XML 133 R106.htm IDEA: XBRL DOCUMENT
v2.4.0.6

Other Investments (Summary of Changes in Fair Value of the Nuclear Decommissioning Trusts) (Details) (USD $) In Millions, unless otherwise specified | 12 Months Ended
--- | ---
Dec. 31, 2012 | Dec. 31, 2011 | Dec. 31, 2010
Summary Of Changes In The Fair Value [Roll Forward] |  |  |
Balance at end of period | $ 4,048 | $ 3,592 |
Southern California Edison |  |  |
Summary Of Changes In The Fair Value [Roll Forward] |  |  |
Balance at beginning of period | 3,592 | 3,480 | 3,140
Gross realized gains | 73 | 108 | 125
Gross realized losses | (5) | (17) | (4)
Unrealized gains (losses), net | 276 | (7) | 148
Other-than-temporary impairments | (36) | (47) | (27)
Interest, dividends, contributions and other | 148 | 75 | 98
Balance at end of period | $ 4,048 | $ 3,592 | $ 3,480

X
- Definition Discloses the amount of interest, dividend, contribution and other receipts during the period. + References No definition available. + Details
Name: | eix_DecommissioningTrustInterestDividendsContributionsAndOther
Namespace Prefix: | eix_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Discloses the amount of other than temporary decline in value that has been recognized by the decommissioning trust during the period. + References No definition available. + Details
Name: | eix_DecommissioningTrustOtherThanTemporaryImpairments
Namespace Prefix: | eix_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition This item represents the amount of realized gain on investments in trust during the period from the sale of securities. + References No definition available. + Details
Name: | eix_DecommissioningTrustRealizedGainOnInvestments
Namespace Prefix: | eix_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition This item represents the amount of realized loss on investments in trust during the period from the sale of securities. + References No definition available. + Details
Name: | eix_DecommissioningTrustRealizedLossOnInvestments
Namespace Prefix: | eix_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition This item represents the amount of net unrealized gain on investments in trust during the period. + References No definition available. + Details
Name: | eix_DecommissioningTrustUnrealizedGainsOnInvestmentsNet
Namespace Prefix: | eix_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

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

X
- Definition The fair value of investments held in a trust fund to pay for the costs of decontaminating and decommissioning facilities, whether such amount is presented as a separate caption or as a parenthetical disclosure on the balance sheet. Additionally, this element may be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 143 -Paragraph 22 -Subparagraph b -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. Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 410 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=6392692&loc=d3e7535-110849 + Details
Name: | us-gaap_DecommissioningTrustAssetsAmount
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant