Non-performing Loans and Impaired Loans - Nonaccrual, Loans Past Due Over 90 Days Still on Accrual, and Troubled Debt Restructured ("TDRs") by Class of Loans (Detail) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual	$ 12,986	$ 13,374
Loans Past Due Over 90 Days Still Accruing	2	54
Non Performing TDR's	5,986	6,649
Performing TDR's	3,507	3,702
Total Non-Performing Loans	22,481	23,779
Commercial [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual	5,416	5,754
Loans Past Due Over 90 Days Still Accruing
Non Performing TDR's	1,688	3,674
Performing TDR's	783	1,265
Total Non-Performing Loans	7,887	10,693
Commercial [Member] | Owner Occupied Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual	464	2,800
Loans Past Due Over 90 Days Still Accruing
Non Performing TDR's	82	1,272
Performing TDR's	783	819
Total Non-Performing Loans	1,329	4,891
Commercial [Member] | Non Owner Occupied Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual	2,829	1,705
Loans Past Due Over 90 Days Still Accruing
Non Performing TDR's	825	1,605
Performing TDR's		446
Total Non-Performing Loans	3,654	3,756
Commercial [Member] | Residential Development [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual
Loans Past Due Over 90 Days Still Accruing
Non Performing TDR's
Performing TDR's
Total Non-Performing Loans
Commercial [Member] | Development & Spec Land Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual	170	705
Loans Past Due Over 90 Days Still Accruing
Non Performing TDR's
Performing TDR's
Total Non-Performing Loans	170	705
Commercial [Member] | Commercial and Industrial [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual	1,953	544
Loans Past Due Over 90 Days Still Accruing
Non Performing TDR's	781	797
Performing TDR's
Total Non-Performing Loans	2,734	1,341
Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual	3,436	4,565
Loans Past Due Over 90 Days Still Accruing	2	2
Non Performing TDR's	2,977	2,827
Performing TDR's	1,678	1,761
Total Non-Performing Loans	8,093	9,155
Real Estate [Member] | Residential mortgage [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual	3,436	4,565
Loans Past Due Over 90 Days Still Accruing	2	2
Non Performing TDR's	2,693	2,536
Performing TDR's	1,678	1,761
Total Non-Performing Loans	7,809	8,864
Real Estate [Member] | Residential Construction [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual
Loans Past Due Over 90 Days Still Accruing
Non Performing TDR's	284	291
Performing TDR's
Total Non-Performing Loans	284	291
Real Estate [Member] | Mortgage Warehouse [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual
Loans Past Due Over 90 Days Still Accruing
Non Performing TDR's
Performing TDR's
Total Non-Performing Loans
Real Estate [Member] | Mortgage Warehousing [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual
Loans Past Due Over 90 Days Still Accruing
Non Performing TDR's
Performing TDR's
Total Non-Performing Loans
Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual	4,134	3,055
Loans Past Due Over 90 Days Still Accruing		52
Non Performing TDR's	1,321	148
Performing TDR's	1,046	676
Total Non-Performing Loans	6,501	3,931
Consumer [Member] | Direct Installment [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual	249	138
Loans Past Due Over 90 Days Still Accruing		26
Non Performing TDR's
Performing TDR's
Total Non-Performing Loans	249	164
Consumer [Member] | Direct Installment Purchased [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual
Loans Past Due Over 90 Days Still Accruing
Non Performing TDR's
Performing TDR's
Total Non-Performing Loans
Consumer [Member] | Indirect Installment [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual	657	866
Loans Past Due Over 90 Days Still Accruing		26
Non Performing TDR's
Performing TDR's
Total Non-Performing Loans	657	892
Consumer [Member] | Home Equity [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual	3,228	2,051
Loans Past Due Over 90 Days Still Accruing
Non Performing TDR's	1,321	148
Performing TDR's	1,046	676
Total Non-Performing Loans	$ 5,595	$ 2,875