INCOME TAXES - RECONCILIATION TO EFFECTIVE TAX RATE (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Effective Income Tax Rate, Continuing Operations, Tax Rate Reconciliation [Line Items]
Income tax expense (benefit)	$ 249	$ 315	$ (49)
Income from continuing operations before income taxes and equity earnings	1,489	1,734	714
Equity earnings, before income tax	294	30	(236)
Pretax income	$ 1,783	$ 1,764	$ 478
Effective Income Tax Rate Reconciliation, Percent [Abstract]
U.S. federal statutory income tax rate	21.00%	21.00%	21.00%
Depreciation	3.00%	3.00%	12.00%
Non-U.S. earnings taxed at lower statutory income tax rates	2.00%	3.00%	10.00%
State income taxes, net of federal income tax benefit	1.00%	2.00%	(8.00%)
Impairment losses	1.00%	0.00%	(32.00%)
Effects of the TCJA	0	0	0.09
Unrecognized income tax benefits	0.00%	0.00%	4.00%
Noncontrolling interests in tax equity arrangements	0.00%	0.00%	3.00%
Resolution of prior years’ income tax items	0.00%	0.00%	(1.00%)
Excess deferred income taxes outside of ratemaking	0.00%	(4.00%)	0.00%
Compensation-related items	(1.00%)	0.00%	3.00%
Valuation allowances	(1.00%)	0.00%	0.00%
Amortization of excess deferred income taxes	(1.00%)	(1.00%)	(4.00%)
Allowance for equity funds used during construction	(1.00%)	(1.00%)	(4.00%)
Tax credits	(1.00%)	(2.00%)	(10.00%)
Foreign exchange and inflation effects	(3.00%)	4.00%	6.00%
Utility self-developed software expenditures	(3.00%)	(2.00%)	(7.00%)
Utility repairs expenditures	(4.00%)	(3.00%)	(13.00%)
Other, net	1.00%	(2.00%)	1.00%
Effective income tax rate	14.00%	18.00%	(10.00%)
San Diego Gas and Electric Company [Member]
Effective Income Tax Rate, Continuing Operations, Tax Rate Reconciliation [Line Items]
Income tax expense (benefit)	$ 190	$ 171	$ 173
Income from continuing operations before income taxes and equity earnings	1,014	945	849
Pretax income	$ 1,014	$ 945	$ 849
Effective Income Tax Rate Reconciliation, Percent [Abstract]
U.S. federal statutory income tax rate	21.00%	21.00%	21.00%
Depreciation	3.00%	3.00%	3.00%
State income taxes, net of federal income tax benefit	5.00%	6.00%	5.00%
Excess deferred income taxes outside of ratemaking	0.00%	(3.00%)	0.00%
Amortization of excess deferred income taxes	(1.00%)	(1.00%)	(1.00%)
Allowance for equity funds used during construction	(2.00%)	(1.00%)	(2.00%)
Utility self-developed software expenditures	(4.00%)	(3.00%)	(2.00%)
Utility repairs expenditures	(3.00%)	(3.00%)	(3.00%)
Other, net	0.00%	(1.00%)	(1.00%)
Effective income tax rate	19.00%	18.00%	20.00%
Southern California Gas Company [Member]
Effective Income Tax Rate, Continuing Operations, Tax Rate Reconciliation [Line Items]
Income tax expense (benefit)	$ 96	$ 120	$ 92
Income from continuing operations before income taxes and equity earnings	601	762	493
Pretax income	$ 601	$ 762	$ 493
Effective Income Tax Rate Reconciliation, Percent [Abstract]
U.S. federal statutory income tax rate	21.00%	21.00%	21.00%
Depreciation	5.00%	4.00%	7.00%
State income taxes, net of federal income tax benefit	2.00%	4.00%	2.00%
Nondeductible expenditures	2.00%	0.00%	0.00%
Unrecognized income tax benefits	0.00%	0.00%	4.00%
Resolution of prior years’ income tax items	0.00%	0.00%	(1.00%)
Excess deferred income taxes outside of ratemaking	0.00%	(5.00%)	0.00%
Compensation-related items	0.00%	0.00%	1.00%
Amortization of excess deferred income taxes	(1.00%)	(1.00%)	(2.00%)
Allowance for equity funds used during construction	(1.00%)	(1.00%)	(2.00%)
Utility self-developed software expenditures	(4.00%)	(2.00%)	(3.00%)
Utility repairs expenditures	(7.00%)	(4.00%)	(7.00%)
Other, net	(1.00%)	0.00%	(1.00%)
Effective income tax rate	16.00%	16.00%	19.00%

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