Revenue recognition - ESP and Voucher Promotions (Details) - USD ($) $ in Millions	May 02, 2020	Feb. 01, 2020	May 04, 2019
Disaggregation of Revenue [Line Items]
Total deferred revenue	$ 991.0	$ 997.7	$ 976.6
Current liabilities	271.2	266.2	277.0
Non-current liabilities	719.8	731.5	699.6
ESP deferred revenue
Disaggregation of Revenue [Line Items]
Total deferred revenue	961.0	960.0	931.3
Voucher promotions and other
Disaggregation of Revenue [Line Items]
Total deferred revenue	$ 30.0	$ 37.7	$ 45.3