SAN ONOFRE NUCLEAR GENERATING STATION (Details) - San Diego Gas and Electric Company - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2022	Dec. 31, 2021
Jointly Owned Utility Plant Interests [Line Items]
Anticipated term of dismantlement work	10 years
Percent of dismantlement work expense (as a percent)	20.00%
ARO related to decommissioning costs	$ 561
Jointly Owned Nuclear Power Plant
Jointly Owned Utility Plant Interests [Line Items]
Jointly owned utility plant, proportionate ownership share (as a percent)	20.00%
SONGS 2 and 3 Decommissioning
Jointly Owned Utility Plant Interests [Line Items]
Nuclear decommissioning trust authorized withdrawal amount		$ 78