REVENUES - DISAGGREGATION OF REVENUE (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	$ 3,007	$ 3,043
Utilities regulatory revenues	(139)	(258)
Other revenues	161	113
Total revenues	3,029	2,898
Utilities service line [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	2,804	2,773
Energy-Related Businesses [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	203	270
Gas market [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	1,933	1,956
Electric market [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	1,074	1,087
Operating Segments [Member] | San Diego Gas and Electric Company [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	1,259	1,236
Utilities regulatory revenues	10	(91)
Other revenues	0	0
Total revenues	1,269	1,145
Operating Segments [Member] | San Diego Gas and Electric Company [Member] | Utilities service line [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	1,259	1,236
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
Operating Segments [Member] | San Diego Gas and Electric Company [Member] | Gas market [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	254	239
Operating Segments [Member] | San Diego Gas and Electric Company [Member] | Electric market [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	1,005	997
Operating Segments [Member] | Southern California Gas Company [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	1,544	1,528
Utilities regulatory revenues	(149)	(167)
Other revenues	0	0
Total revenues	1,395	1,361
Operating Segments [Member] | Southern California Gas Company [Member] | Utilities service line [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	1,544	1,528
Operating Segments [Member] | Southern California Gas Company [Member] | Energy-Related Businesses [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	0	0
Operating Segments [Member] | Southern California Gas Company [Member] | Gas market [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	1,544	1,528
Operating Segments [Member] | Southern California Gas Company [Member] | Electric market [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	0	0
Operating Segments [Member] | Sempra Mexico [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	218	284
Utilities regulatory revenues	0	0
Other revenues	91	99
Total revenues	309	383
Operating Segments [Member] | Sempra Mexico [Member] | Utilities service line [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	20	27
Operating Segments [Member] | Sempra Mexico [Member] | Energy-Related Businesses [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	198	257
Operating Segments [Member] | Sempra Mexico [Member] | Gas market [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	147	198
Operating Segments [Member] | Sempra Mexico [Member] | Electric market [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	71	86
Operating Segments [Member] | Sempra Renewables [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	0	4
Utilities regulatory revenues	0	0
Other revenues	0	3
Total revenues	0	7
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	0	4
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	0	4
Operating Segments [Member] | Sempra LNG [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	12	68
Utilities regulatory revenues	0	0
Other revenues	111	73
Total revenues	123	141
Operating Segments [Member] | Sempra LNG [Member] | Utilities service line [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	0	0
Operating Segments [Member] | Sempra LNG [Member] | Energy-Related Businesses [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	12	68
Operating Segments [Member] | Sempra LNG [Member] | Gas market [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	11	67
Operating Segments [Member] | Sempra LNG [Member] | Electric market [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	1	1
Consolidation, Eliminations [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	(26)	(77)
Utilities regulatory revenues	0	0
Other revenues	(41)	(62)
Total revenues	(67)	(139)
Consolidation, Eliminations [Member] | Utilities service line [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	(19)	(18)
Consolidation, Eliminations [Member] | Energy-Related Businesses [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	(7)	(59)
Consolidation, Eliminations [Member] | Gas market [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	(23)	(76)
Consolidation, Eliminations [Member] | Electric market [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	$ (3)	$ (1)