Earnings (loss) per common share (EPS) - Schedule of Earnings per Share (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended		9 Months Ended
	Oct. 31, 2020	Nov. 02, 2019	Oct. 31, 2020	Nov. 02, 2019
EPS – basic
Net income (loss) attributable to common shareholders	$ 0.9	$ (43.7)	$ (294.4)	$ (106.2)
Weighted average common shares outstanding (shares)	52.1	51.8	51.9	51.7
EPS – basic (usd per share)	$ 0.02	$ (0.84)	$ (5.67)	$ (2.05)
EPS – diluted
Net income (loss) attributable to common shareholders	$ 0.9	$ (43.7)	$ (294.4)	$ (106.2)
Plus: Dilutive effect of share awards	1.3	0.0	0.0	0.0
Weighted average common shares outstanding (shares)	53.4	51.8	51.9	51.7
EPS – diluted (usd per share)	$ 0.02	$ (0.84)	$ (5.67)	$ (2.05)