Financial Instruments (Fair Values Of Derivatives Instruments) (Detail) (USD $) In Millions, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014
Schedule of Cost-method Investments [Line Items]
Fair Value, Asset Derivatives	$ 18	$ 6
Fair Value, Liability Derivatives	21	16
Designated As Hedging Instruments [Member] \| Interest Rate Swaps [Member]
Schedule of Cost-method Investments [Line Items]
Fair Value, Asset Derivatives	0	1
Fair Value, Liability Derivatives	8	3
Not Designated As Hedging Instruments [Member] \| Interest Rate Swaps [Member]
Schedule of Cost-method Investments [Line Items]
Fair Value, Asset Derivatives	0	0
Fair Value, Liability Derivatives	0	0
Not Designated As Hedging Instruments [Member] \| Foreign Exchange Contract [Member]
Schedule of Cost-method Investments [Line Items]
Fair Value, Asset Derivatives	17	5
Fair Value, Liability Derivatives	8	2
Not Designated As Hedging Instruments [Member] \| Interest Rate Contracts [Member]
Schedule of Cost-method Investments [Line Items]
Fair Value, Asset Derivatives	0	0
Fair Value, Liability Derivatives	5	10
Not Designated As Hedging Instruments [Member] \| Commodity Contracts [Member]
Schedule of Cost-method Investments [Line Items]
Fair Value, Asset Derivatives	1	0
Fair Value, Liability Derivatives	$ 0	$ 1

Fair value, after offset of derivative liability, 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, before offset against an obligation to return collateral under a master netting arrangement. Includes assets elected not to be offset. Excludes assets not subject to a master netting arrangement.

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Fair value, after offset of derivative asset, 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 and before offset against a right to receive collateral under a master netting arrangement. Includes liabilities elected not to be offset. Excludes liabilities not subject to a master netting arrangement.

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