Condensed Consolidated Statements of Comprehensive Loss - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Nov. 01, 2020	Oct. 31, 2019	Nov. 01, 2020	Oct. 31, 2019
Statement of Comprehensive Income [Abstract]
Net loss	$ (74,222)	$ (29,982)	$ (229,783)	$ (196,336)
Other comprehensive income (loss) net of tax:
Unrealized net gains (losses) on available-for-sale securities	(2,869)	1,927	4,736	5,725
Less: reclassification adjustment for net gains on available-for-sale securities included in net loss	(257)	(220)	(1,126)	(271)
Change in unrealized net gains (losses) on available-for-sale securities	(3,126)	1,707	3,610	5,454
Comprehensive loss	$ (77,348)	$ (28,275)	$ (226,173)	$ (190,882)