Debt - Interest Expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Jan. 31, 2021	Feb. 02, 2020	Jan. 31, 2019
Debt Instrument [Line Items]
Total amortization of debt discount and debt issuance costs	$ 29,070	$ 27,179	$ 21,031
Convertible Senior Notes
Debt Instrument [Line Items]
Amortization of debt discount	26,863	25,344
Amortization of debt issuance costs	1,944	1,835
Total amortization of debt discount and debt issuance costs	28,807	27,179
Contractual interest expense	718	718
Total interest expense related to the Notes	$ 29,525	$ 27,897
Effective interest rate of the liability component ( as a percent)	5.60%	5.60%