This element represents additional power generating capacity of turbines to be deployed in the future under settlement agreement.

Name:	eix_AdditionalPowerGeneratingCapacityOfTurbinesToBeDeployedInFuture
Namespace Prefix:	eix
Data Type:	us-types:powerItemType
Balance Type:	na
Period Type:	duration

- Definition

This element represents the additional wind turbines to be deployed in the future under settlement agreement.

+ Details

Name:	eix_AdditionalWindTurbinesToBeDeployedInFuture
Namespace Prefix:	eix
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	eix_CapitalExpendituresAbstract
Namespace Prefix:	eix
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents the commitments to purchase turbines due in remainder of year.

+ Details

Name:	eix_CommitmentsToPurchaseTurbines
Namespace Prefix:	eix
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Represents the commitments to purchase turbines due in the second year after the balance sheet date.

+ Details

Name:	eix_CommitmentsToPurchaseTurbinesInYearTwo
Namespace Prefix:	eix
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

The amount of the charge on termination of a contract for default.

+ Details

Name:	eix_ContractTerminationChargesForDefault
Namespace Prefix:	eix
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Details

Name:	eix_GuaranteesAndIndemnitiesAbstract
Namespace Prefix:	eix
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

The aggregate estimated amount the entity contracted to spend under the long-term purchase commitment following the balance sheet date.

+ Details

Name:	eix_LongTermPurchaseCommitmentAggregateAmount
Namespace Prefix:	eix
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

The estimated amount the entity contracted to spend under the long-term purchase commitment during the remainder of the current fiscal year.

+ Details

Name:	eix_LongTermPurchaseCommitmentAmountRemainderOfFiscalYear
Namespace Prefix:	eix
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

The estimated amount the entity contracted to spend under the long-term purchase commitment during the (a) second full fiscal year following the completion of the current fiscal year if the balance sheet date is for an interim period end or (b) the third full fiscal year if the balance sheet date is for the fiscal year end.

+ Details

Name:	eix_LongTermPurchaseCommitmentAmountYearThree
Namespace Prefix:	eix
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

The estimated amount the entity contracted to spend under the long-term purchase commitment during the (a) first full fiscal year following the completion of the current fiscal year if the balance sheet date is for an interim period end or (b) the second full fiscal year if the balance sheet date is for the fiscal year end.

+ Details

Name:	eix_LongTermPurchaseCommitmentAmountYearTwo
Namespace Prefix:	eix
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

The maximum aggregate potential liability under the purchase agreement for damages and other amounts in connection with environmental liabilities.

+ Details

Name:	eix_MaximumLiabilityPerPurchaseAgreementForDamages
Namespace Prefix:	eix
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Details

Name:	eix_OtherCommitmentsAbstract
Namespace Prefix:	eix
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

The percentage of asbestos claims and related expenses for which the entity is responsible under the terms of the reimbursement agreement.

+ Details

Name:	eix_PercentageReimbursementObligationForAsbestosClaims
Namespace Prefix:	eix
Data Type:	us-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

The period of time after which the entity may be obligated to make an additional payment if it has not elected to deploy the additional turbines and if certain other criteria apply.

+ Details

Name:	eix_PeriodAfterWhichPaymentMayBeDue
Namespace Prefix:	eix
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

This element represents a possible payment obligation to be made following the end of a future period from the date of settlement agreement, if the entity has not elected to deploy the additional turbines.

+ Details

Name:	eix_PossiblePaymentObligationToBeMadeInFuturePeriod
Namespace Prefix:	eix
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

The estimated amount the entity contracted to spend under long-term purchase commitments which were entered into subsequent to the balance sheet date for the fourth full succeeding fiscal year.

+ Details

Name:	eix_SubsequentLongTermPurchaseCommitmentAmountYearFour
Namespace Prefix:	eix
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

The disclosure pertaining to asbestos supplemental agreement term.

+ Details

Name:	eix_TermOfAsbestosSupplementalAgreement
Namespace Prefix:	eix
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	eix_ThirdPartyPowerPurchaseAgreementsAbstract
Namespace Prefix:	eix
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	eix_TurbineCommitmentsAbstract
Namespace Prefix:	eix
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

The amount of payment commitments related to wind turbines due in the remainder of the fiscal year.

+ Details

Name:	eix_WindTurbinePaymentCommitmentsDueInRemainderOfFiscalYear
Namespace Prefix:	eix
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The amount of payment commitments related to wind turbines due in the second year after the balance sheet date.

+ Details

Name:	eix_WindTurbinePaymentCommitmentsDueInSecondYear
Namespace Prefix:	eix
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The amount of payment commitments related to wind turbines due in the third year after the balance sheet date.

+ Details

Name:	eix_WindTurbinePaymentCommitmentsDueInThirdYear
Namespace Prefix:	eix
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The carrying amount as of the balance sheet date of the combined total of loss contingency reserves.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 5
-Paragraph 9, 10, 11, 12

+ Details

Name:	us-gaap_LossContingencyAccrualAtCarryingValue
Namespace Prefix:	us-gaap
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The total amount of pending claims pertaining to a loss contingency accrual as of the balance sheet date.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 5
-Paragraph 9, 10, 11, 12

+ Details

Name:	us-gaap_LossContingencyPendingClaimsNumber
Namespace Prefix:	us-gaap
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

For leases having an initial or remaining non-cancelable letter-terms in excess of one year, required rental payments due within one year of the balance sheet date relating to leases defined as operating.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 13
-Paragraph 122

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 13
-Paragraph 16
-Subparagraph b(i)

+ Details

Name:	us-gaap_OperatingLeasesFutureMinimumPaymentsDueCurrent
Namespace Prefix:	us-gaap
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

For leases having an initial or remaining non-cancelable letter-terms in excess of one year, required rental payments due within the fifth year of the balance sheet date relating to leases defined as operating.

+ References

+ Details

Name:	us-gaap_OperatingLeasesFutureMinimumPaymentsDueInFiveYears
Namespace Prefix:	us-gaap
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

For leases having an initial or remaining non-cancelable letter-terms in excess of one year, required rental payments due within the fourth year of the balance sheet date relating to leases defined as operating.

+ References

+ Details

Name:	us-gaap_OperatingLeasesFutureMinimumPaymentsDueInFourYears
Namespace Prefix:	us-gaap
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

For leases having an initial or remaining non-cancelable letter-terms in excess of one year, required rental payments due within the third year of the balance sheet date relating to leases defined as operating.

+ References

+ Details

Name:	us-gaap_OperatingLeasesFutureMinimumPaymentsDueInThreeYears
Namespace Prefix:	us-gaap
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

For leases having an initial or remaining non-cancelable letter-terms in excess of one year, required rental payments due within the second year of the balance sheet date relating to leases defined as operating.

+ References

+ Details

Name:	us-gaap_OperatingLeasesFutureMinimumPaymentsDueInTwoYears
Namespace Prefix:	us-gaap
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

For leases having an initial or remaining non-cancelable letter-terms in excess of one year, required rental payments due after the fifth year from the balance sheet date on leases defined as operating.

+ References

+ Details

Name:	us-gaap_OperatingLeasesFutureMinimumPaymentsDueThereafter
Namespace Prefix:	us-gaap
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Commitments and Contingencies (Details) (USD $)			6 Months Ended	1 Months Ended			6 Months Ended	1 Months Ended
Commitments and Contingencies (Details) (USD $)	Jun. 30, 2011 Southern California Edison Company Environmental Indemnities	Jun. 30, 2011 Southern California Edison Company Operating Leases - Purchase Power Contracts	Jun. 30, 2011 Edison Mission Group Inc. Turbine commitments	Oct. 31, 2010 Edison Mission Group Inc. Mitsubishi Power Systems Americans, Inc. and Mitsubishi Heavy Industries, Ltd. mW	Jun. 30, 2011 Edison Mission Group Inc. Capital Expenditures	Jun. 30, 2011 Edison Mission Energy Indemnities under International Asset Sale Agreements	Jun. 30, 2011 Midwest Generation and EME Homer City Generation L.P. (Homer City) Purchase of fuel and transportation of gas and coal	Jul. 31, 2011 Midwest Generation LLC. Purchase of fuel and transportation of gas and coal	Feb. 28, 2003 Midwest Generation LLC. Environmental Indemnities under Acquisition Agreement	Jun. 30, 2011 Midwest Generation LLC. Environmental Indemnities under Acquisition Agreement
Third-Party Power Purchase Agreements
Estimated additional commitments in 2011		$ 6,000,000
Estimated additional commitments in 2012		116,000,000
Estimated additional commitments in 2013		116,000,000
Estimated additional commitments in 2014		116,000,000
Estimated additional commitments in 2015		116,000,000
Estimated additional commitments for the period remaining thereafter		1,900,000,000
Other Commitments
Purchase commitments, remainder of 2011							277,000,000	6,000,000
Purchase commitments, 2012							304,000,000	28,000,000
Purchase commitments, 2013							53,000,000	145,000,000
Purchase commitments, 2014								150,000,000
Purchase commitments, aggregate							634,000,000
Turbine Commitments
Commitments to purchase turbines in 2011			45,000,000
Commitments to purchase turbines in 2012			8,000,000
Charges for default of termination of turbine commitments			29,000,000
Additional wind turbines to be deployed in future				60
Additional power generating capacity of turbines to be deployed in future (in megawatts)				144
Payment obligation to be made following the end of three year period from date of settlement agreement				30,000,000
Period after which payment may be due (in years)				3
Capital Expenditures
Wind turbine payment commitments in remainder of 2011					242,000,000
Wind turbine payment commitments in 2012					205,000,000
Wind turbine payment commitments in 2013					19,000,000
Guarantees and Indemnities
Percentage reimbursement obligation for asbestos claims (as a percent)									50.00%
Term of asbestos supplemental agreement									The supplemental agreement had an initial five-year term with an automatic renewal provision for subsequent one-year terms (subject to the right of either party to terminate); pursuant to the automatic renewal provision, it has been extended until February 2012.
Number of cases not settled and dismissed creating potential liability										222
Liability under indemnities						45,000,000				55,000,000
Maximum liability under indemnity per Mountainview purchase agreement for damages and other amounts	$ 60,000,000