Earnings (loss) per common share ("EPS") - Schedule of Earnings per Share (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended								12 Months Ended
	Feb. 01, 2020	Nov. 02, 2019	Aug. 03, 2019	May 04, 2019	Feb. 02, 2019	Nov. 03, 2018	Aug. 04, 2018	May 05, 2018	Feb. 01, 2020	Feb. 02, 2019	Feb. 03, 2018
EPS – basic
Net income (loss) attributable to common shareholders									$ 72.6	$ (690.3)	$ 486.4
Weighted average common shares outstanding (in shares)									51.7	54.7	63.0
Earnings per share - basic (usd per share)	$ 3.45	$ (0.84)	$ (0.86)	$ (0.35)	$ (2.25)	$ (0.74)	$ (0.56)	$ (8.48)	$ 1.40	$ (12.62)	$ 7.72
EPS – diluted
Add: Dividends on preferred shares									$ 0.0	$ 0.0	$ 32.9
Numerator for diluted EPS									$ 72.6	$ (690.3)	$ 519.3
Dilutive effect of share awards (in shares)									0.1	0.0	0.1
Dilutive effect of preferred shares (in shares)									0.0	0.0	6.7
Diluted weighted average number of common shares outstanding									51.8	54.7	69.8
Earnings per share - diluted (usd per share)	$ 3.14	$ (0.84)	$ (0.86)	$ (0.35)	$ (2.25)	$ (0.74)	$ (0.56)	$ (8.48)	$ 1.40	$ (12.62)	$ 7.44