Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Revenues:
Product	$ 99,090	$ 176,141	$ 155,285
Service	34,678	36,251	29,308
Total revenue	133,768	212,392	184,593
Cost of sales:
Product	84,193	127,771	107,031
Service	21,098	20,826	17,548
Amortization of purchased technology	7,707	7,707	7,862
Total cost of sales	112,998	156,304	132,441
Gross margin	20,770	56,088	52,152
Research and development	23,416	24,068	25,529
Selling, general and administrative	32,792	33,722	30,628
Intangible assets amortization	3,006	5,040	5,040
Restructuring and other charges, net	8,339	2,917	5,020
Loss from operations	(46,783)	(9,659)	(14,065)
Interest expense	(1,199)	(482)	(515)
Interest income	179	189	96
Other income (expense)	(1,074)	2,135	1,548
Loss before income tax expense	(48,877)	(7,817)	(12,936)
Income tax expense	3,727	2,434	1,742
Net loss	$ (52,604)	$ (10,251)	$ (14,678)
Net loss per share:
Basic	$ (1.35)	$ (0.27)	$ (0.40)
Diluted	$ (1.35)	$ (0.27)	$ (0.40)
Weighted average shares outstanding:
Basic	38,994	37,668	36,789
Diluted	38,994	37,668	36,789