QUARTERLY FINANCIAL DATA (UNAUDITED) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Quarterly Financial Information Disclosure [Abstract]
Revenue	$ 77,127	$ 78,305	$ 73,733	$ 78,035	$ 82,261	$ 72,756	$ 63,464	$ 63,653	$ 307,200	$ 282,134	$ 250,080
Gross profit	10,675	10,347	7,011	8,388	9,716	3,159	5,312	6,117	36,421	24,304	30,472
Net income (loss)	1,192	856	(1,684)	31	333	(7,705)	(5,069)	(3,175)	395	(15,616)	(5,460)
Income tax expense	384	163	46	125	(105)	219	163	187	718	464	564
Comprehensive income (loss)	$ 1,133	$ 855	$ (1,570)	$ 310	$ (276)	$ (8,340)	$ (4,240)	$ (3,234)	$ 697	$ (16,090)	$ (5,276)
Net income (loss) per common share - basic	$ 0.08	$ 0.05	$ (0.11)	$ 0.00	$ 0.02	$ (0.49)	$ (0.33)	$ (0.21)	$ 0.03	$ (1.01)	$ (0.35)
Net income (loss) per common share - diluted	$ 0.07	$ 0.05	$ (0.11)	$ 0.00	$ 0.02	$ (0.49)	$ (0.33)	$ (0.21)	$ 0.02	$ (1.01)	$ (0.35)