Long-term debt - Schedule of Long-term Debt (Details) - USD ($) $ in Millions	Jul. 29, 2023	Jan. 28, 2023	Jul. 30, 2022
Debt Instrument [Line Items]
Gross debt	$ 147.7	$ 147.7	$ 147.7
Less: Current portion of long-term debt	(147.5)	0.0	0.0
Less: Unamortized debt issuance costs	(0.2)	(0.3)	(0.5)
Long-term debt	0.0	147.4	147.2
Senior unsecured notes due 2024, net of unamortized discount | Senior Unsecured Notes
Debt Instrument [Line Items]
Gross debt	$ 147.7	$ 147.7	$ 147.7