Earnings (loss) per common share (“EPS”) - Schedule of Antidilutive Securities Excluded From Computation of Earnings Per Share (Details) - shares shares in Millions	9 Months Ended
	Oct. 28, 2017	Oct. 29, 2016
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive shares excluded from the calculation of earnings per share (shares)	7.0	7.0
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)	0.3	0.3
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)	6.7	6.7