SIGNIFICANT ACCOUNTING POLICIES AND OTHER FINANCIAL DATA - WILDFIRE FUND (Details) - USD ($) $ in Millions	1 Months Ended	12 Months Ended
	Jul. 31, 2019	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Sep. 30, 2019
Loss Contingencies [Line Items]
Noncurrent portion of the Wildfire Fund asset		$ 303.0	$ 331.0
San Diego Gas and Electric Company
Loss Contingencies [Line Items]
Initial liability cap		1,200.0
Initial shareholder contributions						$ 322.5
Additional annual contributions, aggregate value		129.0
Wildfire fund asset					$ 451.5
Annual contributions		$ 12.9
Amortization of wildfire fund asset		15 years
Current portion of Wildfire fund		$ 29.0	29.0
Noncurrent portion of the Wildfire Fund asset		303.0	331.0
Wildfire fund obligations in current liabilities		13.0	13.0
Noncurrent Wildfire Fund obligation		53.0	64.0
Amortization of Wildfire Fund asset		29.0	29.0	$ 29.0
Wildfire Fund asset, impairment losses		0.0	3.0	0.0
Accretion of Wildfire Fund obligation		2.0	$ 2.0	$ 2.0
Wildfire Fund
Loss Contingencies [Line Items]
Wildfire fund, threshold amount to seek payment	$ 1,000.0
Wildfire fund, threshold percentage of equity portion of electric transmission	20.00%
Liquidity fund, maximum borrowing capacity		10,500.0
Initial shareholder contributions		7,500.0
Additional annual contributions, aggregate value		$ 3,000.0
Period of annual contributions		10 years