Commitments and Contingencies - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended		12 Months Ended
	Jul. 29, 2017	Jul. 29, 2017	Jul. 30, 2016	Jan. 28, 2017
Commitments and Contingencies [Line Items]
Loss Contingency, Estimate of Possible Loss	$ 0	$ 0	$ 0	$ 0
Insurance proceeds related to loss on property and equipment		59	$ 0
Fire [Member]
Commitments and Contingencies [Line Items]
Total fire-related costs	10	15		133
Partial Insurance Settlement				159
Insured Event, Gain (Loss)	64			73
Insurance Proceeds	29	102		174
Insurance settlements receivable	$ 9	9		$ 32
Insurance proceeds related to loss on property and equipment		$ 59