Components of Provision for Income Taxes, Net (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended																12 Months Ended
	Dec. 31, 2012		Sep. 30, 2012		Jun. 30, 2012		Mar. 31, 2012		Dec. 31, 2011		Sep. 30, 2011		Jun. 30, 2011		Mar. 31, 2011		Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Current taxes:
U.S. and state																	$ 562	$ 103	$ 311
International																	131	52	37
Current taxes																	693	155	348
Deferred taxes:
U.S. and state																	(156)	157	1
International																	(109)	(21)	3
Deferred taxes																	(265)	136	4
Provision for income taxes, net	$ 86	[1]	$ 67	[1]	$ 49	[1]	$ 89	[1]	$ 194	[1]	$ 83	[1]	$ 109	[1]	$ 43	[1]	$ 428	$ 291	$ 352

[1] The sum of quarterly amounts, including per share amounts, may not equal amounts reported for year-to-date periods. This is due to the effects of rounding and changes in the number of weighted-average shares outstanding for each period.