Loans - Recorded Investment of Individual Loan Categories (Detail) - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015	Mar. 31, 2015	Dec. 31, 2014
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan Balance	$ 1,716,660	$ 1,745,340
Net loans	1,702,424	1,730,806
Interest Due	4,988	5,115
Deferred Fees / (Costs)	3,412	3,792
Recorded Investment	1,725,060	1,754,247
Recorded Investment	1,710,824	1,739,713
Allowance for loan losses	(14,236)	(14,534)	$ (16,634)	$ (16,501)
Commercial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan Balance	795,701	802,792
Interest Due	2,106	2,207
Deferred Fees / (Costs)	2,053	2,203
Recorded Investment	799,860	807,202
Real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan Balance	560,318	579,367
Interest Due	1,797	1,789
Deferred Fees / (Costs)	2,364	2,470
Recorded Investment	564,479	583,626
Consumer [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan Balance	360,641	363,181
Interest Due	1,085	1,119
Deferred Fees / (Costs)	(1,005)	(881)
Recorded Investment	360,721	363,419
Owner Occupied Real Estate [Member] | Commercial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan Balance	264,899	268,281
Interest Due	611	613
Deferred Fees / (Costs)	1,205	1,328
Recorded Investment	266,715	270,222
Non Owner Occupied Real Estate [Member] | Commercial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan Balance	324,824	326,399
Interest Due	336	306
Deferred Fees / (Costs)	506	497
Recorded Investment	325,666	327,202
Residential Spec Homes [Member] | Commercial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan Balance	7,011	5,018
Interest Due	12	9
Deferred Fees / (Costs)	17	17
Recorded Investment	7,040	5,044
Development & Spec Land Loans [Member] | Commercial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan Balance	19,961	18,183
Interest Due	46	33
Deferred Fees / (Costs)	18	26
Recorded Investment	20,025	18,242
Commercial and Industrial [Member] | Commercial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan Balance	179,006	184,911
Interest Due	1,101	1,246
Deferred Fees / (Costs)	307	335
Recorded Investment	180,414	186,492
Residential Mortgage [Member] | Real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan Balance	421,422	414,924
Interest Due	1,283	1,275
Deferred Fees / (Costs)	2,364	2,470
Recorded Investment	425,069	418,669
Residential Construction [Member] | Real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan Balance	19,020	19,751
Interest Due	34	34
Recorded Investment	19,054	19,785
Mortgage Warehousing [Member] | Real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan Balance	119,876	144,692
Interest Due	480	480
Recorded Investment	120,356	145,172
Direct Installment [Member] | Consumer [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan Balance	56,767	54,341
Interest Due	160	168
Deferred Fees / (Costs)	(360)	(359)
Recorded Investment	56,567	54,150
Direct Installment Purchased [Member] | Consumer [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan Balance	140	153
Recorded Investment	140	153
Indirect Installment [Member] | Consumer [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan Balance	147,574	151,523
Interest Due	304	323
Recorded Investment	147,878	151,846
Home Equity Loan [Member] | Consumer [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan Balance	156,160	157,164
Interest Due	621	628
Deferred Fees / (Costs)	(645)	(522)
Recorded Investment	$ 156,136	$ 157,270