Summary of Loans, Net of Unearned Income (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment, net of unearned income	$ 1,567,176	$ 1,559,039
Covered under loss share agreements	122,240	151,682
Total Loans held for investment, net of unearned income	1,689,416	1,710,721
Loans held for sale	1,792us-gaap_LoansReceivableHeldForSaleNet	883us-gaap_LoansReceivableHeldForSaleNet
Loans held for investment, net of unearned income, percentage	92.76%	91.13%
Covered loan percentage	7.24%	8.87%
Loans and leases receivable net reported amount covered and not covered percentage	100.00%	100.00%
Commercial Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment, net of unearned income	862,043	847,315
Loans held for investment, net of unearned income, percentage	51.02%	49.53%
Commercial Loans \| Construction Development And Other Land
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment, net of unearned income	41,271	35,255
Covered under loss share agreements	13,100	15,865
Loans held for investment, net of unearned income, percentage	2.44%	2.06%
Commercial Loans \| Commercial and Industrial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment, net of unearned income	83,099	95,455
Covered under loss share agreements	2,662	3,325
Loans held for investment, net of unearned income, percentage	4.92%	5.58%
Commercial Loans \| Multi-family Residential
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment, net of unearned income	97,480	70,197
Covered under loss share agreements	1,584	1,933
Loans held for investment, net of unearned income, percentage	5.77%	4.10%
Commercial Loans \| Single-family Non-owner Occupied
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment, net of unearned income	135,171	135,559
Covered under loss share agreements	5,918	7,449
Loans held for investment, net of unearned income, percentage	8.00%	7.92%
Commercial Loans \| Non-farm Non-residential Loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment, net of unearned income	473,906	475,911
Covered under loss share agreements	25,317	34,646
Loans held for investment, net of unearned income, percentage	28.05%	27.82%
Commercial Loans \| Agricultural
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment, net of unearned income	1,599	2,324
Covered under loss share agreements	43	164
Loans held for investment, net of unearned income, percentage	0.09%	0.14%
Commercial Loans \| Farmland Loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment, net of unearned income	29,517	32,614
Covered under loss share agreements	716	873
Loans held for investment, net of unearned income, percentage	1.75%	1.91%
Consumer Real Estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment, net of unearned income	629,231	636,485
Loans held for investment, net of unearned income, percentage	37.25%	37.20%
Consumer Real Estate \| Home Equity Lines
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment, net of unearned income	110,957	111,770
Covered under loss share agreements	60,391	69,206
Loans held for investment, net of unearned income, percentage	6.57%	6.53%
Consumer Real Estate \| Single Family Owner Occupied
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment, net of unearned income	485,475	496,012
Covered under loss share agreements	11,968	16,919
Loans held for investment, net of unearned income, percentage	28.74%	28.99%
Consumer Real Estate \| Owner occupied construction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment, net of unearned income	32,799	28,703
Covered under loss share agreements	453	1,184
Loans held for investment, net of unearned income, percentage	1.94%	1.68%
Consumer and Other Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment, net of unearned income	75,902	75,239
Loans held for investment, net of unearned income, percentage	4.49%	4.40%
Consumer and Other Loans \| Consumer Loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment, net of unearned income	69,347	71,313
Covered under loss share agreements	88	118
Loans held for investment, net of unearned income, percentage	4.10%	4.17%
Consumer and Other Loans \| Other Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment, net of unearned income	$ 6,555	$ 3,926
Loans held for investment, net of unearned income, percentage	0.39%	0.23%

Loans and leases receivable gross carrying amount covered percentage.

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Loans held for investment net of unearned incomes.

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Amount before allowance and after deduction of deferred interest and fees, unamortized costs and premiums and discounts from face amounts, of loans and leases held in portfolio, including but not limited to, commercial and consumer loans. Excludes loans and leases covered under loss sharing agreements.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

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Amount after allowance and deduction of deferred interest and fees, unamortized costs and premiums over and discounts from face amounts, of loans and leases held in portfolio, including but not limited to, commercial and consumer loans. Includes loans and leases covered under loss sharing agreements.

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Amount classified as loans attributable to disposal group held for sale or disposed of. Excludes loans and leases covered under loss sharing agreements and loans classified as debt securities.

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