Derivative Instruments (Schedule Of Notional Amounts Of Derivatives Outstanding) (Details) - USD ($) $ in Millions	Jul. 29, 2017	Jul. 30, 2016
Derivative [Line Items]
Derivatives	$ 11,590	$ 15,414
Derivatives designated as hedging instruments: | Foreign currency derivatives
Derivative [Line Items]
Derivatives	1,696	2,683
Derivatives designated as hedging instruments: | Interest rate derivatives
Derivative [Line Items]
Derivatives	6,750	9,900
Derivatives designated as hedging instruments: | Net investment hedging instruments
Derivative [Line Items]
Derivatives	351	298
Derivatives not designated as hedging instruments: | Foreign currency derivatives
Derivative [Line Items]
Derivatives	2,258	2,057
Derivatives not designated as hedging instruments: | Total return swaps—deferred compensation
Derivative [Line Items]
Derivatives	$ 535	$ 476