Derivatives And Other Financial Instruments (Fair Value Gains And Losses on Derivatives Contracts) (Details) (USD $) In Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2011	Jun. 30, 2010
Amount of Gain or (Loss) Recognized in Earnings on Derivatives	$ 16	$ 25	$ 28	$ (18)
Sales [Member] | Aluminum Contracts [Member]
Amount of Gain or (Loss) Recognized in Earnings on Derivatives	(2)	(5)	1	(4)
Other (Income) Expenses, Net [Member] | Aluminum Contracts [Member]
Amount of Gain or (Loss) Recognized in Earnings on Derivatives	3	23	(11)	15
Other (Income) Expenses, Net [Member] | Embedded Credit Derivative [Member]
Amount of Gain or (Loss) Recognized in Earnings on Derivatives	(6)	(3)	3	(9)
Other (Income) Expenses, Net [Member] | Energy Contract [Member]
Amount of Gain or (Loss) Recognized in Earnings on Derivatives	19	14	31	(19)
Other (Income) Expenses, Net [Member] | Foreign Exchange Contracts [Member]
Amount of Gain or (Loss) Recognized in Earnings on Derivatives	$ 2	$ (4)	$ 4	$ (1)