Condensed Consolidated Statements of Comprehensive Loss - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Oct. 31, 2021	Nov. 01, 2020	Oct. 31, 2021	Nov. 01, 2020
Statement of Comprehensive Income [Abstract]
Net loss	$ (28,731)	$ (74,222)	$ (158,202)	$ (229,783)
Other comprehensive income (loss):
Unrealized net (losses) gains on available-for-sale securities	(3,710)	(2,869)	(7,121)	4,736
Less: reclassification adjustment for net gains on available-for-sale securities included in net loss	(78)	(257)	(596)	(1,126)
Change in unrealized net (losses) gains on available-for-sale securities	(3,788)	(3,126)	(7,717)	3,610
Comprehensive loss	$ (32,519)	$ (77,348)	$ (165,919)	$ (226,173)