Share Repurchases (Details) - USD ($) shares in Millions, $ in Millions	6 Months Ended
	Jan. 31, 2016	Feb. 01, 2015
Statement [Line Items]
Shares repurchased, value	$ 86	$ 133
June 2011 Program [Member]
Statement [Line Items]
Authorized amount for shares repurchase	1,000
Stock Repurchase Program, Remaining Authorized Repurchase Amount	$ 500
Treasury Stock [Member]
Statement [Line Items]
Treasury stock purchased, shares	2	3
Shares repurchased, value	$ 86	$ 133
Treasury Stock [Member] | June 2011 Program [Member]
Statement [Line Items]
Shares repurchased, value	$ 50