Comprehensive Income (Loss) - AOCI Components (Details) - USD ($) $ in Millions	9 Months Ended
	May 01, 2021	Apr. 25, 2020
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance	$ 37,920	$ 33,571
Other comprehensive income (loss) before reclassifications	230	(289)
(Gains) losses reclassified out of AOCI	(55)	(17)
Tax benefit (expense)	56	(11)
Ending balance	40,205	35,708
Accumulated Other Comprehensive Income (Loss)
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance	(519)	(792)
Ending balance	(288)	(1,109)
Net Unrealized Gains (Losses) on Available-for-Sale Investments
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance	315	0
Other comprehensive income (loss) before reclassifications	(150)	169
(Gains) losses reclassified out of AOCI	(46)	(20)
Tax benefit (expense)	59	(12)
Ending balance	178	137
Net Unrealized Gains (Losses) Cash Flow Hedging Instruments
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance	(6)	(14)
Other comprehensive income (loss) before reclassifications	16	14
(Gains) losses reclassified out of AOCI	(12)	1
Tax benefit (expense)	(2)	(1)
Ending balance	(4)	0
Cumulative Translation Adjustment and Actuarial Gains (Losses)
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance	(828)	(778)
Other comprehensive income (loss) before reclassifications	364	(472)
(Gains) losses reclassified out of AOCI	3	2
Tax benefit (expense)	(1)	2
Ending balance	$ (462)	$ (1,246)