Loans and Allowance - Summary of Troubled Debt Restructurings by Modification Type (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Financing Receivable, Modifications [Line Items]
Modification	$ 1,078	$ 2,908
Term Modification
Financing Receivable, Modifications [Line Items]
Modification		1,803
Rate Modification
Financing Receivable, Modifications [Line Items]
Modification	$ 467	26
Combination
Financing Receivable, Modifications [Line Items]
Modification	611	1,079
Commercial and industrial loans
Financing Receivable, Modifications [Line Items]
Modification	$ 260	1,332
Commercial and industrial loans | Term Modification
Financing Receivable, Modifications [Line Items]
Modification		253
Commercial and industrial loans | Rate Modification
Financing Receivable, Modifications [Line Items]
Modification
Commercial and industrial loans | Combination
Financing Receivable, Modifications [Line Items]
Modification	$ 260	1,079
Agricultural production financing and other loans to farmers
Financing Receivable, Modifications [Line Items]
Modification	331
Agricultural production financing and other loans to farmers | Rate Modification
Financing Receivable, Modifications [Line Items]
Modification	331
Real estate loans - Construction
Financing Receivable, Modifications [Line Items]
Modification		2
Real estate loans - Construction | Term Modification
Financing Receivable, Modifications [Line Items]
Modification		$ 2
Real estate loans - Construction | Rate Modification
Financing Receivable, Modifications [Line Items]
Modification
Real estate loans - Construction | Combination
Financing Receivable, Modifications [Line Items]
Modification
Real estate loans - Commercial and farmland
Financing Receivable, Modifications [Line Items]
Modification	$ 351	$ 1,548
Real estate loans - Commercial and farmland | Term Modification
Financing Receivable, Modifications [Line Items]
Modification		$ 1,548
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	$ 351
Real estate loans - Residential
Financing Receivable, Modifications [Line Items]
Modification	$ 123	$ 26
Real estate loans - Residential | Term Modification
Financing Receivable, Modifications [Line Items]
Modification
Real estate loans - Residential | Rate Modification
Financing Receivable, Modifications [Line Items]
Modification	$ 123	$ 26
Real estate loans - Residential | Combination
Financing Receivable, Modifications [Line Items]
Modification
Individuals' loans for household and other personal expenditures
Financing Receivable, Modifications [Line Items]
Modification	$ 13
Individuals' loans for household and other personal expenditures | Rate Modification
Financing Receivable, Modifications [Line Items]
Modification	$ 13
Individuals' loans for household and other personal expenditures | Combination
Financing Receivable, Modifications [Line Items]
Modification