Income taxes - Additional Information (Detail) - USD ($) $ in Millions	12 Months Ended
	Jan. 30, 2021	Feb. 01, 2020	Feb. 02, 2019	Feb. 03, 2018
Operating Loss Carryforwards [Line Items]
Statutory tax rate (percent)	21.00%	21.00%	21.00%
Income tax benefit, two year carryforward	$ 74.0
Income tax benefit, five year carryforward	26.4
Valuation allowance	83.9	$ 38.4
Capital loss carryforwards	13.9	12.9
Increase in valuation allowance	45.5
Unrecognized tax benefits	25.4	23.5	$ 18.1	$ 12.0
Accrued interest related to unrecognized tax benefits	4.1
Accrued penalties	0.6
Increase resulting from settlements with taxing authorities	23.3
State and Local Jurisdiction
Operating Loss Carryforwards [Line Items]
Valuation allowance	50.0
Domestic Tax Authority
Operating Loss Carryforwards [Line Items]
Net operating loss carry forwards	29.5
Capital loss carryforwards	2.7
Internal Revenue Service (IRS)
Operating Loss Carryforwards [Line Items]
Net operating loss carry forwards	11.5
Foreign Tax Authority
Operating Loss Carryforwards [Line Items]
Net operating loss carry forwards	18.3
Deferred tax assets	8.7
Foreign capital loss carry forward	$ 11.2	$ 10.5
Bermuda
Operating Loss Carryforwards [Line Items]
Statutory tax rate (percent)	0.00%