Revenue recognition - ESP and Voucher Promotions (Details) - USD ($) $ in Millions	Jul. 31, 2021	May 01, 2021	Jan. 30, 2021	Aug. 01, 2020	May 02, 2020	Feb. 01, 2020
Disaggregation of Revenue [Line Items]
Total deferred revenue	$ 1,107.3		$ 1,072.0	$ 1,030.2
Current liabilities	297.9		288.7	330.9
Non-current liabilities	809.4		783.3	699.3
ESP deferred revenue
Disaggregation of Revenue [Line Items]
Total deferred revenue	1,063.8	$ 1,049.4	1,028.9	990.5	$ 961.0	$ 960.0
Customer and eCommerce Orders
Disaggregation of Revenue [Line Items]
Total deferred revenue	$ 43.5		$ 43.1	$ 39.7