Income Taxes - Provision for Income Taxes (Details) - USD ($) $ in Millions	12 Months Ended
	Jul. 27, 2019	Jul. 28, 2018	Jul. 29, 2017
Federal:
Current	$ 1,760	$ 9,900	$ 1,300
Deferred	(84)	1,156	(42)
Total	1,676	11,056	1,258
State:
Current	302	340	86
Deferred	(2)	(232)	56
Total	300	108	142
Foreign:
Current	1,238	1,789	1,416
Deferred	(264)	(24)	(138)
Total	974	1,765	1,278
Total	$ 2,950	$ 12,929	$ 2,678