Loans and Allowance - Summary of Troubled Debt Restructurings (Details) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016 USD ($) loan	Sep. 30, 2015 USD ($) loan	Sep. 30, 2016 USD ($) loan	Sep. 30, 2015 USD ($) loan
Financing Receivable, Modifications [Line Items]
Pre-Modification Recorded Balance	$ 753	$ 1,357	$ 6,797	$ 5,765
Post-Modification Recorded Balance	$ 831	$ 1,217	$ 6,702	$ 6,370
Number of Loans | loan	14	5	32	16
Commercial and industrial loans
Financing Receivable, Modifications [Line Items]
Pre-Modification Recorded Balance		$ 363	$ 260	$ 4,111
Post-Modification Recorded Balance		$ 218	$ 260	$ 2,115
Number of Loans | loan		2	3	7
Agricultural production financing and other loans to farmers
Financing Receivable, Modifications [Line Items]
Pre-Modification Recorded Balance			$ 1,606
Post-Modification Recorded Balance			$ 1,472
Number of Loans | loan			5
Real estate loans - Construction
Financing Receivable, Modifications [Line Items]
Pre-Modification Recorded Balance				$ 79
Post-Modification Recorded Balance				$ 80
Number of Loans | loan				1
Real estate loans - Commercial and farmland
Financing Receivable, Modifications [Line Items]
Pre-Modification Recorded Balance	$ 87	$ 744	$ 3,978	$ 1,281
Post-Modification Recorded Balance	$ 95	$ 744	$ 3,955	$ 3,025
Number of Loans | loan	1	1	7	3
Real estate loans - Residential
Financing Receivable, Modifications [Line Items]
Pre-Modification Recorded Balance	$ 611	$ 11	$ 724	$ 55
Post-Modification Recorded Balance	$ 678	$ 13	$ 811	$ 908
Number of Loans | loan	11	1	14	4
Real estate loans - Home Equity
Financing Receivable, Modifications [Line Items]
Pre-Modification Recorded Balance	$ 55	$ 239	$ 229	$ 239
Post-Modification Recorded Balance	$ 58	$ 242	$ 204	$ 242
Number of Loans | loan	2	1	3	1