DEBT AND CREDIT FACILITIES - LINES OF CREDIT (Details)		1 Months Ended		2 Months Ended	9 Months Ended
	Mar. 30, 2020	Oct. 31, 2020 USD ($)	Mar. 31, 2020 USD ($)	Apr. 30, 2020 USD ($)	Sep. 30, 2020 USD ($) customer
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					$ 560,000,000
Sempra Energy [Member]
Line of Credit Facility [Line Items]
Maximum borrowing capacity					1,250,000,000
Option to request					500,000,000
Sempra Global [Member]
Line of Credit Facility [Line Items]
Maximum borrowing capacity					3,185,000,000
San Diego Gas and Electric Company [Member]
Line of Credit Facility [Line Items]
Maximum borrowing capacity					1,500,000,000
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
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%
Sempra U.S. Businesses [Member]
Line of Credit Facility [Line Items]
Maximum borrowing capacity					$ 6,700,000,000
Foreign Line of Credit [Member] | Sempra Mexico [Member]
Line of Credit Facility [Line Items]
Maximum borrowing capacity					1,780,000,000
Amount outstanding					(772,000,000)
Available unused credit					1,008,000,000
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					(492,000,000)
Available unused credit					$ 1,008,000,000
Term of debt instrument					5 years
Number of lenders | customer					10
Foreign Committed Lines of Credit, Due February 2024 [Member] | Foreign Line of Credit [Member] | Sempra Mexico [Member] | LIBOR [Member]
Line of Credit Facility [Line Items]
Spread on variable rate (as a percent)					0.80%
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
Term of debt instrument					2 years
Foreign Committed Lines of Credit, Due September 2021 [Member] | Foreign Line of Credit [Member] | Sempra Mexico [Member] | LIBOR [Member]
Line of Credit Facility [Line Items]
Spread on variable rate (as a percent)					0.54%
Foreign Uncommitted Revolving Credit Facility Due April 2022 [Member] | Foreign Line of Credit [Member] | Sempra Mexico [Member]
Line of Credit Facility [Line Items]
Maximum borrowing capacity					$ 100,000,000
Available unused credit					$ 100,000,000
Term of debt instrument					3 years
Uncommitted Revolving Credit Facility with Bank of Nova Scotia [Member] | Foreign Line of Credit [Member] | Sempra Mexico [Member] | Subsequent Event [Member]
Line of Credit Facility [Line Items]
Maximum borrowing capacity		$ 100,000,000
Term of debt instrument		3 years
Uncommitted Revolving Credit Facility with Scotiabank Inverlat S.A. [Member] | Foreign Line of Credit [Member] | Sempra Mexico [Member] | Subsequent Event [Member]
Line of Credit Facility [Line Items]
Maximum borrowing capacity		$ 20,000,000
Term of debt instrument		3 years
Term Loan [Member] | Sempra Energy [Member]
Line of Credit Facility [Line Items]
Net proceeds of debt				$ 1,599,000,000
Debt issuance costs				$ 1,000,000
Term Loan [Member] | San Diego Gas and Electric Company [Member]
Line of Credit Facility [Line Items]
Spread on variable rate (as a percent)	0.80%				0.95%
Net proceeds of debt			$ 200,000,000