Non-performing Loans and Impaired Loans - Loans Transferred and Classified as Troubled Debt Restructured Loans Nonaccrual (Detail) (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Sep. 30, 2013 Defaults	Sep. 30, 2012 Defaults
Financing Receivable Modifications Number Of Contracts [Line Items]
Number of Defaults	11,000	7,000
Unpaid Principal Balance	$ 1,724	$ 2,411
Commercial [Member]
Financing Receivable Modifications Number Of Contracts [Line Items]
Number of Defaults	3,000	5,000
Unpaid Principal Balance	149	1,734
Commercial [Member] | Owner Occupied Real Estate [Member]
Financing Receivable Modifications Number Of Contracts [Line Items]
Number of Defaults	2,000	3,000
Unpaid Principal Balance	81	1,473
Commercial [Member] | Non Owner Occupied Real Estate [Member]
Financing Receivable Modifications Number Of Contracts [Line Items]
Number of Defaults	1,000	2,000
Unpaid Principal Balance	68	261
Commercial [Member] | Residential Development [Member]
Financing Receivable Modifications Number Of Contracts [Line Items]
Number of Defaults
Unpaid Principal Balance
Commercial [Member] | Development & Spec Land Loans [Member]
Financing Receivable Modifications Number Of Contracts [Line Items]
Number of Defaults
Unpaid Principal Balance
Commercial [Member] | Commercial and Industrial [Member]
Financing Receivable Modifications Number Of Contracts [Line Items]
Number of Defaults
Unpaid Principal Balance
Real Estate [Member]
Financing Receivable Modifications Number Of Contracts [Line Items]
Number of Defaults	4,000	2,000
Unpaid Principal Balance	400	677
Real Estate [Member] | Residential mortgage [Member]
Financing Receivable Modifications Number Of Contracts [Line Items]
Number of Defaults	4,000	2,000
Unpaid Principal Balance	400	677
Real Estate [Member] | Residential Construction [Member]
Financing Receivable Modifications Number Of Contracts [Line Items]
Number of Defaults
Unpaid Principal Balance
Real Estate [Member] | Mortgage Warehousing [Member]
Financing Receivable Modifications Number Of Contracts [Line Items]
Number of Defaults
Unpaid Principal Balance
Consumer [Member]
Financing Receivable Modifications Number Of Contracts [Line Items]
Number of Defaults	4,000
Unpaid Principal Balance	1,175
Consumer [Member] | Direct Installment [Member]
Financing Receivable Modifications Number Of Contracts [Line Items]
Number of Defaults
Unpaid Principal Balance
Consumer [Member] | Direct Installment Purchased [Member]
Financing Receivable Modifications Number Of Contracts [Line Items]
Number of Defaults
Unpaid Principal Balance
Consumer [Member] | Indirect Installment [Member]
Financing Receivable Modifications Number Of Contracts [Line Items]
Number of Defaults
Unpaid Principal Balance
Consumer [Member] | Home Equity [Member]
Financing Receivable Modifications Number Of Contracts [Line Items]
Number of Defaults	4,000
Unpaid Principal Balance	$ 1,175