Derivatives (Details 3) (Net Investment Hedges) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended		1 Months Ended	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2012 USD ($)	Sep. 30, 2011 USD ($)	Sep. 30, 2012 USD ($)	Sep. 30, 2011 USD ($)	Jul. 31, 2007 Foreign Currency Denominated Debt EUR (€)	Sep. 30, 2012 Foreign Currency Denominated Debt USD ($)	Sep. 30, 2011 Foreign Currency Denominated Debt USD ($)	Sep. 30, 2012 Foreign Currency Denominated Debt USD ($)	Sep. 30, 2011 Foreign Currency Denominated Debt USD ($)	Dec. 31, 2007 Foreign Currency Denominated Debt EUR (€)
Net investment hedges
Pretax Gain (Loss) Recognized as Cumulative Translation within Other Comprehensive Income on Effective Portion of Instrument	$ (45)	$ 85	$ 5	$ (35)		$ (45)	$ 85	$ 5	$ (35)
Ineffective portion of gain (loss) on derivative and amount excluded from effectiveness testing recognized in income	0	0	0	0		0	0	0	0
Term of debt instrument					7 years					7 years
Face amount					€ 750					€ 275