Financial Instruments (Schedule Of Effect Of Derivatives Recognized) (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Schedule of Cost-method Investments [Line Items]
Derivatives not designated as hedging instruments	$ (4)	$ (8)	$ 2	$ (8)
Designated As Hedging Instruments [Member] | Interest Rate Swaps [Member]
Schedule of Cost-method Investments [Line Items]
Interest rate swaps		8	11	24
Not Designated As Hedging Instruments [Member] | Foreign Exchange Contracts [Member]
Schedule of Cost-method Investments [Line Items]
Derivatives not designated as hedging instruments	(2)	(13)		(29)
Not Designated As Hedging Instruments [Member] | Commodity Contracts [Member]
Schedule of Cost-method Investments [Line Items]
Derivatives not designated as hedging instruments	3	(3)	4	(2)
Not Designated As Hedging Instruments [Member] | Interest Rate Contracts [Member]
Schedule of Cost-method Investments [Line Items]
Derivatives not designated as hedging instruments	$ (5)		$ (13)	$ (1)