REGULATORY MATTERS - BILLING PRACTICES (Details) - USD ($)	1 Months Ended	12 Months Ended
	Jan. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Public Utilities, General Disclosures [Line Items]
Litigation fines		$ 6,000,000	$ 0	$ 0
Penalties related to billing practices		0	8,000,000	0
Energy Efficiency Program Inquiry [Member] | California Public Utilities Commission [Member]
Public Utilities, General Disclosures [Line Items]
Energy Efficiency Program Inquiry fines that reduce revenue		51,000,000
Litigation fines		6,000,000
Litigation fines, after tax		44,000,000
Southern California Gas Company [Member]
Public Utilities, General Disclosures [Line Items]
Energy efficiency codes and standards advocacy, amount				9,000
Penalties related to billing practices	$ 8,000,000	0	8,000,000	0
Penalties payable	3,000,000
Penalties credited to customers	$ 5,000,000
Days customers bills were delayed	45 days
Penalty credit per customer	$ 100
San Diego Gas and Electric Company [Member]
Public Utilities, General Disclosures [Line Items]
Litigation fines		6,000,000	$ 0	$ 0
San Diego Gas and Electric Company [Member] | Energy Efficiency Program Inquiry [Member] | California Public Utilities Commission [Member]
Public Utilities, General Disclosures [Line Items]
Energy Efficiency Program Inquiry fines that reduce revenue		51,000,000
Litigation fines		6,000,000
Litigation fines, after tax		$ 44,000,000