REVENUES - DISAGGREGATION OF REVENUE (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	$ 2,470	$ 2,124	$ 5,611	$ 5,131
Utilities regulatory revenues	210	291	182	152
Other revenues	61	111	207	272
Total revenues	2,741	2,526	6,000	5,555
Utilities service line [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	2,224	1,942	5,097	4,746
Energy-Related Businesses [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	246	182	514	385
Gas market [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	1,385	1,161	3,503	3,094
Electric market [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	1,085	963	2,108	2,037
Operating Segments [Member] | San Diego Gas and Electric Company [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	1,170	1,050	2,386	2,309
Utilities regulatory revenues	148	185	269	195
Other revenues	0	0	0	0
Total revenues	1,318	1,235	2,655	2,504
Operating Segments [Member] | San Diego Gas and Electric Company [Member] | Utilities service line [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	1,170	1,050	2,386	2,309
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	162	138	435	392
Operating Segments [Member] | San Diego Gas and Electric Company [Member] | Electric market [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	1,008	912	1,951	1,917
Operating Segments [Member] | Southern California Gas Company [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	1,062	904	2,719	2,448
Utilities regulatory revenues	62	106	(87)	(43)
Other revenues	0	0	0	0
Total revenues	1,124	1,010	2,632	2,405
Operating Segments [Member] | Southern California Gas Company [Member] | Utilities service line [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	1,062	904	2,719	2,448
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	1,062	904	2,719	2,448
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	271	184	579	402
Utilities regulatory revenues	0	0	0	0
Other revenues	133	91	192	182
Total revenues	404	275	771	584
Operating Segments [Member] | Sempra Mexico [Member] | Utilities service line [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	17	10	44	30
Operating Segments [Member] | Sempra Mexico [Member] | Energy-Related Businesses [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	254	174	535	372
Operating Segments [Member] | Sempra Mexico [Member] | Gas market [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	180	133	404	280
Operating Segments [Member] | Sempra Mexico [Member] | Electric market [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	91	51	175	122
Operating Segments [Member] | Sempra LNG [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	48	9	116	21
Utilities regulatory revenues	0	0	0	0
Other revenues	4	60	132	171
Total revenues	52	69	248	192
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	48	9	116	21
Operating Segments [Member] | Sempra LNG [Member] | Gas market [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	47	7	114	18
Operating Segments [Member] | Sempra LNG [Member] | Electric market [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	1	2	2	3
Consolidation, Eliminations [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	(81)	(23)	(189)	(49)
Utilities regulatory revenues	0	0	0	0
Other revenues	(76)	(40)	(117)	(81)
Total revenues	(157)	(63)	(306)	(130)
Consolidation, Eliminations [Member] | Utilities service line [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	(25)	(22)	(52)	(41)
Consolidation, Eliminations [Member] | Energy-Related Businesses [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	(56)	(1)	(137)	(8)
Consolidation, Eliminations [Member] | Gas market [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	(66)	(21)	(169)	(44)
Consolidation, Eliminations [Member] | Electric market [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	$ (15)	$ (2)	$ (20)	$ (5)