CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jul. 01, 2016	Jun. 30, 2017	Jul. 01, 2016
Income Statement [Abstract]
Product	$ 50,190	$ 77,413	$ 100,594	$ 135,057
Services	32,125	32,158	64,664	56,346
Total net revenue	82,315	109,571	165,258	191,403
Product	32,005	44,049	58,107	71,238
Services	16,495	14,482	32,928	28,471
Total cost of revenue	48,500	58,531	91,035	99,709
Total gross profit	33,815	51,040	74,223	91,694
Operating expenses:
Research and development	27,055	26,507	51,937	50,070
Selling, general and administrative	32,625	36,516	67,256	69,386
Amortization of intangibles	780	4,232	1,554	6,597
Restructuring and related charges	777	1,903	2,056	4,515
Total operating expenses	61,237	69,158	122,803	130,568
Loss from operations	(27,422)	(18,118)	(48,580)	(38,874)
Interest expense, net	(2,680)	(2,651)	(5,270)	(5,072)
Other (expense) income, net	(819)	332	(1,330)	323
Loss on impairment of long-term investment	0	0	0	(1,476)
Loss before income taxes	(30,921)	(20,437)	(55,180)	(45,099)
Provision for income taxes	579	242	347	760
Net loss	$ (31,500)	$ (20,679)	$ (55,527)	$ (45,859)
Net loss per share:
Basic and diluted	$ (0.39)	$ (0.27)	$ (0.69)	$ (0.59)
Shares used in per share calculation:
Basic and diluted	80,590	77,342	80,203	77,168