Earnings (loss) per common share (EPS) - Schedule of Antidilutive Securities Excluded From Computation of Earnings Per Share (Details) - shares shares in Millions	3 Months Ended		9 Months Ended
	Oct. 31, 2020	Nov. 02, 2019	Oct. 31, 2020	Nov. 02, 2019
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive shares excluded from the calculation of earnings per share (shares)	8.5	8.7	9.3	8.5
Share awards
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive shares excluded from the calculation of earnings per share (shares)	0.7	1.3	1.6	1.3
Potential impact of preferred shares
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive shares excluded from the calculation of earnings per share (shares)	7.8	7.4	7.7	7.2