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Commitments and Contingencies (Contingencies Textual) (Details) | 1 Months Ended | 12 Months Ended |  |  |
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Dec. 31, 2015 USD ($) sites invoices | Oct. 31, 2015 USD ($) | Aug. 31, 2015 communication | Oct. 31, 2013 USD ($) | Jun. 30, 2010 USD ($) | Dec. 31, 2015 USD ($) sites communication invoices | Dec. 31, 2014 USD ($) | Dec. 31, 2013 USD ($) | Dec. 31, 2012 USD ($) | Jun. 01, 2015 USD ($) | Aug. 31, 2014 USD ($) | Aug. 30, 2014 USD ($)
Insurance Claims |  |  |  |  |  |  |  |  |  |  |  |
Schedule Of Commitments And Contingencies [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Federal Limit on Public Liability Claims from Nuclear Incident, Approximate |  |  |  |  |  | $ 13,500,000,000 |  |  |  |  |  |
San Onofre | Insurance Claims |  |  |  |  |  |  |  |  |  |  |  |
Schedule Of Commitments And Contingencies [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Loss Contingency, Estimate of Possible Loss |  |  |  |  |  |  |  |  |  |  |  | $ 433,000,000
Pre tax damages awarded to SCE |  | $ 400,000,000 |  |  |  |  |  |  |  |  |  |
Southern California Edison |  |  |  |  |  |  |  |  |  |  |  |
Schedule Of Commitments And Contingencies [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Loss Contingency, Damages Sought, Value |  |  |  |  | $ 112,000,000 |  |  |  |  |  |  |
Accrual for environmental loss contingencies (immaterial sites) | $ 3,000,000 |  |  |  |  | $ 3,000,000 |  |  |  |  |  |
Number of Material Sites Identified for Environmental Remediation | sites | 19 |  |  |  |  | 19 |  |  |  |  |  |
Minimum costs to be Identified Material Site |  |  |  |  |  | $ 1,000,000 |  |  |  |  |  |
Accrual for Environmental Loss Contingencies (material sites) | $ 131,000,000 |  |  |  |  | $ 131,000,000 |  |  |  |  |  |
Number of Immaterial Sites for Environmental Remediation | sites |  |  |  |  |  | 39 |  |  |  |  |  |
Accrued Environmental Loss Contingencies, Noncurrent | 134,000,000 |  |  |  |  | $ 134,000,000 |  |  |  |  |  |
Regulatory Assets, Noncurrent, Environmental Remediation | 129,000,000 |  |  |  |  | 129,000,000 |  |  |  |  |  |
Portion of Recorded Liability Recoverable From Incentive Mechanism |  |  |  |  |  | $ 47,000,000 |  |  |  |  |  |
Percentage of Environmental Remediation Costs Recoverable From Incentive Mechanism |  |  |  |  |  | 90.00% |  |  |  |  |  |
Recorded Liability Incurred at Majority of Remaining Sites Through Customer Rates | 82,000,000 |  |  |  |  | $ 82,000,000 |  |  |  |  |  |
Percentage of Environmental Remediation Costs to be Recovered |  |  |  |  |  | 100.00% |  |  |  |  |  |
Amount that Cleanup Costs for Identified Material Sites Could Exceed Recorded Liability |  |  |  |  |  | $ 164,000,000 |  |  |  |  |  |
Amount that Cleanup Costs for Immaterial Sites Could Exceed Recorded Liability |  |  |  |  |  | $ 8,000,000 |  |  |  |  |  |
Maximum Expected Period for Clean Up of Identified Sites |  |  |  |  |  | 30 years |  |  |  |  |  |
Expected Annual Environmental Remediation Costs, Period for Cost Estimates |  |  |  |  |  | 5 years |  |  |  |  |  |
Expected Annual Environmental Remediation Costs, Low End of Range |  |  |  |  |  | $ 7,000,000 |  |  |  |  |  |
Expected Annual Environmental Remediation Costs, High End of Range |  |  |  |  |  | 26,000,000 |  |  |  |  |  |
Environmental Remediation Expense |  |  |  |  |  | 5,000,000 | $ 4,000,000 | $ 8,000,000 |  |  |  |
Insurance Coverage for Wildfire Liabilities Limit |  |  |  |  |  |  |  |  |  | $ 610,000,000 |  |
Increase In Self Insurance Retention Per Wildfire Occurrence |  |  |  |  |  |  |  |  |  | $ 10,000,000 |  |
Additional Coverage for Certain Wildfire Liabilities | 390,000,000 |  |  |  |  | 390,000,000 |  |  |  |  |  |
Wildfire Threshold For Additional Coverage | 610,000,000 |  |  |  |  | 610,000,000 |  |  |  |  |  |
Southern California Edison | Insurance Claims |  |  |  |  |  |  |  |  |  |  |  |
Schedule Of Commitments And Contingencies [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Maximum Deferred Insurance Premium Per Nuclear Incident |  |  |  |  |  | 255,000,000 |  |  |  |  |  |
Maximum Yearly Assessment Per Nuclear Incident |  |  |  |  |  | 38,000,000 |  |  |  |  |  |
Limit on Assessment of Retrospective Premium Adjustments, Per Year, Approximate |  |  |  |  |  | $ 45,000,000 |  |  |  |  |  |
Southern California Edison | San Onofre |  |  |  |  |  |  |  |  |  |  |  |
Schedule Of Commitments And Contingencies [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Number Of Communications That Should Have Been Reported | communication |  |  | 9 |  |  | 8 |  |  |  |  |  |
Penalties | 16,740,000 |  |  |  |  |  |  |  |  |  |  |
Accrual for Environmental Loss Contingencies (material sites) | 80,000,000 |  |  |  |  | $ 80,000,000 |  |  |  |  |  |
Southern California Edison | San Onofre | 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 (under accidental outage insurance) |  |  |  |  |  | 50.00% |  |  |  |  |  |
Ratepayer Allocation of Recovery from Recoveries, Initial Amount of Settlement |  |  |  |  |  | $ 282,000,000 |  |  |  |  |  |
Southern California Edison | San Onofre | Insurance Claims |  |  |  |  |  |  |  |  |  |  |  |
Schedule Of Commitments And Contingencies [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Loss Contingency, Estimate of Possible Loss |  |  |  |  |  |  |  |  |  |  | $ 339,000,000 |
Pre tax damages awarded to SCE |  | $ 313,000,000 |  |  |  | $ 20,000,000 |  |  |  |  |  |
Ratepayer Allocation of Recovery from Recoveries |  |  |  |  |  | 95.00% |  |  |  |  |  |
Entity Allocation of Recovery from Recoveries (under accidental outage insurance) |  |  |  |  |  | 5.00% |  |  |  |  |  |
Southern California Edison | Replacement Steam Generators | San Onofre |  |  |  |  |  |  |  |  |  |  |  |
Schedule Of Commitments And Contingencies [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Warranty Period |  |  |  |  |  | 20 years |  |  |  |  |  |
SCE And Other Owners Of San Onofre And Palo Verde |  |  |  |  |  |  |  |  |  |  |  |
Schedule Of Commitments And Contingencies [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Loss Contingency, Damages Sought, Value |  |  |  |  | $ 142,000,000 | $ 182,000,000 |  |  |  |  |  |
SCE And Other Owners Of San Onofre And Palo Verde | Insurance Claims |  |  |  |  |  |  |  |  |  |  |  |
Schedule Of Commitments And Contingencies [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Private Primary Insurance Purchased |  |  |  |  |  | 375,000,000 |  |  |  |  |  |
SCE And Other Owners Of San Onofre And Palo Verde | Tort Claims For Onsite Workers |  |  |  |  |  |  |  |  |  |  |  |
Schedule Of Commitments And Contingencies [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Private Primary Insurance Purchased |  |  |  |  |  | 375,000,000 |  |  |  |  |  |
SCE And Other Owners Of San Onofre And Palo Verde | San Onofre and Palo Verde | Insurance Claims |  |  |  |  |  |  |  |  |  |  |  |
Schedule Of Commitments And Contingencies [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Loss Limit, Property Damage Insurance, Federal Minimum Requirement |  |  |  |  |  | 1,060,000,000 |  |  |  |  |  |
Mitsubishi Heavy Industries Ltd | San Onofre |  |  |  |  |  |  |  |  |  |  |  |
Schedule Of Commitments And Contingencies [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Maximum Liability Per Purchase Agreement for Damages | $ 138,000,000 |  |  |  |  | $ 138,000,000 |  |  |  |  |  |
Loss Contingency Counter Claim Amount |  |  |  | $ 41,000,000 |  |  |  |  |  |  |  |
Mitsubishi Heavy Industries Ltd | Southern California Edison | San Onofre |  |  |  |  |  |  |  |  |  |  |  |
Schedule Of Commitments And Contingencies [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Loss Contingency, Damages Sought, Value |  |  |  | $ 4,000,000,000 |  |  |  |  |  |  |  |
Number of Invoices for Reimbursement | invoices | 7 |  |  |  |  | 7 |  |  |  |  |  |
Gain Contingency, Invoiced Amount for Reimbursement | $ 149,000,000 |  |  |  |  | $ 149,000,000 |  |  |  |  |  |
Gain Contingency, Invoiced Amount Paid for Reimbursement |  |  |  |  |  | $ 45,000,000 |  |  |  |  |  |
Public Utilities, Incremental Inspection and Repair Costs, Payments from Third Party |  |  |  |  |  |  |  |  | $ 35,000,000 |  |  |

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- Definition The potential estimated cleanup costs for identified material sites in excess of the minimum liability that is accrued as of the balance sheet date for environmental loss contingencies. + References No definition available. + Details
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- Definition The potential estimated cleanup costs for immaterial sites in excess of the minimum liability that is accrued as of the balance sheet date for environmental loss contingencies. + References No definition available. + Details
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- Definition The high end of the range of expected remediation costs in each of the next several years. + References No definition available. + Details
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- Definition The low end of the range of expected remediation costs in each of the next several years. + References No definition available. + Details
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- Definition This element represents the increase in self insurance retention per wildfire occurrence. + References No definition available. + Details
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- Definition The approximate maximum yearly retrospective premium adjustments that could be assessed against the entity. + References No definition available. + Details
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- Definition Maximum Expected Period for Clean Up of Identified Sites + References No definition available. + Details
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- Definition The maximum aggregate potential liability under the purchase agreement for damages and other amounts in connection with environmental liabilities. + References No definition available. + Details
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- Definition The maximum amount of additional insurance premium per yearly assessment charged for each nuclear incident. + References No definition available. + Details
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- Definition The upper end of the range of a site's cost estimate must be at least this amount to be classified as a material identified site. Below this amount an identified site will be an immaterial site. + References No definition available. + Details
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- Definition Number Of Communications That Should Have Been Reported + References No definition available. + Details
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- Definition The number of immaterial identified sites which have a recorded environmental remediation liability as the costs can be estimated and are probable. + References No definition available. + Details
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- Definition The number of material identified sites which have a recorded environmental remediation liability as the costs can be estimated and are probable. + References No definition available. + Details
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- Definition The percentage of environmental remediation costs entity will recover through incentive mechanism. + References No definition available. + Details
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- Definition Represents the percentage of environmental remediation costs to be recovered. + References No definition available. + Details
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- Definition The portion of the recorded liability for environmental remediation costs recoverable through incentive mechanism. + References No definition available. + Details
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- Definition The maximum amount of private primary insurance available, which was purchased. + References No definition available. + Details
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- Definition Public Utilities, Incremental Inspection and Repair Costs, Payments from Third Party + References No definition available. + Details
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- Definition Represents the recorded liability incurred at majority of the remaining sites through customer rates. + References No definition available. + Details
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- Definition Regulatory Assets, Noncurrent, Environmental Remediation + References No definition available. + Details
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- Definition Schedule Of Commitments And Contingencies [Line Items] + References No definition available. + Details
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- Definition Wildfire Threshold For Additional Coverage + References No definition available. + Details
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- Definition The charge against earnings in the period for known or estimated future costs arising from requirements to perform environmental remediation activities. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 410 -SubTopic 30 -Section 50 -Paragraph 12 -URI http://asc.fasb.org/extlink&oid=6393242&loc=d3e13296-110859 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 28 -URI http://asc.fasb.org/extlink&oid=56944662&loc=d3e3602-108585 + Details
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- Definition Amount of damages awarded to the plaintiff in the legal matter. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 450 -SubTopic 20 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=25496072&loc=d3e14326-108349 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 450 -SubTopic 20 -Section 50 -Paragraph 4 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=25496072&loc=d3e14435-108349 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 450 -SubTopic 20 -Section 50 -Paragraph 9 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=25496072&loc=d3e14557-108349 + Details
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