Summary of Significant Accounting Policies (Narrative) (Details) (USD $)	3 Months Ended								12 Months Ended			6 Months Ended
	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	$ 1,310,000,000	$ 1,260,000,000
Asset retirement obligations	2,821,000,000				3,418,000,000				2,821,000,000	3,418,000,000
Regulatory assets	7,612,000,000				7,241,000,000				7,612,000,000	7,241,000,000
Assets	50,186,000,000				46,646,000,000				50,186,000,000	46,646,000,000
Liabilities	37,198,000,000				34,955,000,000				37,198,000,000	34,955,000,000
Net income (loss)	420,000,000	480,000,000	536,000,000	176,000,000	301,000,000	438,000,000	(94,000,000)	271,000,000	1,612,000,000	915,000,000	(183,000,000)
Stock Compensation Plan
Significant Accounting Policies [Line Items]
Antidilutive Securities Excluded from Computation of Earnings Per Share, number of shares									125,345	3,977,894	7,492,552
San Onofre 2 and 3
Significant Accounting Policies [Line Items]
Asset retirement obligations	2,100,000,000								2,100,000,000
Asset Retirement Obligation, Revision of Estimate, Increase (Decrease)									(688,000,000)
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%	4.20%	4.30%
Public Utilities, Allowance for Funds Used During Construction, Capitalized Cost of Equity									65,000,000	72,000,000	96,000,000
Allowance for Funds Used During Construction, Debt									25,000,000	33,000,000	40,000,000
Asset retirement obligations	2,819,000,000				3,418,000,000				2,819,000,000	3,418,000,000	2,782,000,000
Decommissioning Active and Inactive Nuclear Facilities Asset Retirement Obligation	2,700,000,000								2,700,000,000
Estimated Decommissioning Costs									3,000,000,000
Asset Retirement Obligation, Revision of Estimate, Increase (Decrease)									(790,000,000)	455,000,000
Decommissioning Estimated Cost									7,400,000,000
Decommissioning Cost Escalated Rates, Low End of Range	1.00%								1.00%
Decommissioning Cost Escalated Rates, High End of Range	7.30%								7.30%
Decommissioning Funds Estimated Annual Earnings, Net of Tax Percentage, Low End of Range									3.30%
Decommissioning Funds Estimated Annual Earnings, Net of Tax Percentage, High End of Range									4.10%
Decommissioning Expense under Rate Making Method									5,000,000	22,000,000
Regulatory assets	7,612,000,000				7,241,000,000				7,612,000,000	7,241,000,000
Unamortized Debt Issuance Expense	75,000,000				79,000,000				75,000,000	79,000,000
Franchise Fees Billed to Customers									134,000,000	116,000,000	98,000,000
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%
Capacity to Pay Additional Dividends									87,000,000
Restriction on net assets	13,200,000,000								13,200,000,000
Assets	49,456,000,000				46,050,000,000				49,456,000,000	46,050,000,000
Liabilities	36,174,000,000				33,912,000,000				36,174,000,000	33,912,000,000
Net income (loss)	380,000,000	503,000,000	362,000,000	208,000,000	258,000,000	477,000,000	(91,000,000)	256,000,000	1,453,000,000	900,000,000	1,569,000,000
Southern California Edison | Loss on Reacquired Debt
Significant Accounting Policies [Line Items]
Regulatory assets	201,000,000				222,000,000				201,000,000	222,000,000
Southern California Edison | San Onofre 2 and 3
Significant Accounting Policies [Line Items]
Reclassification To Regulatory Assets Amount													1,521,000,000
Asset impairment and other charges				231,000,000			575,000,000		163,000,000			575,000,000
Asset impairment net of tax				96,000,000			365,000,000		72,000,000			365,000,000
Asset Retirement Obligation, Discount Rate	6.30%								6.30%
Asset Retirement Obligation, Period Increase (Decrease)									124,000,000
Southern California Edison | Palo Verde
Significant Accounting Policies [Line Items]
Asset Retirement Obligation, Discount Rate	4.08%								4.08%
Asset Retirement Obligation, Period Increase (Decrease)									(253,000,000)
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								602,000,000
Southern California Edison | Other Current Assets
Significant Accounting Policies [Line Items]
Greenhouse Gas Allowances	204,000,000				135,000,000				204,000,000	135,000,000
Southern California Edison | Other Current Liabilities
Significant Accounting Policies [Line Items]
Greenhouse Gas Emission Obligations	211,000,000				128,000,000				211,000,000	128,000,000
Edison International
Significant Accounting Policies [Line Items]
Unamortized Debt Issuance Expense	83,000,000				84,000,000				83,000,000	84,000,000
Weighted Average Common Equity Component Minimum Percentage Authorization Set By C P U C									48.00%
Assets	13,674,000,000				11,681,000,000				13,674,000,000	11,681,000,000
Net income (loss)									1,612,000,000	915,000,000	(183,000,000)
Unidentified Subsidiary, Limited Liability Company
Significant Accounting Policies [Line Items]
Assets	64,000,000								64,000,000
Liabilities	39,000,000								39,000,000
Net income (loss)									$ 3,000,000
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
Power generating capacity for majority interest (in megawatts)		35
Percent of taxable profits and losses and tax credits attributable to tax equity investors, period one									99.00%
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%
Percent of taxable profits and losses and tax credits attributable to tax equity investors, period two									5.00%
Electric Utility | Southern California Edison
Significant Accounting Policies [Line Items]
Supply Of Electricity Area Covered (in square miles)									50,000