Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Income Statement [Abstract]
Revenues	$ 184,593	$ 192,742	$ 237,863
Cost of sales:
Cost of sales	124,579	132,730	165,166
Amortization of purchased technology	7,862	8,210	8,559
Total cost of sales	132,441	140,940	173,725
Gross margin	52,152	51,802	64,138
Research and development	25,529	31,958	45,000
Selling, general and administrative	30,628	35,862	41,210
Intangible assets amortization	5,040	5,077	5,215
Restructuring and other charges, net	5,020	4,205	7,479
Loss from operations	(14,065)	(25,300)	(34,766)
Interest expense	(515)	(1,242)	(1,220)
Interest income	96	64	26
Other income	1,548	1,389	1,511
Loss before income tax expense	(12,936)	(25,089)	(34,449)
Income tax expense	1,742	2,492	14,955
Net loss	$ (14,678)	$ (27,581)	$ (49,404)
Net loss per share:
Basic	$ (0.40)	$ (0.79)	$ (1.72)
Diluted	$ (0.40)	$ (0.79)	$ (1.72)
Weighted average shares outstanding:
Basic	36,789	34,699	28,805
Diluted	36,789	34,699	28,805