GENERAL INFORMATION AND OTHER FINANCIAL DATA - CAPITALIZED FINANCING COSTS (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Capitalized Financing Costs Disclosure [Line Items]
Capitalized interest costs	$ 52	$ 51	$ 166	$ 149
San Diego Gas and Electric Company [Member]
Capitalized Financing Costs Disclosure [Line Items]
Capitalized interest costs	24	26	82	79
Southern California Gas Company [Member]
Capitalized Financing Costs Disclosure [Line Items]
Capitalized interest costs	$ 18	$ 14	$ 49	$ 39