DERIVATIVE FINANCIAL INSTRUMENTS - DERIVATIVE COMMODITY VOLUMES (Details) MWh in Millions, MMBTU in Millions	9 Months Ended	12 Months Ended
	Sep. 30, 2017 MWh MMBTU	Dec. 31, 2016 MWh MMBTU
SDG&E [Member] | Natural gas [Member]
Derivatives, Fair Value [Line Items]
Net derivative energy volumes	43	48
SDG&E [Member] | Electricity [Member]
Derivatives, Fair Value [Line Items]
Net derivative energy volumes | MWh	3	4
SDG&E [Member] | Congestion revenue rights [Member]
Derivatives, Fair Value [Line Items]
Net derivative energy volumes | MWh	60	48
SoCalGas [Member] | Natural gas [Member]
Derivatives, Fair Value [Line Items]
Net derivative energy volumes	1	1
Sempra LNG & Midstream [Member] | Natural gas [Member]
Derivatives, Fair Value [Line Items]
Net derivative energy volumes	4	31
Sempra Mexico [Member] | Natural gas [Member]
Derivatives, Fair Value [Line Items]
Net derivative energy volumes	4	0