Derivative Instruments (Schedule Of Notional Amounts Of Derivatives Outstanding) (Details) - USD ($)	Apr. 29, 2017	Jul. 30, 2016
Derivative [Line Items]
Derivatives	$ 11,760,000,000	$ 15,414,000,000
Derivatives designated as hedging instruments: | Foreign currency derivatives
Derivative [Line Items]
Derivatives	1,885,000,000	2,683,000,000
Derivatives designated as hedging instruments: | Interest rate derivatives
Derivative [Line Items]
Derivatives	6,750,000,000	9,900,000,000
Derivatives designated as hedging instruments: | Net investment hedging instruments
Derivative [Line Items]
Derivatives	340,000,000	298,000,000
Derivatives not designated as hedging instruments: | Foreign currency derivatives
Derivative [Line Items]
Derivatives	2,262,000,000	2,057,000,000
Derivatives not designated as hedging instruments: | Total return swaps—deferred compensation
Derivative [Line Items]
Derivatives	$ 523,000,000	$ 476,000,000