Nonaccrual Loans by Loan Class (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Financing Receivable, Impaired [Line Items]
Total	$ 22,506	$ 28,246
Purchased impaired loans	8	8
Total nonaccrual loans	22,514	28,254
Commercial Loans \| Construction Development And Other Land
Financing Receivable, Impaired [Line Items]
Total	1,948	2,395
Commercial Loans \| Commercial and Industrial
Financing Receivable, Impaired [Line Items]
Total	5,433	3,947
Commercial Loans \| Multi-family Residential
Financing Receivable, Impaired [Line Items]
Total		378
Commercial Loans \| Single-family Non-owner Occupied
Financing Receivable, Impaired [Line Items]
Total	2,188	7,092
Commercial Loans \| Non-farm, Non-residential
Financing Receivable, Impaired [Line Items]
Total	2,685	6,889
Commercial Loans \| Agricultural
Financing Receivable, Impaired [Line Items]
Total		2
Commercial Loans \| Farmland Loan
Financing Receivable, Impaired [Line Items]
Total	742
Consumer Real Estate \| Home Equity Lines
Financing Receivable, Impaired [Line Items]
Total	997	1,308
Consumer Real Estate \| Single Family Owner Occupied
Financing Receivable, Impaired [Line Items]
Total	8,122	6,050
Consumer Real Estate \| Owner occupied construction
Financing Receivable, Impaired [Line Items]
Total	190	59
Consumer and Other \| Consumer Loan
Financing Receivable, Impaired [Line Items]
Total	201	126
Non Covered Loans
Financing Receivable, Impaired [Line Items]
Total	19,153	23,923
Purchased impaired loans	8	8
Total nonaccrual loans	19,161	23,931
Non Covered Loans \| Commercial Loans \| Construction Development And Other Land
Financing Receivable, Impaired [Line Items]
Total	1,187	405
Non Covered Loans \| Commercial Loans \| Commercial and Industrial
Financing Receivable, Impaired [Line Items]
Total	5,341	3,912
Non Covered Loans \| Commercial Loans \| Multi-family Residential
Financing Receivable, Impaired [Line Items]
Total		378
Non Covered Loans \| Commercial Loans \| Single-family Non-owner Occupied
Financing Receivable, Impaired [Line Items]
Total	1,966	7,071
Non Covered Loans \| Commercial Loans \| Non-farm, Non-residential
Financing Receivable, Impaired [Line Items]
Total	2,685	5,938
Non Covered Loans \| Commercial Loans \| Agricultural
Financing Receivable, Impaired [Line Items]
Total		2
Non Covered Loans \| Commercial Loans \| Farmland Loan
Financing Receivable, Impaired [Line Items]
Total	441
Non Covered Loans \| Consumer Real Estate \| Home Equity Lines
Financing Receivable, Impaired [Line Items]
Total	765	872
Non Covered Loans \| Consumer Real Estate \| Single Family Owner Occupied
Financing Receivable, Impaired [Line Items]
Total	6,567	5,219
Non Covered Loans \| Consumer and Other \| Consumer Loan
Financing Receivable, Impaired [Line Items]
Total	201	126
Covered Loans
Financing Receivable, Impaired [Line Items]
Total	3,353	4,323
Total nonaccrual loans	3,353	4,323
Covered Loans \| Commercial Loans \| Construction Development And Other Land
Financing Receivable, Impaired [Line Items]
Total	761	1,990
Covered Loans \| Commercial Loans \| Commercial and Industrial
Financing Receivable, Impaired [Line Items]
Total	92	35
Covered Loans \| Commercial Loans \| Single-family Non-owner Occupied
Financing Receivable, Impaired [Line Items]
Total	222	21
Covered Loans \| Commercial Loans \| Non-farm, Non-residential
Financing Receivable, Impaired [Line Items]
Total		951
Covered Loans \| Commercial Loans \| Farmland Loan
Financing Receivable, Impaired [Line Items]
Total	301
Covered Loans \| Consumer Real Estate \| Home Equity Lines
Financing Receivable, Impaired [Line Items]
Total	232	436
Covered Loans \| Consumer Real Estate \| Single Family Owner Occupied
Financing Receivable, Impaired [Line Items]
Total	1,555	831
Covered Loans \| Consumer Real Estate \| Owner occupied construction
Financing Receivable, Impaired [Line Items]
Total	$ 190	$ 59