DERIVATIVE FINANCIAL INSTRUMENTS - DERIVATIVE IMPACT ON INCOME (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Derivative [Line Items]
Pretax (loss) gain on derivatives recognized in earnings	$ (153)	$ 13
Designated as Hedging Instrument [Member] | Cash Flow Hedging [Member]
Derivative [Line Items]
Pretax (loss) gain recognized in OCI	(243)	(74)
Pretax (loss) gain reclassified from AOCI into earnings	(39)	0
Designated as Hedging Instrument [Member] | Interest Expense [Member] | Cash Flow Hedging [Member] | Interest rate and foreign exchange instruments [Member]
Derivative [Line Items]
Pretax (loss) gain recognized in OCI	(92)	(3)
Pretax (loss) gain reclassified from AOCI into earnings	(2)	(1)
Designated as Hedging Instrument [Member] | Other Income, Net [Member] | Cash Flow Hedging [Member] | Interest rate and foreign exchange instruments [Member]
Derivative [Line Items]
Pretax (loss) gain reclassified from AOCI into earnings	(41)	3
Designated as Hedging Instrument [Member] | Other Income, Net [Member] | Cash Flow Hedging [Member] | Foreign Exchange Instruments [Member]
Derivative [Line Items]
Pretax (loss) gain reclassified from AOCI into earnings	2	0
Designated as Hedging Instrument [Member] | Equity Earnings [Member] | Cash Flow Hedging [Member] | Interest rate and foreign exchange instruments [Member]
Derivative [Line Items]
Pretax (loss) gain recognized in OCI	(172)	(68)
Pretax (loss) gain reclassified from AOCI into earnings	0	(1)
Designated as Hedging Instrument [Member] | Revenues: Energy-Related Businesses [Member] | Cash Flow Hedging [Member] | Foreign Exchange Instruments [Member]
Derivative [Line Items]
Pretax (loss) gain recognized in OCI	21	(3)
Pretax (loss) gain reclassified from AOCI into earnings	2	(1)
Not Designated as Hedging Instrument [Member]
Derivative [Line Items]
Pretax (loss) gain on derivatives recognized in earnings	(75)	14
Not Designated as Hedging Instrument [Member] | Other Income, Net [Member] | Foreign Exchange Instruments [Member]
Derivative [Line Items]
Pretax (loss) gain on derivatives recognized in earnings	(114)	10
Not Designated as Hedging Instrument [Member] | Revenues: Energy-Related Businesses [Member] | Commodity Contracts not subject to rate recovery [Member]
Derivative [Line Items]
Pretax (loss) gain on derivatives recognized in earnings	51	0
Not Designated as Hedging Instrument [Member] | Cost of Electric Fuel and Purchased Power [Member] | Commodity Contracts Subject To Rate Recovery [Member]
Derivative [Line Items]
Pretax (loss) gain on derivatives recognized in earnings	(9)	2
Not Designated as Hedging Instrument [Member] | Cost of Natural Gas [Member] | Commodity Contracts Subject To Rate Recovery [Member]
Derivative [Line Items]
Pretax (loss) gain on derivatives recognized in earnings	(3)	2
San Diego Gas and Electric Company [Member] | Designated as Hedging Instrument [Member] | Interest Expense [Member] | Cash Flow Hedging [Member] | Interest Rate Contract [Member]
Derivative [Line Items]
Pretax (loss) gain recognized in OCI	0	0
Pretax (loss) gain reclassified from AOCI into earnings	0	(1)
San Diego Gas and Electric Company [Member] | Not Designated as Hedging Instrument [Member] | Cost of Electric Fuel and Purchased Power [Member] | Commodity Contracts Subject To Rate Recovery [Member]
Derivative [Line Items]
Pretax (loss) gain on derivatives recognized in earnings	(9)	2
Southern California Gas Company [Member] | Not Designated as Hedging Instrument [Member] | Cost of Natural Gas [Member] | Commodity Contracts Subject To Rate Recovery [Member]
Derivative [Line Items]
Pretax (loss) gain on derivatives recognized in earnings	$ (3)	$ 2