Retirement plans - Components of UK Net Asset Recognized (Details) - Pension plan - Foreign Plan - USD ($) $ in Millions	Jan. 29, 2022	Jan. 30, 2021
Defined Benefit Plan Disclosure [Line Items]
Other assets (non current)	$ 0.0	$ 51.6
Other liabilities (non-current)	$ (7.7)	$ 0.0

Amount of asset, recognized in statement of financial position, for overfunded defined benefit pension and other postretirement plans.

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