Equity (Details 1) (USD $) In Millions	9 Months Ended
	Sep. 30, 2011	Sep. 30, 2010
Accumulated balances related to each component of other comprehensive income (loss)
Derivatives, Beginning Balance	$ 41	$ (42)
Derivatives, Other comprehensive income (loss)	(77)	30
Derivatives, Ending Balance	(36)	(12)
Investments, Beginning Balance	31	33
Investments, Other comprehensive income (loss)	(11)	17
Investments, Ending Balance	20	50
Employee Benefit Plans, Beginning Balance	(2,043)	(2,469)
Employee Benefit Plans, Other comprehensive income (loss)	59	142
Employee Benefit Plans, Ending Balance	(1,984)	(2,327)
Cumulative Translation Adjustment, Beginning Balance	(1,245)	(289)
Cumulative Translation Adjustment, Other comprehensive income (loss)	532	(912)
Cumulative Translation Adjustment, Ending Balance	(713)	(1,201)
Accumulated Other Comprehensive Income (Loss), Beginning Balance	(3,216)	(2,767)
Other comprehensive income (loss)	503	(723)
Accumulated Other Comprehensive Income (Loss), Ending Balance	$ (2,713)	$ (3,490)