DERIVATIVE FINANCIAL INSTRUMENTS - CASH FLOW HEDGES (Details) $ in Millions	3 Months Ended
	Mar. 31, 2019 USD ($)
Derivative [Line Items]
Cash flow hedge gain (loss) to be reclassified	$ 5
Term of interest rate cash flow hedge	13 years
San Diego Gas and Electric Company [Member]
Derivative [Line Items]
Term of interest rate cash flow hedge	1 year
San Diego Gas and Electric Company [Member] | Noncontrolling Interest [Member]
Derivative [Line Items]
Cash flow hedge gain (loss) to be reclassified	$ (1)
Southern California Gas Company [Member]
Derivative [Line Items]
Cash flow hedge gain (loss) to be reclassified	$ (1)
Equity Method Investee [Member]
Derivative [Line Items]
Term of interest rate cash flow hedge	15 years