Loans and Allowance for Loan Losses - Summary of Troubled Debt Restructurings by Loan Class of Covered Loans, Classified Separately Under Terms (Detail) (Covered Loans [Member], USD $) In Thousands, unless otherwise specified	Dec. 31, 2013 Contract	Dec. 31, 2012 Contract
Loans Currently Paying Under Restructured Terms [Member]
Financing Receivable, Modifications [Line Items]
Number of contracts	95	56
Troubled debt restructuring loans	$ 20,077	$ 15,430
Loans Currently Paying Under Restructured Terms [Member] | Commercial, Financial and Agricultural [Member]
Financing Receivable, Modifications [Line Items]
Number of contracts	5	2
Troubled debt restructuring loans	45	37
Loans Currently Paying Under Restructured Terms [Member] | Real Estate - Construction and Development [Member]
Financing Receivable, Modifications [Line Items]
Number of contracts	5	5
Troubled debt restructuring loans	3,273	2,908
Loans Currently Paying Under Restructured Terms [Member] | Real Estate - Commercial and Farmland [Member]
Financing Receivable, Modifications [Line Items]
Number of contracts	15	7
Troubled debt restructuring loans	7,543	4,964
Loans Currently Paying Under Restructured Terms [Member] | Real Estate - Residential [Member]
Financing Receivable, Modifications [Line Items]
Number of contracts	68	42
Troubled debt restructuring loans	9,206	7,522
Loans Currently Paying Under Restructured Terms [Member] | Consumer Installment Loans [Member]
Financing Receivable, Modifications [Line Items]
Number of contracts	2
Troubled debt restructuring loans	10
Loans that have Defaulted Under Restructured Terms [Member]
Financing Receivable, Modifications [Line Items]
Number of contracts	29	27
Troubled debt restructuring loans	7,187	11,932
Loans that have Defaulted Under Restructured Terms [Member] | Commercial, Financial and Agricultural [Member]
Financing Receivable, Modifications [Line Items]
Number of contracts	1
Troubled debt restructuring loans	40
Loans that have Defaulted Under Restructured Terms [Member] | Real Estate - Construction and Development [Member]
Financing Receivable, Modifications [Line Items]
Number of contracts	2	5
Troubled debt restructuring loans	34	819
Loans that have Defaulted Under Restructured Terms [Member] | Real Estate - Commercial and Farmland [Member]
Financing Receivable, Modifications [Line Items]
Number of contracts	3	10
Troubled debt restructuring loans	3,658	9,079
Loans that have Defaulted Under Restructured Terms [Member] | Real Estate - Residential [Member]
Financing Receivable, Modifications [Line Items]
Number of contracts	23	12
Troubled debt restructuring loans	3,455	2,034
Loans that have Defaulted Under Restructured Terms [Member] | Consumer Installment Loans [Member]
Financing Receivable, Modifications [Line Items]
Number of contracts
Troubled debt restructuring loans