SELECTED QUARTERLY FINANCIAL DATA (UNAUDITED) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018
Summary of the quarterly operating results
Revenue	$ 66,807	$ 56,862	$ 71,466	$ 50,652	$ 44,355	$ 53,467	$ 47,975	$ 43,121	$ 245,787	$ 188,918
Gross profit	9,070	5,956	9,192	6,682	5,332	10,212	6,747	6,450	30,900	28,741
Income (loss) from continuing operations	$ (296)	$ (363)	$ 1,286	$ 395	$ (2,688)	$ (2,840)	$ (6,024)	$ (2,238)	$ 1,022	$ (13,790)
Income (loss) per common share from continuing operations:
Basic	$ (0.02)	$ (0.02)	$ 0.07	$ 0.02	$ (0.15)	$ (0.16)	$ (0.33)	$ (0.12)	$ 0.05	$ (0.76)
Diluted	$ (0.02)	$ (0.02)	$ 0.07	$ 0.02	$ (0.15)	$ (0.16)	$ (0.33)	$ (0.12)	$ 0.05	$ (0.76)