DEBT AND CREDIT FACILITIES - SUMMARY OF LINES OF CREDIT (Details)	1 Months Ended	12 Months Ended
	Oct. 31, 2020 USD ($)	Dec. 31, 2020 USD ($) lender customer
Line of Credit Facility [Line Items]
Number of lenders | lender		23
Lenders, percent of facility		6.00%
Commercial paper [Member]
Line of Credit Facility [Line Items]
Line of credit outstanding		$ (113,000,000)
Sempra Energy [Member]
Line of Credit Facility [Line Items]
Total facility		1,250,000,000
Available unused credit		1,250,000,000
Committed lines of credit, capacity for issuance of letters of credit		200,000,000
Line of credit, increase limit		500,000,000
Sempra Energy [Member] | Commercial paper [Member]
Line of Credit Facility [Line Items]
Line of credit outstanding		0
Sempra Global [Member]
Line of Credit Facility [Line Items]
Total facility		3,185,000,000
Available unused credit		3,185,000,000
Sempra Global [Member] | Commercial paper [Member]
Line of Credit Facility [Line Items]
Line of credit outstanding		0
San Diego Gas and Electric Company [Member]
Line of Credit Facility [Line Items]
Total facility		1,500,000,000
Available unused credit		1,500,000,000
San Diego Gas and Electric Company [Member] | Commercial paper [Member]
Line of Credit Facility [Line Items]
Line of credit outstanding		0
Southern California Gas Company [Member]
Line of Credit Facility [Line Items]
Total facility		750,000,000
Available unused credit		637,000,000
Committed lines of credit, capacity for issuance of letters of credit		100,000,000
Line of credit, increase limit		250,000,000
Southern California Gas Company [Member] | Commercial paper [Member]
Line of Credit Facility [Line Items]
Line of credit outstanding		(113,000,000)
Sempra U.S. Businesses [Member]
Line of Credit Facility [Line Items]
Total facility		6,685,000,000
Available unused credit		$ 6,572,000,000
Maximum ratio of indebtedness to total capitalization (as a percent)		65.00%
Sempra Mexico [Member] | Foreign Line of Credit [Member]
Line of Credit Facility [Line Items]
Total facility		$ 1,780,000,000
Line of credit outstanding		(672,000,000)
Available unused credit		$ 1,108,000,000
U.S. Committed Lines of Credit [Member]
Line of Credit Facility [Line Items]
Term of contract		5 years
Foreign Committed Lines of Credit, Due February 2024 [Member] | Sempra Mexico [Member] | Foreign Line of Credit [Member]
Line of Credit Facility [Line Items]
Total facility		$ 1,500,000,000
Line of credit outstanding		(392,000,000)
Available unused credit		$ 1,108,000,000
Term of contract		5 years
Number of Lenders | customer		10
Foreign Committed Lines of Credit, Due February 2024 [Member] | Sempra Mexico [Member] | Foreign Line of Credit [Member] | LIBOR [Member]
Line of Credit Facility [Line Items]
Variable percentage rate		0.80%
Foreign Committed Lines of Credit, Due September 2021 [Member] | Sempra Mexico [Member] | Foreign Line of Credit [Member]
Line of Credit Facility [Line Items]
Total facility		$ 280,000,000
Line of credit outstanding		(280,000,000)
Available unused credit		$ 0
Term of contract		2 years
Foreign Committed Lines of Credit, Due September 2021 [Member] | Sempra Mexico [Member] | Foreign Line of Credit [Member] | LIBOR [Member]
Line of Credit Facility [Line Items]
Variable percentage rate		0.54%
Uncommitted Revolving Credit Facility with Scotiabank Inverlat S.A. [Member] | Sempra Mexico [Member] | Foreign Line of Credit [Member]
Line of Credit Facility [Line Items]
Total facility	$ 20,000,000
Term of contract	3 years
Uncommitted Revolving Credit Facility with Bank of Nova Scotia [Member] | Sempra Mexico [Member] | Foreign Line of Credit [Member]
Line of Credit Facility [Line Items]
Total facility	$ 100,000,000
Term of contract	3 years
Foreign Uncommitted Revolving Credit Facility Due April 2022 [Member] | Sempra Mexico [Member] | Foreign Line of Credit [Member]
Line of Credit Facility [Line Items]
Available unused credit		$ 20,000,000