Loans and Allowance for Loan Losses - 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	Dec. 31, 2013 Contract
Loans Currently Paying Under Restructured Terms [Member]
Financing Receivable Modifications Number Of Contracts [Line Items]
Number of contracts	16
Troubled debt restructuring loans	$ 4,229
Loans Currently Paying Under Restructured Terms [Member] | Real Estate - Construction and Development [Member]
Financing Receivable Modifications Number Of Contracts [Line Items]
Number of contracts	1
Troubled debt restructuring loans	8
Loans Currently Paying Under Restructured Terms [Member] | Real Estate - Commercial and Farmland [Member]
Financing Receivable Modifications Number Of Contracts [Line Items]
Number of contracts	8
Troubled debt restructuring loans	3,068
Loans Currently Paying Under Restructured Terms [Member] | Consumer Installment Loans [Member]
Financing Receivable Modifications Number Of Contracts [Line Items]
Number of contracts	7
Troubled debt restructuring loans	1,153
Loans that have Defaulted Under Restructured Terms [Member]
Financing Receivable Modifications Number Of Contracts [Line Items]
Number of contracts	18
Troubled debt restructuring loans	2,921
Loans that have Defaulted Under Restructured Terms [Member] | Commercial, Financial and Agricultural [Member]
Financing Receivable Modifications Number Of Contracts [Line Items]
Number of contracts	1
Troubled debt restructuring loans	6
Loans that have Defaulted Under Restructured Terms [Member] | Real Estate - Construction and Development [Member]
Financing Receivable Modifications Number Of Contracts [Line Items]
Number of contracts	2
Troubled debt restructuring loans	17
Loans that have Defaulted Under Restructured Terms [Member] | Real Estate - Commercial and Farmland [Member]
Financing Receivable Modifications Number Of Contracts [Line Items]
Number of contracts	2
Troubled debt restructuring loans	296
Loans that have Defaulted Under Restructured Terms [Member] | Real Estate - Residential [Member]
Financing Receivable Modifications Number Of Contracts [Line Items]
Number of contracts	4
Troubled debt restructuring loans	1,696
Loans that have Defaulted Under Restructured Terms [Member] | Consumer Installment Loans [Member]
Financing Receivable Modifications Number Of Contracts [Line Items]
Number of contracts	9
Troubled debt restructuring loans	$ 906