Loans and Allowance - Summary of Troubled Debt Restructurings by Modification Type (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Financing Receivable, Modifications [Line Items]
Modification	$ 814	$ 1,212	$ 5,968	$ 5,378
Term Modification
Financing Receivable, Modifications [Line Items]
Modification		138	1,314	2,993
Rate Modification
Financing Receivable, Modifications [Line Items]
Modification	719	255	970	301
Combination
Financing Receivable, Modifications [Line Items]
Modification	95	819	3,684	2,084
Commercial and industrial loans
Financing Receivable, Modifications [Line Items]
Modification		213	197	1,886
Commercial and industrial loans | Term Modification
Financing Receivable, Modifications [Line Items]
Modification		138		806
Commercial and industrial loans | Rate Modification
Financing Receivable, Modifications [Line Items]
Modification
Commercial and industrial loans | Combination
Financing Receivable, Modifications [Line Items]
Modification		75	197	1,080
Agricultural production financing and other loans to farmers
Financing Receivable, Modifications [Line Items]
Modification			898
Agricultural production financing and other loans to farmers | Term Modification
Financing Receivable, Modifications [Line Items]
Modification			898
Agricultural production financing and other loans to farmers | Rate Modification
Financing Receivable, Modifications [Line Items]
Modification
Agricultural production financing and other loans to farmers | Combination
Financing Receivable, Modifications [Line Items]
Modification
Real estate loans - Commercial and farmland
Financing Receivable, Modifications [Line Items]
Modification	95	744	3,903	2,341
Real estate loans - Commercial and farmland | Term Modification
Financing Receivable, Modifications [Line Items]
Modification			416	1,337
Real estate loans - Commercial and farmland | Rate Modification
Financing Receivable, Modifications [Line Items]
Modification
Real estate loans - Commercial and farmland | Combination
Financing Receivable, Modifications [Line Items]
Modification	95	744	3,487	1,004
Real estate loans - Residential
Financing Receivable, Modifications [Line Items]
Modification	663	13	773	909
Real estate loans - Residential | Term Modification
Financing Receivable, Modifications [Line Items]
Modification				850
Real estate loans - Residential | Rate Modification
Financing Receivable, Modifications [Line Items]
Modification	663	13	773	59
Real estate loans - Residential | Combination
Financing Receivable, Modifications [Line Items]
Modification
Real estate loans - Home Equity
Financing Receivable, Modifications [Line Items]
Modification	56	242	197	242
Real estate loans - Home Equity | Term Modification
Financing Receivable, Modifications [Line Items]
Modification
Real estate loans - Home Equity | Rate Modification
Financing Receivable, Modifications [Line Items]
Modification	56	242	197	242
Real estate loans - Home Equity | Combination
Financing Receivable, Modifications [Line Items]
Modification