Derivatives And Other Financial Instruments (Schedule Of Outstanding Forward Contracts That Were Entered Into To Hedge Forward Transactions) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010
Foreign Exchange Contracts [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Foreign exchange contracts		20
Energy Contracts [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Energy contracts (electricity - megawatt hours)	100,578,295	100,578,295
Aluminum Contracts [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Aluminum contracts (kmt)	1,294	1,285