GENERAL INFORMATION AND OTHER FINANCIAL DATA - CAPITALIZED FINANCING COSTS (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Capitalized Financing Costs Disclosure [Line Items]
Capitalized interest costs	$ 59	$ 48
San Diego Gas and Electric Company [Member]
Capitalized Financing Costs Disclosure [Line Items]
Capitalized interest costs	30	27
Southern California Gas Company [Member]
Capitalized Financing Costs Disclosure [Line Items]
Capitalized interest costs	$ 16	$ 11