COMMITMENTS AND CONTINGENCIES - LEGAL PROCEEDINGS (Details)		1 Months Ended				3 Months Ended	6 Months Ended	12 Months Ended
	Aug. 03, 2020 plaintiff lawsuit	Oct. 31, 2018 plaintiff	Aug. 31, 2018 USD ($)	Jan. 31, 2017 lawsuit	Feb. 29, 2016 USD ($)	Jun. 30, 2020 USD ($) lawsuit	Jun. 30, 2020 USD ($) lawsuit	Dec. 31, 2018 claimant	Mar. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)	[1]
Loss Contingencies [Line Items]
Liability for legal proceedings						$ 416,000,000	$ 416,000,000
Reserve for Aliso Canyon costs						$ 256,000,000	256,000,000			$ 9,000,000
Consolidated Class Action Complaints [Member]
Loss Contingencies [Line Items]
Number of lawsuits filed | lawsuit				2
Property Class Action [Member]
Loss Contingencies [Line Items]
Number of lawsuits filed | lawsuit				1
Complaints Filed by Public Entities [Member]
Loss Contingencies [Line Items]
Number of lawsuits filed | lawsuit						3
Southern California Gas Company [Member]
Loss Contingencies [Line Items]
Liability for legal proceedings						$ 270,000,000	270,000,000
Insurance settlements receivable						1,277,000,000	1,277,000,000
Reserve for Aliso Canyon costs						256,000,000	256,000,000			$ 9,000,000
Southern California Gas Company [Member] | Aliso Canyon Natural Gas Storage Facility Gas Leak [Member]
Loss Contingencies [Line Items]
Liability for legal proceedings						260,000,000	260,000,000
Loss contingency accrual						1,411,000,000	1,411,000,000		$ 277,000,000
Net book value of Aliso Canyon facility						775,000,000	775,000,000
Payable related to natural gas leak, noncurrent						256,000,000	256,000,000
Receivable related to natural gas leak						$ 505,000,000	505,000,000
Insurance proceeds							$ 772,000,000
Southern California Gas Company [Member] | Shareholder Derivative Complaint [Member]
Loss Contingencies [Line Items]
Number of lawsuits | lawsuit						4	4
Southern California Gas Company [Member] | Damages from Product Defects [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
Southern California Gas Company [Member] | Complaints Filed by Firefighters [Member] | Aliso Canyon Natural Gas Storage Facility Gas Leak [Member]
Loss Contingencies [Line Items]
Number of plaintiffs | plaintiff		51
Southern California Gas Company [Member] | Complaints Filed by Public Entities [Member] | Funding for Environmental Projects [Member]
Loss Contingencies [Line Items]
Settlement amount payable			$ 120,000,000
Southern California Gas Company [Member] | Complaints Filed by Public Entities [Member] | Civil Penalties [Member]
Loss Contingencies [Line Items]
Settlement amount payable			$ 21,000,000
Sempra Mexico [Member] | ECA LNG Regasification facility [Member]
Loss Contingencies [Line Items]
Number of lawsuits | lawsuit						4	4
Number of plaintiffs | claimant								2
Subsequent Event [Member] | Southern California Gas Company [Member] | Aliso Canyon Natural Gas Storage Facility Gas Leak [Member]
Loss Contingencies [Line Items]
Number of lawsuits | lawsuit	394
Number of plaintiffs | plaintiff	36,000
Subsequent Event [Member] | Energy Future Holdings Corp. [Member]
Loss Contingencies [Line Items]
Number of lawsuits | lawsuit	275
Number of lawsuits filed | lawsuit	182
Deferred Credits and Other [Member] | Southern California Gas Company [Member] | Aliso Canyon Natural Gas Storage Facility Gas Leak [Member]
Loss Contingencies [Line Items]
Reserve for Aliso Canyon costs						$ 7,000,000	$ 7,000,000

[1] Derived from audited financial statements.