DERIVATIVE FINANCIAL INSTRUMENTS - DERIVATIVE IMPACT ON INCOME (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Derivative [Line Items]
Pretax gain (loss) reclassified from AOCI into earnings	$ 29	$ 25	$ 118	$ (135)
Pretax (loss) gain on derivatives recognized in earnings	(3)	19	(26)	(129)
Designated as Hedging Instrument [Member] | Cash Flow Hedging [Member]
Derivative [Line Items]
Pretax gain (loss) recognized in OCI	15	36	91	(225)
Pretax gain (loss) reclassified from AOCI into earnings	(23)	(4)	(63)	(43)
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	7	8	27	(42)
Pretax gain (loss) reclassified from AOCI into earnings	1	(3)	0	(6)
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	(3)	6	(2)	(31)
Pretax gain (loss) reclassified from AOCI into earnings			0	(1)
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	3	25	54	(175)
Pretax gain (loss) reclassified from AOCI into earnings	(19)	(5)	(57)	(8)
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	(1)	5	9
Pretax gain (loss) reclassified from AOCI into earnings	0	0	(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	5	(2)	7	14
Pretax gain (loss) reclassified from AOCI into earnings	0	0	(1)	2
Designated as Hedging Instrument [Member] | Other Income (Expense), Net [Member] | Cash Flow Hedging [Member] | Foreign Exchange Instruments [Member]
Derivative [Line Items]
Pretax gain (loss) reclassified from AOCI into earnings			0	1
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 gain (loss) reclassified from AOCI into earnings	(5)	4	(4)	(33)
Not Designated as Hedging Instrument [Member]
Derivative [Line Items]
Pretax (loss) gain on derivatives recognized in earnings	(170)	17	(339)	(37)
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	(154)	(39)	(344)	25
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	2	15	(22)	(97)
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	8	41	51	41
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	(26)	0	(24)	(6)
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	8	41	51	41
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	$ (26)	$ 0	$ (24)	$ (6)