Commitments And Contingencies (Schedule Of Environmental Remediation Activity) (Details) (USD $) In Millions, unless otherwise specified	6 Months Ended
Jun. 30, 2013	Jun. 30, 2012
Commitments and Contingencies Disclosure [Abstract]
Beginning balance – January 1	$ 710	$ 758
Reductions for payments made	(37)	(33)
Changes in estimates	25	45
Ending balance – June 30	$ 698	$ 770

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-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009.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-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009.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