Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Revenues:
Product	$ 176,141	$ 155,285	$ 166,255
Service	36,251	29,308	26,487
Total revenue	212,392	184,593	192,742
Cost of sales:
Product	127,771	107,031	115,699
Service	20,826	17,548	17,031
Amortization of purchased technology	7,707	7,862	8,210
Total cost of sales	156,304	132,441	140,940
Gross margin	56,088	52,152	51,802
Research and development	24,068	25,529	31,958
Selling, general and administrative	33,722	30,628	35,862
Intangible assets amortization	5,040	5,040	5,077
Restructuring and other charges, net	2,917	5,020	4,205
Loss from operations	(9,659)	(14,065)	(25,300)
Interest expense	(482)	(515)	(1,242)
Interest income	189	96	64
Other income	2,135	1,548	1,389
Loss before income tax expense	(7,817)	(12,936)	(25,089)
Income tax expense	2,434	1,742	2,492
Net loss	$ (10,251)	$ (14,678)	$ (27,581)
Net loss per share:
Basic	$ (0.27)	$ (0.40)	$ (0.79)
Diluted	$ (0.27)	$ (0.40)	$ (0.79)
Weighted average shares outstanding:
Basic	37,668	36,789	34,699
Diluted	37,668	36,789	34,699