DEBT AND CREDIT FACILITIES - LINES OF CREDIT (Details) - USD ($)	1 Months Ended			9 Months Ended
	Sep. 30, 2021	Jul. 31, 2021	May 31, 2021	Sep. 30, 2021	Nov. 01, 2021	Jun. 30, 2021
Line of Credit Facility [Line Items]
Maximum borrowing capacity	$ 6,685,000,000			$ 6,685,000,000
Capacity for issuance of letters of credit	$ 200,000,000			$ 200,000,000
Maximum ratio of indebtedness to total capitalization	65.00%			65.00%
Standby letters of credit outstanding	$ 697,000,000			$ 697,000,000
Sempra U.S. Businesses [Member]
Line of Credit Facility [Line Items]
Maximum borrowing capacity	6,700,000,000			6,700,000,000
Available unused credit	4,573,000,000			4,573,000,000
Sempra Energy [Member]
Line of Credit Facility [Line Items]
Maximum borrowing capacity	4,435,000,000		$ 3,200,000,000	4,435,000,000
Term of debt instrument			5 years
Available unused credit	2,323,000,000			2,323,000,000
Option to request	500,000,000			500,000,000
Sempra Energy [Member] | Subsequent Event [Member]
Line of Credit Facility [Line Items]
Debt amount					$ 2,350,000,000
San Diego Gas and Electric Company [Member]
Line of Credit Facility [Line Items]
Maximum borrowing capacity	1,500,000,000			1,500,000,000
Available unused credit	1,500,000,000			1,500,000,000
Capacity for issuance of letters of credit	100,000,000			100,000,000
Option to request	$ 250,000,000			$ 250,000,000
Maximum ratio of indebtedness to total capitalization	65.00%			65.00%
San Diego Gas and Electric Company [Member] | Term Loan Due 2022 | Secured Debt
Line of Credit Facility [Line Items]
Debt amount						$ 375,000,000
Proceeds from debt issuance		$ 375,000,000
Spread on variable rate (as a percent)		0.625%
Southern California Gas Company [Member]
Line of Credit Facility [Line Items]
Maximum borrowing capacity	$ 750,000,000			$ 750,000,000
Available unused credit	750,000,000			750,000,000
Capacity for issuance of letters of credit	100,000,000			100,000,000
Option to request	$ 250,000,000			$ 250,000,000
Maximum ratio of indebtedness to total capitalization	65.00%			65.00%
Commercial Paper
Line of Credit Facility [Line Items]
Amount outstanding	$ (2,112,000,000)			$ (2,112,000,000)
Commercial Paper | Sempra Energy [Member]
Line of Credit Facility [Line Items]
Amount outstanding	(2,112,000,000)			(2,112,000,000)
Commercial Paper | San Diego Gas and Electric Company [Member]
Line of Credit Facility [Line Items]
Amount outstanding	0			0
Commercial Paper | Southern California Gas Company [Member]
Line of Credit Facility [Line Items]
Amount outstanding	0			0
Foreign Line of Credit [Member] | Sempra Mexico [Member]
Line of Credit Facility [Line Items]
Maximum borrowing capacity	1,850,000,000			1,850,000,000
Amount outstanding	(294,000,000)			(294,000,000)
Available unused credit	1,556,000,000			1,556,000,000
Foreign Unsecured Line of Credit | Sempra Mexico [Member]
Line of Credit Facility [Line Items]
Maximum borrowing capacity	470,000,000			470,000,000
Amount outstanding	(287,000,000)			(287,000,000)
Available unused credit	183,000,000			183,000,000
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			1,500,000,000
Amount outstanding	0			0
Available unused credit	1,500,000,000			1,500,000,000
Foreign Committed Lines of Credit, Due September 2023 [Member] | Foreign Line of Credit [Member] | Sempra Mexico [Member]
Line of Credit Facility [Line Items]
Maximum borrowing capacity	350,000,000			350,000,000
Amount outstanding	(294,000,000)			(294,000,000)
Available unused credit	56,000,000			56,000,000
Foreign Committed Lines of Credit, Due September 2023 [Member] | Foreign Line of Credit [Member] | IEnova [Member]
Line of Credit Facility [Line Items]
Maximum borrowing capacity	$ 350,000,000			$ 350,000,000		$ 280,000,000
Spread on variable rate (as a percent)	0.54%
Foreign Uncommitted Revolving Credit Facility September 2022 | IEnova [Member] | LIBOR [Member]
Line of Credit Facility [Line Items]
Spread on variable rate (as a percent)				0.10%
Foreign Uncommitted Revolving Credit Facility September 2022 | Foreign Line of Credit [Member] | Sempra Mexico [Member]
Line of Credit Facility [Line Items]
Maximum borrowing capacity	$ 250,000,000			$ 250,000,000
Amount outstanding	(250,000,000)			(250,000,000)
Available unused credit	0			0
Foreign Uncommitted Revolving Credit Facility Due August 2023 | Foreign Line of Credit [Member] | Sempra LNG [Member]
Line of Credit Facility [Line Items]
Maximum borrowing capacity	100,000,000			100,000,000
Amount outstanding	(37,000,000)			(37,000,000)
Available unused credit	63,000,000			$ 63,000,000
Foreign Uncommitted Revolving Credit Facility Due August 2023 | Foreign Unsecured Line of Credit | Sempra LNG [Member] | LIBOR [Member]
Line of Credit Facility [Line Items]
Spread on variable rate (as a percent)				1.05%
Foreign Uncommitted Revolving Credit Facility Due October 2023 | IEnova [Member] | LIBOR [Member]
Line of Credit Facility [Line Items]
Spread on variable rate (as a percent)				0.52%
Foreign Uncommitted Revolving Credit Facility Due October 2023 | Foreign Line of Credit [Member] | Sempra Mexico [Member]
Line of Credit Facility [Line Items]
Maximum borrowing capacity	100,000,000			$ 100,000,000
Amount outstanding	0			0
Available unused credit	100,000,000			100,000,000
Foreign Uncommitted Revolving Credit Facility Due October 2023-2 | Foreign Line of Credit [Member] | Sempra Mexico [Member]
Line of Credit Facility [Line Items]
Maximum borrowing capacity	20,000,000			20,000,000
Amount outstanding	0			0
Available unused credit	$ 20,000,000			$ 20,000,000