COMMITMENTS AND CONTINGENCIES - SITE CONTINGENCY (Details) $ in Millions	12 Months Ended
	Dec. 31, 2019 USD ($) site
Site Contingency [Line Items]
Accrual for environmental loss contingencies	$ 51
Expected future payments for accruals, 2020	9
Expected future payments for accruals, 2021	32
Expected future payments for accruals, 2022	2
Expected future payments for accruals, 2023	2
Expected future payments for accruals, 2024	1
Payments For Accrued Environmental Loss Contingencies, After Year Five	50
Manufactured Gas Sites [Member]
Site Contingency [Line Items]
Accrual for environmental loss contingencies	43
Waste Disposal Sites [Member]
Site Contingency [Line Items]
Accrual for environmental loss contingencies	5
Other Hazardous Waste Sites [Member]
Site Contingency [Line Items]
Accrual for environmental loss contingencies	3
San Diego Gas and Electric Company [Member]
Site Contingency [Line Items]
Accrual for environmental loss contingencies	5
Accrual for environmental loss contingencies, current	1
Accrual for environmental loss contingencies, noncurrent	$ 4
San Diego Gas and Electric Company [Member] | Manufactured Gas Sites [Member]
Site Contingency [Line Items]
Site Contingency, Sites Completed | site	3
Site Contingency, Sites In Process | site	0
Accrual for environmental loss contingencies	$ 0
San Diego Gas and Electric Company [Member] | Waste Disposal Sites [Member]
Site Contingency [Line Items]
Site Contingency, Sites Completed | site	2
Site Contingency, Sites In Process | site	1
Accrual for environmental loss contingencies	$ 2
San Diego Gas and Electric Company [Member] | Other Hazardous Waste Sites [Member]
Site Contingency [Line Items]
Accrual for environmental loss contingencies	3
San Diego Gas and Electric Company [Member] | California Coastal Reef Expansion [Member]
Site Contingency [Line Items]
Estimated SONGS mitigation costs, recoverable in rates	4
SONGS mitigation costs incurred	3
SONGS mitigation costs remaining	1
San Diego Gas and Electric Company [Member] | SONGS Sites [Member]
Site Contingency [Line Items]
Estimated SONGS mitigation costs, recoverable in rates	85
SONGS mitigation costs incurred	46
SONGS mitigation costs remaining	39
Southern California Gas Company [Member]
Site Contingency [Line Items]
Accrual for environmental loss contingencies	45
Accrual for environmental loss contingencies, current	6
Accrual for environmental loss contingencies, noncurrent	$ 39
Southern California Gas Company [Member] | Manufactured Gas Sites [Member]
Site Contingency [Line Items]
Site Contingency, Sites Completed | site	39
Site Contingency, Sites In Process | site	3
Accrual for environmental loss contingencies	$ 43
Southern California Gas Company [Member] | Waste Disposal Sites [Member]
Site Contingency [Line Items]
Site Contingency, Sites Completed | site	5
Site Contingency, Sites In Process | site	2
Accrual for environmental loss contingencies	$ 2
Southern California Gas Company [Member] | Other Hazardous Waste Sites [Member]
Site Contingency [Line Items]
Accrual for environmental loss contingencies	0
Other Sempra Energy [Member]
Site Contingency [Line Items]
Accrual for environmental loss contingencies	1
Other Sempra Energy [Member] | Manufactured Gas Sites [Member]
Site Contingency [Line Items]
Accrual for environmental loss contingencies	0
Other Sempra Energy [Member] | Waste Disposal Sites [Member]
Site Contingency [Line Items]
Accrual for environmental loss contingencies	1
Other Sempra Energy [Member] | Other Hazardous Waste Sites [Member]
Site Contingency [Line Items]
Accrual for environmental loss contingencies	0
Sempra Energy [Member]
Site Contingency [Line Items]
Accrual for environmental loss contingencies, current	7
Accrual for environmental loss contingencies, noncurrent	$ 44