DERIVATIVE FINANCIAL INSTRUMENTS - DERIVATIVE IMPACT ON INCOME (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Derivative [Line Items]
Pretax (loss) gain on derivatives recognized in earnings	$ (30)	$ (153)
Designated as Hedging Instrument [Member] | Cash Flow Hedging [Member]
Derivative [Line Items]
Pretax gain (loss) recognized in OCI	109	(243)
Pretax (loss) gain reclassified from AOCI into earnings	(29)	(39)
Designated as Hedging Instrument [Member] | Interest Expense [Member] | Cash Flow Hedging [Member] | Interest Rate Contract [Member]
Derivative [Line Items]
Pretax gain (loss) recognized in OCI	26	(47)
Pretax (loss) gain reclassified from AOCI into earnings	(2)	(2)
Designated as Hedging Instrument [Member] | Interest Expense [Member] | Cash Flow Hedging [Member] | Interest rate and foreign exchange instruments [Member]
Derivative [Line Items]
Pretax gain (loss) recognized in OCI	(6)	(45)
Designated as Hedging Instrument [Member] | Equity Earnings [Member] | Cash Flow Hedging [Member] | Interest Rate Contract [Member]
Derivative [Line Items]
Pretax gain (loss) recognized in OCI	83	(185)
Pretax (loss) gain reclassified from AOCI into earnings	(19)	(2)
Designated as Hedging Instrument [Member] | Equity Earnings [Member] | Cash Flow Hedging [Member] | Foreign Exchange Instruments [Member]
Derivative [Line Items]
Pretax gain (loss) recognized in OCI	3	13
Pretax (loss) gain reclassified from AOCI into earnings	(1)	2
Designated as Hedging Instrument [Member] | Revenues: Energy-Related Businesses [Member] | Cash Flow Hedging [Member] | Foreign Exchange Instruments [Member]
Derivative [Line Items]
Pretax gain (loss) recognized in OCI	3	21
Pretax (loss) gain reclassified from AOCI into earnings	(1)	2
Designated as Hedging Instrument [Member] | Other Income (Expense), Net [Member] | Cash Flow Hedging [Member] | Foreign Exchange Instruments [Member]
Derivative [Line Items]
Pretax (loss) gain reclassified from AOCI into earnings	0	2
Designated as Hedging Instrument [Member] | Other Income (Expense), Net [Member] | Cash Flow Hedging [Member] | Interest rate and foreign exchange instruments [Member]
Derivative [Line Items]
Pretax (loss) gain reclassified from AOCI into earnings	(6)	(41)
Not Designated as Hedging Instrument [Member]
Derivative [Line Items]
Pretax (loss) gain on derivatives recognized in earnings	(68)	(75)
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	(48)	51
Not Designated as Hedging Instrument [Member] | Other Income (Expense), Net [Member] | Foreign Exchange Instruments [Member]
Derivative [Line Items]
Pretax (loss) gain on derivatives recognized in earnings	(24)	(114)
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	2	(9)
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	2	(3)
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	2	(9)
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	$ 2	$ (3)