Income Taxes - Provision for Income Taxes (Details) - USD ($) $ in Millions	12 Months Ended
	Jul. 25, 2020	Jul. 27, 2019	Jul. 28, 2018
Federal:
Current	$ 1,101	$ 1,760	$ 9,900
Deferred	(374)	(84)	1,156
Total	727	1,676	11,056
State:
Current	264	302	340
Deferred	287	(2)	(232)
Total	551	300	108
Foreign:
Current	1,429	1,238	1,789
Deferred	49	(264)	(24)
Total	1,478	974	1,765
Total	$ 2,756	$ 2,950	$ 12,929