Accumulated Other Comprehensive Loss (Reclassifications from Accumulated Other Comprehensive Loss) (Details) $ in Millions	9 Months Ended
	Oct. 28, 2017 USD ($)
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items]
Net periodic benefit cost (see Note 12)	$ 9
Income tax benefit	(3)
Net of tax	6
Pension Benefits [Member]
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items]
Net periodic benefit cost (see Note 12)	10
Postretirement Benefits [Member]
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items]
Net periodic benefit cost (see Note 12)	$ (1)