Earnings (loss) per common share (EPS) - Schedule of Earnings per Share (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended		6 Months Ended
	Jul. 31, 2021	Aug. 01, 2020	Jul. 31, 2021	Aug. 01, 2020
EPS – basic
Net income (loss) attributable to common shareholders	$ 216.0	$ (90.0)	$ 345.8	$ (295.3)
Add: Dividends on Preferred Shares	$ 8.6	$ 0.0	$ 17.2	$ 0.0
EPS – basic (usd per share)	$ 4.10	$ (1.73)	$ 6.60	$ (5.69)
Numerator for diluted EPS	$ 224.6	$ (90.0)	$ 363.0	$ (295.3)
EPS – diluted
Basic weighted average common shares outstanding (shares)	52.7	52.0	52.4	51.9
Plus: Dilutive effect of share awards	1.7	0.0	1.8	0.0
Plus: Dilutive effect of Preferred Shares	8.0	0.0	8.0	0.0
Diluted weighted average common shares outstanding (shares)	62.4	52.0	62.2	51.9
EPS – diluted (usd per share)	$ 3.60	$ (1.73)	$ 5.84	$ (5.69)