CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Income Statement [Abstract]
Product	$ 285,260	$ 276,876	$ 343,186
Service	120,651	100,151	90,371
Total net revenue	405,911	377,027	433,557
Product	145,714	121,988	172,280
Service	59,447	52,327	48,929
Total cost of revenue	205,161	174,315	221,209
Total gross profit	200,750	202,712	212,348
Operating expenses:
Research and development	98,401	87,545	93,061
Selling, general and administrative	144,381	120,960	131,322
Amortization of intangibles	10,402	5,783	6,775
Restructuring and related charges	14,602	1,372	2,761
Total operating expenses	267,786	215,660	233,919
Loss from operations	(67,036)	(12,948)	(21,571)
Interest (expense) income, net	(10,628)	(333)	132
Other expense, net	(31)	(282)	(356)
Loss on impairment of long-term investment	(2,735)	(2,505)	0
Loss before income taxes	(80,430)	(16,068)	(21,795)
Provision for (benefit from) income taxes	(8,116)	(407)	24,453
Net loss	$ (72,314)	$ (15,661)	$ (46,248)
Net loss per share:
Basic and diluted	$ (0.93)	$ (0.18)	$ (0.50)
Shares used in per share calculations:
Basic and diluted	77,705	87,514	92,508