Financial Instruments (Schedule Of The Fair Value Of Derivative Instruments) (Details) - USD ($) $ in Millions	Jan. 29, 2017	Jul. 31, 2016
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	$ 6	$ 5
Derivative Liability, Fair Value, Gross Liability	21	60
Derivatives Designated As Hedges [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	0	1
Derivative Liability, Fair Value, Gross Liability	17	48
Derivatives Designated As Hedges [Member] | Foreign Exchange Forward Contracts [Member] | Other Current Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	0	1
Derivatives Designated As Hedges [Member] | Foreign Exchange Forward Contracts [Member] | Accrued Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative Liability, Fair Value, Gross Liability	2	4
Derivatives Designated As Hedges [Member] | Interest Rate Contract [Member] | Accrued Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative Liability, Fair Value, Gross Liability	15	0
Derivatives Designated As Hedges [Member] | Interest Rate Contract [Member] | Other Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative Liability, Fair Value, Gross Liability	0	44
Derivatives Not Designated As Hedges [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	6	4
Derivative Liability, Fair Value, Gross Liability	4	12
Derivatives Not Designated As Hedges [Member] | Foreign Exchange Forward Contracts [Member] | Accrued Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative Liability, Fair Value, Gross Liability	1	7
Derivatives Not Designated As Hedges [Member] | Commodity Derivative Contracts [Member] | Other Current Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	5	3
Derivatives Not Designated As Hedges [Member] | Commodity Derivative Contracts [Member] | Accrued Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative Liability, Fair Value, Gross Liability	3	4
Derivatives Not Designated As Hedges [Member] | Deferred Compensation Derivative Contracts [Member] | Other Current Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	1	1
Derivatives Not Designated As Hedges [Member] | Deferred Compensation Derivative Contracts [Member] | Accrued Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative Liability, Fair Value, Gross Liability	$ 0	$ 1