Financial Instruments (Schedule Of The Fair Value Of Derivative Instruments) (Details) (USD $) In Millions, unless otherwise specified	Apr. 28, 2013	Jul. 29, 2012
Derivatives, Fair Value [Line Items]
Asset Derivatives	$ 15	$ 45
Liability Derivatives	79	83
Cash Flow Hedging [Member] | Cross-Currency Swap Contracts [Member] | Accrued Liabilities [Member]
Derivatives, Fair Value [Line Items]
Liability Derivatives	23	0
Cash Flow Hedging [Member] | Cross-Currency Swap Contracts [Member] | Other Liabilities [Member]
Derivatives, Fair Value [Line Items]
Liability Derivatives	0	25
Cash Flow Hedging [Member] | Foreign Exchange Forward Contracts [Member] | Other Current Assets [Member]
Derivatives, Fair Value [Line Items]
Asset Derivatives	0	1
Cash Flow Hedging [Member] | Foreign Exchange Forward Contracts [Member] | Accrued Liabilities [Member]
Derivatives, Fair Value [Line Items]
Liability Derivatives	1	0
Cash Flow Hedging [Member] | Interest Rate Swap [Member] | Other Current Assets [Member]
Derivatives, Fair Value [Line Items]
Asset Derivatives	0	1
Cash Flow Hedging [Member] | Interest Rate Swap [Member] | Other Assets [Member]
Derivatives, Fair Value [Line Items]
Asset Derivatives	3	1
Fair Value Hedging [Member] | Interest Rate Swap [Member] | Other Current Assets [Member]
Derivatives, Fair Value [Line Items]
Asset Derivatives	4	4
Fair Value Hedging [Member] | Interest Rate Swap [Member] | Other Assets [Member]
Derivatives, Fair Value [Line Items]
Asset Derivatives	0	9
Derivatives Designated As Hedges [Member]
Derivatives, Fair Value [Line Items]
Asset Derivatives	7	16
Liability Derivatives	24	25
Derivatives Not Designated As Hedges [Member]
Derivatives, Fair Value [Line Items]
Asset Derivatives	8	29
Liability Derivatives	55	58
Derivatives Not Designated As Hedges [Member] | Commodity Derivative Contracts [Member] | Other Current Assets [Member]
Derivatives, Fair Value [Line Items]
Asset Derivatives	3	8
Derivatives Not Designated As Hedges [Member] | Commodity Derivative Contracts [Member] | Accrued Liabilities [Member]
Derivatives, Fair Value [Line Items]
Liability Derivatives	6	4
Derivatives Not Designated As Hedges [Member] | Cross-Currency Swap Contracts [Member] | Other Current Assets [Member]
Derivatives, Fair Value [Line Items]
Asset Derivatives	4	19
Derivatives Not Designated As Hedges [Member] | Cross-Currency Swap Contracts [Member] | Accrued Liabilities [Member]
Derivatives, Fair Value [Line Items]
Liability Derivatives	48	25
Derivatives Not Designated As Hedges [Member] | Cross-Currency Swap Contracts [Member] | Other Liabilities [Member]
Derivatives, Fair Value [Line Items]
Liability Derivatives	1	29
Derivatives Not Designated As Hedges [Member] | Foreign Exchange Forward Contracts [Member] | Other Current Assets [Member]
Derivatives, Fair Value [Line Items]
Asset Derivatives	0	1
Derivatives Not Designated As Hedges [Member] | Deferred Compensation Derivative Contracts [Member] | Other Current Assets [Member]
Derivatives, Fair Value [Line Items]
Asset Derivatives	$ 1	$ 1