Loans and Allowance for Loan Losses - Summary of Troubled Debt Restructurings by Loan Class, Excluding Purchased Non-Covered and Covered Loans, Classified Separately Under Restructured Terms (Detail) (Excluding Purchased Non-Covered and 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	67	54
Troubled debt restructuring loans	$ 15,596	$ 18,738
Loans Currently Paying Under Restructured Terms [Member] | Commercial, Financial and Agricultural [Member]
Financing Receivable, Modifications [Line Items]
Number of contracts	4	5
Troubled debt restructuring loans	515	802
Loans Currently Paying Under Restructured Terms [Member] | Real Estate - Construction and Development [Member]
Financing Receivable, Modifications [Line Items]
Number of contracts	8	5
Troubled debt restructuring loans	1,896	1,735
Loans Currently Paying Under Restructured Terms [Member] | Real Estate - Commercial and Farmland [Member]
Financing Receivable, Modifications [Line Items]
Number of contracts	16	16
Troubled debt restructuring loans	6,396	8,947
Loans Currently Paying Under Restructured Terms [Member] | Real Estate - Residential [Member]
Financing Receivable, Modifications [Line Items]
Number of contracts	32	28
Troubled debt restructuring loans	6,699	7,254
Loans Currently Paying Under Restructured Terms [Member] | Consumer Installment Loans [Member]
Financing Receivable, Modifications [Line Items]
Number of contracts	7
Troubled debt restructuring loans	90
Loans that have Defaulted Under Restructured Terms [Member]
Financing Receivable, Modifications [Line Items]
Number of contracts	25	6
Troubled debt restructuring loans	5,301	5,177
Loans that have Defaulted Under Restructured Terms [Member] | Commercial, Financial and Agricultural [Member]
Financing Receivable, Modifications [Line Items]
Number of contracts	3
Troubled debt restructuring loans	525
Loans that have Defaulted Under Restructured Terms [Member] | Real Estate - Construction and Development [Member]
Financing Receivable, Modifications [Line Items]
Number of contracts	2
Troubled debt restructuring loans	32
Loans that have Defaulted Under Restructured Terms [Member] | Real Estate - Commercial and Farmland [Member]
Financing Receivable, Modifications [Line Items]
Number of contracts	5	3
Troubled debt restructuring loans	2,789	4,149
Loans that have Defaulted Under Restructured Terms [Member] | Real Estate - Residential [Member]
Financing Receivable, Modifications [Line Items]
Number of contracts	13	2
Troubled debt restructuring loans	1,953	1,022
Loans that have Defaulted Under Restructured Terms [Member] | Consumer Installment Loans [Member]
Financing Receivable, Modifications [Line Items]
Number of contracts	2	1
Troubled debt restructuring loans	$ 2	$ 6