Financial Instruments (Fair Values Of Derivatives Instruments) (Detail) (USD $) In Millions, unless otherwise specified	Jun. 30, 2013		Dec. 31, 2012
Schedule of Cost-method Investments [Line Items]
Fair Value, Asset Derivatives	$ 27		$ 3
Fair Value, Liability Derivatives	18		25
Designated As Hedging Instruments [Member] | Interest Rate Swaps [Member]
Schedule of Cost-method Investments [Line Items]
Fair Value, Asset Derivatives	0	[1]	0	[1]
Fair Value, Liability Derivatives	0	[1]	1	[1]
Not Designated As Hedging Instruments [Member] | Interest Rate Swaps [Member]
Schedule of Cost-method Investments [Line Items]
Fair Value, Asset Derivatives	0	[1]	0	[1]
Fair Value, Liability Derivatives	5	[1]	12	[1]
Not Designated As Hedging Instruments [Member] | Foreign Exchange Contracts [Member]
Schedule of Cost-method Investments [Line Items]
Fair Value, Asset Derivatives	24	[2]	3	[2]
Fair Value, Liability Derivatives	5	[2]	8	[2]
Not Designated As Hedging Instruments [Member] | Interest Rate Contracts [Member]
Schedule of Cost-method Investments [Line Items]
Fair Value, Asset Derivatives	3	[3]	0	[3]
Fair Value, Liability Derivatives	8	[3]	4	[3]
Not Designated As Hedging Instruments [Member] | Commodity Contracts [Member]
Schedule of Cost-method Investments [Line Items]
Fair Value, Asset Derivatives	0		0
Fair Value, Liability Derivatives	$ 0		$ 0

[1] Included in other non-current liabilities.

[2] Included in other current assets and other current liabilities.

[3] Included in assets under vehicle programs and liabilities under vehicle programs.