Derivative Instruments (Schedule Of Notional Amounts Of Derivatives Outstanding) (Details) - USD ($) $ in Millions	Jan. 23, 2016	Jul. 25, 2015
Derivative [Line Items]
Derivatives	$ 15,268	$ 15,278
Derivatives designated as hedging instruments: | Foreign currency derivatives
Derivative [Line Items]
Derivatives	684	1,201
Derivatives designated as hedging instruments: | Interest rate derivatives
Derivative [Line Items]
Derivatives	11,400	11,400
Derivatives designated as hedging instruments: | Net investment hedging instruments
Derivative [Line Items]
Derivatives	283	192
Derivatives not designated as hedging instruments: | Foreign currency derivatives
Derivative [Line Items]
Derivatives	2,469	2,023
Derivatives not designated as hedging instruments: | Total return swaps—deferred compensation
Derivative [Line Items]
Derivatives	$ 432	$ 462