Financial Instruments (Schedule Of The Fair Value Of Derivative Instruments) (Details) - USD ($) $ in Millions	Jan. 27, 2019	Jul. 29, 2018
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	$ 9	$ 10
Derivative Liability, Fair Value, Gross Liability	7	6
Derivatives Designated As Hedges [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	0	1
Derivative Liability, Fair Value, Gross Liability	2	2
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	2
Derivatives Not Designated As Hedges [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	9	9
Derivative Liability, Fair Value, Gross Liability	5	4
Derivatives Not Designated As Hedges [Member] | Foreign Exchange Forward Contracts [Member] | Other Current Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	3	3
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	0
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	4	5
Derivatives Not Designated As Hedges [Member] | Commodity Derivative Contracts [Member] | Accrued Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative Liability, Fair Value, Gross Liability	4	3
Derivatives Not Designated As Hedges [Member] | Commodity Derivative Contracts [Member] | Other Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative Liability, Fair Value, Gross Liability	0	1
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	$ 2	$ 1