Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Income Statement [Abstract]
Total revenues	$ 50,321	$ 61,701
Costs and expenses
Cost of sales (excludes amortization of intangible assets of $1,590 and $1,571, respectively)	19,249	21,112
Research and development	12,707	8,051
Sales and marketing	12,317	11,788
General and administrative	7,289	9,860
Amortization of intangible assets from acquired businesses and technology	2,219	2,201
Total costs and expenses	53,781	53,012
Operating (loss) income	(3,460)	8,689
Interest expense, net	(2,689)	(2,895)
(Loss) income before (benefit) provision for taxes	(6,149)	5,794
(Benefit) provision for income taxes	(2,703)	1,803
Net (loss) income	$ (3,446)	$ 3,991
Basic (loss) earnings per share (in dollars per share)	$ (0.11)	$ 0.12
Diluted (loss) earnings per share (in dollars per share)	$ (0.11)	$ 0.11
Shares used in basic (loss) earnings per share (weighted-average common shares outstanding)	32,727	34,641
Shares used in diluted per share calculation (in shares)	32,727	35,745