Other Income, Net - Schedule of Other Income, Net (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Component of Other Income, Nonoperating [Line Items]
Equity loss	$ 12	$ 2
Interest income	(4)	(6)
Foreign currency gains, net	(6)	(11)
Net (gain) loss from asset sales	(5)	2
Net (gain) loss on mark-to-market derivative contracts	(17)	6
Other, net	(7)	(9)
Other income, net	$ (27)	$ (16)