Derivative Instruments - Schedule of Notional Amounts of Derivatives Outstanding (Details) - USD ($) $ in Millions	Oct. 24, 2020	Jul. 25, 2020
Derivative [Line Items]
Derivatives	$ 7,459	$ 7,395
Foreign currency derivatives
Derivative [Line Items]
Derivatives	4,338	4,315
Interest rate derivatives
Derivative [Line Items]
Derivatives	2,500	2,500
Total return swaps—deferred compensation
Derivative [Line Items]
Derivatives	$ 621	$ 580