Commitments and Contingencies (Commitments Textual) (Details) (Southern California Edison, USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Schedule Of Commitments And Contingencies [Line Items]
Operating lease rent expense	$ 75,000,000	$ 66,000,000	$ 62,000,000
Decommissioning liability	2,700,000,000
Decommissioning estimated cost	8,600,000,000
Decommissioning cost escalated rates, low end of range (percent)	1.80%
Decommissioning cost escalated rates, high end of range (percent)	6.90%
Decommissioning trusts contribution amount per year	23,000,000	23,000,000	23,000,000
Decommissioning funds estimated annual earnings, net of tax percentage, low end of range (percent)	4.20%
Decommissioning funds estimated annual earnings, net of tax percentage, high end of range (percent)	5.70%
Decommissioning inactive nuclear facilities asset retirement obligation	68,000,000
Decommissioning expenditures to date	598,000,000
Decommissioning expense under rate making method	23,000,000	23,000,000	30,000,000
Decommissioning active nuclear facilities asset retirement obligation	2,600,000,000	2,500,000,000
Renewable Energy Contracts
Schedule Of Commitments And Contingencies [Line Items]
Number of renewable energy contracts (number of contracts)	53
Qualifying Facility Power Purchase Agreements
Schedule Of Commitments And Contingencies [Line Items]
Number of qualifying small power production facility contracts (number of contracts)	155
Combined Heat and Power Contracts
Schedule Of Commitments And Contingencies [Line Items]
Number of combined heat and power contracts (number of contracts)	10
Other Purchase Agreements
Schedule Of Commitments And Contingencies [Line Items]
Number of tolling arrangements (number of agreements)	14
Number of power call options (options)	19
Number of resource adequacy contracts (number of contracts)	112
Other Contractual Obligations
Schedule Of Commitments And Contingencies [Line Items]
Costs incurred for other commitments	249,000,000	281,000,000	177,000,000
Operating Leases Purchase Power Contracts
Schedule Of Commitments And Contingencies [Line Items]
Operating lease expense	1,300,000,000	1,400,000,000	1,300,000,000
Capital Leases Power Contracts
Schedule Of Commitments And Contingencies [Line Items]
Capital lease power purchase agreement	216,000,000	222,000,000
Capital leases accumulated amortization	33,000,000	27,000,000
Capital leases future minimum payments, current	6,000,000	6,000,000
Capital leases future minimum payments, noncurrent	210,000,000	216,000,000
Purchase contract, met requirements for capital lease treatment	667,000,000
Environmental Indemnities
Schedule Of Commitments And Contingencies [Line Items]
Maximum liability under indemnity per Mountainview purchase agreement for damages and other amounts	$ 60,000,000