Net Income per Share (Calculation Of Basic And Diluted Net Income Per Share) (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended
	Oct. 29, 2016	Oct. 24, 2015
Earnings Per Share [Abstract]
Net income	$ 2,322	$ 2,430
Weighted-average shares—basic (in shares)	5,027	5,080
Effect of dilutive potential common shares (in shares)	39	33
Weighted-average shares—diluted (in shares)	5,066	5,113
Net income per share—basic (in dollars per share)	$ 0.46	$ 0.48
Net income per share—diluted (in dollars per share)	$ 0.46	$ 0.48
Antidilutive employee share-based awards, excluded (in shares)	67	86