Income Taxes - Total Provision for Income Taxes (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Current taxes:
Federal	$ (150)	$ 64	$ 25
State		2	4
Foreign	2,349	2,197	1,193
Current tax, net	2,199	2,263	1,222
Deferred taxes:
Federal	596	656	431
State	10	17	7
Foreign	71	573	514
Deferred taxes, net	677	1,246	952
Total	$ 2,876	$ 3,509	$ 2,174