Available-for-Sale Debt and Equity Investments - Additional Information (Details) $ in Millions	3 Months Ended
	Oct. 24, 2020 USD ($) entity	Oct. 26, 2019 USD ($)	Jul. 25, 2020 USD ($)
Schedule of Investments [Line Items]
Net loss (gain) to non-marketable equity securities measured using the measurement alternative	$ (1)	$ 1
Number of variable interest entities required to be consolidated (entity) | entity	0
Investments in privately held companies	$ 1,400		$ 1,300
Funding commitments	300
Variable Interest Entity, Not Primary Beneficiary
Schedule of Investments [Line Items]
Investments in privately held companies	700
Private equity funds | Fair value measured at NAV per share
Schedule of Investments [Line Items]
Equity interests held in certain private equity funds	$ 700		$ 700