Condensed Consolidated Statements of Comprehensive Loss - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Aug. 02, 2020	Jul. 31, 2019	Aug. 02, 2020	Jul. 31, 2019
Statement of Comprehensive Income [Abstract]
Net loss	$ (64,967)	$ (66,018)	$ (155,561)	$ (166,354)
Other comprehensive income net of tax:
Unrealized net gains on available-for-sale securities	2,715	2,173	7,605	3,798
Less: reclassification adjustment for net gains on available-for-sale securities included in net loss	(703)	(53)	(869)	(51)
Change in unrealized net gains on available-for-sale securities	2,012	2,120	6,736	3,747
Comprehensive loss	$ (62,955)	$ (63,898)	$ (148,825)	$ (162,607)