COMMITMENTS AND CONTINGENCIES - CONTRACTUAL COMMITMENTS (Details) $ in Millions	9 Months Ended
Sep. 30, 2018 USD ($)
Sempra LNG & Midstream [Member] \| Liquefied Natural Gas Contracts [Member]
Unrecorded Unconditional Purchase Obligation [Line Items]
Increase (decrease) in commitment amount, 2018	$ (288)
Increase (decrease) in commitment amount, 2019	23
Increase (decrease) in commitment amount, 2020	(22)
Increase (decrease) in commitment amount, 2021	(41)
Increase (decrease) in commitment amount, 2022	(56)
Increase (decrease) in commitment amount, thereafter	(230)
Operating Lease [Member] \| Southern California Gas Company [Member] \| Interstate Pipeline Agreements [Member]
Unrecorded Unconditional Purchase Obligation [Line Items]
Increase (decrease) in commitment amount	158
Increase (decrease) in commitment amount, 2018	(79)
Increase (decrease) in commitment amount, 2019	57
Increase (decrease) in commitment amount, 2020	89
Increase (decrease) in commitment amount, 2021	79
Increase (decrease) in commitment amount, 2022	12
Operating Lease [Member] \| Sempra LNG & Midstream [Member] \| Natural Gas Contracts [Member]
Unrecorded Unconditional Purchase Obligation [Line Items]
Increase (decrease) in commitment amount	(61)
Increase (decrease) in commitment amount, 2018	(147)
Increase (decrease) in commitment amount, 2019	33
Increase (decrease) in commitment amount, 2020	10
Increase (decrease) in commitment amount, 2021	6
Increase (decrease) in commitment amount, 2022	4
Increase (decrease) in commitment amount, thereafter	33
Marine Terminal in the Port of Topolobampo in Sinaloa [Member] \| Sempra Mexico [Member]
Unrecorded Unconditional Purchase Obligation [Line Items]
Increase (decrease) in commitment amount	110
Increase (decrease) in commitment amount, 2018	19
Increase (decrease) in commitment amount, 2019	2
Increase (decrease) in commitment amount, 2020	2
Increase (decrease) in commitment amount, 2021	3
Increase (decrease) in commitment amount, 2022	3
Increase (decrease) in commitment amount, thereafter	81
Liquid Fuels Terminals and Renewables Projects [Member] \| Sempra Mexico [Member]
Unrecorded Unconditional Purchase Obligation [Line Items]
Increase (decrease) in commitment amount	90
Increase (decrease) in commitment amount, 2018	54
Increase (decrease) in commitment amount, 2019	34
Increase (decrease) in commitment amount, thereafter	$ 2

Increase (Decrease) in Unrecorded Unconditional Purchase Obligation

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Increase (Decrease) in Unrecorded Unconditional Purchase Obligation, After Five Years

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Increase (Decrease) in Unrecorded Unconditional Purchase Obligation, Remainder of Fiscal Year

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Increase (Decrease) in Unrecorded Unconditional Purchase Obligation, Year Five

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Increase (Decrease) in Unrecorded Unconditional Purchase Obligation, Year Four

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Increase (Decrease) in Unrecorded Unconditional Purchase Obligation, Year Three

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Increase (Decrease) in Unrecorded Unconditional Purchase Obligation, Year Two

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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.

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