Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Income Statement [Abstract]
Revenue	$ 262,832	$ 269,966	$ 319,852
Cost of revenue	172,154	173,660	189,088
Gross profit	90,678	96,306	130,764
Expenses:
Selling, general and administrative	80,150	70,276	61,236
Depreciation and amortization	8,530	7,108	6,141
Research and development	9,320	6,657	4,787
Gain on disposal of long-lived assets	(18)	(13)	(19)
Total expenses	97,982	84,028	72,145
(Loss) income from operations	(7,304)	12,278	58,619
Other income (expense):
Interest expense	(1,979)	(1,521)	(1,373)
Gain on legal settlement	12,730	0	0
Other (expense) income, net	(303)	(123)	(376)
Total other income (expense)	10,448	(1,644)	(1,749)
Income before income taxes	3,144	10,634	56,870
Income tax expense	(1,237)	(3,476)	(17,248)
Income from continuing operations	1,907	7,158	39,622
(Loss) income from discontinued operations, net of tax	(51,037)	(20,620)	13,981
Net (loss) income	$ (49,130)	$ (13,462)	$ 53,603
Basic earnings (loss) per common share:
Continuing operations (in dollars per share)	$ 0.03	$ 0.13	$ 0.73
Discontinued operations, net of tax (in dollars per share)	(0.91)	(0.38)	0.26
Basic earnings (loss) per common share (in dollars per share)	(0.88)	(0.25)	0.99
Diluted earnings (loss) per common share:
Continuing operations (in dollars per share)	0.03	0.13	0.71
Discontinued operations (in dollars per share)	(0.91)	(0.37)	0.25
Diluted earnings (loss) per common share (in dollars per share)	$ (0.88)	$ (0.24)	$ 0.96
Weighted average common shares:
Weighted average common shares used in computing basic earnings (loss) per common share (in shares)	56,087	54,459	54,511
Weighted average common shares used in computing diluted earnings (loss) per common share (in shares)	56,350	54,992	55,526