Loans and Allowance - Summary of Troubled Debt Restructurings by Modification (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Financing Receivable, Modifications [Line Items]
Total Modification	$ 6,263	$ 5,378
Term Modification
Financing Receivable, Modifications [Line Items]
Total Modification	1,195	2,815
Rate Modification
Financing Receivable, Modifications [Line Items]
Total Modification	1,215	439
Combination
Financing Receivable, Modifications [Line Items]
Total Modification	3,853	2,124
Commercial and industrial loans
Financing Receivable, Modifications [Line Items]
Total Modification	397	1,814
Commercial and industrial loans | Term Modification
Financing Receivable, Modifications [Line Items]
Total Modification		761
Commercial and industrial loans | Combination
Financing Receivable, Modifications [Line Items]
Total Modification	397	1,053
Agriculture production financing and other loans to farmers
Financing Receivable, Modifications [Line Items]
Total Modification	672
Agriculture production financing and other loans to farmers | Term Modification
Financing Receivable, Modifications [Line Items]
Total Modification	660
Agriculture production financing and other loans to farmers | Rate Modification
Financing Receivable, Modifications [Line Items]
Total Modification	12
Commercial and farmland
Financing Receivable, Modifications [Line Items]
Total Modification	3,753	2,257
Commercial and farmland | Term Modification
Financing Receivable, Modifications [Line Items]
Total Modification	297	1,231
Commercial and farmland | Rate Modification
Financing Receivable, Modifications [Line Items]
Total Modification
Commercial and farmland | Combination
Financing Receivable, Modifications [Line Items]
Total Modification	3,456	1,026
Residential
Financing Receivable, Modifications [Line Items]
Total Modification	1,166	1,038
Residential | Term Modification
Financing Receivable, Modifications [Line Items]
Total Modification	238	823
Residential | Rate Modification
Financing Receivable, Modifications [Line Items]
Total Modification	928	170
Residential | Combination
Financing Receivable, Modifications [Line Items]
Total Modification		45
Home equity
Financing Receivable, Modifications [Line Items]
Total Modification	266	242
Home equity | Term Modification
Financing Receivable, Modifications [Line Items]
Total Modification
Home equity | Rate Modification
Financing Receivable, Modifications [Line Items]
Total Modification	266	242
Home equity | Combination
Financing Receivable, Modifications [Line Items]
Total Modification
Individuals' loans for household and other personal expenditures
Financing Receivable, Modifications [Line Items]
Total Modification	9	27
Individuals' loans for household and other personal expenditures | Term Modification
Financing Receivable, Modifications [Line Items]
Total Modification
Individuals' loans for household and other personal expenditures | Rate Modification
Financing Receivable, Modifications [Line Items]
Total Modification	$ 9	27
Individuals' loans for household and other personal expenditures | Combination
Financing Receivable, Modifications [Line Items]
Total Modification