GENERAL INFORMATION AND OTHER FINANCIAL DATA - WILDFIRE FUND (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2020	Dec. 31, 2019		Jul. 25, 2019
Loss Contingencies [Line Items]
Noncurrent portion of the Wildfire Fund asset	$ 385.0	$ 392.0	[1]
San Diego Gas and Electric Company [Member]
Loss Contingencies [Line Items]
Wildfire Fund asset				$ 451.5
Estimated period of benefit	15 years
Current portion of the Wildfire Fund asset	$ 29.0	29.0
Noncurrent portion of the Wildfire Fund asset	385.0	392.0	[1]
Wildfire fund asset, amortization expense	7.0
Wildfire Fund obligation				$ 451.5
Wildfire Fund obligation in other current liabilities	12.9	12.9
Wildfire Fund obligation in deferred credits and other	$ 86.0	$ 86.0

[1] Derived from audited financial statements.