Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Income Statement [Abstract]
Total revenues	$ 50,894	$ 138,795	$ 162,853	$ 49,341
Costs and expenses
Cost of sales (excludes amortization of intangible assets of $1,877, $1,590, $5,122 and $4,770, respectively)	19,391	54,295	60,716	17,728
Research and development	7,468	31,164	22,970	8,801
Sales and marketing	12,898	36,376	38,813	11,853
General and administrative	6,580	19,964	20,483	6,364
Amortization of intangible assets from acquired businesses and technology	2,503	6,782	7,184	2,273
Acquisition and integration costs	4,591	568	7,022	197
Total costs and expenses	53,431	149,149	157,188	47,216
Operating (loss) income	(2,537)	(10,354)	5,665	2,125
Interest expense, net	(2,784)	(8,619)	(8,387)	(3,006)
Loss before income taxes	(5,321)	(18,973)	(2,722)	(881)
Provision (benefit) for income taxes	204	(7,115)	355	(309)
Net loss	$ (5,525)	$ (11,858)	$ (3,077)	$ (572)
Basic and diluted earnings (loss) per share (in dollars per share)	$ (0.16)	$ (0.36)	$ (0.09)	$ (0.02)
Shares used in basic and diluted per share calculation (in shares)	33,913	32,645	33,538	32,673