GENERAL INFORMATION AND OTHER FINANCIAL DATA - INCOME TAXES (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Income Tax Expense And Effective Income Tax Rates Disclosure [Line Items]
Income tax expense (benefit) from continuing operations	$ 139	$ 168	$ 297	$ (39)
Income from continuing operations before income taxes and equity earnings	281	463	1,049	860
Equity earnings (losses), before income tax:	185	84	320	41
Pretax income	$ 466	$ 547	$ 1,369	$ 901
Effective income tax rate (as a percent)	30.00%	31.00%	22.00%	(4.00%)
Income tax benefit related to the increase in outside basis differences from 2019 earnings since January 25, 2019				$ 7
San Diego Gas and Electric Company [Member]
Income Tax Expense And Effective Income Tax Rates Disclosure [Line Items]
Income tax expense (benefit) from continuing operations	$ 33	$ 70	$ 78	128
Income from continuing operations before income taxes and equity earnings	$ 219	$ 263	$ 476	$ 583
Effective income tax rate (as a percent)	15.00%	27.00%	16.00%	22.00%
Southern California Gas Company [Member]
Income Tax Expense And Effective Income Tax Rates Disclosure [Line Items]
Income tax expense (benefit) from continuing operations	$ 8	$ 49	$ 102	$ 101
Income from continuing operations before income taxes and equity earnings	$ 103	$ 196	$ 604	$ 551
Effective income tax rate (as a percent)	8.00%	25.00%	17.00%	18.00%