Loans and Allowance - Summary of Troubled Debt Restructurings by Modification (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Financing Receivable, Modifications [Line Items]
Modification	$ 4,519	$ 11,955
Troubled Debt Restructurings, Term Modifications
Financing Receivable, Modifications [Line Items]
Modification	1,823	7,452
Troubled Debt Restructurings, Rate Modifications
Financing Receivable, Modifications [Line Items]
Modification	275	1,290
Troubled Debt Restructurings, Rate and Term Modifications
Financing Receivable, Modifications [Line Items]
Modification	2,421	3,213
Commercial and industrial loans
Financing Receivable, Modifications [Line Items]
Modification	267	1,288
Commercial and industrial loans | Troubled Debt Restructurings, Term Modifications
Financing Receivable, Modifications [Line Items]
Modification	207	259
Commercial and industrial loans | Troubled Debt Restructurings, Rate and Term Modifications
Financing Receivable, Modifications [Line Items]
Modification	60	1,029
Construction
Financing Receivable, Modifications [Line Items]
Modification		625
Construction | Troubled Debt Restructurings, Rate and Term Modifications
Financing Receivable, Modifications [Line Items]
Modification		625
Commercial and farmland
Financing Receivable, Modifications [Line Items]
Modification	3,373	7,952
Commercial and farmland | Troubled Debt Restructurings, Term Modifications
Financing Receivable, Modifications [Line Items]
Modification	1,388	6,668
Commercial and farmland | Troubled Debt Restructurings, Rate Modifications
Financing Receivable, Modifications [Line Items]
Modification		903
Commercial and farmland | Troubled Debt Restructurings, Rate and Term Modifications
Financing Receivable, Modifications [Line Items]
Modification	1,985	381
Residential
Financing Receivable, Modifications [Line Items]
Modification	755	1,900
Residential | Troubled Debt Restructurings, Term Modifications
Financing Receivable, Modifications [Line Items]
Modification	167	525
Residential | Troubled Debt Restructurings, Rate Modifications
Financing Receivable, Modifications [Line Items]
Modification	237	380
Residential | Troubled Debt Restructurings, Rate and Term Modifications
Financing Receivable, Modifications [Line Items]
Modification	351	995
Consumer
Financing Receivable, Modifications [Line Items]
Modification	124	190
Consumer | Troubled Debt Restructurings, Term Modifications
Financing Receivable, Modifications [Line Items]
Modification	61
Consumer | Troubled Debt Restructurings, Rate Modifications
Financing Receivable, Modifications [Line Items]
Modification	38	7
Consumer | Troubled Debt Restructurings, Rate and Term Modifications
Financing Receivable, Modifications [Line Items]
Modification	$ 25	$ 183