 family residential [Member]
Summary of credit quality indicators by type of loans [Abstract]
Loans and receivable	73,404	57,864
Real Estate: Construction, 1 to 4 family residential [Member] | Excellent [Member]
Summary of credit quality indicators by type of loans [Abstract]
Loans and receivable	548	0
Real Estate: Construction, 1 to 4 family residential [Member] | Good [Member]
Summary of credit quality indicators by type of loans [Abstract]
Loans and receivable	6,773	1,701
Real Estate: Construction, 1 to 4 family residential [Member] | Satisfactory [Member]
Summary of credit quality indicators by type of loans [Abstract]
Loans and receivable	49,639	44,138
Real Estate: Construction, 1 to 4 family residential [Member] | Monitor [Member]
Summary of credit quality indicators by type of loans [Abstract]
Loans and receivable	15,248	8,896
Real Estate: Construction, 1 to 4 family residential [Member] | Special Mention [Member]
Summary of credit quality indicators by type of loans [Abstract]
Loans and receivable	897	972
Real Estate: Construction, 1 to 4 family residential [Member] | Substandard [Member]
Summary of credit quality indicators by type of loans [Abstract]
Loans and receivable	299	2,157
Real Estate: Construction, land development and commercial [Member]
Summary of credit quality indicators by type of loans [Abstract]
Loans and receivable	107,170	121,561
Real Estate: Construction, land development and commercial [Member] | Excellent [Member]
Summary of credit quality indicators by type of loans [Abstract]
Loans and receivable	2,950	244
Real Estate: Construction, land development and commercial [Member] | Good [Member]
Summary of credit quality indicators by type of loans [Abstract]
Loans and receivable	26,216	25,337
Real Estate: Construction, land development and commercial [Member] | Satisfactory [Member]
Summary of credit quality indicators by type of loans [Abstract]
Loans and receivable	41,317	46,758
Real Estate: Construction, land development and commercial [Member] | Monitor [Member]
Summary of credit quality indicators by type of loans [Abstract]
Loans and receivable	33,226	44,487
Real Estate: Construction, land development and commercial [Member] | Special Mention [Member]
Summary of credit quality indicators by type of loans [Abstract]
Loans and receivable	2,607	4,250
Real Estate: Construction, land development and commercial [Member] | Substandard [Member]
Summary of credit quality indicators by type of loans [Abstract]
Loans and receivable	854	485
Real Estate: Mortgage, farmland [Member]
Summary of credit quality indicators by type of loans [Abstract]
Loans and receivable	208,982	202,340	$ 193,819
Real Estate: Mortgage, farmland [Member] | Excellent [Member]
Summary of credit quality indicators by type of loans [Abstract]
Loans and receivable	5,102	2,916
Real Estate: Mortgage, farmland [Member] | Good [Member]
Summary of credit quality indicators by type of loans [Abstract]
Loans and receivable	52,634	47,569
Real Estate: Mortgage, farmland [Member] | Satisfactory [Member]
Summary of credit quality indicators by type of loans [Abstract]
Loans and receivable	105,155	105,971
Real Estate: Mortgage, farmland [Member] | Monitor [Member]
Summary of credit quality indicators by type of loans [Abstract]
Loans and receivable	34,985	29,778
Real Estate: Mortgage, farmland [Member] | Special Mention [Member]
Summary of credit quality indicators by type of loans [Abstract]
Loans and receivable	2,434	7,004
Real Estate: Mortgage, farmland [Member] | Substandard [Member]
Summary of credit quality indicators by type of loans [Abstract]
Loans and receivable	8,672	9,102
Real Estate: Mortgage, 1 to 4 family first liens [Member]
Summary of credit quality indicators by type of loans [Abstract]
Loans and receivable	823,529	767,469
Real Estate: Mortgage, 1 to 4 family first liens [Member] | Excellent [Member]
Summary of credit quality indicators by type of loans [Abstract]
Loans and receivable	2,064	1,196
Real Estate: Mortgage, 1 to 4 family first liens [Member] | Good [Member]
Summary of credit quality indicators by type of loans [Abstract]
Loans and receivable	29,490	15,725
Real Estate: Mortgage, 1 to 4 family first liens [Member] | Satisfactory [Member]
Summary of credit quality indicators by type of loans [Abstract]
Loans and receivable	681,699	647,191
Real Estate: Mortgage, 1 to 4 family first liens [Member] | Monitor [Member]
Summary of credit quality indicators by type of loans [Abstract]
Loans and receivable	77,461	66,164
Real Estate: Mortgage, 1 to 4 family first liens [Member] | Special Mention [Member]
Summary of credit quality indicators by type of loans [Abstract]
Loans and receivable	11,136	12,914
Real Estate: Mortgage, 1 to 4 family first liens [Member] | Substandard [Member]
Summary of credit quality indicators by type of loans [Abstract]
Loans and receivable	21,679	24,279
Real Estate: Mortgage, 1 to 4 family junior liens [Member]
Summary of credit quality indicators by type of loans [Abstract]
Loans and receivable	137,271	125,400
Real Estate: Mortgage, 1 to 4 family junior liens [Member] | Excellent [Member]
Summary of credit quality indicators by type of loans [Abstract]
Loans and receivable	494	65
Real Estate: Mortgage, 1 to 4 family junior liens [Member] | Good [Member]
Summary of credit quality indicators by type of loans [Abstract]
Loans and receivable	3,569	3,002
Real Estate: Mortgage, 1 to 4 family junior liens [Member] | Satisfactory [Member]
Summary of credit quality indicators by type of loans [Abstract]
Loans and receivable	124,625	113,433
Real Estate: Mortgage, 1 to 4 family junior liens [Member] | Monitor [Member]
Summary of credit quality indicators by type of loans [Abstract]
Loans and receivable	4,869	4,877
Real Estate: Mortgage, 1 to 4 family junior liens [Member] | Special Mention [Member]
Summary of credit quality indicators by type of loans [Abstract]
Loans and receivable	1,328	1,566
Real Estate: Mortgage, 1 to 4 family junior liens [Member] | Substandard [Member]
Summary of credit quality indicators by type of loans [Abstract]
Loans and receivable	2,386	2,457
Real Estate: Mortgage, multi-family [Member]
Summary of credit quality indicators by type of loans [Abstract]
Loans and receivable	335,439	302,831
Real Estate: Mortgage, multi-family [Member] | Excellent [Member]
Summary of credit quality indicators by type of loans [Abstract]
Loans and receivable	5,712	5,970
Real Estate: Mortgage, multi-family [Member] | Good [Member]
Summary of credit quality indicators by type of loans [Abstract]
Loans and receivable	82,368	71,822
Real Estate: Mortgage, multi-family [Member] | Satisfactory [Member]
Summary of credit quality indicators by type of loans [Abstract]
Loans and receivable	188,549	180,651
Real Estate: Mortgage, multi-family [Member] | Monitor [Member]
Summary of credit quality indicators by type of loans [Abstract]
Loans and receivable	52,341	40,444
Real Estate: Mortgage, multi-family [Member] | Special Mention [Member]
Summary of credit quality indicators by type of loans [Abstract]
Loans and receivable	0	3,636
Real Estate: Mortgage, multi-family [Member] | Substandard [Member]
Summary of credit quality indicators by type of loans [Abstract]
Loans and receivable	6,469	308
Real Estate: Mortgage, commercial [Member]
Summary of credit quality indicators by type of loans [Abstract]
Loans and receivable	359,332	334,198
Real Estate: Mortgage, commercial [Member] | Excellent [Member]
Summary of credit quality indicators by type of loans [Abstract]
Loans and receivable	18,735	15,873
Real Estate: Mortgage, commercial [Member] | Good [Member]
Summary of credit quality indicators by type of loans [Abstract]
Loans and receivable	103,662	89,801
Real Estate: Mortgage, commercial [Member] | Satisfactory [Member]
Summary of credit quality indicators by type of loans [Abstract]
Loans and receivable	183,140	185,650
Real Estate: Mortgage, commercial [Member] | Monitor [Member]
Summary of credit quality indicators by type of loans [Abstract]
Loans and receivable	44,316	34,979
Real Estate: Mortgage, commercial [Member] | Special Mention [Member]
Summary of credit quality indicators by type of loans [Abstract]
Loans and receivable	7,037	3,797
Real Estate: Mortgage, commercial [Member] | Substandard [Member]
Summary of credit quality indicators by type of loans [Abstract]
Loans and receivable	2,442	4,098
Loans to individuals [Member]
Summary of credit quality indicators by type of loans [Abstract]
Loans and receivable	26,223	25,157
Loans to individuals [Member] | Excellent [Member]
Summary of credit quality indicators by type of loans [Abstract]
Loans and receivable	0	0
Loans to individuals [Member] | Good [Member]
Summary of credit quality indicators by type of loans [Abstract]
Loans and receivable	476	65
Loans to individuals [Member] | Satisfactory [Member]
Summary of credit quality indicators by type of loans [Abstract]
Loans and receivable	24,962	24,446
Loans to individuals [Member] | Monitor [Member]
Summary of credit quality indicators by type of loans [Abstract]
Loans and receivable	349	293
Loans to individuals [Member] | Special Mention [Member]
Summary of credit quality indicators by type of loans [Abstract]
Loans and receivable	216	195
Loans to individuals [Member] | Substandard [Member]
Summary of credit quality indicators by type of loans [Abstract]
Loans and receivable	220	158
Obligations of state and political subdivisions [Member]
Summary of credit quality indicators by type of loans [Abstract]
Loans and receivable	57,861	54,462
Obligations of state and political subdivisions [Member] | Excellent [Member]
Summary of credit quality indicators by type of loans [Abstract]
Loans and receivable	8,961	0
Obligations of state and political subdivisions [Member] | Good [Member]
Summary of credit quality indicators by type of loans [Abstract]
Loans and receivable	29,137	37,539
Obligations of state and political subdivisions [Member] | Satisfactory [Member]
Summary of credit quality indicators by type of loans [Abstract]
Loans and receivable	16,186	16,417
Obligations of state and political subdivisions [Member] | Monitor [Member]
Summary of credit quality indicators by type of loans [Abstract]
Loans and receivable	3,577	506
Obligations of state and political subdivisions [Member] | Special Mention [Member]
Summary of credit quality indicators by type of loans [Abstract]
Loans and receivable	0	0
Obligations of state and political subdivisions [Member] | Substandard [Member]
Summary of credit quality indicators by type of loans [Abstract]
Loans and receivable	$ 0	$ 0

Loans, Past Due Receivables (De

Loans, Past Due Receivables (Details) $ in Thousands	Sep. 30, 2017USD ($)	Dec. 31, 2016USD ($)	Sep. 30, 2016USD ($)
Financing Receivable, Recorded Investment, Past Due [Line Items]
Number of accruing loans past due 90 days or more	10	6
Schedule of past due loans [Abstract]
Total Past Due	$ 12,288	$ 12,239
Current	2,407,606	2,264,909
Total Loans Receivable	2,419,894	2,277,148	$ 2,226,932
Accruing Loans Past Due 90 Days or More	1,791	635
Agricultural [Member]
Schedule of past due loans [Abstract]
Total Past Due	1,393	358
Current	75,091	92,513
Total Loans Receivable	76,484	92,871	88,104
Accruing Loans Past Due 90 Days or More	1,121	0
Commercial and Financial [Member]
Schedule of past due loans [Abstract]
Total Past Due	906	863
Current	213,293	192,132
Total Loans Receivable	214,199	192,995	188,365
Accruing Loans Past Due 90 Days or More	200	0
Real Estate: Construction, 1 to 4 family residential [Member]
Schedule of past due loans [Abstract]
Total Past Due	22	0
Current	73,382	57,864
Total Loans Receivable	73,404	57,864
Accruing Loans Past Due 90 Days or More	0	0
Real Estate: Construction, land development and commercial [Member]
Schedule of past due loans [Abstract]
Total Past Due	3,320	316
Current	103,850	121,245
Total Loans Receivable	107,170	121,561
Accruing Loans Past Due 90 Days or More	0	0
Real Estate: Mortgage, farmland [Member]
Schedule of past due loans [Abstract]
Total Past Due	1,438	319
Current	207,544	202,021
Total Loans Receivable	208,982	202,340	$ 193,819
Accruing Loans Past Due 90 Days or More	0	0
Real Estate: Mortgage, 1 to 4 family first liens [Member]
Schedule of past due loans [Abstract]
Total Past Due	4,546	8,570
Current	818,983	758,899
Total Loans Receivable	823,529	767,469
Accruing Loans Past Due 90 Days or More	412	192
Real Estate: Mortgage, 1 to 4 family junior liens [Member]
Schedule of past due loans [Abstract]
Total Past Due	400	960
Current	136,871	124,440
Total Loans Receivable	137,271	125,400
Accruing Loans Past Due 90 Days or More	58	443
Real Estate: Mortgage, multi-family [Member]
Schedule of past due loans [Abstract]
Total Past Due	0	40
Current	335,439	302,791
Total Loans Receivable	335,439	302,831
Accruing Loans Past Due 90 Days or More	0	0
Real Estate: Mortgage, commercial [Member]
Schedule of past due loans [Abstract]
Total Past Due	158	578
Current	359,174	333,620
Total Loans Receivable	359,332	334,198
Accruing Loans Past Due 90 Days or More	0	0
Loans to individuals [Member]
Schedule of past due loans [Abstract]
Total Past Due	105	235
Current	26,118	24,922
Total Loans Receivable	26,223	25,157
Accruing Loans Past Due 90 Days or More	0	0
Obligations of state and political subdivisions [Member]
Schedule of past due loans [Abstract]
Total Past Due	0	0
Current	57,861	54,462
Total Loans Receivable	57,861	54,462
Accruing Loans Past Due 90 Days or More	0	0
30 - 59 Days Past Due [Member]
Schedule of past due loans [Abstract]
Total Past Due	4,817	6,952
30 - 59 Days Past Due [Member] | Agricultural [Member]
Schedule of past due loans [Abstract]
Total Past Due	3	56
30 - 59 Days Past Due [Member] | Commercial and Financial [Member]
Schedule of past due loans [Abstract]
Total Past Due	380	24
30 - 59 Days Past Due [Member] | Real Estate: Construction, 1 to 4 family residential [Member]
Schedule of past due loans [Abstract]
Total Past Due	0	0
30 - 59 Days Past Due [Member] | Real Estate: Construction, land development and commercial [Member]
Schedule of past due loans [Abstract]
Total Past Due	3,320	0
30 - 59 Days Past Due [Member] | Real Estate: Mortgage, farmland [Member]
Schedule of past due loans [Abstract]
Total Past Due	0	319
30 - 59 Days Past Due [Member] | Real Estate: Mortgage, 1 to 4 family first liens [Member]
Schedule of past due loans [Abstract]
Total Past Due	733	5,649
30 - 59 Days Past Due [Member] | Real Estate: Mortgage, 1 to 4 family junior liens [Member]
Schedule of past due loans [Abstract]
Total Past Due	201	330
30 - 59 Days Past Due [Member] | Real Estate: Mortgage, multi-family [Member]
Schedule of past due loans [Abstract]
Total Past Due	0	0
30 - 59 Days Past Due [Member] | Real Estate: Mortgage, commercial [Member]
Schedule of past due loans [Abstract]
Total Past Due	142	371
30 - 59 Days Past Due [Member] | Loans to individuals [Member]
Schedule of past due loans [Abstract]
Total Past Due	38	203
30 - 59 Days Past Due [Member] | Obligations of state and political subdivisions [Member]
Schedule of past due loans [Abstract]
Total Past Due	0	0
60 - 89 Days Past Due [Member]
Schedule of past due loans [Abstract]
Total Past Due	3,444	1,413
60 - 89 Days Past Due [Member] | Agricultural [Member]
Schedule of past due loans [Abstract]
Total Past Due	23	0
60 - 89 Days Past Due [Member] | Commercial and Financial [Member]
Schedule of past due loans [Abstract]
Total Past Due	262	121
60 - 89 Days Past Due [Member] | Real Estate: Construction, 1 to 4 family residential [Member]
Schedule of past due loans [Abstract]
Total Past Due	22	0
60 - 89 Days Past Due [Member] | Real Estate: Construction, land development and commercial [Member]
Schedule of past due loans [Abstract]
Total Past Due	0	231
60 - 89 Days Past Due [Member] | Real Estate: Mortgage, farmland [Member]
Schedule of past due loans [Abstract]
Total Past Due	1,355	0
60 - 89 Days Past Due [Member] | Real Estate: Mortgage, 1 to 4 family first liens [Member]
Schedule of past due loans [Abstract]
Total Past Due	1,578	978
60 - 89 Days Past Due [Member] | Real Estate: Mortgage, 1 to 4 family junior liens [Member]
Schedule of past due loans [Abstract]
Total Past Due	137	51
60 - 89 Days Past Due [Member] | Real Estate: Mortgage, multi-family [Member]
Schedule of past due loans [Abstract]
Total Past Due	0	0
60 - 89 Days Past Due [Member] | Real Estate: Mortgage, commercial [Member]
Schedule of past due loans [Abstract]
Total Past Due	0	0
60 - 89 Days Past Due [Member] | Loans to individuals [Member]
Schedule of past due loans [Abstract]
Total Past Due	67	32
60 - 89 Days Past Due [Member] | Obligations of state and political subdivisions [Member]
Schedule of past due loans [Abstract]
Total Past Due	0	0
90 Days or More Past Due [Member]
Schedule of past due loans [Abstract]
Total Past Due	4,027	3,874
90 Days or More Past Due [Member] | Agricultural [Member]
Schedule of past due loans [Abstract]
Total Past Due	1,367	302
90 Days or More Past Due [Member] | Commercial and Financial [Member]
Schedule of past due loans [Abstract]
Total Past Due	264	718
90 Days or More Past Due [Member] | Real Estate: Construction, 1 to 4 family residential [Member]
Schedule of past due loans [Abstract]
Total Past Due	0	0
90 Days or More Past Due [Member] | Real Estate: Construction, land development and commercial [Member]
Schedule of past due loans [Abstract]
Total Past Due	0	85
90 Days or More Past Due [Member] | Real Estate: Mortgage, farmland [Member]
Schedule of past due loans [Abstract]
Total Past Due	83	0
90 Days or More Past Due [Member] | Real Estate: Mortgage, 1 to 4 family first liens [Member]
Schedule of past due loans [Abstract]
Total Past Due	2,235	1,943
90 Days or More Past Due [Member] | Real Estate: Mortgage, 1 to 4 family junior liens [Member]
Schedule of past due loans [Abstract]
Total Past Due	62	579
90 Days or More Past Due [Member] | Real Estate: Mortgage, multi-family [Member]
Schedule of past due loans [Abstract]
Total Past Due	0	40
90 Days or More Past Due [Member] | Real Estate: Mortgage, commercial [Member]
Schedule of past due loans [Abstract]
Total Past Due	16	207
90 Days or More Past Due [Member] | Loans to individuals [Member]
Schedule of past due loans [Abstract]
Total Past Due	0	0
90 Days or More Past Due [Member] | Obligations of state and political subdivisions [Member]
Schedule of past due loans [Abstract]
Total Past Due	$ 0	$ 0

Loans, Impaired Financing Recei

Loans, Impaired Financing Receivable Loan Type (Details) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2017USD ($)	Sep. 30, 2017USD ($)	Dec. 31, 2016USD ($)
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Average Recorded Investment	$ 34,789	$ 34,024
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	21,020	20,576
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	13,769	13,448
Summary of certain impaired loan information [Abstract]
Non-accrual loans	9,337	9,337	$ 9,938
Accruing loans past due 90 days or more	1,791	1,791	635
TDR loans	$ 8,570	8,570	$ 5,408
Decrease accruing loans past due 90 days or more		$ 1,160
Number of accruing loans past due 90 days or more	10	10	6
Average 90 days or more past due loan balance	$ 180	$ 180	$ 110
Impaired Financing Receivable, with No Related Allowance, Interest Income, Accrual Method	147	48
Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method	707	234
Impaired Financing Receivable, Interest Income, Accrual Method	854	282
Agricultural [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Average Recorded Investment	6,675	6,258
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	4,897	4,491
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	1,778	1,767
Summary of certain impaired loan information [Abstract]
Non-accrual loans	1,656	1,656	1,741
Accruing loans past due 90 days or more	1,121	1,121	0
TDR loans	2,446	2,446	91
Impaired Financing Receivable, with No Related Allowance, Interest Income, Accrual Method	3	1
Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method	169	53
Impaired Financing Receivable, Interest Income, Accrual Method	172	54
Commercial and financial [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Average Recorded Investment	3,330	3,118
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	1,732	1,743
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	1,598	1,375
Summary of certain impaired loan information [Abstract]
Non-accrual loans	947	947	1,354
Accruing loans past due 90 days or more	200	200	0
TDR loans	1,839	1,839	1,057
Impaired Financing Receivable, with No Related Allowance, Interest Income, Accrual Method	17	5
Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method	62	21
Impaired Financing Receivable, Interest Income, Accrual Method	79	26
Real Estate: Construction, 1 to 4 family residential [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Average Recorded Investment	252	296
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	136	180
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	116	116
Summary of certain impaired loan information [Abstract]
Non-accrual loans	0	0	0
Accruing loans past due 90 days or more	0	0	0
TDR loans	0	0	265
Impaired Financing Receivable, with No Related Allowance, Interest Income, Accrual Method	4	1
Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method	5	2
Impaired Financing Receivable, Interest Income, Accrual Method	9	3
Real Estate: Construction, land development and commercial [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Average Recorded Investment	666	696
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	321	354
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	345	342
Summary of certain impaired loan information [Abstract]
Non-accrual loans	0	0	85
Accruing loans past due 90 days or more	0	0	0
TDR loans	341	341	118
Impaired Financing Receivable, with No Related Allowance, Interest Income, Accrual Method	10	3
Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method	11	4
Impaired Financing Receivable, Interest Income, Accrual Method	21	7
Real Estate: Mortgage, farmland [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Average Recorded Investment	8,180	8,187
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	5,667	5,584
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	2,513	2,603
Summary of certain impaired loan information [Abstract]
Non-accrual loans	1,454	1,454	1,205
Accruing loans past due 90 days or more	0	0	0
TDR loans	1,462	1,462	1,389
Impaired Financing Receivable, with No Related Allowance, Interest Income, Accrual Method	42	14
Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method	183	61
Impaired Financing Receivable, Interest Income, Accrual Method	225	75
Real Estate: Mortgage, 1 to 4 family first liens [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Average Recorded Investment	7,195	7,079
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	1,761	1,743
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	5,434	5,336
Summary of certain impaired loan information [Abstract]
Non-accrual loans	4,415	4,415	4,097
Accruing loans past due 90 days or more	412	412	192
TDR loans	1,399	1,399	1,375
Impaired Financing Receivable, with No Related Allowance, Interest Income, Accrual Method	37	13
Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method	54	17
Impaired Financing Receivable, Interest Income, Accrual Method	91	30
Real Estate: Mortgage, 1 to 4 family junior liens [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Average Recorded Investment	111	96
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	86	83
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	25	13
Summary of certain impaired loan information [Abstract]
Non-accrual loans	12	12	136
Accruing loans past due 90 days or more	58	58	443
TDR loans	26	26	26
Impaired Financing Receivable, with No Related Allowance, Interest Income, Accrual Method	0	0
Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method	3	1
Impaired Financing Receivable, Interest Income, Accrual Method	3	1
Real Estate: Mortgage, multi-family [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Average Recorded Investment	6,484	6,454
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	6,251	6,228
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	233	226
Summary of certain impaired loan information [Abstract]
Non-accrual loans	223	223	243
Accruing loans past due 90 days or more	0	0	0
TDR loans	0	0	0
Impaired Financing Receivable, with No Related Allowance, Interest Income, Accrual Method	0	0
Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method	210	71
Impaired Financing Receivable, Interest Income, Accrual Method	210	71
Real Estate: Mortgage, commercial [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Average Recorded Investment	1,808	1,750
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	81	80
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	1,727	1,670
Summary of certain impaired loan information [Abstract]
Non-accrual loans	630	630	1,077
Accruing loans past due 90 days or more	0	0	0
TDR loans	1,057	1,057	1,087
Impaired Financing Receivable, with No Related Allowance, Interest Income, Accrual Method	34	11
Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method	3	1
Impaired Financing Receivable, Interest Income, Accrual Method	37	12
Loans to individuals [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Average Recorded Investment	88	90
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	88	90
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	0	0
Summary of certain impaired loan information [Abstract]
Accruing loans past due 90 days or more	0	0	0
Impaired Financing Receivable, with No Related Allowance, Interest Income, Accrual Method	0	0
Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method	7	3
Impaired Financing Receivable, Interest Income, Accrual Method	7	3
Troubled Debt Restructuring [Member]
Summary of certain impaired loan information [Abstract]
TDR Loans included within nonaccrual loans	$ 3,760	$ 3,760	$ 4,230

Loans, Troubled Debt Restructur

Loans, Troubled Debt Restructuring (Details)	3 Months Ended	9 Months Ended	12 Months Ended
	Sep. 30, 2017USD ($)contract	Sep. 30, 2017USD ($)contract	Dec. 31, 2016USD ($)contract
Summary of information for TDR loans [Abstract]
Number of contracts | contract		55	52
Recorded investment	$ 12,330,000	$ 12,330,000	$ 9,637,000
Commitments outstanding	$ 1,392,000	$ 1,392,000	1,681,000
Summary of troubled debt restructuring loans were modified [Abstract]
Number of contracts | contract	4	15
Pre-modification recorded investment	$ 1,557,000	$ 13,620,000
Post-modification recorded investment	1,557,000	13,620,000
TDR loans default payment		$ 0	$ 0
Agricultural [Member]
Summary of information for TDR loans [Abstract]
Number of contracts | contract		9	4
Recorded investment	3,762,000	$ 3,762,000	$ 1,460,000
Commitments outstanding	$ 267,000	$ 267,000	$ 167,000
Summary of troubled debt restructuring loans were modified [Abstract]
Number of contracts | contract	0	6
Pre-modification recorded investment	$ 0	$ 10,890,000
Post-modification recorded investment	0	$ 10,890,000
Commercial and Financial [Member]
Summary of information for TDR loans [Abstract]
Number of contracts | contract		15	14
Recorded investment	2,526,000	$ 2,526,000	$ 2,053,000
Commitments outstanding	$ 157,000	$ 157,000	$ 117,000
Summary of troubled debt restructuring loans were modified [Abstract]
Number of contracts | contract	3	4
Pre-modification recorded investment	$ 1,451,000	$ 1,546,000
Post-modification recorded investment	1,451,000	$ 1,546,000
Real Estate: Construction, 1 to 4 family residential [Member]
Summary of information for TDR loans [Abstract]
Number of contracts | contract		0	3
Recorded investment	0	$ 0	$ 265,000
Commitments outstanding	$ 193,000	$ 193,000	$ 1,225,000
Summary of troubled debt restructuring loans were modified [Abstract]
Number of contracts | contract	0	0
Pre-modification recorded investment	$ 0	$ 0
Post-modification recorded investment	0	$ 0
Real Estate: Construction, land development and commercial [Member]
Summary of information for TDR loans [Abstract]
Number of contracts | contract		2	1
Recorded investment	341,000	$ 341,000	$ 118,000
Commitments outstanding	$ 721,000	$ 721,000	$ 107,000
Summary of troubled debt restructuring loans were modified [Abstract]
Number of contracts | contract	0	1
Pre-modification recorded investment	$ 0	$ 231,000
Post-modification recorded investment	0	$ 231,000
Real Estate: Mortgage, farmland [Member]
Summary of information for TDR loans [Abstract]
Number of contracts | contract		7	7
Recorded investment	2,834,000	$ 2,834,000	$ 2,594,000
Commitments outstanding	$ 0	$ 0	$ 0
Summary of troubled debt restructuring loans were modified [Abstract]
Number of contracts | contract	0	2
Pre-modification recorded investment	$ 0	$ 598,000
Post-modification recorded investment	0	$ 598,000
Real Estate: Mortgage, 1 to 4 family first liens [Member]
Summary of information for TDR loans [Abstract]
Number of contracts | contract		13	12
Recorded investment	1,486,000	$ 1,486,000	$ 1,471,000
Commitments outstanding	$ 0	$ 0	$ 0
Summary of troubled debt restructuring loans were modified [Abstract]
Number of contracts | contract	1	1
Pre-modification recorded investment	$ 106,000	$ 106,000
Post-modification recorded investment	106,000	$ 106,000
Real Estate: Mortgage, 1 to 4 family junior liens [Member]
Summary of information for TDR loans [Abstract]
Number of contracts | contract		1	1
Recorded investment	26,000	$ 26,000	$ 26,000
Commitments outstanding	$ 54,000	$ 54,000	$ 65,000
Summary of troubled debt restructuring loans were modified [Abstract]
Number of contracts | contract	0	0
Pre-modification recorded investment	$ 0	$ 0
Post-modification recorded investment	0	$ 0
Real Estate: Mortgage, multi-family [Member]
Summary of information for TDR loans [Abstract]
Number of contracts | contract		0	0
Recorded investment	0	$ 0	$ 0
Commitments outstanding	$ 0	$ 0	$ 0
Summary of troubled debt restructuring loans were modified [Abstract]
Number of contracts | contract	0	1
Pre-modification recorded investment	$ 0	$ 249,000
Post-modification recorded investment	0	$ 249,000
Real Estate: Mortgage, commercial [Member]
Summary of information for TDR loans [Abstract]
Number of contracts | contract		8	10
Recorded investment	1,355,000	$ 1,355,000	$ 1,650,000
Commitments outstanding	$ 0	$ 0	$ 0
Summary of troubled debt restructuring loans were modified [Abstract]
Number of contracts | contract	0	0
Pre-modification recorded investment	$ 0	$ 0
Post-modification recorded investment	0	$ 0
Loans to individuals [Member]
Summary of information for TDR loans [Abstract]
Number of contracts | contract		0	0
Recorded investment	0	$ 0	$ 0
Commitments outstanding	$ 0	$ 0	$ 0

Loans, Impaired Financing Rec37

Loans, Impaired Financing Receivables Activity (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2017	Dec. 31, 2016
Recorded Investment
With no related allowance recorded	$ 13,237	$ 13,237	$ 12,563
With an allowance recorded	20,548	20,548	21,101
Total impaired loans	33,785	33,785	33,664
Unpaid Principal Balance
With no related allowance recorded	17,274	17,274	16,365
With an allowance recorded	20,782	20,782	21,377
Total	38,056	38,056	37,742
Related Allowance
With no related allowance recorded	0	0	0
With an allowance recorded	3,000	3,000	2,343
Total	3,000	3,000	$ 2,343
Average Recorded Investment
With no related allowance recorded	13,769	13,448
With an allowance recorded	21,020	20,576
Total	34,789	34,024
Interest Income Recognized
With no related allowance recorded	147	48
With an allowance recorded	707	234
Total	$ 854	282
Decrease in impaired loans		$ 120
Percentages of impaired loans to loans held for investment (in hundredths)	1.40%	1.40%	1.48%
Decrease in nonaccrual loans		$ 600
Increase in TDR Loans		$ 3,160
Prior period within which impairment is being measured		1 year
Number of period within which average appraisals obtained		1 month
Agricultural and Farmland Real Estate [Member]
Interest Income Recognized
Decrease in impaired loans		$ 3,600
Agricultural [Member]
Recorded Investment
With no related allowance recorded	$ 1,739	1,739	$ 800
With an allowance recorded	4,442	4,442	10,920
Total impaired loans	6,181	6,181	11,720
Unpaid Principal Balance
With no related allowance recorded	1,981	1,981	971
With an allowance recorded	4,503	4,503	10,978
Total	6,484	6,484	11,949
Related Allowance
With no related allowance recorded	0	0	0
With an allowance recorded	653	653	856
Total	653	653	856
Average Recorded Investment
With no related allowance recorded	1,778	1,767
With an allowance recorded	4,897	4,491
Total	6,675	6,258
Interest Income Recognized
With no related allowance recorded	3	1
With an allowance recorded	169	53
Total	172	54
Commercial and Financial [Member]
Recorded Investment
With no related allowance recorded	1,333	1,333	1,540
With an allowance recorded	1,652	1,652	937
Total impaired loans	2,985	2,985	2,477
Unpaid Principal Balance
With no related allowance recorded	2,047	2,047	2,175
With an allowance recorded	1,698	1,698	955
Total	3,745	3,745	3,130
Related Allowance
With no related allowance recorded	0	0	0
With an allowance recorded	913	913	718
Total	913	913	718
Average Recorded Investment
With no related allowance recorded	1,598	1,375
With an allowance recorded	1,732	1,743
Total	3,330	3,118
Interest Income Recognized
With no related allowance recorded	17	5
With an allowance recorded	62	21
Total	79	26
Real Estate: Construction, 1 to 4 family residential [Member]
Recorded Investment
With no related allowance recorded	116	116	117
With an allowance recorded	199	199	815
Total impaired loans	315	315	932
Unpaid Principal Balance
With no related allowance recorded	151	151	151
With an allowance recorded	199	199	815
Total	350	350	966
Related Allowance
With no related allowance recorded	0	0	0
With an allowance recorded	13	13	105
Total	13	13	105
Average Recorded Investment
With no related allowance recorded	116	116
With an allowance recorded	136	180
Total	252	296
Interest Income Recognized
With no related allowance recorded	4	1
With an allowance recorded	5	2
Total	9	3
Real Estate: Construction, land development and commercial [Member]
Recorded Investment
With no related allowance recorded	341	341	204
With an allowance recorded	505	505	0
Total impaired loans	846	846	204
Unpaid Principal Balance
With no related allowance recorded	374	374	290
With an allowance recorded	505	505	0
Total	879	879	290
Related Allowance
With no related allowance recorded	0	0	0
With an allowance recorded	33	33	0
Total	33	33	0
Average Recorded Investment
With no related allowance recorded	345	342
With an allowance recorded	321	354
Total	666	696
Interest Income Recognized
With no related allowance recorded	10	3
With an allowance recorded	11	4
Total	21	7
Real Estate: Mortgage, farmland [Member]
Recorded Investment
With no related allowance recorded	2,598	2,598	2,594
With an allowance recorded	5,581	5,581	5,434
Total impaired loans	8,179	8,179	8,028
Unpaid Principal Balance
With no related allowance recorded	2,925	2,925	2,887
With an allowance recorded	5,581	5,581	5,434
Total	8,506	8,506	8,321
Related Allowance
With no related allowance recorded	0	0	0
With an allowance recorded	784	784	390
Total	784	784	390
Average Recorded Investment
With no related allowance recorded	2,513	2,603
With an allowance recorded	5,667	5,584
Total	8,180	8,187
Interest Income Recognized
With no related allowance recorded	42	14
With an allowance recorded	183	61
Total	225	75
Real Estate: Mortgage, 1 to 4 family first liens [Member]
Recorded Investment
With no related allowance recorded	5,268	5,268	5,011
With an allowance recorded	1,734	1,734	1,266
Total impaired loans	7,002	7,002	6,277
Unpaid Principal Balance
With no related allowance recorded	6,640	6,640	6,137
With an allowance recorded	1,861	1,861	1,374
Total	8,501	8,501	7,511
Related Allowance
With no related allowance recorded	0	0	0
With an allowance recorded	106	106	79
Total	106	106	79
Average Recorded Investment
With no related allowance recorded	5,434	5,336
With an allowance recorded	1,761	1,743
Total	7,195	7,079
Interest Income Recognized
With no related allowance recorded	37	13
With an allowance recorded	54	17
Total	91	30
Real Estate: Mortgage, 1 to 4 family junior liens [Member]
Recorded Investment
With no related allowance recorded	12	12	153
With an allowance recorded	83	83	612
Total impaired loans	95	95	765
Unpaid Principal Balance
With no related allowance recorded	485	485	646
With an allowance recorded	83	83	667
Total	568	568	1,313
Related Allowance
With no related allowance recorded	0	0	0
With an allowance recorded	4	4	11
Total	4	4	11
Average Recorded Investment
With no related allowance recorded	25	13
With an allowance recorded	86	83
Total	111	96
Interest Income Recognized
With no related allowance recorded	0	0
With an allowance recorded	3	1
Total	3	1
Real Estate: Mortgage, multi-family [Member]
Recorded Investment
With no related allowance recorded	223	223	243
With an allowance recorded	6,187	6,187	0
Total impaired loans	6,410	6,410	243
Unpaid Principal Balance
With no related allowance recorded	357	357	362
With an allowance recorded	6,187	6,187	0
Total	6,544	6,544	362
Related Allowance
With no related allowance recorded	0	0	0
With an allowance recorded	407	407	0
Total	407	407	0
Average Recorded Investment
With no related allowance recorded	233	226
With an allowance recorded	6,251	6,228
Total	6,484	6,454
Interest Income Recognized
With no related allowance recorded	0	0
With an allowance recorded	210	71
Total	210	71
Real Estate: Mortgage, commercial [Member]
Recorded Investment
With no related allowance recorded	1,607	1,607	1,901
With an allowance recorded	80	80	967
Total impaired loans	1,687	1,687	2,868
Unpaid Principal Balance
With no related allowance recorded	2,300	2,300	2,727
With an allowance recorded	80	80	1,004
Total	2,380	2,380	3,731
Related Allowance
With no related allowance recorded	0	0	0
With an allowance recorded	2	2	34
Total	2	2	34
Average Recorded Investment
With no related allowance recorded	1,727	1,670
With an allowance recorded	81	80
Total	1,808	1,750
Interest Income Recognized
With no related allowance recorded	34	11
With an allowance recorded	3	1
Total	37	12
Loans to individuals [Member]
Recorded Investment
With no related allowance recorded	0	0	0
With an allowance recorded	85	85	150
Total impaired loans	85	85	150
Unpaid Principal Balance
With no related allowance recorded	14	14	19
With an allowance recorded	85	85	150
Total	99	99	169
Related Allowance
With no related allowance recorded	0	0	0
With an allowance recorded	85	85	150
Total	85	85	$ 150
Average Recorded Investment
With no related allowance recorded	0	0
With an allowance recorded	88	90
Total	88	90
Interest Income Recognized
With no related allowance recorded	0	0
With an allowance recorded	7	3
Total	$ 7	$ 3

Fair Value Measurements (Detail

Fair Value Measurements (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Readily Available Market Prices [Member]
Financial instrument assets:
Cash and cash equivalents	$ 36,792	$ 38,197
Investment securities	0	0
Loans held for sale	0	0
Loans
Agricultural	0	0
Commercial and financial	0	0
Real estate:
Construction, 1 to 4 family residential	0	0
Construction, land development and commercial	0	0
Mortgage, farmland	0	0
Mortgage, 1 to 4 family first liens	0	0
Mortgage, 1 to 4 family junior liens	0	0
Mortgage, multi-family	0	0
Mortgage, commercial	0	0
Loans to individuals	0	0
Obligations of state and political subdivisions	0	0
Accrued interest receivable	0	0
Total financial instrument assets	36,792	38,197
Deposits
Noninterest-bearing deposits	0	0
Interest-bearing deposits	0	0
Other borrowings	0	0
Federal Home Loan Bank borrowings	0	0
Interest rate swaps	0
Accrued interest payable	0	0
Total financial instrument liabilities	0	0
Financial instrument with off-balance sheet risk:
Loan commitments	0	0
Letters of credit	0	0
Total financial instrument liabilities with off-balance-sheet risk	0	0
Observable Market Prices [Member]
Financial instrument assets:
Cash and cash equivalents	0	0
Investment securities	271,110	279,950
Loans held for sale	6,717	9,806
Loans
Agricultural	0	0
Commercial and financial	0	0
Real estate:
Construction, 1 to 4 family residential	0	0
Construction, land development and commercial	0	0
Mortgage, farmland	0	0
Mortgage, 1 to 4 family first liens	0	0
Mortgage, 1 to 4 family junior liens	0	0
Mortgage, multi-family	0	0
Mortgage, commercial	0	0
Loans to individuals	0	0
Obligations of state and political subdivisions	0	0
Accrued interest receivable	11,484	9,121
Total financial instrument assets	289,311	298,877
Deposits
Noninterest-bearing deposits	349,883	348,505
Interest-bearing deposits	1,727,433	1,691,679
Other borrowings	13,761	33,489
Federal Home Loan Bank borrowings	312,026	231,232
Interest rate swaps	3,464	3,938
Accrued interest payable	1,079	984
Total financial instrument liabilities	2,407,646	2,309,827
Financial instrument with off-balance sheet risk:
Loan commitments	0	0
Letters of credit	0	0
Total financial instrument liabilities with off-balance-sheet risk	0	0
Company Determined Market Prices [Member]
Financial instrument assets:
Cash and cash equivalents	0	0
Investment securities	0	0
Loans held for sale	0	0
Loans
Agricultural	73,954	89,862
Commercial and financial	209,387	188,292
Real estate:
Construction, 1 to 4 family residential	72,151	56,715
Construction, land development and commercial	105,340	119,716
Mortgage, farmland	205,401	199,043
Mortgage, 1 to 4 family first liens	813,125	764,174
Mortgage, 1 to 4 family junior liens	140,222	129,339
Mortgage, multi-family	330,677	297,646
Mortgage, commercial	354,673	328,948
Loans to individuals	25,575	24,499
Obligations of state and political subdivisions	56,681	52,860
Accrued interest receivable	0	0
Total financial instrument assets	2,387,186	2,251,094
Deposits
Noninterest-bearing deposits	0	0
Interest-bearing deposits	0	0
Other borrowings	0	0
Federal Home Loan Bank borrowings	0	0
Interest rate swaps	0
Accrued interest payable	0	0
Total financial instrument liabilities	0	0
Financial instrument with off-balance sheet risk:
Loan commitments	0	0
Letters of credit	0	0
Total financial instrument liabilities with off-balance-sheet risk	0	0
Carrying Amount [Member]
Financial instrument assets:
Cash and cash equivalents	36,792	38,197
Investment securities	271,110	279,950
Loans held for sale	6,717	9,806
Loans
Agricultural	74,022	89,924
Commercial and financial	209,458	188,464
Real estate:
Construction, 1 to 4 family residential	72,141	56,841
Construction, land development and commercial	105,417	119,694
Mortgage, farmland	204,974	198,923
Mortgage, 1 to 4 family first liens	817,072	760,909
Mortgage, 1 to 4 family junior liens	136,028	124,283
Mortgage, multi-family	332,893	301,162
Mortgage, commercial	356,436	331,822
Loans to individuals	25,591	24,515
Obligations of state and political subdivisions	57,398	54,081
Accrued interest receivable	11,484	9,121
Total financial instrument assets	2,717,533	2,587,692
Deposits
Noninterest-bearing deposits	349,883	348,505
Interest-bearing deposits	1,723,159	1,687,807
Other borrowings	13,761	33,489
Federal Home Loan Bank borrowings	323,000	235,000
Interest rate swaps	3,464	3,938
Accrued interest payable	1,079	984
Total financial instrument liabilities	2,414,346	2,309,723
Financial instrument with off-balance sheet risk:
Loan commitments	413,805	388,666
Letters of credit	11,398	9,024
Total financial instrument liabilities with off-balance-sheet risk	425,203	397,690
Estimated Fair Value [Member]
Financial instrument assets:
Cash and cash equivalents	36,792	38,197
Investment securities	271,110	279,950
Loans held for sale	6,717	9,806
Loans
Agricultural	73,954	89,862
Commercial and financial	209,387	188,292
Real estate:
Construction, 1 to 4 family residential	72,151	56,715
Construction, land development and commercial	105,340	119,716
Mortgage, farmland	205,401	199,043
Mortgage, 1 to 4 family first liens	813,125	764,174
Mortgage, 1 to 4 family junior liens	140,222	129,339
Mortgage, multi-family	330,677	297,646
Mortgage, commercial	354,673	328,948
Loans to individuals	25,575	24,499
Obligations of state and political subdivisions	56,681	52,860
Accrued interest receivable	11,484	9,121
Total financial instrument assets	2,713,289	2,588,168
Deposits
Noninterest-bearing deposits	349,883	348,505
Interest-bearing deposits	1,727,433	1,691,679
Other borrowings	13,761	33,489
Federal Home Loan Bank borrowings	312,026	231,232
Interest rate swaps	3,464	3,938
Accrued interest payable	1,079	984
Total financial instrument liabilities	2,407,646	2,309,827
Financial instrument with off-balance sheet risk:
Loan commitments	0	0
Letters of credit	0	0
Total financial instrument liabilities with off-balance-sheet risk	$ 0	$ 0

Fair Value Measurements, Assets

Fair Value Measurements, Assets and Liabilities Recurring Basis (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Summary of assets and liabilities measured at fair value on a recurring basis [Abstract]
Securities available for sale	$ 254,984	$ 267,537
U.S. Treasury [Member]
Summary of assets and liabilities measured at fair value on a recurring basis [Abstract]
Securities available for sale	39,894	27,482
State and political subdivisions [Member]
Summary of assets and liabilities measured at fair value on a recurring basis [Abstract]
Securities available for sale	166,331	178,395
Readily Available Market Prices [Member]
Summary of assets and liabilities measured at fair value on a recurring basis [Abstract]
Derivative Financial Instruments	0
Total	36,792	38,197
Observable Market Prices [Member]
Summary of assets and liabilities measured at fair value on a recurring basis [Abstract]
Derivative Financial Instruments	(3,464)	(3,938)
Total	289,311	298,877
Company Determined Market Prices [Member]
Summary of assets and liabilities measured at fair value on a recurring basis [Abstract]
Derivative Financial Instruments	0
Total	2,387,186	2,251,094
Recurring Basis [Member]
Summary of assets and liabilities measured at fair value on a recurring basis [Abstract]
Total	251,520	263,599
Recurring Basis [Member] | U.S. Treasury [Member]
Summary of assets and liabilities measured at fair value on a recurring basis [Abstract]
Securities available for sale	39,894	27,482
Recurring Basis [Member] | State and political subdivisions [Member]
Summary of assets and liabilities measured at fair value on a recurring basis [Abstract]
Securities available for sale	166,331	178,395
Recurring Basis [Member] | Other securities (FHLB, FHLMC and FNMA) [Member]
Summary of assets and liabilities measured at fair value on a recurring basis [Abstract]
Securities available for sale	48,759	61,660
Recurring Basis [Member] | Interest rate swaps [Member]
Summary of assets and liabilities measured at fair value on a recurring basis [Abstract]
Derivative Financial Instruments	(3,464)	(3,938)
Recurring Basis [Member] | Readily Available Market Prices [Member]
Summary of assets and liabilities measured at fair value on a recurring basis [Abstract]
Total	0	0
Recurring Basis [Member] | Readily Available Market Prices [Member] | U.S. Treasury [Member]
Summary of assets and liabilities measured at fair value on a recurring basis [Abstract]
Securities available for sale	0	0
Recurring Basis [Member] | Readily Available Market Prices [Member] | State and political subdivisions [Member]
Summary of assets and liabilities measured at fair value on a recurring basis [Abstract]
Securities available for sale	0	0
Recurring Basis [Member] | Readily Available Market Prices [Member] | Other securities (FHLB, FHLMC and FNMA) [Member]
Summary of assets and liabilities measured at fair value on a recurring basis [Abstract]
Securities available for sale	0	0
Recurring Basis [Member] | Observable Market Prices [Member]
Summary of assets and liabilities measured at fair value on a recurring basis [Abstract]
Total	251,520	263,599
Recurring Basis [Member] | Observable Market Prices [Member] | U.S. Treasury [Member]
Summary of assets and liabilities measured at fair value on a recurring basis [Abstract]
Securities available for sale	39,894	27,482
Recurring Basis [Member] | Observable Market Prices [Member] | State and political subdivisions [Member]
Summary of assets and liabilities measured at fair value on a recurring basis [Abstract]
Securities available for sale	166,331	178,395
Recurring Basis [Member] | Observable Market Prices [Member] | Other securities (FHLB, FHLMC and FNMA) [Member]
Summary of assets and liabilities measured at fair value on a recurring basis [Abstract]
Securities available for sale	48,759	61,660
Recurring Basis [Member] | Observable Market Prices [Member] | Interest rate swaps [Member]
Summary of assets and liabilities measured at fair value on a recurring basis [Abstract]
Derivative Financial Instruments	(3,464)	(3,938)
Recurring Basis [Member] | Company Determined Market Prices [Member]
Summary of assets and liabilities measured at fair value on a recurring basis [Abstract]
Total	0	0
Recurring Basis [Member] | Company Determined Market Prices [Member] | U.S. Treasury [Member]
Summary of assets and liabilities measured at fair value on a recurring basis [Abstract]
Securities available for sale	0	0
Recurring Basis [Member] | Company Determined Market Prices [Member] | State and political subdivisions [Member]
Summary of assets and liabilities measured at fair value on a recurring basis [Abstract]
Securities available for sale	0	0
Recurring Basis [Member] | Company Determined Market Prices [Member] | Other securities (FHLB, FHLMC and FNMA) [Member]
Summary of assets and liabilities measured at fair value on a recurring basis [Abstract]
Securities available for sale	$ 0	$ 0

Fair Value Measurements, Asse40

Fair Value Measurements, Assets and Liabilities on a Nonrecurring Basis (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended	12 Months Ended
	Sep. 30, 2017	Sep. 30, 2017	Dec. 31, 2016
Readily Available Market Prices [Member]
Loans
Agricultural	$ 0	$ 0	$ 0
Commercial and financial	0	0	0
Real Estate [Abstract]
Construction, land development and commercial	0	0	0
Mortgage, farmland	0	0	0
Mortgage, 1 to 4 family first liens	0	0	0
Mortgage, 1 to 4 family junior liens	0	0	0
Mortgage, multi-family	0	0	0
Mortgage, commercial	0	0	0
Loans to individuals	0	0	0
Total financial instrument assets	36,792	36,792	38,197
Observable Market Prices [Member]
Loans
Agricultural	0	0	0
Commercial and financial	0	0	0
Real Estate [Abstract]
Construction, land development and commercial	0	0	0
Mortgage, farmland	0	0	0
Mortgage, 1 to 4 family first liens	0	0	0
Mortgage, 1 to 4 family junior liens	0	0	0
Mortgage, multi-family	0	0	0
Mortgage, commercial	0	0	0
Loans to individuals	0	0	0
Total financial instrument assets	289,311	289,311	298,877
Company Determined Market Prices [Member]
Loans
Agricultural	73,954	73,954	89,862
Commercial and financial	209,387	209,387	188,292
Real Estate [Abstract]
Construction, land development and commercial	105,340	105,340	119,716
Mortgage, farmland	205,401	205,401	199,043
Mortgage, 1 to 4 family first liens	813,125	813,125	764,174
Mortgage, 1 to 4 family junior liens	140,222	140,222	129,339
Mortgage, multi-family	330,677	330,677	297,646
Mortgage, commercial	354,673	354,673	328,948
Loans to individuals	25,575	25,575	24,499
Total financial instrument assets	2,387,186	2,387,186	2,251,094
Nonrecurring Basis [Member]
Loans
Agricultural	4,350	4,350	10,773
Commercial and financial	1,667	1,667	1,397
Real Estate [Abstract]
Construction, 1 to 4 family residential	186	186	827
Construction, land development and commercial	697	697	85
Mortgage, farmland	6,862	6,862	7,077
Mortgage, 1 to 4 family first liens	6,214	6,214	5,424
Mortgage, 1 to 4 family junior liens	34	34	194
Mortgage, multi-family	6,003	6,003	244
Mortgage, commercial	1,101	1,101	1,541
Loans to individuals	0	0	0
Foreclosed assets	0	0	75
Total financial instrument assets	27,114	27,114	27,637
Total Losses	206	527	984
Nonrecurring Basis [Member] | Agricultural [Member]
Real Estate [Abstract]
Total Losses	0	23	0
Nonrecurring Basis [Member] | Commercial and financial [Member]
Real Estate [Abstract]
Total Losses	8	135	143
Nonrecurring Basis [Member] | Real Estate: Construction, 1 to 4 family residential [Member]
Real Estate [Abstract]
Total Losses	0	0	0
Nonrecurring Basis [Member] | Real Estate: Construction, land development and commercial [Member]
Real Estate [Abstract]
Total Losses	0	0	0
Nonrecurring Basis [Member] | Real Estate: Mortgage, farmland [Member]
Real Estate [Abstract]
Total Losses	0	0	0
Nonrecurring Basis [Member] | Real Estate: Mortgage, 1 to 4 family first liens [Member]
Real Estate [Abstract]
Total Losses	31	150	756
Nonrecurring Basis [Member] | Real Estate: Mortgage, 1 to 4 family junior liens [Member]
Real Estate [Abstract]
Total Losses	71	88	0
Nonrecurring Basis [Member] | Real Estate: Mortgage, multi-family [Member]
Real Estate [Abstract]
Total Losses	0	0	0
Nonrecurring Basis [Member] | Real Estate: Mortgage, commercial [Member]
Real Estate [Abstract]
Total Losses	86	111	65
Nonrecurring Basis [Member] | Loans to individuals [Member]
Real Estate [Abstract]
Total Losses	10	20	0
Nonrecurring Basis [Member] | Foreclosed assets [Member]
Real Estate [Abstract]
Total Losses	0	0	20
Nonrecurring Basis [Member] | Readily Available Market Prices [Member]
Loans
Agricultural	0	0	0
Commercial and financial	0	0	0
Real Estate [Abstract]
Construction, 1 to 4 family residential	0	0	0
Construction, land development and commercial	0	0	0
Mortgage, farmland	0	0	0
Mortgage, 1 to 4 family first liens	0	0	0
Mortgage, 1 to 4 family junior liens	0	0	0
Mortgage, multi-family	0	0	0
Mortgage, commercial	0	0	0
Loans to individuals	0	0	0
Foreclosed assets	0	0	0
Total financial instrument assets	0	0	0
Nonrecurring Basis [Member] | Observable Market Prices [Member]
Loans
Agricultural	0	0	0
Commercial and financial	0	0	0
Real Estate [Abstract]
Construction, 1 to 4 family residential	0	0	0
Construction, land development and commercial	0	0	0
Mortgage, farmland	0	0	0
Mortgage, 1 to 4 family first liens	0	0	0
Mortgage, 1 to 4 family junior liens	0	0	0
Mortgage, multi-family	0	0	0
Mortgage, commercial	0	0	0
Loans to individuals	0	0	0
Foreclosed assets	0	0	0
Total financial instrument assets	0	0	0
Nonrecurring Basis [Member] | Company Determined Market Prices [Member]
Loans
Agricultural	4,350	4,350	10,773
Commercial and financial	1,667	1,667	1,397
Real Estate [Abstract]
Construction, 1 to 4 family residential	186	186	827
Construction, land development and commercial	697	697	85
Mortgage, farmland	6,862	6,862	7,077
Mortgage, 1 to 4 family first liens	6,214	6,214	5,424
Mortgage, 1 to 4 family junior liens	34	34	194
Mortgage, multi-family	6,003	6,003	244
Mortgage, commercial	1,101	1,101	1,541
Loans to individuals	0	0	0
Foreclosed assets	0	0	75
Total financial instrument assets	$ 27,114	$ 27,114	$ 27,637

Stock Repurchase Program (Detai

Stock Repurchase Program (Details) - $ / shares	3 Months Ended	9 Months Ended		146 Months Ended
	Sep. 30, 2017	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Jul. 26, 2005
Equity [Abstract]
Maximum number of share authorized to repurchase under the program (in shares)					1,500,000
Common stock purchased during the period (in shares)	14,538	40,265	62,266	1,003,216
Average price per share (in dollars per share)	$ 52.80

Commitments and Contingencies42

Commitments and Contingencies (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
State and political subdivisions [Member]
Concentration Risk [Line Items]
Investment in securities issued by state and political subdivisions within the state of Iowa	$ 68,950
Home equity loans [Member]
Firm loan commitments and unused portion of lines of credit [Abstract]
Total financial instrument liabilities with off-balance-sheet risk	54,200	$ 48,785
Credit cards [Member]
Firm loan commitments and unused portion of lines of credit [Abstract]
Total financial instrument liabilities with off-balance-sheet risk	49,107	45,738
Commercial, real estate and home construction [Member]
Firm loan commitments and unused portion of lines of credit [Abstract]
Total financial instrument liabilities with off-balance-sheet risk	138,982	113,251
Commercial lines and real estate purchase loan [Member]
Firm loan commitments and unused portion of lines of credit [Abstract]
Total financial instrument liabilities with off-balance-sheet risk	171,516	180,892
Outstanding letters of credit [Member]
Firm loan commitments and unused portion of lines of credit [Abstract]
Total financial instrument liabilities with off-balance-sheet risk	$ 11,398	$ 9,024

Income Taxes (Details)

Income Taxes (Details)	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016
Income Tax Examination [Line Items]
Effective tax rate	30.48%	31.40%
Internal Revenue Service (IRS) [Member]
Income Tax Examination [Line Items]
Income tax examination, years under examination	December 31, 2016, 2015, and 2014
State and Local Jurisdiction [Member]
Income Tax Examination [Line Items]
Income tax examination, years under examination	December 31, 2016, 2015, and 2014

Derivative Financial Instrume44

Derivative Financial Instruments (Details)	9 Months Ended	12 Months Ended
	Sep. 30, 2017USD ($)	Dec. 31, 2016USD ($)	Nov. 07, 2013USD ($)derivative
Derivatives, Fair Value [Line Items]
Owned and pledged as collateral	$ 3,460,000
Interest Rate Swap 1 [Member] | Interest Expense [Member]
Gain (Loss) Recognized in Other Comprehensive Income, Net [Abstract]
Amount of Gain (Loss), Reclassified from AOCI into Income (Effective Portion)	0	$ 0
Interest Rate Swap 1 [Member] | Other Income [Member]
Gain (Loss) Recognized in Other Comprehensive Income, Net [Abstract]
Amount of Gain (Loss), Recognized in Income on Derivatives (Ineffective Portion)	0	0
Interest Rate Swap 1 [Member] | Other Liabilities [Member]
Derivative instrument according to type of hedges [Abstract]
Notional Amount	25,000,000	25,000,000	$ 25,000,000
Fair Value	$ (853,000)	$ (1,097,000)
Maturity	Nov. 9, 2020	Nov. 9, 2020
Interest Rate Swap 1 [Member] | Accumulated Other Comprehensive Income (Loss) [Member]
Gain (Loss) Recognized in Other Comprehensive Income, Net [Abstract]
Amount of Gain (Loss), Recognized in OCI (Effective Portion)	$ 151,000	$ 250,000
Interest Rate Swap 2 [Member] | Interest Expense [Member]
Gain (Loss) Recognized in Other Comprehensive Income, Net [Abstract]
Amount of Gain (Loss), Reclassified from AOCI into Income (Effective Portion)	0	0
Interest Rate Swap 2 [Member] | Other Income [Member]
Gain (Loss) Recognized in Other Comprehensive Income, Net [Abstract]
Amount of Gain (Loss), Recognized in Income on Derivatives (Ineffective Portion)	0	0
Interest Rate Swap 2 [Member] | Other Liabilities [Member]
Derivative instrument according to type of hedges [Abstract]
Notional Amount	25,000,000	25,000,000	$ 25,000,000
Fair Value	$ (2,611,000)	$ (2,841,000)
Maturity	Nov. 7, 2023	Nov. 7, 2023
Interest Rate Swap 2 [Member] | Accumulated Other Comprehensive Income (Loss) [Member]
Gain (Loss) Recognized in Other Comprehensive Income, Net [Abstract]
Amount of Gain (Loss), Recognized in OCI (Effective Portion)	$ 142,000	$ (101,000)
Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Number of interest rate swaps held | derivative			2
Designated as Hedging Instrument [Member] | Interest Rate Swap 1 [Member]
Derivatives, Fair Value [Line Items]
Number of interest rate swaps held | derivative			1