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Summary of Significant Accounting Policies (Narrative) (Details) (USD $) | 3 Months Ended | 12 Months Ended | 6 Months Ended |
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Dec. 31, 2014 | Sep. 30, 2014 | Jun. 30, 2014 | Mar. 31, 2014 | Dec. 31, 2013 | Sep. 30, 2013 | Jun. 30, 2013 | Mar. 31, 2013 | Dec. 31, 2014 | Dec. 31, 2013 | Dec. 31, 2012 | Jun. 30, 2013 | May 31, 2013
Significant Accounting Policies [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |
Maximum Maturity of Cash Equivalent Investments Period |  |  |  |  |  |  |  |  | 3 months |  |  |  |
Depreciation |  |  |  |  |  |  |  |  | $ 1,330,000,000 us-gaap_Depreciation | $ 1,310,000,000 us-gaap_Depreciation | $ 1,260,000,000 us-gaap_Depreciation |  |
Asset retirement obligations | 2,821,000,000 us-gaap_AssetRetirementObligationsNoncurrent |  |  |  | 3,418,000,000 us-gaap_AssetRetirementObligationsNoncurrent |  |  |  | 2,821,000,000 us-gaap_AssetRetirementObligationsNoncurrent | 3,418,000,000 us-gaap_AssetRetirementObligationsNoncurrent |  |  |
Regulatory assets | 7,612,000,000 us-gaap_RegulatoryAssetsNoncurrent |  |  |  | 7,241,000,000 us-gaap_RegulatoryAssetsNoncurrent |  |  |  | 7,612,000,000 us-gaap_RegulatoryAssetsNoncurrent | 7,241,000,000 us-gaap_RegulatoryAssetsNoncurrent |  |  |
Assets | 50,186,000,000 us-gaap_Assets |  |  |  | 46,646,000,000 us-gaap_Assets |  |  |  | 50,186,000,000 us-gaap_Assets | 46,646,000,000 us-gaap_Assets |  |  |
Liabilities | 37,198,000,000 us-gaap_Liabilities |  |  |  | 34,955,000,000 us-gaap_Liabilities |  |  |  | 37,198,000,000 us-gaap_Liabilities | 34,955,000,000 us-gaap_Liabilities |  |  |
Net income (loss) | 420,000,000 us-gaap_NetIncomeLoss | 480,000,000 us-gaap_NetIncomeLoss | 536,000,000 us-gaap_NetIncomeLoss | 176,000,000 us-gaap_NetIncomeLoss | 301,000,000 us-gaap_NetIncomeLoss | 438,000,000 us-gaap_NetIncomeLoss | (94,000,000)us-gaap_NetIncomeLoss | 271,000,000 us-gaap_NetIncomeLoss | 1,612,000,000 us-gaap_NetIncomeLoss | 915,000,000 us-gaap_NetIncomeLoss | (183,000,000)us-gaap_NetIncomeLoss |  |
Stock Compensation Plan |  |  |  |  |  |  |  |  |  |  |  |  |
Significant Accounting Policies [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |
Antidilutive Securities Excluded from Computation of Earnings Per Share, number of shares |  |  |  |  |  |  |  |  | 125,345 us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount / us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis = us-gaap_StockCompensationPlanMember | 3,977,894 us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount / us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis = us-gaap_StockCompensationPlanMember | 7,492,552 us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount / us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis = us-gaap_StockCompensationPlanMember |  |
San Onofre 2 and 3 |  |  |  |  |  |  |  |  |  |  |  |  |
Significant Accounting Policies [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |
Asset retirement obligations | 2,100,000,000 us-gaap_AssetRetirementObligationsNoncurrent / us-gaap_JointlyOwnedUtilityPlantAxis = eix_SanOnofreMember |  |  |  |  |  |  |  | 2,100,000,000 us-gaap_AssetRetirementObligationsNoncurrent / us-gaap_JointlyOwnedUtilityPlantAxis = eix_SanOnofreMember |  |  |  |
Asset Retirement Obligation, Revision of Estimate, Increase (Decrease) |  |  |  |  |  |  |  |  | (688,000,000)us-gaap_AssetRetirementObligationRevisionOfEstimate / us-gaap_JointlyOwnedUtilityPlantAxis = eix_SanOnofreMember |  |  |  |
Southern California Edison |  |  |  |  |  |  |  |  |  |  |  |  |
Significant Accounting Policies [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |
Public Utilities Depreciation Expense Stated As A Percentage Of Average Original Cost Of Depreciable Utility Plant |  |  |  |  |  |  |  |  | 4.00%eix_PublicUtilitiesDepreciationExpenseStatedAsPercentageOfAverageOriginalCostOfDepreciableUtilityPlant / dei_LegalEntityAxis = eix_SouthernCaliforniaEdisonCompanyMember | 4.20%eix_PublicUtilitiesDepreciationExpenseStatedAsPercentageOfAverageOriginalCostOfDepreciableUtilityPlant / dei_LegalEntityAxis = eix_SouthernCaliforniaEdisonCompanyMember | 4.30%eix_PublicUtilitiesDepreciationExpenseStatedAsPercentageOfAverageOriginalCostOfDepreciableUtilityPlant / dei_LegalEntityAxis = eix_SouthernCaliforniaEdisonCompanyMember |  |
Public Utilities, Allowance for Funds Used During Construction, Capitalized Cost of Equity |  |  |  |  |  |  |  |  | 65,000,000 us-gaap_PublicUtilitiesAllowanceForFundsUsedDuringConstructionCapitalizedCostOfEquity / dei_LegalEntityAxis = eix_SouthernCaliforniaEdisonCompanyMember | 72,000,000 us-gaap_PublicUtilitiesAllowanceForFundsUsedDuringConstructionCapitalizedCostOfEquity / dei_LegalEntityAxis = eix_SouthernCaliforniaEdisonCompanyMember | 96,000,000 us-gaap_PublicUtilitiesAllowanceForFundsUsedDuringConstructionCapitalizedCostOfEquity / dei_LegalEntityAxis = eix_SouthernCaliforniaEdisonCompanyMember |  |
Allowance for Funds Used During Construction, Debt |  |  |  |  |  |  |  |  | 25,000,000 us-gaap_PublicUtilitiesAllowanceForFundsUsedDuringConstructionCapitalizedInterest / dei_LegalEntityAxis = eix_SouthernCaliforniaEdisonCompanyMember | 33,000,000 us-gaap_PublicUtilitiesAllowanceForFundsUsedDuringConstructionCapitalizedInterest / dei_LegalEntityAxis = eix_SouthernCaliforniaEdisonCompanyMember | 40,000,000 us-gaap_PublicUtilitiesAllowanceForFundsUsedDuringConstructionCapitalizedInterest / dei_LegalEntityAxis = eix_SouthernCaliforniaEdisonCompanyMember |  |
Asset retirement obligations | 2,819,000,000 us-gaap_AssetRetirementObligationsNoncurrent / dei_LegalEntityAxis = eix_SouthernCaliforniaEdisonCompanyMember |  |  |  | 3,418,000,000 us-gaap_AssetRetirementObligationsNoncurrent / dei_LegalEntityAxis = eix_SouthernCaliforniaEdisonCompanyMember |  |  |  | 2,819,000,000 us-gaap_AssetRetirementObligationsNoncurrent / dei_LegalEntityAxis = eix_SouthernCaliforniaEdisonCompanyMember | 3,418,000,000 us-gaap_AssetRetirementObligationsNoncurrent / dei_LegalEntityAxis = eix_SouthernCaliforniaEdisonCompanyMember | 2,782,000,000 us-gaap_AssetRetirementObligationsNoncurrent / dei_LegalEntityAxis = eix_SouthernCaliforniaEdisonCompanyMember |  |
Decommissioning Active and Inactive Nuclear Facilities Asset Retirement Obligation | 2,700,000,000 eix_DecommissioningActiveAndInactiveNuclearFacilitiesAssetRetirementObligation / dei_LegalEntityAxis = eix_SouthernCaliforniaEdisonCompanyMember |  |  |  |  |  |  |  | 2,700,000,000 eix_DecommissioningActiveAndInactiveNuclearFacilitiesAssetRetirementObligation / dei_LegalEntityAxis = eix_SouthernCaliforniaEdisonCompanyMember |  |  |  |
Estimated Decommissioning Costs |  |  |  |  |  |  |  |  | 3,000,000,000 eix_EstimatedDecommissioningCosts / dei_LegalEntityAxis = eix_SouthernCaliforniaEdisonCompanyMember |  |  |  |
Asset Retirement Obligation, Revision of Estimate, Increase (Decrease) |  |  |  |  |  |  |  |  | (790,000,000)us-gaap_AssetRetirementObligationRevisionOfEstimate / dei_LegalEntityAxis = eix_SouthernCaliforniaEdisonCompanyMember | 455,000,000 us-gaap_AssetRetirementObligationRevisionOfEstimate / dei_LegalEntityAxis = eix_SouthernCaliforniaEdisonCompanyMember |  |  |
Decommissioning Estimated Cost |  |  |  |  |  |  |  |  | 7,400,000,000 eix_DecommissioningEstimatedCost / dei_LegalEntityAxis = eix_SouthernCaliforniaEdisonCompanyMember |  |  |  |
Decommissioning Cost Escalated Rates, Low End of Range | 1.00%eix_DecommissioningCostEscalatedRatesLowEndOfRange / dei_LegalEntityAxis = eix_SouthernCaliforniaEdisonCompanyMember |  |  |  |  |  |  |  | 1.00%eix_DecommissioningCostEscalatedRatesLowEndOfRange / dei_LegalEntityAxis = eix_SouthernCaliforniaEdisonCompanyMember |  |  |  |
Decommissioning Cost Escalated Rates, High End of Range | 7.30%eix_DecommissioningCostEscalatedRatesHighEndOfRange / dei_LegalEntityAxis = eix_SouthernCaliforniaEdisonCompanyMember |  |  |  |  |  |  |  | 7.30%eix_DecommissioningCostEscalatedRatesHighEndOfRange / dei_LegalEntityAxis = eix_SouthernCaliforniaEdisonCompanyMember |  |  |  |
Decommissioning Funds Estimated Annual Earnings, Net of Tax Percentage, Low End of Range |  |  |  |  |  |  |  |  | 3.30%eix_DecommissioningFundsEstimatedAnnualEarningsNetOfTaxPercentageLowEndOfRange / dei_LegalEntityAxis = eix_SouthernCaliforniaEdisonCompanyMember |  |  |  |
Decommissioning Funds Estimated Annual Earnings, Net of Tax Percentage, High End of Range |  |  |  |  |  |  |  |  | 4.10%eix_DecommissioningFundsEstimatedAnnualEarningsNetOfTaxPercentageHighEndOfRange / dei_LegalEntityAxis = eix_SouthernCaliforniaEdisonCompanyMember |  |  |  |
Decommissioning Expense under Rate Making Method |  |  |  |  |  |  |  |  | 5,000,000 eix_DecommissioningExpenseUnderRateMakingMethod / dei_LegalEntityAxis = eix_SouthernCaliforniaEdisonCompanyMember | 22,000,000 eix_DecommissioningExpenseUnderRateMakingMethod / dei_LegalEntityAxis = eix_SouthernCaliforniaEdisonCompanyMember |  |  |
Regulatory assets | 7,612,000,000 us-gaap_RegulatoryAssetsNoncurrent / dei_LegalEntityAxis = eix_SouthernCaliforniaEdisonCompanyMember |  |  |  | 7,241,000,000 us-gaap_RegulatoryAssetsNoncurrent / dei_LegalEntityAxis = eix_SouthernCaliforniaEdisonCompanyMember |  |  |  | 7,612,000,000 us-gaap_RegulatoryAssetsNoncurrent / dei_LegalEntityAxis = eix_SouthernCaliforniaEdisonCompanyMember | 7,241,000,000 us-gaap_RegulatoryAssetsNoncurrent / dei_LegalEntityAxis = eix_SouthernCaliforniaEdisonCompanyMember |  |  |
Unamortized Debt Issuance Expense | 75,000,000 us-gaap_UnamortizedDebtIssuanceExpense / dei_LegalEntityAxis = eix_SouthernCaliforniaEdisonCompanyMember |  |  |  | 79,000,000 us-gaap_UnamortizedDebtIssuanceExpense / dei_LegalEntityAxis = eix_SouthernCaliforniaEdisonCompanyMember |  |  |  | 75,000,000 us-gaap_UnamortizedDebtIssuanceExpense / dei_LegalEntityAxis = eix_SouthernCaliforniaEdisonCompanyMember | 79,000,000 us-gaap_UnamortizedDebtIssuanceExpense / dei_LegalEntityAxis = eix_SouthernCaliforniaEdisonCompanyMember |  |  |
Franchise Fees Billed to Customers |  |  |  |  |  |  |  |  | 134,000,000 eix_FranchiseFeesBilledToCustomers / dei_LegalEntityAxis = eix_SouthernCaliforniaEdisonCompanyMember | 116,000,000 eix_FranchiseFeesBilledToCustomers / dei_LegalEntityAxis = eix_SouthernCaliforniaEdisonCompanyMember | 98,000,000 eix_FranchiseFeesBilledToCustomers / dei_LegalEntityAxis = eix_SouthernCaliforniaEdisonCompanyMember |  |
Weighted-average common equity component authorization, set by CPUC remaining over number of months (in months) |  |  |  |  |  |  |  |  | 13 months |  |  |  |
Period for calculation of weighted average common equity component (months) |  |  |  |  |  |  |  |  | 13 months |  |  |  |
Weighted Average Common Equity Component, Percentage of Total Capitalization |  |  |  |  |  |  |  |  | 48.40%eix_WeightedAverageCommonEquityComponentPercentageOfTotalCapitalization / dei_LegalEntityAxis = eix_SouthernCaliforniaEdisonCompanyMember |  |  |  |
Capacity to Pay Additional Dividends |  |  |  |  |  |  |  |  | 87,000,000 eix_CapacityToPayAdditionalDividends / dei_LegalEntityAxis = eix_SouthernCaliforniaEdisonCompanyMember |  |  |  |
Restriction on net assets | 13,200,000,000 eix_RestrictionOnNetAssets / dei_LegalEntityAxis = eix_SouthernCaliforniaEdisonCompanyMember |  |  |  |  |  |  |  | 13,200,000,000 eix_RestrictionOnNetAssets / dei_LegalEntityAxis = eix_SouthernCaliforniaEdisonCompanyMember |  |  |  |
Assets | 49,456,000,000 us-gaap_Assets / dei_LegalEntityAxis = eix_SouthernCaliforniaEdisonCompanyMember |  |  |  | 46,050,000,000 us-gaap_Assets / dei_LegalEntityAxis = eix_SouthernCaliforniaEdisonCompanyMember |  |  |  | 49,456,000,000 us-gaap_Assets / dei_LegalEntityAxis = eix_SouthernCaliforniaEdisonCompanyMember | 46,050,000,000 us-gaap_Assets / dei_LegalEntityAxis = eix_SouthernCaliforniaEdisonCompanyMember |  |  |
Liabilities | 36,174,000,000 us-gaap_Liabilities / dei_LegalEntityAxis = eix_SouthernCaliforniaEdisonCompanyMember |  |  |  | 33,912,000,000 us-gaap_Liabilities / dei_LegalEntityAxis = eix_SouthernCaliforniaEdisonCompanyMember |  |  |  | 36,174,000,000 us-gaap_Liabilities / dei_LegalEntityAxis = eix_SouthernCaliforniaEdisonCompanyMember | 33,912,000,000 us-gaap_Liabilities / dei_LegalEntityAxis = eix_SouthernCaliforniaEdisonCompanyMember |  |  |
Net income (loss) | 380,000,000 us-gaap_NetIncomeLoss / dei_LegalEntityAxis = eix_SouthernCaliforniaEdisonCompanyMember | 503,000,000 us-gaap_NetIncomeLoss / dei_LegalEntityAxis = eix_SouthernCaliforniaEdisonCompanyMember | 362,000,000 us-gaap_NetIncomeLoss / dei_LegalEntityAxis = eix_SouthernCaliforniaEdisonCompanyMember | 208,000,000 us-gaap_NetIncomeLoss / dei_LegalEntityAxis = eix_SouthernCaliforniaEdisonCompanyMember | 258,000,000 us-gaap_NetIncomeLoss / dei_LegalEntityAxis = eix_SouthernCaliforniaEdisonCompanyMember | 477,000,000 us-gaap_NetIncomeLoss / dei_LegalEntityAxis = eix_SouthernCaliforniaEdisonCompanyMember | (91,000,000)us-gaap_NetIncomeLoss / dei_LegalEntityAxis = eix_SouthernCaliforniaEdisonCompanyMember | 256,000,000 us-gaap_NetIncomeLoss / dei_LegalEntityAxis = eix_SouthernCaliforniaEdisonCompanyMember | 1,453,000,000 us-gaap_NetIncomeLoss / dei_LegalEntityAxis = eix_SouthernCaliforniaEdisonCompanyMember | 900,000,000 us-gaap_NetIncomeLoss / dei_LegalEntityAxis = eix_SouthernCaliforniaEdisonCompanyMember | 1,569,000,000 us-gaap_NetIncomeLoss / dei_LegalEntityAxis = eix_SouthernCaliforniaEdisonCompanyMember |  |
Southern California Edison | Loss on Reacquired Debt |  |  |  |  |  |  |  |  |  |  |  |  |
Significant Accounting Policies [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |
Regulatory assets | 201,000,000 us-gaap_RegulatoryAssetsNoncurrent / dei_LegalEntityAxis = eix_SouthernCaliforniaEdisonCompanyMember / eix_RegulatoryAssetsAndLiabilitiesAxis = us-gaap_LossOnReacquiredDebtMember |  |  |  | 222,000,000 us-gaap_RegulatoryAssetsNoncurrent / dei_LegalEntityAxis = eix_SouthernCaliforniaEdisonCompanyMember / eix_RegulatoryAssetsAndLiabilitiesAxis = us-gaap_LossOnReacquiredDebtMember |  |  |  | 201,000,000 us-gaap_RegulatoryAssetsNoncurrent / dei_LegalEntityAxis = eix_SouthernCaliforniaEdisonCompanyMember / eix_RegulatoryAssetsAndLiabilitiesAxis = us-gaap_LossOnReacquiredDebtMember | 222,000,000 us-gaap_RegulatoryAssetsNoncurrent / dei_LegalEntityAxis = eix_SouthernCaliforniaEdisonCompanyMember / eix_RegulatoryAssetsAndLiabilitiesAxis = us-gaap_LossOnReacquiredDebtMember |  |  |
Southern California Edison | San Onofre 2 and 3 |  |  |  |  |  |  |  |  |  |  |  |  |
Significant Accounting Policies [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |
Reclassification To Regulatory Assets Amount |  |  |  |  |  |  |  |  |  |  |  |  | 1,521,000,000 eix_ReclassificationToRegulatoryAssetsAmount / us-gaap_JointlyOwnedUtilityPlantAxis = eix_SanOnofreMember / dei_LegalEntityAxis = eix_SouthernCaliforniaEdisonCompanyMember
Asset impairment and other charges |  |  |  | 231,000,000 eix_AssetImpairmentAndOtherCharges / us-gaap_JointlyOwnedUtilityPlantAxis = eix_SanOnofreMember / dei_LegalEntityAxis = eix_SouthernCaliforniaEdisonCompanyMember |  |  | 575,000,000 eix_AssetImpairmentAndOtherCharges / us-gaap_JointlyOwnedUtilityPlantAxis = eix_SanOnofreMember / dei_LegalEntityAxis = eix_SouthernCaliforniaEdisonCompanyMember |  | 163,000,000 eix_AssetImpairmentAndOtherCharges / us-gaap_JointlyOwnedUtilityPlantAxis = eix_SanOnofreMember / dei_LegalEntityAxis = eix_SouthernCaliforniaEdisonCompanyMember |  |  | 575,000,000 eix_AssetImpairmentAndOtherCharges / us-gaap_JointlyOwnedUtilityPlantAxis = eix_SanOnofreMember / dei_LegalEntityAxis = eix_SouthernCaliforniaEdisonCompanyMember |
Asset impairment net of tax |  |  |  | 96,000,000 eix_Assetimpairmentnetoftax / us-gaap_JointlyOwnedUtilityPlantAxis = eix_SanOnofreMember / dei_LegalEntityAxis = eix_SouthernCaliforniaEdisonCompanyMember |  |  | 365,000,000 eix_Assetimpairmentnetoftax / us-gaap_JointlyOwnedUtilityPlantAxis = eix_SanOnofreMember / dei_LegalEntityAxis = eix_SouthernCaliforniaEdisonCompanyMember |  | 72,000,000 eix_Assetimpairmentnetoftax / us-gaap_JointlyOwnedUtilityPlantAxis = eix_SanOnofreMember / dei_LegalEntityAxis = eix_SouthernCaliforniaEdisonCompanyMember |  |  | 365,000,000 eix_Assetimpairmentnetoftax / us-gaap_JointlyOwnedUtilityPlantAxis = eix_SanOnofreMember / dei_LegalEntityAxis = eix_SouthernCaliforniaEdisonCompanyMember |
Asset Retirement Obligation, Discount Rate | 6.30%eix_AssetRetirementObligationDiscountRate / us-gaap_JointlyOwnedUtilityPlantAxis = eix_SanOnofreMember / dei_LegalEntityAxis = eix_SouthernCaliforniaEdisonCompanyMember |  |  |  |  |  |  |  | 6.30%eix_AssetRetirementObligationDiscountRate / us-gaap_JointlyOwnedUtilityPlantAxis = eix_SanOnofreMember / dei_LegalEntityAxis = eix_SouthernCaliforniaEdisonCompanyMember |  |  |  |
Asset Retirement Obligation, Period Increase (Decrease) |  |  |  |  |  |  |  |  | 124,000,000 us-gaap_AssetRetirementObligationPeriodIncreaseDecrease / us-gaap_JointlyOwnedUtilityPlantAxis = eix_SanOnofreMember / dei_LegalEntityAxis = eix_SouthernCaliforniaEdisonCompanyMember |  |  |  |
Southern California Edison | Palo Verde |  |  |  |  |  |  |  |  |  |  |  |  |
Significant Accounting Policies [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |
Asset Retirement Obligation, Discount Rate | 4.08%eix_AssetRetirementObligationDiscountRate / us-gaap_JointlyOwnedUtilityPlantAxis = eix_PaloVerdeMember / dei_LegalEntityAxis = eix_SouthernCaliforniaEdisonCompanyMember |  |  |  |  |  |  |  | 4.08%eix_AssetRetirementObligationDiscountRate / us-gaap_JointlyOwnedUtilityPlantAxis = eix_PaloVerdeMember / dei_LegalEntityAxis = eix_SouthernCaliforniaEdisonCompanyMember |  |  |  |
Asset Retirement Obligation, Period Increase (Decrease) |  |  |  |  |  |  |  |  | (253,000,000)us-gaap_AssetRetirementObligationPeriodIncreaseDecrease / us-gaap_JointlyOwnedUtilityPlantAxis = eix_PaloVerdeMember / dei_LegalEntityAxis = eix_SouthernCaliforniaEdisonCompanyMember |  |  |  |
Asset Retirement Obligation, Revision of Estimate, License Extension |  |  |  |  |  |  |  |  | 20 years |  |  |  |
Southern California Edison | San Onofre 1 |  |  |  |  |  |  |  |  |  |  |  |  |
Significant Accounting Policies [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |
Decommissioning Expenditures to Date | 602,000,000 eix_DecommissioningExpendituresToDate / us-gaap_JointlyOwnedUtilityPlantAxis = eix_SanOnofre1Member / dei_LegalEntityAxis = eix_SouthernCaliforniaEdisonCompanyMember |  |  |  |  |  |  |  | 602,000,000 eix_DecommissioningExpendituresToDate / us-gaap_JointlyOwnedUtilityPlantAxis = eix_SanOnofre1Member / dei_LegalEntityAxis = eix_SouthernCaliforniaEdisonCompanyMember |  |  |  |
Southern California Edison | Other Current Assets |  |  |  |  |  |  |  |  |  |  |  |  |
Significant Accounting Policies [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |
Greenhouse Gas Allowances | 204,000,000 eix_GreenhouseGasAllowances / us-gaap_BalanceSheetLocationAxis = us-gaap_OtherCurrentAssetsMember / dei_LegalEntityAxis = eix_SouthernCaliforniaEdisonCompanyMember |  |  |  | 135,000,000 eix_GreenhouseGasAllowances / us-gaap_BalanceSheetLocationAxis = us-gaap_OtherCurrentAssetsMember / dei_LegalEntityAxis = eix_SouthernCaliforniaEdisonCompanyMember |  |  |  | 204,000,000 eix_GreenhouseGasAllowances / us-gaap_BalanceSheetLocationAxis = us-gaap_OtherCurrentAssetsMember / dei_LegalEntityAxis = eix_SouthernCaliforniaEdisonCompanyMember | 135,000,000 eix_GreenhouseGasAllowances / us-gaap_BalanceSheetLocationAxis = us-gaap_OtherCurrentAssetsMember / dei_LegalEntityAxis = eix_SouthernCaliforniaEdisonCompanyMember |  |  |
Southern California Edison | Other Current Liabilities |  |  |  |  |  |  |  |  |  |  |  |  |
Significant Accounting Policies [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |
Greenhouse Gas Emission Obligations | 211,000,000 eix_GreenhouseGasEmissionObligations / us-gaap_BalanceSheetLocationAxis = us-gaap_OtherCurrentLiabilitiesMember / dei_LegalEntityAxis = eix_SouthernCaliforniaEdisonCompanyMember |  |  |  | 128,000,000 eix_GreenhouseGasEmissionObligations / us-gaap_BalanceSheetLocationAxis = us-gaap_OtherCurrentLiabilitiesMember / dei_LegalEntityAxis = eix_SouthernCaliforniaEdisonCompanyMember |  |  |  | 211,000,000 eix_GreenhouseGasEmissionObligations / us-gaap_BalanceSheetLocationAxis = us-gaap_OtherCurrentLiabilitiesMember / dei_LegalEntityAxis = eix_SouthernCaliforniaEdisonCompanyMember | 128,000,000 eix_GreenhouseGasEmissionObligations / us-gaap_BalanceSheetLocationAxis = us-gaap_OtherCurrentLiabilitiesMember / dei_LegalEntityAxis = eix_SouthernCaliforniaEdisonCompanyMember |  |  |
Edison International |  |  |  |  |  |  |  |  |  |  |  |  |
Significant Accounting Policies [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |
Unamortized Debt Issuance Expense | 83,000,000 us-gaap_UnamortizedDebtIssuanceExpense / dei_LegalEntityAxis = us-gaap_ParentCompanyMember |  |  |  | 84,000,000 us-gaap_UnamortizedDebtIssuanceExpense / dei_LegalEntityAxis = us-gaap_ParentCompanyMember |  |  |  | 83,000,000 us-gaap_UnamortizedDebtIssuanceExpense / dei_LegalEntityAxis = us-gaap_ParentCompanyMember | 84,000,000 us-gaap_UnamortizedDebtIssuanceExpense / dei_LegalEntityAxis = us-gaap_ParentCompanyMember |  |  |
Weighted Average Common Equity Component Minimum Percentage Authorization Set By C P U C |  |  |  |  |  |  |  |  | 48.00%eix_WeightedAverageCommonEquityComponentMinimumPercentageAuthorizationSetByCPUC / dei_LegalEntityAxis = us-gaap_ParentCompanyMember |  |  |  |
Assets | 13,674,000,000 us-gaap_Assets / dei_LegalEntityAxis = us-gaap_ParentCompanyMember |  |  |  | 11,681,000,000 us-gaap_Assets / dei_LegalEntityAxis = us-gaap_ParentCompanyMember |  |  |  | 13,674,000,000 us-gaap_Assets / dei_LegalEntityAxis = us-gaap_ParentCompanyMember | 11,681,000,000 us-gaap_Assets / dei_LegalEntityAxis = us-gaap_ParentCompanyMember |  |  |
Net income (loss) |  |  |  |  |  |  |  |  | 1,612,000,000 us-gaap_NetIncomeLoss / dei_LegalEntityAxis = us-gaap_ParentCompanyMember | 915,000,000 us-gaap_NetIncomeLoss / dei_LegalEntityAxis = us-gaap_ParentCompanyMember | (183,000,000)us-gaap_NetIncomeLoss / dei_LegalEntityAxis = us-gaap_ParentCompanyMember |  |
Unidentified Subsidiary, Limited Liability Company |  |  |  |  |  |  |  |  |  |  |  |  |
Significant Accounting Policies [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |
Assets | 64,000,000 us-gaap_Assets / dei_LegalEntityAxis = eix_UnidentifiedSubsidiaryLimitedLiabilityCompanyMember |  |  |  |  |  |  |  | 64,000,000 us-gaap_Assets / dei_LegalEntityAxis = eix_UnidentifiedSubsidiaryLimitedLiabilityCompanyMember |  |  |  |
Liabilities | 39,000,000 us-gaap_Liabilities / dei_LegalEntityAxis = eix_UnidentifiedSubsidiaryLimitedLiabilityCompanyMember |  |  |  |  |  |  |  | 39,000,000 us-gaap_Liabilities / dei_LegalEntityAxis = eix_UnidentifiedSubsidiaryLimitedLiabilityCompanyMember |  |  |  |
Net income (loss) |  |  |  |  |  |  |  |  | $ 3,000,000 us-gaap_NetIncomeLoss / dei_LegalEntityAxis = eix_UnidentifiedSubsidiaryLimitedLiabilityCompanyMember |  |  |  |
Unidentified Subsidiary, Limited Liability Company | Call Option |  |  |  |  |  |  |  |  |  |  |  |  |
Significant Accounting Policies [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |
Term of derivative contract |  |  |  |  |  |  |  |  | 9 months |  |  |  |
Cooldown period after completion of project |  |  |  |  |  |  |  |  | 5 years |  |  |  |
Indirect Subsidiaries |  |  |  |  |  |  |  |  |  |  |  |  |
Significant Accounting Policies [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |
Number of new financings |  | 3 eix_NumberOfNewFinancings / dei_LegalEntityAxis = eix_IndirectSubsidiariesMember |  |  |  |  |  |  |  |  |  |  |
Power generating capacity for majority interest (in megawatts) |  | 35 eix_PowerGeneratingCapacityOfProjectsOwnedControlled / dei_LegalEntityAxis = eix_IndirectSubsidiariesMember |  |  |  |  |  |  |  |  |  |  |
Percent of taxable profits and losses and tax credits attributable to tax equity investors, period one |  |  |  |  |  |  |  |  | 99.00%eix_NetIncomeLossAttributableToNoncontrollingInterestsPercentPeriodOne / dei_LegalEntityAxis = eix_IndirectSubsidiariesMember |  |  |  |
Period of taxable profits and losses and tax credits attributable to tax equity investors, period one |  |  |  |  |  |  |  |  | 6 years |  |  |  |
Priority return on investment for noncontrolling interest holders |  |  |  |  |  |  |  |  | 2.00%eix_NoncontrollingInterestsPriorityReturn / dei_LegalEntityAxis = eix_IndirectSubsidiariesMember |  |  |  |
Percent of taxable profits and losses and tax credits attributable to tax equity investors, period two |  |  |  |  |  |  |  |  | 5.00%eix_NetIncomeLossAttributableToNoncontrollingInterestsPercentPeriodTwo / dei_LegalEntityAxis = eix_IndirectSubsidiariesMember |  |  |  |
Electric Utility | Southern California Edison |  |  |  |  |  |  |  |  |  |  |  |  |
Significant Accounting Policies [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |
Supply Of Electricity Area Covered (in square miles) |  |  |  |  |  |  |  |  | 50,000 eix_SupplyOfElectricityAreaCovered1 / dei_LegalEntityAxis = eix_SouthernCaliforniaEdisonCompanyMember / us-gaap_StatementBusinessSegmentsAxis = eix_ElectricUtilityMember |  |  |  |

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- Definition Asset impairment and other charges + References No definition available. + Details
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- Definition Asset impairment net of tax + References No definition available. + Details
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- Definition Asset Retirement Obligation, Discount Rate + References No definition available. + Details
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- Definition Asset Retirement Obligation, Revision of Estimate, License Extension + References No definition available. + Details
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- Definition This element represents the capacity of the entity to pay additional dividends. + References No definition available. + Details
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- Definition This element represents the asset retirement obligation for decommissioning active and inactive nuclear facilities at the balance sheet date. + References No definition available. + Details
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- Definition This element represents the total estimated cost to decommission its active nuclear facilities. + References No definition available. + Details
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- Definition This element represents the total nuclear decommissioning expense incurred over the life of the San Onofre Unit 1 project. + References No definition available. + Details
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- Definition This element represents the nuclear decommissioning expense under the rate-making method. + References No definition available. + Details
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- Definition This element represents the high end of the range of the estimated annual after-tax earnings on the decommissioning funds. + References No definition available. + Details
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- Definition This element represents the low end of the range of the estimated annual after-tax earnings on the decommissioning funds. + References No definition available. + Details
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- Definition This element represents the franchise fees billed to customers. + References No definition available. + Details
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- Definition This element represents the maximum maturity period of the investments considered as cash equivalents. + References No definition available. + Details
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- Definition Power generating capacity of the project owned and/or controlled by the entity. + References No definition available. + Details
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- Definition This element represents the depreciation expense expressed as a percentage of average original cost of depreciable utility plant. + References No definition available. + Details
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- Definition Supply Of Electricity Area Covered 1 + References No definition available. + Details
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- Definition This element represents the authorized percentage of weighted-average common equity component of total capitalization required to distribute the dividend. + References No definition available. + Details
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- Definition Securities (including those issuable pursuant to contingent stock agreements) that could potentially dilute basic earnings per share (EPS) or earnings per unit (EPU) in the future that were not included in the computation of diluted EPS or EPU because to do so would increase EPS or EPU amounts or decrease loss per share or unit amounts for the period presented. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 260 -SubTopic 10 -Section 50 -Paragraph 1 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=6371337&loc=d3e3550-109257 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Antidilution -URI http://asc.fasb.org/extlink&oid=6505113 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Diluted Earnings Per Share -URI http://asc.fasb.org/extlink&oid=6510752 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Contingent Stock Agreement -URI http://asc.fasb.org/extlink&oid=6508534 + Details
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- Definition Net Increase or Decrease in the asset retirement obligation during the period. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 410 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=6392692&loc=d3e7535-110849 + Details
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- Definition The amount of expense recognized in the current period that reflects the allocation of the cost of tangible assets over the assets' useful lives. Includes production and non-production related depreciation. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 28 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3602-108585 + Details
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