Share Repurchases (Details) - USD ($) shares in Millions, $ in Millions	9 Months Ended
	May. 01, 2016	May. 03, 2015
Statement [Line Items]
Shares repurchased, value	$ 118	$ 192
June 2011 Program [Member]
Statement [Line Items]
Authorized amount for shares repurchase	1,000
Stock Repurchase Program, Remaining Authorized Repurchase Amount	$ 475
Treasury Stock [Member]
Statement [Line Items]
Treasury stock purchased, shares	2	4
Shares repurchased, value	$ 118	$ 192
Treasury Stock [Member] | June 2011 Program [Member]
Statement [Line Items]
Shares repurchased, value	$ 75