Environmental Matters (Accrued Liability For Asbestos Suits And Workers' Compensation Proceedings) (Details) (USD $) In Millions	Sep. 30, 2011	Dec. 31, 2010
Site Contingency [Line Items]
Regulatory assets	$ 7,316	$ 7,886
Asbestos Suits [Member]
Site Contingency [Line Items]
Accrued liability	10	10
Regulatory assets	10	10
Workers' Compensation [Member]
Site Contingency [Line Items]
Accrued liability	99	106
Regulatory assets	$ 25	$ 31

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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Reference 4: 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-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009.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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