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. 25, 2020	Apr. 27, 2019	Apr. 25, 2020	Apr. 27, 2019
Earnings Per Share [Abstract]
Net income	$ 2,774	$ 3,044	$ 8,578	$ 9,415
Weighted-average shares—basic (in shares)	4,230	4,370	4,239	4,468
Effect of dilutive potential common shares (in shares)	13	45	19	41
Weighted-average shares—diluted (in shares)	4,243	4,415	4,258	4,509
Net income per share—basic (in dollars per share)	$ 0.66	$ 0.70	$ 2.02	$ 2.11
Net income per share—diluted (in dollars per share)	$ 0.65	$ 0.69	$ 2.01	$ 2.09
Antidilutive employee share-based awards, excluded (in shares)	14	5	42	32