Income Taxes - Components of Income Tax Table (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Current [Abstract]
Federal	$ 45	$ (381)	$ 305
State	25	1	18
Foreign	891	977	628
Total	961	597	951
Deferred [Abstract]
Federal	(30)	(1,470)	(72)
State	115	(68)	(11)
Foreign	74	85	(48)
Total	159	(1,453)	(131)
Income tax expense (benefit)	$ 1,120	$ (856)	$ 820