Financial Instruments (Offsetting Assets and Liabilities) (Details) (USD $) In Millions, unless otherwise specified	Oct. 27, 2013	Jul. 28, 2013
General Discussion of Derivative Instruments and Hedging Activities [Abstract]
Derivative Asset, Fair Value, Gross Asset	$ 29	$ 32
Derivative Asset, Fair Value, Amount Not Offset Against Collateral	(13)	(8)
Derivative Asset	16	24
Derivative Liability, Fair Value, Gross Liability	29	36
Derivative Liability, Fair Value, Amount Not Offset Against Collateral	(13)	(8)
Derivative Liability	$ 16	$ 28

Fair value, after the effects of master netting arrangements, of a financial asset or other contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes assets not subject to a master netting arrangement and not elected to be offset.

+ References+ Details

Fair value of financial asset or other contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset, elected not to be offset against an obligation to return collateral under a master netting arrangement.

+ References+ Details

- Definition

Fair value of financial liability or contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset, elected not to be offset against a right to receive collateral under a master netting arrangement.

+ References+ Details

- Definition

Fair value, after the effects of master netting arrangements, of a financial liability or contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes assets not subject to a master netting arrangement and not elected to be offset.

+ References+ Details