Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Income Statement [Abstract]
Total revenues	$ 46,812	$ 41,193	$ 143,717	$ 120,205
Costs and expenses
Cost of sales (excludes amortization of intangible assets of $1,590, $1,571, $4,751, and $4,713, respectively)	16,961	16,768	53,566	52,917
Research and development	8,419	11,506	25,575	28,714
Sales and marketing	12,112	11,396	35,823	31,567
General and administrative	5,889	5,879	22,039	18,949
Amortization of intangible assets from acquired businesses and technology	2,219	2,207	6,638	6,623
Impairment loss	0	3,558	0	3,558
Total costs and expenses	45,600	51,314	143,641	142,328
Operating income (loss)	1,212	(10,121)	76	(22,123)
Interest expense, net	(3,090)	(224)	(9,046)	(955)
Loss before benefit for income taxes	(1,878)	(10,345)	(8,970)	(23,078)
Benefit for income taxes	(1,116)	(4,578)	(3,268)	(8,891)
Net loss	$ (762)	$ (5,767)	$ (5,702)	$ (14,187)
Basic and diluted loss per share	$ (0.02)	$ (0.17)	$ (0.17)	$ (0.41)
Weighted shares used in basic and diluted per share calculation	33,683	34,480	34,313	34,340