Condensed Consolidated Statements of Comprehensive Loss - USD ($) $ in Thousands	3 Months Ended
	Mar. 30, 2019	Mar. 31, 2018
Statement of Comprehensive Income [Abstract]
Net loss	$ (79,465)	$ (80,877)
Cash flow hedges:
Change in unrealized gain (loss) on cash flow hedges, net of tax benefit (expense) of $43, $192, $709 and $(7), respectively	0	664
Less: reclassification for realized net gains included in net loss, net of tax expense (benefit) of $(115), $-, $(244) and $7, respectively	0	0
Net change, net of tax	0	664
Available-for-sale investments:
Change in unrealized gain (loss) on available-for-sale investments, net of tax	162	(326)
Less reclassification for realized net gain	0	0
Other comprehensive income	162	338
Net change, net of tax		(326)
Comprehensive loss	$ (79,303)	$ (80,539)