Liabilities, Commitments And Contingencies (Schedule Of Environmental Matter Activity) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
Dec. 31, 2011	Dec. 31, 2010
Liabilities Commitments And Contingencies [Abstract]
Beginning balance - January 1	$ 721	$ 706
Reductions for payments made	(118)	(93)
Changes in estimates	155	108
Ending balance - December 31	$ 758	$ 721

Total costs accrued as of the balance sheet date for environmental loss contingencies.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 410

-SubTopic 30

-Section 50

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Reference 2: http://www.xbrl.org/2003/role/presentationRef

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-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

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-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

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