Revenue recognition - ESP and Voucher Promotions (Details) - USD ($) $ in Millions	Aug. 01, 2020	Feb. 01, 2020	Aug. 03, 2019
Disaggregation of Revenue [Line Items]
Total deferred revenue	$ 1,030.2	$ 997.7	$ 965.2
Current liabilities	330.9	266.2	265.4
Non-current liabilities	699.3	731.5	699.8
ESP deferred revenue
Disaggregation of Revenue [Line Items]
Total deferred revenue	990.5	960.0	930.2
Voucher promotions and other
Disaggregation of Revenue [Line Items]
Total deferred revenue	$ 39.7	$ 37.7	$ 35.0