Derivative Instruments (Schedule Of Notional Amounts Of Derivatives Outstanding) (Detail) (USD $) In Millions, unless otherwise specified	Jul. 27, 2013	Jul. 28, 2012
Derivative [Line Items]
Derivative, Notional Amount	$ 12,992	$ 14,410
Derivatives Designated As Hedging Instrument | Foreign Currency Derivatives
Derivative [Line Items]
Derivative, Notional Amount	1,885	2,910
Derivatives Designated As Hedging Instrument | Interest Rate Derivatives
Derivative [Line Items]
Derivative, Notional Amount	5,250	4,250
Derivatives Designated As Hedging Instrument | Net Investment Hedging [Member]
Derivative [Line Items]
Derivative, Notional Amount	662	468
Derivatives Designated As Hedging Instrument | Equity [Member]
Derivative [Line Items]
Derivative, Notional Amount	1,098	272
Derivatives Not Designated As Hedging Instruments | Foreign Currency Derivatives
Derivative [Line Items]
Derivative, Notional Amount	3,739	6,241
Derivatives Not Designated As Hedging Instruments | Total Return Swap [Member]
Derivative [Line Items]
Derivative, Notional Amount	$ 358	$ 269