Financial Instruments (Schedule of the Fair Values of Derivative Instruments) (Details) (USD $) In Millions	May 01, 2011	Aug. 01, 2010
Asset Derivatives	$ 45	$ 69
Liability Derivatives	150	43
Derivatives Designated as Hedges [Member]
Asset Derivatives	38	51
Liability Derivatives	48	26
Derivatives Designated as Hedges [Member] | Foreign Exchange Contracts [Member] | Other Current Assets [Member]
Asset Derivatives	1	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	2	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	10
Derivatives Designated as Hedges [Member] | Cross-currency Swap Contracts [Member] | Other Liabilities [Member]
Liability Derivatives	31	24
Derivatives Designated as Hedges [Member] | Interest Rate Swaps [Member] | Other Assets [Member]
Asset Derivatives	35	46
Derivatives not Designated as Hedges [Member]
Asset Derivatives	7	18
Liability Derivatives	102	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	5	1
Derivatives not Designated as Hedges [Member] | Equity Contracts [Member] | Other Current Assets [Member]
Asset Derivatives	1
Derivatives not Designated as Hedges [Member] | Equity Contracts [Member] | Accrued Liabilities [Member]
Liability Derivatives		2
Derivatives not Designated as Hedges [Member] | Commodity Derivative Contracts [Member] | Other Current Assets [Member]
Asset Derivatives	6	3
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
Derivatives not Designated as Hedges [Member] | Cross-currency Swap Contracts [Member] | Accrued Liabilities [Member]
Liability Derivatives	6
Derivatives not Designated as Hedges [Member] | Cross-currency Swap Contracts [Member] | Other Liabilities [Member]
Liability Derivatives	$ 91	$ 14