Loans - Summary of Troubled Debt Restructurings by Loan Class of Purchased Non-Covered Loans, Classified Separately under Restructured Terms (Detail) (Purchased Non-Covered Loans [Member], USD $) In Thousands, unless otherwise specified	Mar. 31, 2014 Contract	Dec. 31, 2013 Contract
Loans Currently Paying Under Restructured Terms [Member]
Financing Receivable, Modifications [Line Items]
Number of contracts	15	16
Troubled debt restructuring loans	$ 3,439	$ 4,229
Loans Currently Paying Under Restructured Terms [Member] | Commercial, Financial and Agricultural [Member]
Financing Receivable, Modifications [Line Items]
Number of contracts
Troubled debt restructuring loans
Loans Currently Paying Under Restructured Terms [Member] | Real Estate - Construction and Development [Member]
Financing Receivable, Modifications [Line Items]
Number of contracts	6	1
Troubled debt restructuring loans	2,244	8
Loans Currently Paying Under Restructured Terms [Member] | Real Estate - Commercial and Farmland [Member]
Financing Receivable, Modifications [Line Items]
Number of contracts		8
Troubled debt restructuring loans		3,068
Loans Currently Paying Under Restructured Terms [Member] | Real Estate - Residential [Member]
Financing Receivable, Modifications [Line Items]
Number of contracts	8
Troubled debt restructuring loans	1,187
Loans Currently Paying Under Restructured Terms [Member] | Consumer Installment Loans [Member]
Financing Receivable, Modifications [Line Items]
Number of contracts	1	7
Troubled debt restructuring loans	8	1,153
Loans That Have Defaulted Under Restructured Terms [Member]
Financing Receivable, Modifications [Line Items]
Number of contracts	18	18
Troubled debt restructuring loans	3,020	2,921
Loans That Have Defaulted Under Restructured Terms [Member] | Commercial, Financial and Agricultural [Member]
Financing Receivable, Modifications [Line Items]
Number of contracts	1	1
Troubled debt restructuring loans	6	6
Loans That Have Defaulted Under Restructured Terms [Member] | Real Estate - Construction and Development [Member]
Financing Receivable, Modifications [Line Items]
Number of contracts	3	2
Troubled debt restructuring loans	463	17
Loans That Have Defaulted Under Restructured Terms [Member] | Real Estate - Commercial and Farmland [Member]
Financing Receivable, Modifications [Line Items]
Number of contracts	4	2
Troubled debt restructuring loans	1,687	296
Loans That Have Defaulted Under Restructured Terms [Member] | Real Estate - Residential [Member]
Financing Receivable, Modifications [Line Items]
Number of contracts	8	4
Troubled debt restructuring loans	847	1,696
Loans That Have Defaulted Under Restructured Terms [Member] | Consumer Installment Loans [Member]
Financing Receivable, Modifications [Line Items]
Number of contracts	2	9
Troubled debt restructuring loans	$ 17	$ 906