Derivative Instruments (Schedule Of Notional Amounts Of Derivatives Outstanding) (Detail) (USD $) In Millions, unless otherwise specified	Jul. 28, 2012	Jul. 30, 2011
Derivative [Line Items]
Interest rate derivatives	$ 0	$ 0
Total	14,410	12,583
Derivatives Designated As Hedging Instrument
Derivative [Line Items]
Foreign currency derivatives-cash flow hedges	2,910	3,433
Interest rate derivatives	4,250	4,250
Net investment hedging instruments	468	73
Equity derivatives	272
Derivatives Not Designated As Hedging Instruments
Derivative [Line Items]
Foreign currency derivatives	6,241	4,565
Total return swaps-deferred compensation	$ 269	$ 262