Summary of Significant Accounting Policies - Gift Cards (Details) - USD ($) $ in Millions	12 Months Ended
	Jan. 28, 2017	Jan. 30, 2016	Jan. 31, 2015
Accounting Policies [Abstract]
Gift Card Redeemability, Determination Period	24 months
Gift card breakage income	$ 37	$ 46	$ 19