GENERAL INFORMATION AND OTHER FINANCIAL DATA - RECLASSIFICATION FROM ACCUMULATED OTHER COMPREHENSIVE INCOME (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Interest expense	$ (243)	$ (259)
Equity earnings	326	318
Energy-related businesses	383	414
Other Income, Net	38	35
Income before income taxes and equity earnings	665	768
Income tax expense	(334)	(158)
Net income	657	928
Earnings Attributable to Noncontrolling Interests	(34)	(33)
Southern California Gas Company
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Interest expense	(40)	(39)
Other Income, Net	34	39
Income before income taxes and equity earnings	418	501
Income tax expense	(84)	(94)
Net income	334	407
Reclassification out of Accumulated Other Comprehensive Income
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Earnings attributable to common shares	6	26
Reclassification out of Accumulated Other Comprehensive Income | Southern California Gas Company
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Earnings attributable to common shares	1	0
Reclassification out of Accumulated Other Comprehensive Income | Accumulated Gain (Loss), Cash Flow Hedge, Including Noncontrolling Interest
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Income before income taxes and equity earnings	5	29
Income tax expense	(1)	(8)
Net income	4	21
Reclassification out of Accumulated Other Comprehensive Income | Accumulated Gain (Loss), Cash Flow Hedge, Including Noncontrolling Interest | Interest rate instruments
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Interest expense	(1)	2
Equity earnings	14	19
Reclassification out of Accumulated Other Comprehensive Income | Accumulated Gain (Loss), Cash Flow Hedge, Including Noncontrolling Interest | Foreign exchange instruments
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Equity earnings	(1)	1
Energy-related businesses	(1)	1
Reclassification out of Accumulated Other Comprehensive Income | Accumulated Gain (Loss), Cash Flow Hedge, Including Noncontrolling Interest | Interest rate and foreign exchange instruments
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Other Income, Net	(6)	6
Reclassification out of Accumulated Other Comprehensive Income | Gains (Losses) on Cash Flow hedges Attributable to Noncontrolling Interests
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Earnings Attributable to Noncontrolling Interests	0	(2)
Reclassification out of Accumulated Other Comprehensive Income | Amortization of actuarial loss
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Other Income, Net	2	2
Reclassification out of Accumulated Other Comprehensive Income | Amortization of actuarial loss | Southern California Gas Company
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Other Income, Net	1	0
Reclassification out of Accumulated Other Comprehensive Income | Amortization of prior service cost
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Other Income, Net	1	1
Reclassification out of Accumulated Other Comprehensive Income | Settlement charges
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Other Income, Net	0	7
Reclassification out of Accumulated Other Comprehensive Income | Pension and other postretirement benefits
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Income before income taxes and equity earnings	3	10
Income tax expense	(1)	(3)
Net income	2	7
Reclassification out of Accumulated Other Comprehensive Income | Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Parent
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Earnings attributable to common shares	$ 4	$ 19