GENERAL INFORMATION AND OTHER FINANCIAL DATA - ASSET RETIREMENT OBLIGATIONS (Details) - USD ($) $ in Millions	1 Months Ended	6 Months Ended
Jun. 30, 2018	Jun. 30, 2018	Jun. 30, 2017
Asset Retirement Obligations, Roll Forward Analysis [Roll Forward]
Beginning balance		$ 2,877	$ 2,553
Accretion expense		60	54
Liabilities incurred		7	20
Reclassifications		(60)	0
Payments		(23)	(26)
Revisions		28	(6)
Ending balance	$ 2,889	2,889	2,595
TdM [Member]
Asset Retirement Obligations, Roll Forward Analysis [Roll Forward]
Reclassifications	5
San Diego Gas and Electric Company [Member]
Asset Retirement Obligations, Roll Forward Analysis [Roll Forward]
Beginning balance		839	830
Accretion expense		19	19
Liabilities incurred		0	17
Reclassifications		0	0
Payments		(21)	(25)
Revisions		29	0
Ending balance	866	866	841
Southern California Gas Company [Member]
Asset Retirement Obligations, Roll Forward Analysis [Roll Forward]
Beginning balance		1,953	1,659
Accretion expense		38	33
Liabilities incurred		0	0
Reclassifications		0	0
Payments		(2)	(1)
Revisions		(1)	(6)
Ending balance	1,988	$ 1,988	$ 1,685
Sempra Renewables [Member]
Asset Retirement Obligations, Roll Forward Analysis [Roll Forward]
Reclassifications	(57)
Sempra LNG & Midstream [Member]
Asset Retirement Obligations, Roll Forward Analysis [Roll Forward]
Reclassifications	$ 8

Asset retirement obligations, reclassification.

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- Definition

The carrying amount of a liability for an asset retirement obligation. An asset retirement obligation is a legal obligation associated with the disposal or retirement of a tangible long-lived asset that results from the acquisition, construction or development, or the normal operations of a long-lived asset, except for certain obligations of lessees.

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- Definition

Amount of accretion expense recognized during the period that is associated with an asset retirement obligation. Accretion expense measures and incorporates changes due to the passage of time into the carrying amount of the liability.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 410
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (c)(3)
-URI http://asc.fasb.org/extlink&oid=6392692&loc=d3e7535-110849

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 410
-SubTopic 20
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6392676&loc=d3e7480-110848

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Amount of asset retirement obligations incurred during the period.

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Amount of asset retirement obligations settled, or otherwise disposed of, during the period. This may include asset retirement obligations transferred to third parties associated with the sale of a long-lived asset.

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Amount of increase (decrease) in the asset retirement obligation from changes in the amount or timing of the estimated cash flows associated with the settlement of the obligation.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 410
-SubTopic 20
-Section 35
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=6392603&loc=d3e7123-110846

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-Publisher FASB
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-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (c)(4)
-URI http://asc.fasb.org/extlink&oid=6392692&loc=d3e7535-110849

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A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

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