Debt - Interest Expense (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Nov. 01, 2020	Oct. 31, 2019	Nov. 01, 2020	Oct. 31, 2019
Debt Instrument [Line Items]
Total amortization of debt discount and debt issuance costs			$ 21,525	$ 20,186
Convertible Senior Notes
Debt Instrument [Line Items]
Amortization of debt discount	$ 6,799	$ 6,431	19,970	18,824
Amortization of debt issuance costs	491	465	1,445	1,362
Total amortization of debt discount and debt issuance costs	7,290	6,896	21,415	20,186
Contractual interest expense	181	181	539	539
Total interest expense related to the Notes	$ 7,471	$ 7,077	$ 21,954	$ 20,725
Effective interest rate of the liability component	5.60%	5.60%	5.60%	5.60%