Loans and Allowance for Loan Losses (Details) (USD $)	Mar. 31, 2013	Dec. 31, 2012	Mar. 31, 2012
Components of loan portfolio disaggregated by class of loan and percentage change in total loans
Total loans	$ 1,022,956,000	$ 1,041,189,000	$ 1,051,674,000
Loan portfolio classes and segments as a percentage of aggregate loans	100.00%	100.00%
Loans and leases receivable net of deferred income increase decrease percentage	(1.80%)
Commercial and industrial [Member]
Components of loan portfolio disaggregated by class of loan and percentage change in total loans
Total loans	272,890,000	285,322,000
Loan portfolio classes and segments as a percentage of aggregate loans	26.70%	27.40%
Loans and leases receivable net of deferred income increase decrease percentage	(4.40%)
Vacant land, land development, and residential construction [Member]
Components of loan portfolio disaggregated by class of loan and percentage change in total loans
Total loans	45,174,000	48,099,000
Loan portfolio classes and segments as a percentage of aggregate loans	4.40%	4.60%
Loans and leases receivable net of deferred income increase decrease percentage	(6.10%)
Real estate - owner occupied [Member]
Components of loan portfolio disaggregated by class of loan and percentage change in total loans
Total loans	253,089,000	259,277,000
Loan portfolio classes and segments as a percentage of aggregate loans	24.70%	24.90%
Loans and leases receivable net of deferred income increase decrease percentage	(2.40%)
Real estate - non-owner occupied [Member]
Components of loan portfolio disaggregated by class of loan and percentage change in total loans
Total loans	327,776,000	324,886,000
Loan portfolio classes and segments as a percentage of aggregate loans	32.10%	31.20%
Loans and leases receivable net of deferred income increase decrease percentage	0.90%
Real estate - multi-family and residential rental [Member]
Components of loan portfolio disaggregated by class of loan and percentage change in total loans
Total loans	50,035,000	50,922,000
Loan portfolio classes and segments as a percentage of aggregate loans	4.90%	4.90%
Loans and leases receivable net of deferred income increase decrease percentage	(1.70%)
Total commercial [Member]
Components of loan portfolio disaggregated by class of loan and percentage change in total loans
Total loans	948,964,000	968,506,000
Loan portfolio classes and segments as a percentage of aggregate loans	92.80%	93.00%
Loans and leases receivable net of deferred income increase decrease percentage	(2.00%)
Retail home equity and other [Member]
Components of loan portfolio disaggregated by class of loan and percentage change in total loans
Total loans	38,257,000	38,917,000
Loan portfolio classes and segments as a percentage of aggregate loans	3.70%	3.70%
Loans and leases receivable net of deferred income increase decrease percentage	(1.70%)
Retail 1-4 family mortgages [Member]
Components of loan portfolio disaggregated by class of loan and percentage change in total loans
Total loans	35,735,000	33,766,000
Loan portfolio classes and segments as a percentage of aggregate loans	3.50%	3.30%
Loans and leases receivable net of deferred income increase decrease percentage	5.80%
Total retail [Member]
Components of loan portfolio disaggregated by class of loan and percentage change in total loans
Total loans	$ 73,992,000	$ 72,683,000
Loan portfolio classes and segments as a percentage of aggregate loans	7.20%	7.00%
Loans and leases receivable net of deferred income increase decrease percentage	1.80%