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
	Nov. 02, 2019	Nov. 03, 2018	Nov. 02, 2019	Nov. 03, 2018
EPS – basic
Net income (loss) attributable to common shareholders	$ (43.7)	$ (38.1)	$ (106.2)	$ (574.1)
Weighted average common shares outstanding (shares)	51.8	51.5	51.7	55.7
EPS – basic (usd per share)	$ (0.84)	$ (0.74)	$ (2.05)	$ (10.31)
EPS – diluted
Net income (loss) attributable to common shareholders	$ (43.7)	$ (38.1)	$ (106.2)	$ (574.1)
Weighted average common shares outstanding (shares)	51.8	51.5	51.7	55.7
EPS – diluted (usd per share)	$ (0.84)	$ (0.74)	$ (2.05)	$ (10.31)