Net Income Per Share (Details) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011	Dec. 31, 2011
Net income per share
Net income	$ 2,641	$ 2,283	$ 4,652	$ 4,312	$ 8,991
Weighted average common shares outstanding	14,297,524	14,231,692	14,290,806	14,239,180
Dilutive effect of common stock options, warrants and restricted stock	360,711	272,010	344,262	256,565
Shares used in computation of net income per common share - diluted	14,658,235	14,503,702	14,635,068	14,495,745
Net income per common share - basic	$ 0.18	$ 0.16	$ 0.33	$ 0.30
Net income per common share - diluted	$ 0.18	$ 0.16	$ 0.32	$ 0.30