Loans and Allowance - Summary of Troubled Debt Restructurings (Details) $ in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2017 USD ($) loan	Jun. 30, 2016 USD ($) loan	Jun. 30, 2017 USD ($) loan	Jun. 30, 2016 USD ($) loan
Financing Receivable, Modifications [Line Items]
Pre-Modification Recorded Balance	$ 973	$ 4,854	$ 1,323	$ 6,044
Post-Modification Recorded Balance	$ 696	$ 4,795	$ 1,059	$ 5,871
Number of Loans \| loan	9	9	14	18
Commercial and industrial loans
Financing Receivable, Modifications [Line Items]
Pre-Modification Recorded Balance	$ 394		$ 394	$ 260
Post-Modification Recorded Balance	$ 170		$ 170	$ 260
Number of Loans \| loan	1		1	3
Agricultural production financing and other loans to farmers
Financing Receivable, Modifications [Line Items]
Pre-Modification Recorded Balance		$ 1,141		$ 1,606
Post-Modification Recorded Balance		$ 1,141		$ 1,472
Number of Loans \| loan		3		5
Commercial and farmland
Financing Receivable, Modifications [Line Items]
Pre-Modification Recorded Balance	$ 250	$ 3,539	$ 357	$ 3,891
Post-Modification Recorded Balance	$ 250	$ 3,508	$ 491	$ 3,860
Number of Loans \| loan	3	5	6	6
Real estate loans - Residential
Financing Receivable, Modifications [Line Items]
Pre-Modification Recorded Balance	$ 329		$ 450	$ 113
Post-Modification Recorded Balance	$ 276		$ 398	$ 133
Number of Loans \| loan	5		7	3
Real estate loans - Home equity
Financing Receivable, Modifications [Line Items]
Pre-Modification Recorded Balance		$ 174	$ 122	$ 174
Post-Modification Recorded Balance		$ 146		$ 146
Number of Loans \| loan		1		1

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Number of financing receivables that have been modified by troubled debt restructurings.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 33
-URI http://asc.fasb.org/extlink&oid=84173941&loc=SL6953676-111524

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