REVENUES - DISAGGREGATION OF REVENUE (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	$ 2,383	$ 2,618	$ 7,506	$ 7,058
Utilities regulatory revenues	267	(195)	34	(131)
Other revenues	108	142	346	349
Total revenues	2,758	2,565	7,886	7,276
Utilities service line [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	2,131	2,297	6,774	6,243
Midstream service line [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	167	205	497	550
Renewables service line [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	34	46	88	123
Other service line [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	51	70	147	142
Gas market [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	1,029	1,020	4,112	3,464
Electric market [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	1,354	1,598	3,394	3,594
Operating Segments [Member] | San Diego Gas and Electric Company [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	1,370	1,577	3,604	3,707
Utilities regulatory revenues	57	(278)	62	(302)
Other revenues	0	0	0	0
Total revenues	1,427	1,299	3,666	3,405
Operating Segments [Member] | San Diego Gas and Electric Company [Member] | Utilities service line [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	1,370	1,577	3,604	3,707
Operating Segments [Member] | San Diego Gas and Electric Company [Member] | Midstream service line [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	0	0	0	0
Operating Segments [Member] | San Diego Gas and Electric Company [Member] | Renewables service line [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	0	0	0	0
Operating Segments [Member] | San Diego Gas and Electric Company [Member] | Other service line [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	0	0	0	0
Operating Segments [Member] | San Diego Gas and Electric Company [Member] | Gas market [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	100	91	441	372
Operating Segments [Member] | San Diego Gas and Electric Company [Member] | Electric market [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	1,270	1,486	3,163	3,335
Operating Segments [Member] | Southern California Gas Company [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	765	719	3,170	2,529
Utilities regulatory revenues	210	83	(28)	171
Other revenues	0	0	0	0
Total revenues	975	802	3,142	2,700
Operating Segments [Member] | Southern California Gas Company [Member] | Utilities service line [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	765	719	3,170	2,529
Operating Segments [Member] | Southern California Gas Company [Member] | Midstream service line [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	0	0	0	0
Operating Segments [Member] | Southern California Gas Company [Member] | Renewables service line [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	0	0	0	0
Operating Segments [Member] | Southern California Gas Company [Member] | Other service line [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	0	0	0	0
Operating Segments [Member] | Southern California Gas Company [Member] | Gas market [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	765	719	3,170	2,529
Operating Segments [Member] | Southern California Gas Company [Member] | Electric market [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	0	0	0	0
Operating Segments [Member] | Sempra Mexico [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	256	314	757	769
Utilities regulatory revenues	0	0	0	0
Other revenues	101	96	301	259
Total revenues	357	410	1,058	1,028
Operating Segments [Member] | Sempra Mexico [Member] | Utilities service line [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	14	17	56	58
Operating Segments [Member] | Sempra Mexico [Member] | Midstream service line [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	158	194	472	484
Operating Segments [Member] | Sempra Mexico [Member] | Renewables service line [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	32	32	82	85
Operating Segments [Member] | Sempra Mexico [Member] | Other service line [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	52	71	147	142
Operating Segments [Member] | Sempra Mexico [Member] | Gas market [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	171	214	527	545
Operating Segments [Member] | Sempra Mexico [Member] | Electric market [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	85	100	230	224
Operating Segments [Member] | Sempra Renewables [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	0	14	5	37
Utilities regulatory revenues	0	0	0	0
Other revenues	0	24	5	66
Total revenues	0	38	10	103
Operating Segments [Member] | Sempra Renewables [Member] | Utilities service line [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	0	0	0	0
Operating Segments [Member] | Sempra Renewables [Member] | Midstream service line [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	0	0	0	0
Operating Segments [Member] | Sempra Renewables [Member] | Renewables service line [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	0	14	5	37
Operating Segments [Member] | Sempra Renewables [Member] | Other service line [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	0	0	0	0
Operating Segments [Member] | Sempra Renewables [Member] | Gas market [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	0	0	0	0
Operating Segments [Member] | Sempra Renewables [Member] | Electric market [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	0	14	5	37
Operating Segments [Member] | Sempra LNG [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	50	84	139	178
Utilities regulatory revenues	0	0	0	0
Other revenues	50	63	188	152
Total revenues	100	147	327	330
Operating Segments [Member] | Sempra LNG [Member] | Utilities service line [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	0	0	0	0
Operating Segments [Member] | Sempra LNG [Member] | Midstream service line [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	48	82	134	171
Operating Segments [Member] | Sempra LNG [Member] | Renewables service line [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	0	1	0	2
Operating Segments [Member] | Sempra LNG [Member] | Other service line [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	2	1	5	5
Operating Segments [Member] | Sempra LNG [Member] | Gas market [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	48	82	134	171
Operating Segments [Member] | Sempra LNG [Member] | Electric market [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	2	2	5	7
Consolidation, Eliminations [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	(58)	(90)	(169)	(162)
Utilities regulatory revenues	0	0	0	0
Other revenues	(43)	(41)	(148)	(128)
Total revenues	(101)	(131)	(317)	(290)
Consolidation, Eliminations [Member] | Utilities service line [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	(18)	(16)	(56)	(51)
Consolidation, Eliminations [Member] | Midstream service line [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	(39)	(71)	(109)	(105)
Consolidation, Eliminations [Member] | Renewables service line [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	2	(1)	1	(1)
Consolidation, Eliminations [Member] | Other service line [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	(3)	(2)	(5)	(5)
Consolidation, Eliminations [Member] | Gas market [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	(55)	(86)	(160)	(153)
Consolidation, Eliminations [Member] | Electric market [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	$ (3)	$ (4)	$ (9)	$ (9)