Available-for-Sale Debt and Equity Investments - Available-for-Sale Investments With Gross Unrealized Losses (Details) - USD ($) $ in Millions	Oct. 30, 2021	Jul. 31, 2021
Debt Securities, Available-for-sale [Line Items]
UNREALIZED LOSSES LESS THAN 12 MONTHS, Fair Value	$ 6,607	$ 2,910
UNREALIZED LOSSES LESS THAN 12 MONTHS, Gross Unrealized Losses	(53)	(15)
UNREALIZED LOSSES 12 MONTHS OR GREATER, Fair Value	81	19
UNREALIZED LOSSES 12 MONTHS OR GREATER, Gross Unrealized Losses	(2)	0
TOTAL, Fair Value	6,688	2,929
TOTAL, Gross Unrealized Losses	(55)	(15)
U.S. government securities
Debt Securities, Available-for-sale [Line Items]
UNREALIZED LOSSES LESS THAN 12 MONTHS, Fair Value	1,341	468
UNREALIZED LOSSES LESS THAN 12 MONTHS, Gross Unrealized Losses	(9)	0
UNREALIZED LOSSES 12 MONTHS OR GREATER, Fair Value	2	0
UNREALIZED LOSSES 12 MONTHS OR GREATER, Gross Unrealized Losses	0	0
TOTAL, Fair Value	1,343	468
TOTAL, Gross Unrealized Losses	(9)	0
U.S. government agency securities
Debt Securities, Available-for-sale [Line Items]
UNREALIZED LOSSES LESS THAN 12 MONTHS, Fair Value	100	26
UNREALIZED LOSSES LESS THAN 12 MONTHS, Gross Unrealized Losses	0	0
UNREALIZED LOSSES 12 MONTHS OR GREATER, Fair Value	0	0
UNREALIZED LOSSES 12 MONTHS OR GREATER, Gross Unrealized Losses	0	0
TOTAL, Fair Value	100	26
TOTAL, Gross Unrealized Losses	0	0
Corporate debt securities
Debt Securities, Available-for-sale [Line Items]
UNREALIZED LOSSES LESS THAN 12 MONTHS, Fair Value	3,204	1,086
UNREALIZED LOSSES LESS THAN 12 MONTHS, Gross Unrealized Losses	(24)	(5)
UNREALIZED LOSSES 12 MONTHS OR GREATER, Fair Value	27	6
UNREALIZED LOSSES 12 MONTHS OR GREATER, Gross Unrealized Losses	(1)	0
TOTAL, Fair Value	3,231	1,092
TOTAL, Gross Unrealized Losses	(25)	(5)
U.S. agency mortgage-backed securities
Debt Securities, Available-for-sale [Line Items]
UNREALIZED LOSSES LESS THAN 12 MONTHS, Fair Value	1,937	1,293
UNREALIZED LOSSES LESS THAN 12 MONTHS, Gross Unrealized Losses	(20)	(10)
UNREALIZED LOSSES 12 MONTHS OR GREATER, Fair Value	52	13
UNREALIZED LOSSES 12 MONTHS OR GREATER, Gross Unrealized Losses	(1)	0
TOTAL, Fair Value	1,989	1,306
TOTAL, Gross Unrealized Losses	(21)	(10)
Commercial paper
Debt Securities, Available-for-sale [Line Items]
UNREALIZED LOSSES LESS THAN 12 MONTHS, Fair Value	25	37
UNREALIZED LOSSES LESS THAN 12 MONTHS, Gross Unrealized Losses	0	0
UNREALIZED LOSSES 12 MONTHS OR GREATER, Fair Value	0	0
UNREALIZED LOSSES 12 MONTHS OR GREATER, Gross Unrealized Losses	0	0
TOTAL, Fair Value	25	37
TOTAL, Gross Unrealized Losses	$ 0	$ 0