Loans and Allowance for Loan Losses - Components of Loan Portfolio Disaggregated by Class of Loan and Percentage Change in Total Loans (Detail) (USD $)	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Financing Receivable, Recorded Investment [Line Items]
Total loans	$ 1,053,243,000	$ 1,041,189,000	$ 1,072,422,000
Percentage of Total Loan Portfolio	100.00%	100.00%
Loans and leases receivable net of deferred income increase decrease percentage	1.20%
Commercial and Industrial [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	286,373,000	285,322,000
Percentage of Total Loan Portfolio	27.20%	27.40%
Loans and leases receivable net of deferred income increase decrease percentage	0.40%
Commercial Vacant Land, Land Development, and Residential Construction [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	36,741,000	48,099,000
Percentage of Total Loan Portfolio	3.50%	4.60%
Loans and leases receivable net of deferred income increase decrease percentage	(23.60%)
Commercial Real Estate - Owner Occupied [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	261,877,000	259,277,000
Percentage of Total Loan Portfolio	24.90%	24.90%
Loans and leases receivable net of deferred income increase decrease percentage	1.00%
Commercial Real Estate - Non-Owner Occupied [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	364,066,000	324,886,000
Percentage of Total Loan Portfolio	34.60%	31.20%
Loans and leases receivable net of deferred income increase decrease percentage	12.10%
Commercial Real Estate - Multi-Family and Residential Rental [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	37,639,000	50,922,000
Percentage of Total Loan Portfolio	3.50%	4.90%
Loans and leases receivable net of deferred income increase decrease percentage	(26.10%)
Commercial Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	986,696,000	968,506,000	996,905,000
Percentage of Total Loan Portfolio	93.70%	93.00%
Loans and leases receivable net of deferred income increase decrease percentage	1.90%
Retail Home Equity and Other [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	35,080,000	38,917,000
Percentage of Total Loan Portfolio	3.30%	3.70%
Loans and leases receivable net of deferred income increase decrease percentage	(9.90%)
Retail 1-4 Family Mortgages [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	31,467,000	33,766,000
Percentage of Total Loan Portfolio	3.00%	3.30%
Loans and leases receivable net of deferred income increase decrease percentage	(6.80%)
Retail Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	$ 66,547,000	$ 72,683,000	$ 75,517,000
Percentage of Total Loan Portfolio	6.30%	7.00%
Loans and leases receivable net of deferred income increase decrease percentage	(8.40%)