DERIVATIVE FINANCIAL INSTRUMENTS - COMMODITY VOLUMES (Details) MWh in Millions, MMBTU in Millions	12 Months Ended
	Dec. 31, 2017 MWh MMBTU	Dec. 31, 2016 MWh MMBTU
SDG&E [Member] | Natural Gas Derivative [Member]
Derivatives, Fair Value [Line Items]
Notional Amount, Energy Measure	39	48
SDG&E [Member] | Electric Energy Derivative [Member]
Derivatives, Fair Value [Line Items]
Notional Amount, Energy Measure | MWh	3	4
SDG&E [Member] | Congestion Revenue Rights Derivative [Member]
Derivatives, Fair Value [Line Items]
Notional Amount, Energy Measure | MWh	59	48
SoCalGas [Member] | Natural Gas Derivative [Member]
Derivatives, Fair Value [Line Items]
Notional Amount, Energy Measure	0	1
Sempra LNG & Midstream [Member] | Natural Gas Derivative [Member]
Derivatives, Fair Value [Line Items]
Notional Amount, Energy Measure	3	31
Sempra Mexico [Member] | Natural Gas Derivative [Member]
Derivatives, Fair Value [Line Items]
Notional Amount, Energy Measure	4	0