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
	Aug. 01, 2020	Aug. 03, 2019	Aug. 01, 2020	Aug. 03, 2019
EPS – basic
Net income (loss) attributable to common shareholders	$ (90.0)	$ (44.3)	$ (295.3)	$ (62.5)
Weighted average common shares outstanding (shares)	52.0	51.7	51.9	51.6
EPS – basic (usd per share)	$ (1.73)	$ (0.86)	$ (5.69)	$ (1.21)
EPS – diluted
Net income (loss) attributable to common shareholders	$ (90.0)	$ (44.3)	$ (295.3)	$ (62.5)
Weighted average common shares outstanding (shares)	52.0	51.7	51.9	51.6
EPS – diluted (usd per share)	$ (1.73)	$ (0.86)	$ (5.69)	$ (1.21)