CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2017	Apr. 01, 2016
Income Statement [Abstract]
Product	$ 50,404	$ 57,644
Services	32,539	24,188
Total net revenue	82,943	81,832
Product	26,102	27,189
Services	16,433	13,989
Total cost of revenue	42,535	41,178
Total gross profit	40,408	40,654
Operating expenses:
Research and development	24,882	23,563
Selling, general and administrative	34,631	32,870
Amortization of intangibles	774	2,365
Restructuring and related charges	1,279	2,612
Total operating expenses	61,566	61,410
Loss from operations	(21,158)	(20,756)
Interest expense, net	(2,590)	(2,421)
Other expense, net	(511)	(9)
Loss on impairment of long-term investment	0	(1,476)
Loss before income taxes	(24,259)	(24,662)
(Benefit from) provision for income taxes	(232)	518
Net loss	$ (24,027)	$ (25,180)
Net loss per share:
Basic and diluted	$ (0.30)	$ (0.33)
Shares used in per share calculation:
Basic and diluted	79,810	76,996