DEBT AND CREDIT FACILITIES - LINES OF CREDIT (Details)	3 Months Ended
	Mar. 31, 2021 USD ($)
Line of Credit Facility [Line Items]
Maximum borrowing capacity	$ 6,685,000,000
Capacity for issuance of letters of credit	$ 200,000,000
Maximum ratio of indebtedness to total capitalization	65.00%
Standby letters of credit outstanding	$ 521,000,000
Sempra U.S. Businesses [Member]
Line of Credit Facility [Line Items]
Maximum borrowing capacity	6,700,000,000
Available unused credit	5,640,000,000
Sempra Energy [Member]
Line of Credit Facility [Line Items]
Maximum borrowing capacity	1,250,000,000
Available unused credit	1,250,000,000
Option to request	500,000,000
Sempra Global
Line of Credit Facility [Line Items]
Maximum borrowing capacity	3,185,000,000
Available unused credit	2,270,000,000
San Diego Gas and Electric Company [Member]
Line of Credit Facility [Line Items]
Maximum borrowing capacity	1,500,000,000
Available unused credit	1,370,000,000
Capacity for issuance of letters of credit	100,000,000
Option to request	$ 250,000,000
Maximum ratio of indebtedness to total capitalization	65.00%
Southern California Gas Company [Member]
Line of Credit Facility [Line Items]
Maximum borrowing capacity	$ 750,000,000
Available unused credit	750,000,000
Capacity for issuance of letters of credit	100,000,000
Option to request	$ 250,000,000
Maximum ratio of indebtedness to total capitalization	65.00%
Commercial Paper
Line of Credit Facility [Line Items]
Amount outstanding	$ (1,045,000,000)
Commercial Paper | Sempra Energy [Member]
Line of Credit Facility [Line Items]
Amount outstanding	0
Commercial Paper | Sempra Global
Line of Credit Facility [Line Items]
Amount outstanding	(915,000,000)
Commercial Paper | San Diego Gas and Electric Company [Member]
Line of Credit Facility [Line Items]
Amount outstanding	(130,000,000)
Commercial Paper | Southern California Gas Company [Member]
Line of Credit Facility [Line Items]
Amount outstanding	0
Foreign Line of Credit [Member] | Sempra Mexico [Member]
Line of Credit Facility [Line Items]
Maximum borrowing capacity	1,780,000,000
Amount outstanding	(672,000,000)
Available unused credit	1,108,000,000
Foreign Committed Lines of Credit, Due February 2024 [Member] | Foreign Line of Credit [Member] | Sempra Mexico [Member]
Line of Credit Facility [Line Items]
Maximum borrowing capacity	1,500,000,000
Amount outstanding	(392,000,000)
Available unused credit	1,108,000,000
Foreign Committed Lines of Credit, Due September 2021 [Member] | Foreign Line of Credit [Member] | Sempra Mexico [Member]
Line of Credit Facility [Line Items]
Maximum borrowing capacity	280,000,000
Amount outstanding	(280,000,000)
Available unused credit	0
Uncommitted Revolving Credit Facility with Scotiabank Inverlat S.A. [Member] | Foreign Line of Credit [Member] | Sempra Mexico [Member]
Line of Credit Facility [Line Items]
Maximum borrowing capacity	$ 20,000,000
Term of debt instrument	3 years
Uncommitted Revolving Credit Facility with Bank of Nova Scotia [Member] | Foreign Line of Credit [Member] | Sempra Mexico [Member]
Line of Credit Facility [Line Items]
Maximum borrowing capacity	$ 100,000,000
Term of debt instrument	3 years
Foreign Uncommitted Revolving Credit Facility Due April 2022 [Member] | Foreign Line of Credit [Member] | Sempra Mexico [Member]
Line of Credit Facility [Line Items]
Available unused credit	$ 20,000,000