Fair Value Measurements (Quantitative Information About Level 3 Fair Value Measurements) (Details) - Southern California Edison - Level 3 $ in Millions	9 Months Ended	12 Months Ended
Sep. 30, 2017 USD ($) $ / MWh $ / MMBTU MW	Dec. 31, 2016 USD ($) $ / MWh $ / MMBTU MW
Congestion revenue rights \| Market simulation model and auction prices
Quantitative Information About Level 3 Measurements [Line Items]
Fair Value, Assets \| $	$ 24	$ 67
Fair Value, Liabilities \| $	$ 0	$ 0
Congestion revenue rights \| Market simulation model and auction prices \| Load forecast \| Minimum
Quantitative Information About Level 3 Measurements [Line Items]
Fair value inputs, power units (in megawatts) \| MW	3,708	3,708
Congestion revenue rights \| Market simulation model and auction prices \| Load forecast \| Maximum
Quantitative Information About Level 3 Measurements [Line Items]
Fair value inputs, power units (in megawatts) \| MW	22,840	22,840
Congestion revenue rights \| Market simulation model and auction prices \| Power prices \| Minimum
Quantitative Information About Level 3 Measurements [Line Items]
Fair value inputs, price level ($ per MWh)	3.65	3.65
Congestion revenue rights \| Market simulation model and auction prices \| Power prices \| Maximum
Quantitative Information About Level 3 Measurements [Line Items]
Fair value inputs, price level ($ per MWh)	99.58	99.58
Congestion revenue rights \| Market simulation model and auction prices \| Gas prices \| Minimum
Quantitative Information About Level 3 Measurements [Line Items]
Fair value inputs, price level ($ per MWh) \| $ / MMBTU	2.51	2.51
Congestion revenue rights \| Market simulation model and auction prices \| Gas prices \| Maximum
Quantitative Information About Level 3 Measurements [Line Items]
Fair value inputs, price level ($ per MWh) \| $ / MMBTU	4.87	4.87
Tolling \| Option model
Quantitative Information About Level 3 Measurements [Line Items]
Fair Value, Assets \| $		$ 0
Fair Value, Liabilities \| $		$ 1,154
Tolling \| Option model \| Power prices \| Minimum
Quantitative Information About Level 3 Measurements [Line Items]
Fair value inputs, price level ($ per MWh)		23.40
Expected volatility rate		29.00%
Tolling \| Option model \| Power prices \| Maximum
Quantitative Information About Level 3 Measurements [Line Items]
Fair value inputs, price level ($ per MWh)		51.24
Expected volatility rate		71.00%
Tolling \| Option model \| Power prices \| Weighted Average
Quantitative Information About Level 3 Measurements [Line Items]
Fair value inputs, price level ($ per MWh)		34.70
Expected volatility rate		40.00%
Tolling \| Option model \| Gas prices \| Minimum
Quantitative Information About Level 3 Measurements [Line Items]
Expected volatility rate		15.00%
Tolling \| Option model \| Gas prices \| Maximum
Quantitative Information About Level 3 Measurements [Line Items]
Expected volatility rate		48.00%
Tolling \| Option model \| Gas prices \| Weighted Average
Quantitative Information About Level 3 Measurements [Line Items]
Expected volatility rate		20.00%

Fair Value Inputs, Power Units

No definition available.

Name:	eix_FairValueInputsPowerUnits
Namespace Prefix:	eix_
Data Type:	num:powerItemType
Balance Type:	na
Period Type:	duration

- Definition

Fair Value Inputs, Price Level

+ References

No definition available.

+ Details

Name:	eix_FairValueInputsPriceLevel
Namespace Prefix:	eix_
Data Type:	us-types:perUnitItemType
Balance Type:	na
Period Type:	duration

- Definition

Fair value portion of probable future economic benefits obtained or controlled by an entity as a result of past transactions or events.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=66048111&loc=d3e19207-110258

+ Details

Name:	us-gaap_AssetsFairValueDisclosure
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

Name:	us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Measure of dispersion, in percentage terms (for instance, the standard deviation or variance), for a given stock price.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (bbb)
-URI http://asc.fasb.org/extlink&oid=66048111&loc=d3e19207-110258

+ Details

Name:	us-gaap_FairValueAssumptionsExpectedVolatilityRate
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Fair value of financial and nonfinancial obligations.

+ References

+ Details

Name:	us-gaap_LiabilitiesFairValueDisclosure
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Details

Name:	dei_LegalEntityAxis=eix_SouthernCaliforniaEdisonCompanyMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel3Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DerivativeInstrumentRiskAxis=eix_CongestionRevenueRightsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_ValuationTechniqueAxis=us-gaap_MarketApproachValuationTechniqueMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	eix_UnobservableInputAxis=eix_LoadForecastMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RangeAxis=us-gaap_MinimumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RangeAxis=us-gaap_MaximumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	eix_UnobservableInputAxis=eix_PowerPricesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	eix_UnobservableInputAxis=eix_GasPricesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DerivativeInstrumentRiskAxis=eix_TollingMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_ValuationTechniqueAxis=eix_OptionModelMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RangeAxis=us-gaap_WeightedAverageMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: