Loans and Allowance - Summary of Troubled Debt Restructurings by Modification (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Financing Receivable, Modifications [Line Items]
Modification	$ 4,049	$ 2,567	$ 4,561	$ 4,664
Troubled Debt Restructurings, Term Modifications
Financing Receivable, Modifications [Line Items]
Modification	36	613	60	2,486
Troubled Debt Restructurings Rate Modifications
Financing Receivable, Modifications [Line Items]
Modification	100	258	100	258
Troubled Debt Restructurings, Combination
Financing Receivable, Modifications [Line Items]
Modification	3,913	1,696	4,401	1,920
Commercial and industrial loans
Financing Receivable, Modifications [Line Items]
Modification	36	31	126	269
Commercial and industrial loans | Troubled Debt Restructurings, Term Modifications
Financing Receivable, Modifications [Line Items]
Modification	36		60	238
Commercial and industrial loans | Troubled Debt Restructurings Rate Modifications
Financing Receivable, Modifications [Line Items]
Modification
Commercial and industrial loans | Troubled Debt Restructurings, Combination
Financing Receivable, Modifications [Line Items]
Modification		31	66	31
Real estate loans - Construction
Financing Receivable, Modifications [Line Items]
Modification		346		346
Real estate loans - Construction | Troubled Debt Restructurings Rate Modifications
Financing Receivable, Modifications [Line Items]
Modification
Real estate loans - Construction | Troubled Debt Restructurings, Combination
Financing Receivable, Modifications [Line Items]
Modification		346		346
Real estate loans - Commercial and farm land
Financing Receivable, Modifications [Line Items]
Modification	3,549	681	3,935	2,316
Real estate loans - Commercial and farm land | Troubled Debt Restructurings, Term Modifications
Financing Receivable, Modifications [Line Items]
Modification		82		1,717
Real estate loans - Commercial and farm land | Troubled Debt Restructurings Rate Modifications
Financing Receivable, Modifications [Line Items]
Modification
Real estate loans - Commercial and farm land | Troubled Debt Restructurings, Combination
Financing Receivable, Modifications [Line Items]
Modification	3,549	599	3,935	599
Real estate loans - Residential
Financing Receivable, Modifications [Line Items]
Modification	419	1,509	455	1,733
Real estate loans - Residential | Troubled Debt Restructurings, Term Modifications
Financing Receivable, Modifications [Line Items]
Modification		531		531
Real estate loans - Residential | Troubled Debt Restructurings Rate Modifications
Financing Receivable, Modifications [Line Items]
Modification	100	258	100	258
Real estate loans - Residential | Troubled Debt Restructurings, Combination
Financing Receivable, Modifications [Line Items]
Modification	319	720	355	944
Individuals' loans for household and other personal expenditures
Financing Receivable, Modifications [Line Items]
Modification	45		45
Individuals' loans for household and other personal expenditures | Troubled Debt Restructurings Rate Modifications
Financing Receivable, Modifications [Line Items]
Modification
Individuals' loans for household and other personal expenditures | Troubled Debt Restructurings, Combination
Financing Receivable, Modifications [Line Items]
Modification	$ 45		$ 45