Available-for-Sale Debt and Equity Investments - Gross Realized Gains and Gross Realized Losses Related to Available-for-Sale Investment (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
Apr. 30, 2022	May 01, 2021	Apr. 30, 2022	May 01, 2021
Investments, Debt and Equity Securities [Abstract]
Gross realized gains	$ 8	$ 24	$ 27	$ 48
Gross realized losses	(6)	(2)	(9)	(2)
Total	$ 2	$ 22	$ 18	$ 46

Amount of realized gain on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 9
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=123581744&loc=d3e27357-111563

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- Definition

Amount of realized gain (loss) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 9
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=123581744&loc=d3e27357-111563

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- Definition

Amount of realized loss on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

+ References

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- References

No definition available.

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