Quarterly Financial Data (Unaudited) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 30, 2017	Sep. 30, 2017	Jul. 01, 2017	Apr. 01, 2017	Dec. 31, 2016	Oct. 01, 2016	Jul. 02, 2016	Apr. 02, 2016	Dec. 30, 2017	Dec. 31, 2016	Jan. 02, 2016
Quarterly Financial Information Disclosure [Abstract]
Revenue	$ 95,266	$ 91,971	$ 94,137	$ 104,587	$ 118,108	$ 113,225	$ 99,209	$ 96,512	$ 385,961	$ 427,054	$ 405,966
Gross margin	51,216	53,322	51,209	60,832	63,480	67,424	58,426	57,104
Restructuring charges	2,483	3,071	1,576	66	951	317	2,568	5,431	7,196	9,267	19,239
Net loss	$ (7,213)	$ (43,052)	$ (13,022)	$ (7,275)	$ (8,164)	$ (12,414)	$ (13,810)	$ (19,711)	$ (70,562)	$ (54,099)	$ (159,233)
Net loss per share - basic and diluted (in dollars per share)	$ (0.06)	$ (0.35)	$ (0.11)	$ (0.06)	$ (0.07)	$ (0.10)	$ (0.12)	$ (0.17)	$ (0.58)	$ (0.45)	$ (1.36)