Commitments And Contingencies (Schedule Of Environmental Remediation Activity) (Details) (USD $) In Millions, unless otherwise specified	6 Months Ended
Jun. 30, 2012	Jun. 30, 2011
Commitments and Contingencies Disclosure [Abstract]
Beginning balance - January 1	$ 758	$ 721
Reductions for payments made	(33)	(32)
Changes in estimates	45	99
Ending balance - June 30	$ 770	$ 788

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

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

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-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009.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