SELECTED QUARTERLY FINANCIAL INFORMATION (UNAUDITED) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Quarterly Financial Information Disclosure [Abstract]
Sales	$ 90,175	$ 84,991	$ 78,197	$ 64,557	$ 86,794	$ 67,211	$ 70,186	$ 67,822	$ 317,920	$ 292,013	$ 315,249
Gross Profit	30,937	28,615	26,629	21,387	28,079	23,151	23,553	22,744	107,568	97,527	104,538
Net income	$ 3,173	$ 2,199	$ 2,522	$ (2,048)	$ 3,707	$ (1,383)	$ 145	$ (1,245)	$ 5,846	$ 1,224	$ 2,610
Basic (loss) earnings per share (in dollars per share)	$ 0.25	$ 0.17	$ 0.20	$ (0.16)	$ 0.29	$ (0.11)	$ 0.01	$ (0.10)	$ 0.45	$ 0.10	$ 0.20
Diluted (loss) earnings per share (in dollars per share)	$ 0.24	$ 0.17	$ 0.20	$ (0.16)	$ 0.29	$ (0.11)	$ 0.01	$ (0.10)	$ 0.45	$ 0.09	$ 0.20
Denominator for basic (loss) earnings per share - weighted average shares (in shares)	12,918	12,907	12,894	12,880	12,854	12,835	12,812	12,797	12,900	12,824	12,776
Denominator for diluted (loss) earnings per share - adjusted weighted average shares (in shares)	13,054	12,983	12,938	12,880	12,922	12,835	12,898	12,797	12,971	12,909	12,872