GENERAL INFORMATION AND OTHER FINANCIAL DATA - RECLASSIFICATION FROM ACCUMULATED OTHER COMPREHENSIVE INCOME (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Income from Discontinued Operations, Net of Income Tax	$ 1,775	$ 70	$ 1,847	$ 19
Interest expense	(274)	(258)	(554)	(518)
Other Income (Expense), Net	(62)	(28)	192	(110)
Gain on sale of assets	0	66	0	66
Equity earnings	233	118	496	219
Energy-related businesses	293	335	657	718
Income from continuing operations before income taxes and equity earnings	463	286	860	787
Income tax (expense) benefit	(168)	(47)	39	(89)
Net income	2,305	435	3,252	953
Earnings attributable to noncontrolling interest	(28)	(45)	(179)	(86)
Reclassification out of Accumulated Other Comprehensive Income [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Earnings attributable to common shares	655	25	680	26
Reclassification out of Accumulated Other Comprehensive Income [Member] | Foreign currency translation adjustments [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Income from Discontinued Operations, Net of Income Tax	645	0	645	0
Reclassification out of Accumulated Other Comprehensive Income [Member] | Accumulated Gain (Loss), Cash Flow Hedge, Including Noncontrolling Interest [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Income from continuing operations before income taxes and equity earnings	0	8	39	8
Income tax (expense) benefit	0	(1)	(12)	(1)
Net income	0	7	27	7
Reclassification out of Accumulated Other Comprehensive Income [Member] | Accumulated Gain (Loss), Cash Flow Hedge, Including Noncontrolling Interest [Member] | Interest rate and foreign exchange instruments [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Interest expense	2	0	4	1
Other Income (Expense), Net	(4)	(2)	37	(5)
Equity earnings	1	0	1	1
Reclassification out of Accumulated Other Comprehensive Income [Member] | Accumulated Gain (Loss), Cash Flow Hedge, Including Noncontrolling Interest [Member] | Interest rate instruments [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Gain on sale of assets	0	10	0	10
Reclassification out of Accumulated Other Comprehensive Income [Member] | Accumulated Gain (Loss), Cash Flow Hedge, Including Noncontrolling Interest [Member] | Foreign exchange instruments [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Other Income (Expense), Net	1	0	(1)	0
Energy-related businesses			(2)	1
Reclassification out of Accumulated Other Comprehensive Income [Member] | Gains (Losses) on Cash Flow hedges Attributable to Noncontrolling Interests [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Earnings attributable to noncontrolling interest	2	0	(6)	(1)
Reclassification out of Accumulated Other Comprehensive Income [Member] | Gains (Losses) on Cash Flow hedges Attributable to Parent [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Earnings attributable to common shares	2	7	21	6
Reclassification out of Accumulated Other Comprehensive Income [Member] | Gain (Loss) on Pension and Other Postretirement Benefits [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Income from Discontinued Operations, Net of Income Tax	6	0	6	0
Other Income (Expense), Net	1	2	3	4
Reclassification out of Accumulated Other Comprehensive Income [Member] | Accumulated Defined Benefit Plans Adjustment, Net Prior Service Attributable to Parent [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Other Income (Expense), Net	1	0	2	1
Reclassification out of Accumulated Other Comprehensive Income [Member] | Accumulated Defined Benefit Plans Adjustment, Net Settlements Attributable to Parent [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Other Income (Expense), Net	4	22	9	22
Reclassification out of Accumulated Other Comprehensive Income [Member] | Pension and Other Postretirement Benefits [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Income from Discontinued Operations, Net of Income Tax	(2)	0	(2)	0
Income from continuing operations before income taxes and equity earnings	12	24	20	27
Income tax (expense) benefit	(2)	(6)	(4)	(7)
Net income	8	18	14	20
San Diego Gas and Electric Company [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Interest expense	(103)	(102)	(204)	(205)
Other Income (Expense), Net	(18)	(19)	(49)	(41)
Income from continuing operations before income taxes and equity earnings	263	181	583	363
Income tax (expense) benefit	(70)	(35)	(128)	(40)
Net income	193	146	455	323
Earnings attributable to noncontrolling interest	0	(3)	0	(4)
San Diego Gas and Electric Company [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Earnings attributable to common shares	1	1	1	1
San Diego Gas and Electric Company [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member] | Accumulated Gain (Loss), Cash Flow Hedge, Including Noncontrolling Interest [Member] | Interest rate instruments [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Interest expense	0	1	0	2
San Diego Gas and Electric Company [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member] | Gains (Losses) on Cash Flow hedges Attributable to Noncontrolling Interests [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Earnings attributable to noncontrolling interest	0	(1)	0	(2)
San Diego Gas and Electric Company [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member] | Gains (Losses) on Cash Flow hedges Attributable to Parent [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Earnings attributable to common shares	0	0	0	0
San Diego Gas and Electric Company [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member] | Accumulated Defined Benefit Plans Adjustment, Net Prior Service Attributable to Parent [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Other Income, Net	1	1	1	1
Southern California Gas Company [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Interest expense	(40)	(34)	(80)	(68)
Other Income (Expense), Net	2	(1)	(28)	(17)
Income from continuing operations before income taxes and equity earnings	196	27	551	310
Income tax (expense) benefit	(49)	4	(101)	(15)
Net income	147	31	450	295
Southern California Gas Company [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Earnings attributable to common shares	1	0	1	0
Southern California Gas Company [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member] | Accumulated Defined Benefit Plans Adjustment, Net Prior Service Attributable to Parent [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Other Income, Net	$ 1	$ 0	$ 1	$ 0