Derivative Instruments - Schedule of Notional Amounts of Derivatives Outstanding (Details) - USD ($) $ in Millions	Jul. 27, 2019	Jul. 28, 2018
Derivative [Line Items]
Derivative, notional amount	$ 8,754	$ 10,011
Derivatives designated as hedging instruments | Foreign currency derivatives
Derivative [Line Items]
Derivative, notional amount	663	147
Derivatives designated as hedging instruments | Interest rate derivatives
Derivative [Line Items]
Derivative, notional amount	4,500	6,750
Derivatives designated as hedging instruments | Net investment hedging instruments
Derivative [Line Items]
Derivative, notional amount	309	250
Derivatives not designated as hedging instruments | Foreign currency derivatives
Derivative [Line Items]
Derivative, notional amount	2,708	2,298
Derivatives not designated as hedging instruments | Total return swaps—deferred compensation
Derivative [Line Items]
Derivative, notional amount	$ 574	$ 566