SAN ONOFRE NUCLEAR GENERATING STATION - NARRATIVE (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2020	Dec. 31, 2019
Jointly Owned Utility Plant Interests [Line Items]
Regulatory asset, current	$ 190	$ 222
Regulatory asset, noncurrent	1,822	1,930
San Diego Gas and Electric Company [Member]
Jointly Owned Utility Plant Interests [Line Items]
Regulatory asset, current	174	209
Regulatory asset, noncurrent	$ 534	$ 440
Period of environmental exit	10 years
Percentage of environmental exit costs incurred	20.00%
San Diego Gas and Electric Company [Member] \| Nuclear Plant Closure [Member]
Jointly Owned Utility Plant Interests [Line Items]
Receivable for nuclear plant closure	$ 49
Regulatory asset, current	37
Regulatory asset, noncurrent	$ 12
San Diego Gas and Electric Company [Member] \| San Onofre Nuclear Generating Station (SONGS) [Member]
Jointly Owned Utility Plant Interests [Line Items]
Ownership percentage	20.00%
SONGS 2 and 3 Decommissioning [Member] \| San Diego Gas and Electric Company [Member]
Jointly Owned Utility Plant Interests [Line Items]
Nuclear decommissioning trust authorized withdrawal amount	$ 89

Authorized Recovery Amount, Nuclear Decommissioning Trust Funding.

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- Definition

Environmental Exit Costs, Anticipated Cost, Percentage

+ References

No definition available.

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Environmental Exit Costs, Anticipated Term

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- Definition

Regulatory Asset, Nuclear Plant Closure.

+ References

No definition available.

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

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-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=115995737&loc=d3e659983-123033

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- Definition

Carrying amount as of the balance sheet date of capitalized costs of regulated entities that are expected to be recovered through revenue sources within one year or the normal operating cycle, if longer. Such costs are capitalized if they meet both of the following criteria: a. It is probable that future revenue in an amount at least equal to the capitalized cost will result from inclusion of that cost in allowable costs for rate-making purposes. b. Based on available evidence, the future revenue will be provided to permit recovery of the previously incurred cost rather than to provide for expected levels of similar future costs. If the revenue will be provided through an automatic rate-adjustment clause, this criterion requires that the regulator's intent clearly be to permit recovery of the previously incurred cost.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 980
-SubTopic 340
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6499975&loc=d3e44250-110382

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Carrying amount as of the balance sheet date of capitalized costs of regulated entities that are not expected to be recovered through revenue sources within one year or the normal operating cycle if longer.

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