Liabilities, Commitments And Contingencies (Schedule Of Environmental Remediation Activity) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
Dec. 31, 2012	Dec. 31, 2011
Accrual for Environmental Loss Contingencies [Roll Forward]
Beginning balance - January 1	$ 758	$ 721
Reductions for payments made	(121)	(118)
Changes in estimates	73	155
Ending balance - December 31	$ 710	$ 758

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

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Reference 3: 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-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009.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.

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