Derivatives (Details 2) In Millions, unless otherwise specified	3 Months Ended		1 Months Ended		1 Months Ended		1 Months Ended	3 Months Ended
	Mar. 31, 2012 USD ($)	Mar. 31, 2011 USD ($)	Oct. 31, 2008 Interest rate swaps Floating rate Medium-term note due 2011 USD ($) Y Derivative	Mar. 31, 2012 Fair value hedges Interest rate swaps USD ($)	Jul. 31, 2007 Fair value hedges Interest rate swaps Eurobond 750 Million Euros Issued July2007 EUR (€) Y	Aug. 31, 2010 Fair value hedges Interest rate swaps Eurobond 750 Million Euros Issued July2007 EUR (€)	Jul. 31, 2007 Fair value hedges Interest rate swaps Eurobond 275 Million Euros Issued December2007 EUR (€) Y	Mar. 31, 2012 Derivatives designated as hedging instruments Fair value hedges USD ($)	Mar. 31, 2011 Derivatives designated as hedging instruments Fair value hedges USD ($)
Derivatives in Fair Value Hedging Relationships or Net Investment Hedges
Notional amount, interest rate swaps designated as fair value hedges			$ 800	$ 342	€ 400
Term of debt instrument (in years)			3		7		7
Face amount			800		750		275
Termination of notional amount of fixed-to-floating interest rate swap						150
Gain (loss) on termination of fixed-to-floating interest rate swap will be amortized over this debt's remaining life						18
Number of fixed-to-floating interest rate swaps			2
Interest rate, stated percentage (as a percent)			4.50%
Gain (Loss) on Derivative Recognized in income	(1)	(10)						(1)	(10)
Gain (Loss) on Hedged Item Recognized in Income	$ 1	$ 10						$ 1	$ 10