QUARTERLY FINANCIAL DATA (UNAUDITED) - Summary of quarterly results of operations (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
Quarterly Financial Information Disclosure [Abstract]
Revenue	$ 19,104	$ 19,916	$ 21,956	$ 21,583	$ 19,879	$ 21,062	$ 21,536	$ 20,253	$ 82,559	$ 82,730	$ 82,184
Gross profit	6,475	7,444	8,014	8,609	7,213	8,769	8,708	7,967	30,542	32,657	33,029
Net earnings (loss)	$ (323)	$ 690	$ 838	$ 934	$ 280	$ 1,141	$ 1,185	$ 458	$ 2,139	$ 3,064	$ 2,070
Net earnings (loss) per common share
Basic (in dollars per share)	$ (0.01)	$ 0.02	$ 0.02	$ 0.03	$ 0.01	$ 0.03	$ 0.04	$ 0.01	$ 0.07	$ 0.09	$ 0.06
Diluted (in dollars per share)	$ (0.01)	$ 0.02	$ 0.02	$ 0.03	$ 0.01	$ 0.03	$ 0.04	$ 0.01	$ 0.07	$ 0.09	$ 0.06