Property, Plant and Equipment (Jointly Owned Utility Projects) (Details) - SCE - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Jointly Owned Utility Plant Interests [Line Items]
Nuclear Fuel (at amortized cost)	$ 126	$ 126
Eldorado
Jointly Owned Utility Plant Interests [Line Items]
Plant in Service	237
Construction Work in Progress	14
Accumulated Depreciation	24
Nuclear Fuel (at amortized cost)	0
Net Book Value	$ 227
Ownership Interest (percent)	59.00%
Pacific Intertie
Jointly Owned Utility Plant Interests [Line Items]
Plant in Service	$ 192
Construction Work in Progress	41
Accumulated Depreciation	78
Nuclear Fuel (at amortized cost)	0
Net Book Value	$ 155
Ownership Interest (percent)	50.00%
Palo Verde (nuclear)
Jointly Owned Utility Plant Interests [Line Items]
Plant in Service	$ 2,001
Construction Work in Progress	52
Accumulated Depreciation	1,557
Nuclear Fuel (at amortized cost)	126
Net Book Value	$ 622
Ownership Interest (percent)	16.00%
Total
Jointly Owned Utility Plant Interests [Line Items]
Plant in Service	$ 2,430
Construction Work in Progress	107
Accumulated Depreciation	1,659
Nuclear Fuel (at amortized cost)	126
Net Book Value	$ 1,004

The period end amount owned by the reporting utility of a jointly owned utility plant in service.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 980
-SubTopic 360
-Section S99
-Paragraph 1
-Subparagraph (SAB Topic 10.C)
-URI http://asc.fasb.org/extlink&oid=6500719&loc=d3e659983-123033

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- 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.

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- Definition

The total period end amount of plant in service and construction in progress net of accumulated depreciation for the utility's share of jointly owned electricity generation plant.

+ References

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- Definition

The period end amount of construction work in progress at a jointly owned electricity generation plant.

+ References

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- Definition

The period end amount of accumulated depreciation in a jointly owned electricity generation plant.

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- Definition

The proportionate share of interest (percent) in a jointly owned utility plant.

+ References

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- Definition

The carrying amount as of the balance sheet of nuclear fuel held as property plant and equipment. This amount is net of amortization based on the energy produced over the life of the fuel.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.13(b))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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