Commitments and Contingencies (Details) (USD $)	1 Months Ended		1 Months Ended	9 Months Ended				9 Months Ended	12 Months Ended		1 Months Ended	9 Months Ended						9 Months Ended
	Jun. 30, 2010	Sep. 30, 2013	Dec. 31, 2011 Southern California Edison	Sep. 30, 2013 Southern California Edison sites	Sep. 01, 2013 Southern California Edison	Jun. 01, 2013 Southern California Edison	Sep. 30, 2013 Southern California Edison Environmental Indemnities	Sep. 30, 2013 Edison International sites	Dec. 31, 2007 Malibu Fire Order Instituting Investigation Southern California Edison power_pole	May 31, 2013 Malibu Fire Order Instituting Investigation Southern California Edison	Oct. 31, 2011 Alleged violations of PSD requirements and New Source Performance Standards of the CAA Southern California Edison private_environmental_organization	Sep. 30, 2013 Nuclear Insurance	Sep. 30, 2013 Nuclear Insurance Southern California Edison	Sep. 30, 2013 Nuclear Insurance SCE and other owners of San Onofre and Palo Verde	Jun. 30, 2013 San Onofre (nuclear)	Sep. 30, 2013 San Onofre (nuclear) Southern California Edison	Jun. 30, 2013 San Onofre (nuclear) Southern California Edison	Sep. 30, 2013 San Onofre and Palo Verde Nuclear Insurance Southern California Edison	May 31, 2013 Pole Safety Studies and Remediation Malibu Fire Order Instituting Investigation Southern California Edison	May 31, 2013 Penalty Paid to State General Fund Malibu Fire Order Instituting Investigation Southern California Edison	Sep. 30, 2013 Nuclear fuel supply commitments Southern California Edison	Dec. 31, 2012 Nuclear fuel supply commitments Southern California Edison	Sep. 30, 2013 Dividends Paid By EME to Holdings [Member] Eme Chapter 11 Bankruptcy Filing [Member]	Sep. 30, 2013 Amount Paid By EME Under Tax Allocation Scheme [Member] Eme Chapter 11 Bankruptcy Filing [Member]
Schedule Of Commitments And Contingencies [Line Items]
Supply commitment																						$ 912,000,000
Accrued liabilities related to cancellation of contracts																					33,000,000
Maximum liability for purchase agreement for damages							60,000,000
Notice Of Claim Amount															390,000,000		306,000,000						925,000,000	183,000,000
Number of failed power poles (in power poles)									3
Proposed settlement amount										37,000,000									17,000,000	20,000,000
Number of plaintiffs (entities)											4
Identified material sites for environmental remediation (in number of sites)								19
Minimum costs to be Identified Site								1,000,000
Minimum liability for environmental remediation for material sites				129,000,000												90,000,000
Immaterial sites for environmental remediation (in number of sites)				39
Immaterial sites, range of liability, minimum				4,000,000
Environmental remediation liability				133,000,000
Regulatory assets related to environmental remediation				129,000,000
Portion of recorded liability recoverable from incentive mechanism				38,000,000
Percentage of environmental remediation costs recoverable through an incentive mechanism (as a percent)				90.00%
Liability incurred at majority of the remaining sites through customer rates				91,000,000
Environmental remediation costs to be recovered (as a percent)				100.00%
Amount that cleanup costs could exceed recorded liability for identified material sites				161,000,000
Amount that cleanup costs could exceed recorded liability for immaterial sites				7,000,000
Maximum expected period for cleanup of identified sites (in years)				30 years
Expected annual environmental remediation costs, low end of range				6,000,000
Expected annual environmental remediation costs, high end of range				31,000,000
Environmental remediation costs				5,000,000
Federal limit on public liability claims from nuclear incident, approximate												13,600,000,000
Private primary insurance purchased														375,000,000
Maximum assessment per each nuclear incident													255,000,000
Maximum yearly assessment per nuclear incident													38,000,000
Loss limit, property damage insurance																		500,000,000
Loss limit, property damage insurance, federal minimum requirement																		1,060,000,000
Limit on assessment of retrospective premium adjustments, per year, approximate													52,000,000
Insurance coverage for wildfire liabilities Limit					500,000,000	450,000,000
Self insurance retention per wildfire occurrence					10,000,000
Wildfire Threshold For Additional Coverage		550,000,000
Amount of damages, decision by US Court of Federal Claims, spent nuclear fuel litigation	142,000,000
Damages sought			$ 98,000,000