Derivatives and Other Financial Instruments - Schedule of Gain or Loss on Hedged Items and Derivative Contracts (Parenthetical) (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Derivative Instruments, Gain (Loss) [Line Items]
Amount of gain/loss recognized in earnings related to the ineffective portion of hedging relationships	$ (1)	$ (1)	$ 3
Sales [Member] | Aluminum Contracts [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of gain/loss recognized in earnings related to the ineffective portion of hedging relationships	$ 1	$ (18)	$ 7