Condensed Consolidated Statements of Operations (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Income Statement [Abstract]
Revenue	$ 81,576	$ 76,814	$ 227,195	$ 207,867
Cost of goods sold	61,512	58,635	178,763	162,330
Gross profit	20,064	18,179	48,432	45,537
Operating expenses:
Research and development	11,842	12,227	35,983	33,021
Sales and marketing	3,075	3,580	10,057	10,515
General and administrative	6,712	8,905	23,892	21,853
Restructuring charges	504	450	504	775
Amortization of purchased intangible assets	378	381	1,136	1,128
Adjustment to fair value of contingent consideration		1,026		1,026
Escrow settlement gain			(3,886)
Acquisition-related transaction costs		126		5,317
Total operating expenses	22,511	26,695	67,686	73,635
Loss from operations	(2,447)	(8,516)	(19,254)	(28,098)
Interest income	52	66	155	269
Interest expense	(375)	(251)	(937)	(756)
Other income (expense), net	1,735	115	493	(432)
Total interest and other income (expense), net	1,412	(70)	(289)	(919)
Loss before income taxes	(1,035)	(8,586)	(19,543)	(29,017)
Provision for income taxes	(902)	(777)	(1,761)	(870)
Net loss	$ (1,937)	$ (9,363)	$ (21,304)	$ (29,887)
Basic and diluted net loss per share	$ (0.06)	$ (0.30)	$ (0.67)	$ (0.97)
Basic and diluted weighted average shares used to compute net loss per share	32,383	31,185	31,930	30,848