Revenue recognition - Unamortized Deferred Selling Costs (Details) - USD ($) $ in Millions	Feb. 02, 2019	Feb. 03, 2018
Revenue from Contract with Customer [Abstract]
Other current assets	$ 23.8	$ 30.9
Other assets	75.4	89.5
Total deferred ESP selling costs	$ 99.2	$ 120.4

Amount of other miscellaneous assets expected to be realized or consumed after one year or normal operating cycle, if longer.

No definition available.

Name:	us-gaap_OtherAssetsMiscellaneousNoncurrent
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant