Permanent Retirement of San Onofre (Details) (USD $)	1 Months Ended	3 Months Ended		6 Months Ended				6 Months Ended				1 Months Ended	3 Months Ended	6 Months Ended			6 Months Ended			6 Months Ended
	Apr. 30, 2013 invoices	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012	Apr. 27, 2013	Dec. 31, 2012	Jun. 30, 2013 San Onofre (nuclear)	Jun. 30, 2013 Southern California Edison	Apr. 27, 2013 Southern California Edison	Dec. 31, 2012 Southern California Edison	Jun. 30, 2013 Southern California Edison San Onofre (nuclear)	Jun. 30, 2013 Southern California Edison San Onofre (nuclear)	Jun. 30, 2013 Southern California Edison San Onofre (nuclear) positions	May 31, 2013 Southern California Edison San Onofre (nuclear)	Jun. 30, 2013 Mitsubishi Heavy Industries Ltd [Member] San Onofre (nuclear)	Jun. 30, 2013 Replacement Steam Generators Southern California Edison San Onofre (nuclear)	Jun. 30, 2013 Supporting Ongoing Activities at the Site Southern California Edison San Onofre (nuclear)	Jun. 30, 2013 Employee severance Southern California Edison San Onofre (nuclear)	Jun. 30, 2013 Decommissioning Plan Southern California Edison San Onofre (nuclear) positions
Regulatory Assets [Line Items]
Cumulative amount of revenue collected since January 1, 2012												$ 860,000,000	$ 860,000,000	$ 860,000,000
Cost of service												56,000,000
Decommissioning Nuclear Facilities Net Investment															2,100,000,000
Authorized expenditures by authoritative body												525,000,000	525,000,000	525,000,000
Authorized expenditures by authoritative body, after adjustments for inflation												665,000,000	665,000,000	665,000,000
Jointly Owned Utility Plant, Proportionate Ownership Share												78.21%	78.21%	78.21%
Authorized expenditures by authoritative body, spent to date														602,000,000
Authorized expenditures by authoritative body, market costs incurred														670,000,000
Avoided Nuclear Costs Due To Decision To Retire Plant														138,000,000
Authorized expenditures by authoritative body, Planned Outage Costs														65,000,000
Public Utilities, Incremental Inspection and Repair Costs														115,000,000
Public Utilities, Incremental Inspection and Repair Costs, Payments from Third Party														36,000,000
Amount of assets reclassified to a regulatory asset															1,521,000,000
Regulatory assets		7,494,000,000		7,494,000,000			6,422,000,000		7,494,000,000		6,422,000,000							404,000,000
Asset impairment and other		575,000,000	(1,000,000)	575,000,000	0								575,000,000
Asset impairment net of tax													365,000,000
San Onofre expected number of positions to be eliminated														960						175
Disposal Group, Including Discontinued Operation, Accrued Liabilities																			56,000,000
Increase in regulatory assets												32,000,000
Warranty Period																	20 years
Maximum liability for purchase agreement for damages																138,000,000
Notice of intent to sue, notice time period								90 days
Number of Invoices for Reimbursement	7
Gain Contingency, Invoiced Amount for Reimbursement	149,000,000
Gain Contingency, Invoiced Amount Paid for Reimbursement	45,000,000
Notice Of Claim Amount						$ 352,000,000				$ 276,000,000
Outage Policy Benefit Reduction Percentage				90.00%