Earnings Per Common Share (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Numerator:
Net earnings	$ 1,533	$ 2,565	$ 1,002	$ 292	$ 1,312	$ 422	$ 710	$ 372	$ 5,392	$ 2,816	$ 3,253
Denominator:
Weighted-average common shares outstanding									25,566	24,634	23,906
Basic earnings per common share	$ 0.06	$ 0.10	$ 0.04	$ 0.01	$ 0.05	$ 0.02	$ 0.03	$ 0.02	$ 0.21	$ 0.11	$ 0.14
Numerator:
Net earnings	$ 1,533	$ 2,565	$ 1,002	$ 292	$ 1,312	$ 422	$ 710	$ 372	$ 5,392	$ 2,816	$ 3,253
Denominator:
Weighted-average common shares outstanding									25,566	24,634	23,906
Incremental shares from stock-based compensation plans									571	395	238
Denominator for diluted earnings per common share									26,137	25,029	24,144
Diluted earnings per common share	$ 0.06	$ 0.10	$ 0.04	$ 0.01	$ 0.05	$ 0.02	$ 0.03	$ 0.02	$ 0.21	$ 0.11	$ 0.13