Loans and Allowance for Loan Losses (Details) (USD $)	Jun. 30, 2013	Dec. 31, 2012	Jun. 30, 2012
Components of loan portfolio disaggregated by class of loan and percentage change in total loans
Total loans	$ 1,058,662,000	$ 1,041,189,000	$ 1,060,996,000
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	1.70%
Commercial and industrial [Member]
Components of loan portfolio disaggregated by class of loan and percentage change in total loans
Total loans	279,300,000	285,322,000
Loan portfolio classes and segments as a percentage of aggregate loans	26.40%	27.40%
Loans and leases receivable net of deferred income increase decrease percentage	(2.10%)
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	42,170,000	48,099,000
Loan portfolio classes and segments as a percentage of aggregate loans	4.00%	4.60%
Loans and leases receivable net of deferred income increase decrease percentage	(12.30%)
Real estate - owner occupied [Member]
Components of loan portfolio disaggregated by class of loan and percentage change in total loans
Total loans	253,172,000	259,277,000
Loan portfolio classes and segments as a percentage of aggregate loans	23.90%	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	357,452,000	324,886,000
Loan portfolio classes and segments as a percentage of aggregate loans	33.80%	31.20%
Loans and leases receivable net of deferred income increase decrease percentage	10.00%
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	53,522,000	50,922,000
Loan portfolio classes and segments as a percentage of aggregate loans	5.00%	4.90%
Loans and leases receivable net of deferred income increase decrease percentage	5.10%
Total commercial [Member]
Components of loan portfolio disaggregated by class of loan and percentage change in total loans
Total loans	985,616,000	968,506,000	987,491,000
Loan portfolio classes and segments as a percentage of aggregate loans	93.10%	93.00%
Loans and leases receivable net of deferred income increase decrease percentage	1.80%
Retail Home equity and other [Member]
Components of loan portfolio disaggregated by class of loan and percentage change in total loans
Total loans	37,337,000	38,917,000
Loan portfolio classes and segments as a percentage of aggregate loans	3.50%	3.70%
Loans and leases receivable net of deferred income increase decrease percentage	(4.10%)
Retail 1-4 family mortgages [Member]
Components of loan portfolio disaggregated by class of loan and percentage change in total loans
Total loans	35,709,000	33,766,000
Loan portfolio classes and segments as a percentage of aggregate loans	3.40%	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	$ 73,046,000	$ 72,683,000	$ 73,505,000
Loan portfolio classes and segments as a percentage of aggregate loans	6.90%	7.00%
Loans and leases receivable net of deferred income increase decrease percentage	0.50%