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								12 Months Ended
	Jul. 29, 2017	Apr. 29, 2017	Jan. 28, 2017	Oct. 29, 2016	Jul. 30, 2016	Apr. 30, 2016	Jan. 23, 2016	Oct. 24, 2015	Jul. 29, 2017	Jul. 30, 2016	Jul. 25, 2015
Earnings Per Share [Abstract]
Net income	$ 2,424	$ 2,515	$ 2,348	$ 2,322	$ 2,813	$ 2,349	$ 3,147	$ 2,430	$ 9,609	$ 10,739	$ 8,981
Weighted-average shares—basic (In shares)									5,010	5,053	5,104
Effect of dilutive potential common shares (in shares)									39	35	42
Weighted-average shares—diluted (in shares)									5,049	5,088	5,146
Net income per share—basic (in dollars per share)	$ 0.49	$ 0.50	$ 0.47	$ 0.46	$ 0.56	$ 0.47	$ 0.62	$ 0.48	$ 1.92	$ 2.13	$ 1.76
Net income per share—diluted (in dollars per share)	$ 0.48	$ 0.50	$ 0.47	$ 0.46	$ 0.56	$ 0.46	$ 0.62	$ 0.48	$ 1.90	$ 2.11	$ 1.75
Antidilutive employee share-based awards, excluded (in shares)									136	148	183