Accumulated other comprehensive income (loss) - Reclassifications out of AOCI (Details) - USD ($) $ in Millions	12 Months Ended
	Jan. 30, 2021	Feb. 01, 2020	Feb. 02, 2019
Accumulated Other Comprehensive Income (Loss) [Line Items]
Cost of sales	$ (3,493.0)	$ (3,904.2)	$ (4,024.1)
Other operating income (loss)	2.4	(29.6)	26.2
Interest expense, net	(32.0)	(35.6)	(39.7)
Other non-operating income, net	0.0	7.0	1.7
Total before income tax	(89.7)	129.7	(802.6)
Income taxes	74.5	(24.2)	145.2
Net income (loss)	(15.2)	105.5	(657.4)
Reclassification out of AOCI
Accumulated Other Comprehensive Income (Loss) [Line Items]
Net income (loss)	(11.7)	(0.7)	(0.8)
Reclassification out of AOCI | Gains (losses) on cash flow hedges
Accumulated Other Comprehensive Income (Loss) [Line Items]
Total before income tax	(16.8)	(3.4)	(2.1)
Income taxes	4.2	0.7	0.6
Net income (loss)	(12.6)	(2.7)	(1.5)
Reclassification out of AOCI | Accumulated defined benefit plans adjustment
Accumulated Other Comprehensive Income (Loss) [Line Items]
Total before income tax	1.1	1.2	0.9
Income taxes	(0.2)	(0.2)	(0.2)
Net income (loss)	0.9	1.0	0.7
Reclassification out of AOCI | Actuarial gains (losses)
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other non-operating income, net	1.0	1.2	0.9
Reclassification out of AOCI | Prior service credits (costs)
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other non-operating income, net	0.1	0.0	0.0
Reclassification out of AOCI | Available-for-sale securities
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other operating income (loss)	0.0	1.0	0.0
Income taxes	0.0	0.0	0.0
Net income (loss)	0.0	1.0	0.0
Reclassification out of AOCI | Foreign currency contracts | Gains (losses) on cash flow hedges
Accumulated Other Comprehensive Income (Loss) [Line Items]
Cost of sales	0.0	(1.1)	0.7
Other operating income (loss)	(0.6)	0.0	0.0
Reclassification out of AOCI | Interest rate swaps | Gains (losses) on cash flow hedges
Accumulated Other Comprehensive Income (Loss) [Line Items]
Interest expense, net	0.0	(0.6)	(1.9)
Reclassification out of AOCI | Commodity contracts | Gains (losses) on cash flow hedges
Accumulated Other Comprehensive Income (Loss) [Line Items]
Cost of sales	(6.9)	(1.7)	(0.9)
Other operating income (loss)	$ (9.3)	$ 0.0	$ 0.0