COMMITMENTS AND CONTINGENCIES - LONG-TERM PURCHASE COMMITMENT (Details) - USD ($) $ in Millions		1 Months Ended		12 Months Ended
	Mar. 13, 2017	May 31, 2017	May 31, 2016	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Long-term Purchase Commitment [Line Items]
Litigation settlement payable	$ 118
Sempra LNG & Midstream [Member]
Long-term Purchase Commitment [Line Items]
Loss on release of pipeline capacity			$ 206
Litigation settlement payable		$ 57	47
San Diego Gas and Electric Company [Member]
Long-term Purchase Commitment [Line Items]
Litigation settlement payable	$ 24
Sempra LNG & Midstream [Member]
Long-term Purchase Commitment [Line Items]
Loss on release of pipeline capacity net of tax			$ 123
Natural Gas Contracts [Member]
Unrecorded Unconditional Purchase Obligation, Rolling Maturity [Abstract]
2019				$ 263
2020				173
2021				156
2022				85
2023				63
Thereafter				280
Total estimated payments				1,020
Purchases				1,345	$ 1,429	$ 1,169
Natural Gas Contracts [Member] | SoCalGas [Member]
Unrecorded Unconditional Purchase Obligation, Rolling Maturity [Abstract]
2019				126
2020				122
2021				104
2022				37
2023				24
Thereafter				49
Total estimated payments				462
Purchases				1,169	1,213	966
Natural Gas Storage and Transportation Contracts [Member]
Unrecorded Unconditional Purchase Obligation, Rolling Maturity [Abstract]
2019				230
2020				158
2021				144
2022				73
2023				50
Thereafter				262
Total estimated payments				917
Natural Gas Transportation Contracts [Member] | SoCalGas [Member]
Unrecorded Unconditional Purchase Obligation, Rolling Maturity [Abstract]
2019				114
2020				118
2021				104
2022				37
2023				23
Thereafter				49
Total estimated payments				445
Natural Gas Supply Contracts [Member]
Unrecorded Unconditional Purchase Obligation, Rolling Maturity [Abstract]
2019				33
2020				15
2021				12
2022				12
2023				13
Thereafter				18
Total estimated payments				103
Natural Gas Supply Contracts [Member] | SoCalGas [Member]
Unrecorded Unconditional Purchase Obligation, Rolling Maturity [Abstract]
2019				12
2020				4
2021				0
2022				0
2023				1
Thereafter				0
Total estimated payments				17
Liquefied Natural Gas Contracts [Member] | Sempra LNG & Midstream [Member]
Unrecorded Unconditional Purchase Obligation, Rolling Maturity [Abstract]
2019				289
2020				372
2021				368
2022				373
2023				385
Thereafter				2,475
Total estimated payments				$ 4,262
Long-term Contracts [Member] | San Diego Gas and Electric Company [Member]
Unrecorded Unconditional Purchase Obligation, Rolling Maturity [Abstract]
Purchase commitment component percentage				37.00%
Renewable Energy Contracts Expiring Through 2041 [Member] | San Diego Gas and Electric Company [Member]
Unrecorded Unconditional Purchase Obligation, Rolling Maturity [Abstract]
Purchase commitment component percentage				36.00%
Other Owned Generation [Member] | San Diego Gas and Electric Company [Member]
Unrecorded Unconditional Purchase Obligation, Rolling Maturity [Abstract]
Purchase commitment component percentage				55.00%
Spot Market Purchases [Member] | San Diego Gas and Electric Company [Member]
Unrecorded Unconditional Purchase Obligation, Rolling Maturity [Abstract]
Purchase commitment component percentage				8.00%
Purchased Power Contracts [Member]
Unrecorded Unconditional Purchase Obligation, Rolling Maturity [Abstract]
2019				$ 654
2020				629
2021				631
2022				592
2023				549
Thereafter				5,185
Total estimated payments				8,240
Purchases				1,582	1,694	1,667
Purchased Power Contracts [Member] | SDG&E [Member]
Unrecorded Unconditional Purchase Obligation, Rolling Maturity [Abstract]
2019				527
2020				510
2021				510
2022				496
2023				451
Thereafter				5,026
Total estimated payments				7,520
Purchases				712	$ 781	$ 752
Renewable Energy PPAs [Member] | SDG&E [Member]
Unrecorded Unconditional Purchase Obligation, Rolling Maturity [Abstract]
Total estimated payments				$ 5,200