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		9 Months Ended
	Apr. 29, 2017	Apr. 30, 2016	Apr. 29, 2017	Apr. 30, 2016
Earnings Per Share [Abstract]
Net income	$ 2,515	$ 2,349	$ 7,185	$ 7,926
Weighted-average shares—basic (in shares)	5,005	5,032	5,015	5,060
Effect of dilutive potential common shares (in shares)	40	33	41	35
Weighted-average shares—diluted (in shares)	5,045	5,065	5,056	5,095
Net income per share—basic (in dollars per share)	$ 0.50	$ 0.47	$ 1.43	$ 1.57
Net income per share—diluted (in dollars per share)	$ 0.50	$ 0.46	$ 1.42	$ 1.56
Antidilutive employee share-based awards, excluded (in shares)	6	75	118	149