Consolidated Statements of Operations (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Income Statement [Abstract]
Total revenues	$ 31,488	$ 29,706	$ 78,161	$ 91,701
Costs and expenses
Cost of sales (excludes amortization of intangible assets of $1,571, $1,511, $3,142 and $2,949, respectively)	15,902	13,671	36,149	33,218
Research and development	8,127	7,945	17,208	15,469
Sales and marketing	9,393	7,120	19,320	15,562
General and administrative	5,843	5,901	13,070	13,264
Amortization of intangible assets from acquired businesses and technology	2,208	2,022	4,416	3,786
Total costs and expenses	41,473	36,659	90,163	81,299
Operating (loss) income	(9,985)	(6,953)	(12,002)	10,402
Interest expense, net	(372)	(359)	(731)	(723)
(Loss) income before taxes	(10,357)	(7,312)	(12,733)	9,679
Benefit for income taxes	(3,449)	(5,557)	(4,313)	(933)
Net (loss) income	$ (6,908)	$ (1,755)	$ (8,420)	$ 10,612
Basic (loss) earnings per share	$ (0.20)	$ (0.05)	$ (0.25)	$ 0.31
Diluted (loss) earnings per share	$ (0.20)	$ (0.05)	$ (0.25)	$ 0.30
Shares used in basic per share calculation	34,347	33,802	34,271	33,658
Shares used in diluted per share calculation	34,347	33,802	34,271	34,716