DERIVATIVE INSTRUMENTS - CASH FLOW HEDGES (Details) $ in Millions	3 Months Ended
	Jun. 30, 2016 USD ($)
Derivative Instruments, Gain (Loss) [Line Items]
Cash Flow Hedge Gain (Loss) to be Reclassified within Twelve Months	$ 23
Maximum Length Of Time Hedged In Interest Rate Cash Flow Hedge 1	13 years
Joint Venture Maximum Length Of Time Hedged In Cash Flow Hedge	19 years
Cash Flow Hedge Gain (Loss) To Be Reclassified Within Twelve Months For Noncontrolling Interest	$ 13
San Diego Gas and Electric Company [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Maximum Length Of Time Hedged In Interest Rate Cash Flow Hedge 1	3 years
Cash Flow Hedge Gain (Loss) To Be Reclassified Within Twelve Months For Noncontrolling Interest	$ 13
Southern California Gas Company [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Cash Flow Hedge Gain (Loss) to be Reclassified within Twelve Months	$ 0