Derivatives And Other Financial Instruments (Gains And Losses On Derivatives) (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 OCI on Derivatives (Effective Portion)	$ 104		$ 287		$ (84)		$ 213
Amount of Gain or (Loss) Reclassified from Accumulated OCI into Earnings (Effective Portion)	(42)	[1]	(61)	[1]	(82)	[1]	(79)	[1]
Amount of Gain or (Loss) Recognized in Earnings on Derivatives (Ineffective Portion and Amount Excluded from Effectiveness Testing)	(1)	[2]	1	[2]		[2]	3	[2]
Amount of loss expected to be recognized into earnings over the next 12 months					62
Sales [Member] | Aluminum Contracts [Member]
Amount of Gain or (Loss) Reclassified from Accumulated OCI into Earnings (Effective Portion)	(38)	[1]	(53)	[1]	(76)	[1]	(64)	[1]
Sales [Member] | Foreign Exchange Contracts [Member]
Amount of Gain or (Loss) Reclassified from Accumulated OCI into Earnings (Effective Portion)	1	[1]	(1)	[1]	2	[1]	(4)	[1]
Cost of Goods Sold [Member] | Energy Contract [Member]
Amount of Gain or (Loss) Recognized in OCI on Derivatives (Effective Portion)	8		(3)		8		(13)
Amount of Gain or (Loss) Reclassified from Accumulated OCI into Earnings (Effective Portion)	(3)	[1]	(7)	[1]	(6)	[1]	(11)	[1]
Other (Income) Expenses, Net [Member] | Aluminum Contracts [Member]
Amount of Gain or (Loss) Recognized in Earnings on Derivatives (Ineffective Portion and Amount Excluded from Effectiveness Testing)	(1)	[2]	1	[2]		[2]	3	[2]
Other (Income) Expenses, Net [Member] | Energy Contract [Member]
Amount of Gain or (Loss) Recognized in OCI on Derivatives (Effective Portion)							(1)
Amount of Gain or (Loss) Reclassified from Accumulated OCI into Earnings (Effective Portion)		[1]		[1]		[1]		[1]
Amount of Gain or (Loss) Recognized in Earnings on Derivatives (Ineffective Portion and Amount Excluded from Effectiveness Testing)		[2]		[2]		[2]		[2]
Other (Income) Expenses, Net [Member] | Foreign Exchange Contracts [Member]
Amount of Gain or (Loss) Recognized in Earnings on Derivatives (Ineffective Portion and Amount Excluded from Effectiveness Testing)		[2]		[2]		[2]		[2]
Aluminum Contracts [Member]
Amount of Gain or (Loss) Recognized in OCI on Derivatives (Effective Portion)	97		291		(92)		234
Foreign Exchange Contracts [Member]
Amount of Gain or (Loss) Recognized in OCI on Derivatives (Effective Portion)	$ 1		$ (1)		$ 2		$ (7)

[1] * Assuming market rates remain constant with the rates at June 30, 2011, a loss of $62 is expected to be recognized in earnings over the next 12 months.

[2] ** For all periods presented, the amount of gain or (loss) recognized in earnings related to the ineffective portion of the hedging relationships.