Commitments and Contingencies (Details) (USD $)	3 Months Ended		1 Months Ended	12 Months Ended	0 Months Ended
	Mar. 31, 2015	Mar. 31, 2014	Oct. 31, 2013	Dec. 31, 2012	Apr. 17, 2015	Aug. 31, 2014	Jun. 01, 2014
Nuclear Insurance
Schedule Of Commitments And Contingencies [Line Items]
Federal limit on public liability claims from nuclear incident, approximate	$ 13,600,000,000
Nuclear Insurance | Other
Schedule Of Commitments And Contingencies [Line Items]
San Bernardino settlement amount						433,000,000
Southern California Edison
Schedule Of Commitments And Contingencies [Line Items]
Damages sought	182,000,000
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	116,000,000
Immaterial sites for environmental remediation (in number of sites)	39
Total minimum recorded liability for immaterial sites	4,000,000
Environmental remediation liability	120,000,000
Regulatory assets related to environmental remediation	116,000,000
Portion of recorded liability recoverable from incentive mechanism	30,000,000
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	86,000,000
Environmental remediation costs to be recovered (as a percent)	100.00%
Amount that cleanup costs could exceed recorded liability for identified material sites	158,000,000
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
Remediation cost estimates (period)	5 years
Expected annual environmental remediation costs, low end of range	5,000,000
Expected annual environmental remediation costs, high end of range	23,000,000
Environmental remediation costs	1,000,000	1,000,000
Insurance coverage for wildfire liabilities Limit	450,000,000						547,500,000.0
Self insurance retention per wildfire occurrence							10,000,000
Threshold for wildfire claims (new lines for additional coverage)	550,000,000
Southern California Edison | Other
Schedule Of Commitments And Contingencies [Line Items]
Minimum liability for environmental remediation for material sites	84,000,000
Southern California Edison | Other | Mitsubishi Heavy Industries Ltd
Schedule Of Commitments And Contingencies [Line Items]
Damages sought			4,000,000,000
Number of invoices for reimbursement	7
Invoiced amount for reimbursement	149,000,000
Invoiced amount paid for reimbursement	45,000,000
Share of invoice paid				35,000,000
Southern California Edison | Other | Mitsubishi Heavy Industries Ltd
Schedule Of Commitments And Contingencies [Line Items]
Ratepayer allocation of recovery from recoveries	50.00%
Entity allocation of recovery from recoveries	50.00%
Ratepayer allocation of recovery from recoveries, initial amount of settlement	282,000,000
Southern California Edison | Other | Replacement Steam Generators
Schedule Of Commitments And Contingencies [Line Items]
Warranty period	20 years
Southern California Edison | Other Insurance Claims | Other
Schedule Of Commitments And Contingencies [Line Items]
Ratepayer allocation of recovery from recoveries	82.50%
Entity allocation of recovery from recoveries	17.50%
Southern California Edison | Nuclear Insurance
Schedule Of Commitments And Contingencies [Line Items]
Limit on assessment of retrospective premium adjustments, per year, approximate	52,000,000
Maximum assessment per each nuclear incident	255,000,000
Maximum yearly assessment per nuclear incident	38,000,000
Southern California Edison | Nuclear Insurance | Other
Schedule Of Commitments And Contingencies [Line Items]
Reduction in policy benefits following retirement of assets	90.00%
San Bernardino settlement amount						339,000,000
Ratepayer allocation of recovery from recoveries	95.00%
Entity allocation of recovery from recoveries	5.00%
Mitsubishi Heavy Industries Ltd | Other
Schedule Of Commitments And Contingencies [Line Items]
Maximum liability per purchase agreement for damages	138,000,000
Asserted counterclaim			41,000,000
SCE and other owners of San Onofre and Palo Verde | Nuclear Insurance | San Onofre and Palo Verde
Schedule Of Commitments And Contingencies [Line Items]
Loss limit, property damage insurance, federal minimum requirement	1,060,000,000
Power Purchase Contracts | Southern California Edison
Schedule Of Commitments And Contingencies [Line Items]
2015 additional commitments	6,000,000
2016 additional commitments	34,000,000
2017 additional commitments	117,000,000
2018 additional commitments	166,000,000
2019 additional commitments	204,000,000
Additional commitments due after 2019	1,900,000,000
Subsequent Event | Southern California Edison
Schedule Of Commitments And Contingencies [Line Items]
Damages sought					$ 648,000,000