Covered Loans Held for Investment, Net of Unearned Income (Detail) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2013	Dec. 31, 2012
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans held for investment, net of unearned income	$ 184,076	$ 207,106
Commercial Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans held for investment, net of unearned income	82,128	97,382
Commercial Loans | Construction Development And Other Land
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans held for investment, net of unearned income	23,067	26,595
Commercial Loans | Commercial and Industrial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans held for investment, net of unearned income	4,412	6,948
Commercial Loans | Multi-family Residential
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans held for investment, net of unearned income	2,434	2,611
Commercial Loans | Single-family Non-owner Occupied
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans held for investment, net of unearned income	9,750	11,428
Commercial Loans | Non-farm Non-residential Loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans held for investment, net of unearned income	41,200	48,565
Commercial Loans | Agricultural
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans held for investment, net of unearned income	31	144
Commercial Loans | Farmland Loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans held for investment, net of unearned income	1,234	1,091
Consumer Real Estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans held for investment, net of unearned income	99,237	106,050
Consumer Real Estate | Home Equity Lines
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans held for investment, net of unearned income	77,132	81,445
Consumer Real Estate | Single Family Owner Occupied
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans held for investment, net of unearned income	20,467	22,961
Consumer Real Estate | Owner Occupied Construction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans held for investment, net of unearned income	1,638	1,644
Consumer and Other Loans | Consumer Loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans held for investment, net of unearned income	$ 2,711	$ 3,674