REGULATORY MATTERS - COST OF CAPITAL & FERC (Details) - San Diego Gas and Electric Company [Member] - USD ($) $ in Millions	1 Months Ended	3 Months Ended
	Oct. 31, 2019	Mar. 31, 2020
Public Utilities, General Disclosures [Line Items]
FERC requirement to maintain common equity ratio, at or above (percent)	10.60%
Base ROE	10.10%
Additional Bps	0.50%
Additional FERC revenues		$ 12
Federal Energy Regulatory Commission [Member]
Public Utilities, General Disclosures [Line Items]
Additional FERC revenues		$ 17
Common Equity [Member] | Federal Energy Regulatory Commission [Member]
Public Utilities, General Disclosures [Line Items]
Approved return on equity, percentage		10.05%