Fair Value Measurements (Quantitative Information About Level 3 Fair Value Measurements) (Details) - SCE - Level 3 - Congestion revenue rights - Auction prices $ in Millions	Dec. 31, 2019 USD ($) $ / MWh	Dec. 31, 2018 USD ($) $ / MWh
Quantitative Information About Level 3 Measurements [Line Items]
Fair Value, Assets \| $	$ 83	$ 141
Fair Value, Liabilities \| $	$ 5	$ 0
CAISO CRR auction clearing prices \| Minimum
Quantitative Information About Level 3 Measurements [Line Items]
Derivative Asset (Liability) Net, Measurement Input	(3.59)	(7.41)
CAISO CRR auction clearing prices \| Maximum
Quantitative Information About Level 3 Measurements [Line Items]
Derivative Asset (Liability) Net, Measurement Input	25.32	41.52
CAISO CRR auction clearing prices \| Weighted Average
Quantitative Information About Level 3 Measurements [Line Items]
Derivative Asset (Liability) Net, Measurement Input	1.97	1.62

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

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=117815213&loc=d3e19207-110258

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- Definition

Value of input used to measure net derivative asset (liability).

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (bbb)(2)
-URI http://asc.fasb.org/extlink&oid=117815213&loc=d3e19207-110258

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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.

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- Definition

Fair value of financial and nonfinancial obligations.

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