CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 28, 2018	Sep. 29, 2017	Sep. 28, 2018	Sep. 29, 2017
Total net revenue	$ 100,616	$ 92,014	$ 289,903	$ 257,272
Total cost of revenue	50,514	44,989	141,015	136,024
Total gross profit	50,102	47,025	148,888	121,248
Operating expenses:
Research and development	22,251	21,289	67,250	73,226
Selling, general and administrative	29,723	37,121	88,874	104,377
Amortization of intangibles	792	793	2,396	2,347
Restructuring and related charges	987	2,028	2,704	4,084
Total operating expenses	53,753	61,231	161,224	184,034
Loss from operations	(3,651)	(14,206)	(12,336)	(62,786)
Interest expense, net	(2,872)	(2,794)	(8,492)	(8,064)
Other expense, net	(365)	(498)	(698)	(1,828)
Loss before income taxes	(6,888)	(17,498)	(21,526)	(72,678)
Provision for (benefit from) income taxes	870	(1,915)	2,839	(1,568)
Net loss	$ (7,758)	$ (15,583)	$ (24,365)	$ (71,110)
Net loss per share:
Basic and diluted	$ (0.09)	$ (0.19)	$ (0.29)	$ (0.88)
Shares used in per share calculation:
Basic and diluted	86,321	81,445	85,188	80,618
Product
Total net revenue	$ 62,803	$ 58,161	$ 178,776	$ 158,657
Total cost of revenue	33,224	27,736	91,084	85,843
Service [Member]
Total net revenue	37,813	33,853	111,127	98,615
Total cost of revenue	$ 17,290	$ 17,253	$ 49,931	$ 50,181