REVENUES - DISAGGREGATION OF REVENUE (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	$ 2,124	$ 2,080	$ 5,131	$ 5,123
Utilities regulatory revenues	291	25	152	(233)
Other revenues	111	125	272	238
Total revenues	2,526	2,230	5,555	5,128
Utilities service line [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	1,942	1,870	4,746	4,643
Energy-Related Businesses [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	182	210	385	480
Gas market [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	1,161	1,127	3,094	3,083
Electric market [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	963	953	2,037	2,040
Operating Segments [Member] | San Diego Gas and Electric Company [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	1,050	998	2,309	2,234
Utilities regulatory revenues	185	96	195	5
Other revenues	0	0	0	0
Total revenues	1,235	1,094	2,504	2,239
Operating Segments [Member] | San Diego Gas and Electric Company [Member] | Utilities service line [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	1,050	998	2,309	2,234
Operating Segments [Member] | San Diego Gas and Electric Company [Member] | Energy-Related Businesses [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	138	102	392	341
Operating Segments [Member] | San Diego Gas and Electric Company [Member] | Electric market [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	912	896	1,917	1,893
Operating Segments [Member] | Southern California Gas Company [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	904	877	2,448	2,405
Utilities regulatory revenues	106	(71)	(43)	(238)
Other revenues	0	0	0	0
Total revenues	1,010	806	2,405	2,167
Operating Segments [Member] | Southern California Gas Company [Member] | Utilities service line [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	904	877	2,448	2,405
Operating Segments [Member] | Southern California Gas Company [Member] | Energy-Related Businesses [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	904	877	2,448	2,405
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	184	217	402	501
Utilities regulatory revenues	0	0	0	0
Other revenues	91	101	182	200
Total revenues	275	318	584	701
Operating Segments [Member] | Sempra Mexico [Member] | Utilities service line [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	10	15	30	42
Operating Segments [Member] | Sempra Mexico [Member] | Energy-Related Businesses [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	174	202	372	459
Operating Segments [Member] | Sempra Mexico [Member] | Gas market [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	133	158	280	356
Operating Segments [Member] | Sempra Mexico [Member] | Electric market [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	51	59	122	145
Operating Segments [Member] | Sempra Renewables [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers		1		5
Utilities regulatory revenues		0		0
Other revenues		2		5
Total revenues		3		10
Operating Segments [Member] | Sempra Renewables [Member] | Utilities service line [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers		0		0
Operating Segments [Member] | Sempra Renewables [Member] | Energy-Related Businesses [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers		1		5
Operating Segments [Member] | Sempra Renewables [Member] | Gas market [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers		0		0
Operating Segments [Member] | Sempra Renewables [Member] | Electric market [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers		1		5
Operating Segments [Member] | Sempra LNG [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	9	21	21	89
Utilities regulatory revenues	0	0	0	0
Other revenues	60	65	171	138
Total revenues	69	86	192	227
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] | Energy-Related Businesses [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	9	21	21	89
Operating Segments [Member] | Sempra LNG [Member] | Gas market [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	7	19	18	86
Operating Segments [Member] | Sempra LNG [Member] | Electric market [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	2	2	3	3
Consolidation, Eliminations [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	(23)	(34)	(49)	(111)
Utilities regulatory revenues	0	0	0	0
Other revenues	(40)	(43)	(81)	(105)
Total revenues	(63)	(77)	(130)	(216)
Consolidation, Eliminations [Member] | Utilities service line [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	(22)	(20)	(41)	(38)
Consolidation, Eliminations [Member] | Energy-Related Businesses [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	(1)	(14)	(8)	(73)
Consolidation, Eliminations [Member] | Gas market [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	(21)	(29)	(44)	(105)
Consolidation, Eliminations [Member] | Electric market [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	$ (2)	$ (5)	$ (5)	$ (6)