QUARTERLY FINANCIAL DATA (UNAUDITED) (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 DATA (UNAUDITED)
Net sales	$ 52,519	$ 50,149	$ 48,687	$ 50,212	$ 54,262	$ 54,890	$ 54,165	$ 45,574	$ 201,567	$ 208,891	$ 154,739
Gross profit	16,043	15,349	13,939	14,377	14,840	14,832	15,473	10,302	59,708	55,446	36,950
Net income	$ 2,861	$ 3,754	$ 2,653	$ 2,428	$ 3,599	$ 4,273	$ 3,868	$ 750	$ 11,696	$ 12,491	$ 5,265
Net income per share - basic (in dollars per share)	$ 0.21	$ 0.28	$ 0.20	$ 0.18	$ 0.27	$ 0.32	$ 0.29	$ 0.06	$ 0.87	$ 0.94	$ 0.40
Net income per share - diluted (in dollars per share)	$ 0.21	$ 0.28	$ 0.20	$ 0.18	$ 0.27	$ 0.32	$ 0.29	$ 0.06	$ 0.87	$ 0.93	$ 0.40