Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Statement [Abstract]
Revenue	$ 317,098	$ 262,832	$ 269,966
Costs and expenses:
Cost of revenue (excluding depreciation and amortization)	215,129	170,255	172,033
Depreciation and amortization	12,159	10,429	8,735
Research and development	13,645	9,320	6,657
Loss (gain) on disposal of long-lived assets	292	(18)	(13)
Total costs and expenses	319,953	270,136	257,688
(Loss) income from operations	(2,855)	(7,304)	12,278
Other (expense) income:
Interest expense	(2,168)	(1,979)	(1,521)
Gain on legal settlement	0	12,730	0
Other (expense) income, net	812	(303)	(123)
Total other (expense) income	(1,356)	10,448	(1,644)
(Loss) income before income taxes	(4,211)	3,144	10,634
Income tax expense	(8,842)	(1,237)	(3,476)
(Loss) income from continuing operations	(13,053)	1,907	7,158
Loss from discontinued operations, net of tax	(14,342)	(51,037)	(20,620)
Net loss	$ (27,395)	$ (49,130)	$ (13,462)
Basic earnings (loss) per common share:
Continuing operations (in dollars per share)	$ (0.23)	$ 0.03	$ 0.13
Discontinued operations, net of tax (in dollars per share)	(0.25)	(0.91)	(0.38)
Basic earnings (loss) per common share (in dollars per share)	(0.48)	(0.88)	(0.25)
Diluted earnings (loss) per common share:
Continuing operations (in dollars per share)	(0.23)	0.03	0.13
Discontinued operations, net of tax (in dollars per share)	(0.25)	(0.91)	(0.37)
Diluted earnings (loss) per common share (in dollars per share)	$ (0.48)	$ (0.88)	$ (0.24)
Weighted average common shares:
Weighted average common shares used in computing basic earnings (loss) per common share (in shares)	57,580	56,087	54,459
Weighted average common shares used in computing diluted earnings (loss) per common share (in shares)	57,580	56,350	54,992
Corporate
Income Statement [Abstract]
Revenue	$ 0	$ 0	$ 0
Costs and expenses:
(Loss) income from operations	(43,931)	(45,982)	(40,366)
General, selling, and administrative	41,492	43,745	38,623
Operating Segments
General, selling, and administrative	$ 37,236	$ 36,405	$ 31,653