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. 03, 2019	Aug. 04, 2018	Aug. 03, 2019	Aug. 04, 2018
Earnings Per Share [Abstract]
Net income (loss) attributable to common shareholders	$ (44.3)	$ (31.2)	$ (62.5)	$ (536.0)
Net income	$ (44.3)	$ (31.2)	$ (62.5)	$ (536.0)
Basic weighted average number of shares outstanding (shares)	51.7	56.1	51.6	57.8
Diluted weighted average number of shares outstanding (shares)	51.7	56.1	51.6	57.8
Earnings per common share - basic (usd per share)	$ (0.86)	$ (0.56)	$ (1.21)	$ (9.27)
Earnings per common share - diluted (usd per share)	$ (0.86)	$ (0.56)	$ (1.21)	$ (9.27)