Equity - Accumulated Balances Related to Each Component of Other Comprehensive Income (Loss) (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
Accumulated Other Comprehensive Loss, Beginning Balance			$ (3,132)	$ (3,216)
Accumulated Other Comprehensive Loss, Other comprehensive (loss) income	86	63	92	503
Accumulated Other Comprehensive Loss, Ending Balance	(3,040)	(2,713)	(3,040)	(2,713)
Cumulative Translation Adjustment, beginning balance			(811)	(1,245)
Cumulative Translation Adjustment, Other comprehensive (loss) income	170	(22)	84	532
Cumulative Translation Adjustment, ending balance	(727)	(713)	(727)	(713)
Employee Benefit Plans, Beginning balance			(2,346)	(2,043)
Benefit plan net gain (loss) and prior service cost (credit), net of amortization	27	31	45	59
Employee Benefit Plans, Ending balance	(2,301)	(1,984)	(2,301)	(1,984)
Investments, Beginning balance			21	31
Investments, Other comprehensive (loss) income	32	(6)	62	(11)
Investments, Ending balance	83	20	83	20
Derivatives, Beginning balance			4	41
Derivatives, Other comprehensive (loss) income	(143)	60	(99)	(77)
Derivatives, Ending balance	$ (95)	$ (36)	$ (95)	$ (36)