Loans - Recorded Investment of Individual Loan Categories (Detail) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2013	Jun. 30, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Dec. 31, 2011
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan Balance	$ 1,080,231		$ 1,188,466
Net loans	1,062,383		1,170,196
Interest Due	3,151		3,517
Deferred Fees / (Costs)	1,188		2,251
Recorded Investment	1,066,722		1,175,964
Allowance for loan losses	(17,848)	(18,880)	(18,270)	(18,568)	(18,374)	(18,882)
Commercial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan Balance	498,824		459,558
Interest Due	1,172		1,369
Deferred Fees / (Costs)	760		913
Recorded Investment	500,756		461,840
Real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan Balance	302,436		440,579
Interest Due	1,064		1,058
Deferred Fees / (Costs)	409		583
Recorded Investment	303,909		442,220
Consumer [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan Balance	278,971		288,329
Interest Due	915		1,090
Deferred Fees / (Costs)	19		755
Recorded Investment	279,905		290,174
Loan Receivable [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan Balance	1,080,231		1,188,466
Interest Due	3,151		3,517
Deferred Fees / (Costs)	1,188		2,251
Recorded Investment	1,084,570		1,194,234
Owner Occupied Real Estate [Member] | Commercial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan Balance	153,113		162,694
Interest Due	226		503
Deferred Fees / (Costs)	212		485
Recorded Investment	153,551		163,682
Non Owner Occupied Real Estate [Member] | Commercial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan Balance	229,654		201,763
Interest Due	175		467
Deferred Fees / (Costs)	430		276
Recorded Investment	230,259		202,506
Residential Spec Homes [Member] | Commercial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan Balance	242		1,056
Interest Due			8
Deferred Fees / (Costs)
Recorded Investment	242		1,064
Development & Spec Land Loans [Member] | Commercial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan Balance	15,621		6,963
Interest Due	39		11
Deferred Fees / (Costs)	43
Recorded Investment	15,703		6,974
Commercial and Industrial [Member] | Commercial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan Balance	100,194		87,082
Interest Due	732		380
Deferred Fees / (Costs)	75		152
Recorded Investment	101,001		87,614
Residential mortgage [Member] | Real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan Balance	179,964		181,450
Interest Due	567		565
Deferred Fees / (Costs)	409		583
Recorded Investment	180,940		182,598
Residential Construction [Member] | Real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan Balance	8,881		7,681
Interest Due	17		13
Deferred Fees / (Costs)
Recorded Investment	8,898		7,694
Mortgage Warehouse [Member] | Real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan Balance	113,591		251,448
Interest Due	480		480
Deferred Fees / (Costs)
Recorded Investment	114,071		251,928
Direct Installment [Member] | Consumer [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan Balance	28,968		27,831
Interest Due	92		115
Deferred Fees / (Costs)	(278)		(204)
Recorded Investment	28,782		27,742
Direct Installment Purchased [Member] | Consumer [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan Balance	331		429
Interest Due
Deferred Fees / (Costs)
Recorded Investment	331		429
Indirect Installment [Member] | Consumer [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan Balance	129,450		133,481
Interest Due	306		370
Deferred Fees / (Costs)
Recorded Investment	129,756		133,851
Home Equity [Member] | Consumer [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan Balance	120,222		126,588
Interest Due	517		605
Deferred Fees / (Costs)	297		959
Recorded Investment	$ 121,036		$ 128,152