Comprehensive Income (Loss) (Details) - USD ($) $ in Millions	6 Months Ended
	Jan. 29, 2022	Jan. 23, 2021
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance	$ 41,275	$ 37,920
Other comprehensive income (loss) before reclassifications	(440)	305
(Gains) losses reclassified out of AOCI	(18)	(27)
Tax benefit (expense)	86	23
Ending balance	39,496	39,121
Accumulated Other Comprehensive Income (Loss)
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance	(417)	(519)
Ending balance	(789)	(218)
Net Unrealized Gains (Losses) on Available-for-Sale Investments
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance	182	315
Other comprehensive income (loss) before reclassifications	(296)	(35)
(Gains) losses reclassified out of AOCI	(16)	(24)
Tax benefit (expense)	80	24
Ending balance	(50)	280
Net Unrealized Gains (Losses) Cash Flow Hedging Instruments
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance	(1)	(6)
Other comprehensive income (loss) before reclassifications	18	(5)
(Gains) losses reclassified out of AOCI	(3)	(5)
Tax benefit (expense)	(3)	2
Ending balance	11	(14)
Cumulative Translation Adjustment and Actuarial Gains (Losses)
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance	(598)	(828)
Other comprehensive income (loss) before reclassifications	(162)	345
(Gains) losses reclassified out of AOCI	1	2
Tax benefit (expense)	9	(3)
Ending balance	$ (750)	$ (484)