Derivative Instruments (Schedule Of Notional Amounts Of Derivatives Outstanding) (Details) (USD $) In Millions, unless otherwise specified	Oct. 26, 2013	Jul. 27, 2013
Derivative [Line Items]
Notional amount of derivatives	$ 12,800	$ 12,992
Designated as Hedging Instrument [Member] | Foreign Exchange Contract
Derivative [Line Items]
Notional amount of derivatives	1,772	1,885
Designated as Hedging Instrument [Member] | Interest Rate Derivatives [Member]
Derivative [Line Items]
Notional amount of derivatives	5,750	5,250
Designated as Hedging Instrument [Member] | Net Investment Hedging [Member]
Derivative [Line Items]
Notional amount of derivatives	577	662
Designated as Hedging Instrument [Member] | Equity [Member]
Derivative [Line Items]
Notional amount of derivatives	779	1,098
Derivatives Not Designated As Hedging Instruments [Member] | Foreign Exchange Contract
Derivative [Line Items]
Notional amount of derivatives	3,526	3,739
Derivatives Not Designated As Hedging Instruments [Member] | Total Return Swap [Member]
Derivative [Line Items]
Notional amount of derivatives	$ 396	$ 358