XML 32 R43.htm IDEA: XBRL DOCUMENT
v2.4.0.6

Fair Value Measurements (Level 3 Rollforward) (Details) (Level 3, USD $) In Millions, unless otherwise specified | 3 Months Ended
--- | ---
Mar. 31, 2013 | Mar. 31, 2012
Level 3 |  |
Fair Value Disclosures Level 3 [Roll Forward] |  |
Fair value of net asset (liabilities) at beginning of period | $ (791) | $ (754)
Total realized/unrealized gains (losses): |  |
Included in regulatory assets and liabilities | (82) | (356)
Purchases | 18 | 21
Settlements | (27) | (8)
Fair value of net liabilities at end of period | (882) | (1,097)
Change during the period in unrealized losses related to assets and liabilities held at the end of the period | $ (66) | $ (351)

X
- Details
Name: | eix_FairValueDisclosuresLevel3RollForward
Namespace Prefix: | eix_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition This element represents total gains or losses for the period (realized and unrealized), included in regulatory assets and liabilities measured at fair value on a recurring basis using unobservable inputs (level 3). + References No definition available. + Details
Name: | eix_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetGainLossIncludedInRegulatoryAssetsAndLiabilities
Namespace Prefix: | eix_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition This element represents the change during the period in unrealized gains (losses) for financial instruments, held at the end of the period, with unobservable inputs (level 3). + References No definition available. + Details
Name: | eix_IncreaseDecreaseDuringPeriodInUnrealizedGainsLossesRelatedToLevel3FinancialInstrumentsHeldAtPeriodEnd
Namespace Prefix: | eix_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Details
Name: | eix_NetRealizedOrUnrealizedGainLossAbstract
Namespace Prefix: | eix_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Purchases that have taken place during the period in relation to assets measured at fair value and categorized within Level 3 of the fair value hierarchy. + 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 (c)(2) -URI http://asc.fasb.org/extlink&oid=7578670&loc=d3e19207-110258 + Details
Name: | us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetPurchases
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Settlements that have taken place during the period in relation to assets measured at fair value and categorized within Level 3 of the fair value hierarchy. + 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 (c)(2) -URI http://asc.fasb.org/extlink&oid=7578670&loc=d3e19207-110258 + Details
Name: | us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetSettlements
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition This element represents an asset measured at fair value using significant unobservable inputs (Level 3) which is required for reconciliation purposes of beginning and ending balances. + 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 (c) -URI http://asc.fasb.org/extlink&oid=7578670&loc=d3e19207-110258 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 157 -Paragraph 32 -Subparagraph c -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. + Details
Name: | us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetValue
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant