Income Taxes (Textual) (Details) (USD $) In Millions, unless otherwise specified	Mar. 31, 2013
IRS Examination
Income Tax Disclosure [Line Items]
Estimated potential future federal tax payment as of the balance sheet date, including interest and penalties, based on a proposed adjustment	$ 201
Penalty for understatement of tax liability (as a percent)	40.00%
Southern California Edison
Income Tax Disclosure [Line Items]
Estimated federal tax payment as a result of the proposed adjustment to adjust repair allowance deduction	73
Southern California Edison \| IRS Examination
Income Tax Disclosure [Line Items]
Estimated potential future federal tax payment as of the balance sheet date, including interest and penalties, based on a proposed adjustment	$ 97

The estimated range of reasonably possible losses resulting from an adverse position taken by a taxing authority.

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

-Publisher FASB

-Name FASB Interpretation (FIN)

-Number 14

-Paragraph 3

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009.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 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 740

-SubTopic 10

-Section 50

-Paragraph 15

-Subparagraph (d)(3)

-URI http://asc.fasb.org/extlink&oid=6907707&loc=d3e32718-109319

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