Loans - Analysis of Information Pertaining to Purchased Non-Covered Impaired Loans (Detail) (Purchased Non-Covered Loans [Member], USD $) In Thousands, unless otherwise specified	3 Months Ended		12 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Dec. 31, 2013
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unpaid Contractual Principal Balance	$ 35,136		$ 19,970
Recorded Investment With No Allowance	20,509		12,597
Recorded Investment With Allowance
Total Recorded Investment	20,509		12,597
Related Allowance
Average Recorded Investment	16,553		242
Commercial, Financial and Agricultural [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unpaid Contractual Principal Balance	233		19
Recorded Investment With No Allowance	117		11
Recorded Investment With Allowance
Total Recorded Investment	117		11
Related Allowance
Average Recorded Investment	64
Real Estate - Construction and Development [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unpaid Contractual Principal Balance	6,173		5,719
Recorded Investment With No Allowance	3,574		3,690
Recorded Investment With Allowance
Total Recorded Investment	3,574		3,690
Related Allowance
Average Recorded Investment	3,631		71
Real Estate - Commercial and Farmland [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unpaid Contractual Principal Balance	12,966		4,563
Recorded Investment With No Allowance	7,790		2,881
Recorded Investment With Allowance
Total Recorded Investment	7,790		2,881
Related Allowance
Average Recorded Investment	5,336		55
Real Estate - Residential [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unpaid Contractual Principal Balance	15,524		9,612
Recorded Investment With No Allowance	8,987		5,978
Recorded Investment With Allowance
Total Recorded Investment	8,987		5,978
Related Allowance
Average Recorded Investment	7,483		115
Consumer Installment Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unpaid Contractual Principal Balance	240		57
Recorded Investment With No Allowance	41		37
Recorded Investment With Allowance
Total Recorded Investment	41		37
Related Allowance
Average Recorded Investment	$ 39		$ 1