DERIVATIVE FINANCIAL INSTRUMENTS - DERIVATIVE COMMODITY VOLUMES (Details)	9 Months Ended	12 Months Ended
	Sep. 30, 2020 MWh MMBTU	Dec. 31, 2019 MMBTU MWh
Natural Gas Derivative [Member]
Derivative [Line Items]
Derivative, nonmonetary notional amount | MMBTU	19	32
Electric Energy Derivative [Member]
Derivative [Line Items]
Derivative, nonmonetary notional amount	2	2
Congestion Revenue Rights Derivative [Member]
Derivative [Line Items]
Derivative, nonmonetary notional amount	43	48
SDG&E [Member] | Natural Gas Derivative [Member]
Derivative [Line Items]
Derivative, nonmonetary notional amount | MMBTU	23	37
SDG&E [Member] | Electric Energy Derivative [Member]
Derivative [Line Items]
Derivative, nonmonetary notional amount	1	2
SDG&E [Member] | Congestion Revenue Rights Derivative [Member]
Derivative [Line Items]
Derivative, nonmonetary notional amount	43	48
SoCalGas [Member] | Natural Gas Derivative [Member]
Derivative [Line Items]
Derivative, nonmonetary notional amount | MMBTU	0	2