SELECTED QUARTERLY FINANCIAL DATA Selected Quarterly Financial Data (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	$ 100,314	$ 108,136	$ 113,067	$ 101,227	$ 106,109	$ 110,028	$ 122,743	$ 124,317	$ 422,744	$ 463,197	$ 581,192
Gross margin	42,774	43,542	46,839	41,262	44,439	45,145	50,222	47,904	174,417	187,710	222,845
Operating income (loss)	(671)	(786)	(2,425)	(3,705)	140	(3,826)	13,643	(6,716)	(7,587)	3,241	(17,486)
Income (Loss) from Continuing Operations	(108)	(1,908)	(3,347)	(3,570)	(2,484)	(2,029)	12,774	(6,654)	(8,933)	1,607	(15,786)
Income (Loss) from Discontinued Operations, Net of Taxes	(184)	35	209	83	(142)	(55)	1,103	(184)	143	722	2,592
Net income (loss)	$ (292)	$ (1,873)	$ (3,138)	$ (3,487)	$ (2,626)	$ (2,084)	$ 13,877	$ (6,838)	$ (8,790)	$ 2,329	$ (13,194)
Earnings (loss) per share from continuing operations, basic and diluted	$ 0.00	$ (0.06)	$ (0.10)	$ (0.10)	$ (0.07)	$ (0.06)	$ 0.38	$ (0.20)	$ (0.27)	$ 0.05	$ (0.48)
Earnings (loss) per share from discontinued operations, basic and diluted	(0.01)	0.00	0.01	0.00	0.00	0.00	0.03	(0.01)	0.01	0.02	0.08
Earnings Per Share, Basic and Diluted	$ (0.01)	$ (0.06)	$ (0.09)	$ (0.10)	$ (0.08)	$ (0.06)	$ 0.41	$ (0.21)	$ (0.26)	$ 0.07	$ (0.40)
Weighted Average Number of Shares Outstanding, Basic	32,227,000	33,572,000	33,252,000	34,631,000	34,274,000	34,687,000	33,525,000	33,053,000	33,174,000	33,869,000	32,843,000
Weighted-average common stock outstanding - diluted (in shares)					34,274,000	34,687,000	34,007,000	33,053,000	33,174,000	34,084,000	32,843,000
Common stock equivalents and outstanding stock options excluded from the calculation of diluted earnings (loss) per share (in thousands)	604,000	299,000	548,000	1,345,000	886,000	1,124,000	979,000	1,903,000	603,500	556,000	1,680,739