REGULATORY MATTERS - COST OF CAPITAL & FERC (Details) - USD ($) $ in Millions	1 Months Ended		3 Months Ended	12 Months Ended	36 Months Ended
	Jan. 31, 2020	Oct. 31, 2019	Mar. 31, 2020	Dec. 31, 2018	Dec. 31, 2022
California Public Utilities Commission [Member]
Public Utilities, General Disclosures [Line Items]
CCM benchmark rate, increase (decrease) percent for trigger			1.00%
San Diego Gas and Electric Company [Member]
Public Utilities, General Disclosures [Line Items]
FERC requirement to maintain common equity ratio, at or above (percent)			10.60%
Base ROE			10.10%
Additional FERC revenues		$ 12	$ 17
Additional Bps		0.50%
San Diego Gas and Electric Company [Member] | California Public Utilities Commission [Member]
Public Utilities, General Disclosures [Line Items]
CCM benchmark rate			4.498%
San Diego Gas and Electric Company [Member] | Forecast [Member] | California Public Utilities Commission [Member]
Public Utilities, General Disclosures [Line Items]
Authorized weighting					100.00%
Return on rate base					7.55%
San Diego Gas and Electric Company [Member] | Capital Structure, Long Term Debt [Member] | Forecast [Member] | California Public Utilities Commission [Member]
Public Utilities, General Disclosures [Line Items]
Authorized weighting					45.25%
Return on rate base					4.59%
Weighted return on base rate (as a percent)					2.08%
San Diego Gas and Electric Company [Member] | Common Equity [Member] | Federal Energy Regulatory Commission [Member]
Public Utilities, General Disclosures [Line Items]
Approved return on equity, percentage				10.05%
San Diego Gas and Electric Company [Member] | Common Equity [Member] | Forecast [Member] | California Public Utilities Commission [Member]
Public Utilities, General Disclosures [Line Items]
Authorized weighting					52.00%
Return on rate base					10.20%
Weighted return on base rate (as a percent)					5.30%
San Diego Gas and Electric Company [Member] | Capital Structure, Preferred Stock [Member] | California Public Utilities Commission [Member]
Public Utilities, General Disclosures [Line Items]
Authorized weighting	6.22%
San Diego Gas and Electric Company [Member] | Capital Structure, Preferred Stock [Member] | Forecast [Member] | California Public Utilities Commission [Member]
Public Utilities, General Disclosures [Line Items]
Authorized weighting					2.75%
Return on rate base					6.22%
Weighted return on base rate (as a percent)					0.17%
Southern California Gas Company [Member] | California Public Utilities Commission [Member]
Public Utilities, General Disclosures [Line Items]
CCM benchmark rate			4.029%
Southern California Gas Company [Member] | Forecast [Member] | California Public Utilities Commission [Member]
Public Utilities, General Disclosures [Line Items]
Authorized weighting					100.00%
Return on rate base					7.30%
Southern California Gas Company [Member] | Capital Structure, Long Term Debt [Member] | Forecast [Member] | California Public Utilities Commission [Member]
Public Utilities, General Disclosures [Line Items]
Authorized weighting					45.60%
Return on rate base					4.23%
Weighted return on base rate (as a percent)					1.93%
Southern California Gas Company [Member] | Common Equity [Member] | Forecast [Member] | California Public Utilities Commission [Member]
Public Utilities, General Disclosures [Line Items]
Authorized weighting					52.00%
Return on rate base					10.05%
Weighted return on base rate (as a percent)					5.23%
Southern California Gas Company [Member] | Capital Structure, Preferred Stock [Member] | Forecast [Member] | California Public Utilities Commission [Member]
Public Utilities, General Disclosures [Line Items]
Authorized weighting					2.40%
Return on rate base					6.00%
Weighted return on base rate (as a percent)					0.14%