Loans and Allowance - Summary of Troubled Debt Restructurings (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013 loan	Dec. 31, 2012 loan
Financing Receivable, Modifications [Line Items]
Pre-Modification Recorded Balance	$ 7,753	$ 15,194
Post-Modification Recorded Balance	6,757	14,723
Number of Loans	32	50
Commercial and industrial loans
Financing Receivable, Modifications [Line Items]
Pre-Modification Recorded Balance	295	1,562
Post-Modification Recorded Balance	316	1,547
Number of Loans	5	9
Construction
Financing Receivable, Modifications [Line Items]
Pre-Modification Recorded Balance		794
Post-Modification Recorded Balance		653
Number of Loans		2
Commercial and farmland
Financing Receivable, Modifications [Line Items]
Pre-Modification Recorded Balance	6,506	10,366
Post-Modification Recorded Balance	5,492	10,154
Number of Loans	11	14
Residential
Financing Receivable, Modifications [Line Items]
Pre-Modification Recorded Balance	809	2,302
Post-Modification Recorded Balance	804	2,172
Number of Loans	12	20
Consumer
Financing Receivable, Modifications [Line Items]
Pre-Modification Recorded Balance	143	170
Post-Modification Recorded Balance	$ 145	$ 197
Number of Loans	4	5