CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 29, 2017	Sep. 30, 2016	Sep. 29, 2017	Sep. 30, 2016
Income Statement [Abstract]
Product	$ 58,161	$ 70,285	$ 158,657	$ 205,342
Services	33,853	31,121	98,615	87,467
Total net revenue	92,014	101,406	257,272	292,809
Product	27,736	34,460	85,843	105,698
Services	17,253	15,583	50,181	44,054
Total cost of revenue	44,989	50,043	136,024	149,752
Total gross profit	47,025	51,363	121,248	143,057
Operating expenses:
Research and development	21,289	24,202	73,226	74,272
Selling, general and administrative	37,121	36,112	104,377	105,498
Amortization of intangibles	793	3,009	2,347	9,606
Restructuring and related charges	2,028	(27)	4,084	4,488
Total operating expenses	61,231	63,296	184,034	193,864
Loss from operations	(14,206)	(11,933)	(62,786)	(50,807)
Interest expense, net	(2,794)	(2,734)	(8,064)	(7,806)
Other expense, net	(498)	(328)	(1,828)	(5)
Loss on impairment of long-term investment	0	(1,259)	0	(2,735)
Loss before income taxes	(17,498)	(16,254)	(72,678)	(61,353)
(Benefit from) provision for income taxes	(1,915)	(242)	(1,568)	518
Net loss	$ (15,583)	$ (16,012)	$ (71,110)	$ (61,871)
Net loss per share:
Basic and diluted	$ (0.19)	$ (0.21)	$ (0.88)	$ (0.80)
Shares used in per share calculation:
Basic and diluted	81,445	78,092	80,618	77,475