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]
Revenue	$ 83,560	$ 81,576	$ 250,316	$ 227,195
Cost of goods sold	59,788	61,512	176,345	178,763
Gross profit	23,772	20,064	73,971	48,432
Operating expenses:
Research and development	10,763	11,842	32,702	35,983
Sales and marketing	3,789	3,075	11,439	10,057
General and administrative	7,384	6,712	22,999	23,892
Amortization of purchased intangible assets	447	378	1,344	1,136
Asset impairment charge	368		368
Acquisition-related costs	180		467
Restructuring charges	18	504	44	504
Escrow settlement gain				(3,886)
Total operating expenses	22,949	22,511	69,363	67,686
Income (loss) from operations	823	(2,447)	4,608	(19,254)
Interest income	31	52	84	155
Interest expense	(171)	(375)	(1,133)	(937)
Other income, net	1,852	1,735	2,408	493
Total interest and other income (expense), net	1,712	1,412	1,359	(289)
Income (loss) before income taxes	2,535	(1,035)	5,967	(19,543)
Provision for income taxes	(1,157)	(902)	(2,698)	(1,761)
Net income (loss)	$ 1,378	$ (1,937)	$ 3,269	$ (21,304)
Basic net income (loss) per share	$ 0.03	$ (0.06)	$ 0.09	$ (0.67)
Diluted net income (loss) per share	$ 0.03	$ (0.06)	$ 0.09	$ (0.67)
Weighted average shares used to compute basic net income (loss) per share	40,367	32,383	36,303	31,930
Weighted average shares used to compute diluted net income (loss) per share	42,217	32,383	37,537	31,930