COMMITMENTS AND CONTINGENCIES - LEGAL PROCEEDINGS (Details)			1 Months Ended				3 Months Ended			6 Months Ended
	Jul. 29, 2019 plaintiff lawsuit	Feb. 18, 2016 Bcf	Oct. 31, 2018 plaintiff	Aug. 31, 2018 USD ($)	Jan. 31, 2017 lawsuit	Feb. 29, 2016 USD ($)	Jun. 30, 2019 USD ($) Bcf lawsuit	Sep. 30, 2018 lawsuit	Sep. 30, 2017 USD ($)	Jun. 30, 2019 USD ($) Bcf	Dec. 31, 2018 USD ($)	[1]	Oct. 21, 2016 t
Loss Contingencies [Line Items]
Liability for legal proceedings							$ 107,000,000			$ 107,000,000
Reserve for Aliso Canyon costs							$ 46,000,000			46,000,000	$ 160,000,000
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	3
Southern California Gas Company [Member]
Loss Contingencies [Line Items]
Liability for legal proceedings							$ 59,000,000			59,000,000
Insurance Settlements Receivable							1,053,000,000			1,053,000,000
Reserve for Aliso Canyon costs							46,000,000			46,000,000	$ 160,000,000
Southern California Gas Company [Member] | Aliso Canyon Natural Gas Storage Facility Gas Leak [Member]
Loss Contingencies [Line Items]
Liability for legal proceedings							54,000,000			54,000,000
Amount of natural gas released | Bcf		4.62
Mitigation requirements (in metric tons) | t													109,000
Loss contingency accrual							$ 1,082,000,000			$ 1,082,000,000
Percent of Loss Accrual Allocated to Temporary Relocation Program							52.00%			52.00%
Reserve for Aliso Canyon costs							$ 46,000,000			$ 46,000,000
Receivable related to natural gas leak							$ 381,000,000			381,000,000
Insurance proceeds										$ 672,000,000
Storage facility capacity | Bcf							86			86
Proportion of total gas storage capacity (percentage)							63.00%			63.00%
Working gas target | Bcf							34			34
Net book value of Aliso Canyon facility							$ 762,000,000			$ 762,000,000
Southern California Gas Company [Member] | Aliso Canyon Natural Gas Storage Facility Gas Leak [Member] | Minimum [Member]
Loss Contingencies [Line Items]
Liability insurance coverage							1,200,000,000			1,200,000,000
Southern California Gas Company [Member] | Aliso Canyon Natural Gas Storage Facility Gas Leak [Member] | Maximum [Member]
Loss Contingencies [Line Items]
Liability insurance coverage							1,400,000,000			1,400,000,000
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
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 Energy [Member] | Aliso Canyon Natural Gas Storage Facility Gas Leak [Member]
Loss Contingencies [Line Items]
Reserve for Aliso Canyon costs							$ 9,000,000			$ 9,000,000
San Diego Gas and Electric Company [Member] | Wildfire [Member]
Loss Contingencies [Line Items]
Write-off of wildfire regulatory asset									$ 351,000,000
After-tax charge for nonrecovery of CPUC regulatory assets									$ 208,000,000
IMG [Member] | Corporate Joint Venture [Member] | Sempra Mexico [Member]
Loss Contingencies [Line Items]
Interest percentage							40.00%			40.00%
Service agreement term										25 years
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	395
Number of plaintiffs | plaintiff	36,000
Subsequent Event [Member] | Energy Future Holdings Corp. [Member]
Loss Contingencies [Line Items]
Number of lawsuits | lawsuit	111
Number of lawsuits filed | lawsuit	1,685

[1] Derived from audited financial statements.