Financial Instruments Pre-Tax Effect Of Foreign Exchange Contracts Designated As Other Derivatives (Details) (Foreign Exchange Contract [Member], USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
Interest Expense, Net [Member]
Amount of gain (loss) recognized in earnings	$ (14)	$ (5)
Not Designated as Hedging Instrument [Member]
Gain (Loss) on Foreign Currency Derivative Instruments Not Designated as Hedging Instruments	62	295
Not Designated as Hedging Instrument [Member] | Interest Expense, Net [Member]
Amount of gain (loss) recognized in earnings	$ 1	$ 3