REGULATORY MATTERS - COST OF CAPITAL & FERC (Details) - USD ($) $ in Millions	1 Months Ended		3 Months Ended	6 Months Ended	12 Months Ended	36 Months Ended
	Jan. 31, 2020	Oct. 31, 2019	Jun. 30, 2020	Jun. 30, 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%	10.60%
Base ROE			10.10%	10.10%
Additional Bps				0.50%
Additional FERC revenues		$ 12		$ 17
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%
Weighted return on base rate (as a percent)						7.55%
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%
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%
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%
Weighted return on base rate (as a percent)						7.30%
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%
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%
Energy Efficiency Program Inquiry [Member] | San Diego Gas and Electric Company [Member] | California Public Utilities Commission [Member]
Public Utilities, General Disclosures [Line Items]
Reduction in revenue from inquiry			$ 15