Financial Instruments (Schedule Of The Fair Values Of Derivative Instruments) (Details) (USD $) In Millions	Jul. 31, 2011	Aug. 01, 2010
Asset Derivatives	$ 37	$ 69
Liability Derivatives	143	43
Derivatives Designated As Hedges [Member]
Asset Derivatives	33	51
Liability Derivatives	45	26
Derivatives Designated As Hedges [Member] | Foreign Exchange Contracts [Member] | Other Current Assets [Member]
Asset Derivatives		1
Derivatives Designated As Hedges [Member] | Foreign Exchange Contracts [Member] | Accrued Liabilities [Member]
Liability Derivatives	7	1
Derivatives Designated As Hedges [Member] | Commodity Derivative Contracts [Member] | Other Current Assets [Member]
Asset Derivatives		1
Derivatives Designated As Hedges [Member] | Commodity Derivative Contracts [Member] | Accrued Liabilities [Member]
Liability Derivatives		1
Derivatives Designated As Hedges [Member] | Cross-currency Swap Contracts [Member] | Other Assets [Member]
Asset Derivatives		3
Derivatives Designated As Hedges [Member] | Cross-currency Swap Contracts [Member] | Accrued Liabilities [Member]
Liability Derivatives	8
Derivatives Designated As Hedges [Member] | Cross-currency Swap Contracts [Member] | Other Liabilities [Member]
Liability Derivatives	30	24
Derivatives Designated As Hedges [Member] | Interest Rate Swaps [Member] | Other Assets [Member]
Asset Derivatives	33	46
Derivatives Not Designated As Hedges [Member]
Asset Derivatives	4	18
Liability Derivatives	98	17
Derivatives Not Designated As Hedges [Member] | Foreign Exchange Contracts [Member] | Other Current Assets [Member]
Asset Derivatives		1
Derivatives Not Designated As Hedges [Member] | Foreign Exchange Contracts [Member] | Accrued Liabilities [Member]
Liability Derivatives	2	1
Derivatives Not Designated As Hedges [Member] | Equity Contracts [Member] | Accrued Liabilities [Member]
Liability Derivatives	3	2
Derivatives Not Designated As Hedges [Member] | Commodity Derivative Contracts [Member] | Other Current Assets [Member]
Asset Derivatives	3	3
Derivatives Not Designated As Hedges [Member] | Commodity Derivative Contracts [Member] | Accrued Liabilities [Member]
Liability Derivatives	2
Derivatives Not Designated As Hedges [Member] | Cross-currency Swap Contracts [Member] | Other Current Assets [Member]
Asset Derivatives		13
Derivatives Not Designated As Hedges [Member] | Cross-currency Swap Contracts [Member] | Other Assets [Member]
Asset Derivatives	1	1
Derivatives Not Designated As Hedges [Member] | Cross-currency Swap Contracts [Member] | Accrued Liabilities [Member]
Liability Derivatives	17
Derivatives Not Designated As Hedges [Member] | Cross-currency Swap Contracts [Member] | Other Liabilities [Member]
Liability Derivatives	$ 74	$ 14