Condensed Consolidated Statements of Comprehensive Loss - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jul. 04, 2020	Jun. 29, 2019	Jul. 04, 2020	Jun. 29, 2019
Statement of Comprehensive Income [Abstract]
Net loss	$ (104,097)	$ (68,518)	$ (83,803)	$ (147,983)
Other comprehensive loss
Change in unrealized gain on investments	117	167	162	329
Net change, net of tax	117	167	162	329
Comprehensive loss	$ (103,980)	$ (68,351)	$ (83,641)	$ (147,654)