COMMITMENTS AND CONTINGENCIES - LEGAL PROCEEDINGS (Details) £ in Millions		1 Months Ended					12 Months Ended
	Feb. 22, 2021 lawsuit plaintiff	Nov. 30, 2019 customer	Feb. 28, 2019 USD ($)	Oct. 31, 2018 plaintiff	Jan. 31, 2017 lawsuit	Sep. 30, 2016 USD ($)	Dec. 31, 2020 USD ($) lawsuit claim	Dec. 31, 2020 GBP (£)	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($) claimant	Aug. 31, 2017 lawsuit	Oct. 31, 2014 USD ($)	Oct. 31, 2014 GBP (£)
Loss Contingencies [Line Items]
Loss contingency accrual							$ 616,000,000
Number of alleged violations | customer		330
Reserve for Aliso Canyon costs							141,000,000		$ (144,000,000)	$ 56,000,000
Reserve for Aliso Canyon costs							150,000,000		9,000,000
Equity earnings, before income tax							294,000,000		30,000,000	(236,000,000)
Gas Transmission [Member]
Loss Contingencies [Line Items]
Net book value of pipeline							447,000,000
Southern California Gas Company [Member]
Loss Contingencies [Line Items]
Loss contingency accrual							471,000,000
Recoverable costs through insurance settlement							1,279,000,000
Reserve for Aliso Canyon costs							141,000,000		(144,000,000)	$ 56,000,000
Reserve for Aliso Canyon costs							$ 150,000,000		$ 9,000,000
Energy Future Holdings Corp. [Member]
Loss Contingencies [Line Items]
Proof of claims | claim							28,000
Aliso Canyon Natural Gas Storage Facility Gas Leak [Member] | Southern California Gas Company [Member]
Loss Contingencies [Line Items]
Loss contingency accrual							$ 484,000,000
Net book value Of Aliso Canyon Natural Gas Storage Facility							821,000,000
Recorded estimated costs							1,627,000,000
Reserve for Aliso Canyon costs							451,000,000
Insurance receivable for Aliso Canyon costs							445,000,000
Proceeds from insurance settlement							834,000,000
Aliso Canyon Natural Gas Storage Facility Gas Leak [Member] | Sempra Energy and Southern California Gas Company [Member]
Loss Contingencies [Line Items]
Loss contingency accrual							$ 445,000,000
Shareholder Derivative Complaint [Member] | Southern California Gas Company [Member]
Loss Contingencies [Line Items]
Number of pending claims | lawsuit							4				3
Damages from Product Defects [Member] | Southern California Gas Company [Member]
Loss Contingencies [Line Items]
Maximum occupational safety And health fines						$ 75,000
Penalty assessments						233,500
Reimbursement costs						246,673
Maximum other assessments in settlement of criminal complaint						$ 6,000,000
HMRC VAT Claim [Member] | R B S Sempra Commodities [Member]
Loss Contingencies [Line Items]
VAT tax claim paid upon appeal												$ 138,000,000
HMRC VAT Claim [Member] | Plaintiffs [Member]
Loss Contingencies [Line Items]
Damage awarded							$ 61,000,000	£ 45
HMRC VAT Claim [Member] | Parent Company [Member]
Loss Contingencies [Line Items]
VAT tax claim paid upon appeal | £													£ 86
Maximum [Member] | HMRC VAT Claim [Member] | R B S Sempra Commodities [Member]
Loss Contingencies [Line Items]
VAT tax claim, penalty percentage							100.00%
Consolidated Class Action Complaints [Member]
Loss Contingencies [Line Items]
Number of lawsuits | lawsuit					2
Property Class Action [Member]
Loss Contingencies [Line Items]
Number of lawsuits | lawsuit					1
Complaints Filed by Firefighters [Member] | Aliso Canyon Natural Gas Storage Facility Gas Leak [Member] | Southern California Gas Company [Member]
Loss Contingencies [Line Items]
Number of plaintiffs | plaintiff				51
R B S Sempra Commodities [Member]
Loss Contingencies [Line Items]
Equity earnings, before income tax							$ 100,000,000
Funding for Environmental Projects [Member] | Complaints Filed by Public Entities [Member] | Southern California Gas Company [Member]
Loss Contingencies [Line Items]
Settlement amount payable			$ 120,000,000
Civil Penalties [Member] | Complaints Filed by Public Entities [Member] | Southern California Gas Company [Member]
Loss Contingencies [Line Items]
Settlement amount payable			$ 21,000,000
Subsequent Event [Member] | Energy Future Holdings Corp. [Member]
Loss Contingencies [Line Items]
Number of pending claims | lawsuit	209
Number of lawsuits | lawsuit	77
Subsequent Event [Member] | Aliso Canyon Natural Gas Storage Facility Gas Leak [Member] | Southern California Gas Company [Member]
Loss Contingencies [Line Items]
Number of pending claims | lawsuit	395
Number of plaintiffs | plaintiff	36,000
Sempra Mexico [Member] | ECA LNG Regasification facility [Member]
Loss Contingencies [Line Items]
Number of pending claims | lawsuit							4
Number of plaintiffs | claimant										2
Insurance Receivable for Aliso Canyon Costs [Member] | Aliso Canyon Natural Gas Storage Facility Gas Leak [Member] | Southern California Gas Company [Member]
Loss Contingencies [Line Items]
Loss contingency accrual							$ 177,000,000
Aliso Canyon Litigation and Regulatory Matters [Member] | Aliso Canyon Natural Gas Storage Facility Gas Leak [Member] | Southern California Gas Company [Member]
Loss Contingencies [Line Items]
Loss contingency accrual							307,000,000
Loss accrual, net of tax							$ 233,000,000