Commitments and Contingencies (Details 2) (USD $)			6 Months Ended	1 Months Ended	6 Months Ended			1 Months Ended	6 Months Ended	1 Months Ended	6 Months Ended	1 Months Ended	6 Months Ended
	Jun. 30, 2011	Dec. 31, 2010	Jun. 30, 2011 Edison International	Jun. 30, 2010 Southern California Edison Company	Jun. 30, 2011 Southern California Edison Company	Jun. 30, 2010 Southern California Edison Company	Jun. 30, 2011 Southern California Edison Company Nuclear Insurance	May 31, 2011 Midwest Generation LLC.	Jun. 30, 2011 Midwest Generation LLC.	Aug. 31, 2009 Midwest Generation LLC. Violation of certain operating permit requirements	Jun. 30, 2011 Midwest Generation LLC. Violation of certain operating permit requirements	Jan. 31, 2011 Homer City Violations of the PSD and Title V provisions of the CAA Pending or Threatened Litigation in January 2011	Jun. 30, 2011 SCE and other owners of San Onofre and Palo Verde Nuclear Insurance	Jun. 30, 2011 Nuclear Insurance	Jun. 30, 2011 San Onofre (nuclear)
Contingencies
Number of coal-fired electric generating stations										6
Penalties sought, per violation, per day, minimum end of range										$ 25,000		$ 32,500
Penalties sought, per violation, per day, maximum end of range										37,500		37,500
Number of fully dismissed counts in the complaint filed by the US EPA and the State of Illinois											9
Number of counts in the complaint filed by the US EPA and the State of Illinois											10
Number of complaints filed asserting claims of nuisance, negligence, trespass, and strict liability								2
Number of prior owners of facilities												2
Number of plaintiffs												2
Identified material sites for environmental remediation (in number of sites)			26		24				2
Identified material sites, minimum amount of upper end of range of costs			1,000,000
Minimum liability for environmental remediation			60,000,000		54,000,000										18,000,000
Amount that cleanup costs could exceed recorded liability for identified material sites			192,000,000
Amount that cleanup costs could exceed recorded liability for immaterial sites					7,000,000
Immaterial sites for environmental remediation (in number of sites)					33
Immaterial sites, range of liability, minimum					3,000,000
Percentage of environmental remediation costs recoverable through an incentive mechanism (as a percent)					90.00%
Portion of recorded liability recoverable from incentive mechanism					32,000,000
Environmental remediation costs to be recovered (as a percent)					100.00%
Liability incurred at majority of the remaining sites through customer rates					21,000,000
Regulatory asset, Long-term	4,690,000,000	4,347,000,000			53,000,000
Maximum expected period for cleanup of identified sites (in years)					30Y
Expected annual environmental remediation costs, low end of range					5,000,000
Expected annual environmental remediation costs, high end of range					17,000,000
Environmental remediation costs					7,000,000	3,000,000
Federal limit on public liability claims from nuclear incident, approximate														12,600,000,000
Private primary insurance purchased													375,000,000
Maximum deferred insurance premium per each nuclear incident							235,000,000
Maximum yearly assessment per nuclear incident							35,000,000
Loss limit, property damage insurance							500,000,000
Limit on assessment of retrospective premium adjustments, per year, approximate							48,000,000
Amount of damages, decision by US Court of Federal Claims, spent nuclear fuel litigation				$ 142,000,000