GENERAL INFORMATION AND OTHER FINANCIAL DATA - INCOME TAXES (Details) - USD ($) $ in Millions	3 Months Ended			9 Months Ended
	Sep. 30, 2019	Mar. 31, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Income Tax Expense And Effective Income Tax Rates Disclosure [Line Items]
Income tax expense (benefit) from continuing operations	$ 61		$ 139	$ 150	$ (221)
Income (loss) from continuing operations before income taxes and equity earnings	448		345	1,235	(245)
Equity earnings (losses), before income tax	17		(52)	24	(236)
Pretax income (loss)	$ 465		$ 293	$ 1,259	$ (481)
Effective income tax rate	13.00%		47.00%	12.00%	46.00%
Income tax expense (benefit) related to outside basis differences existing prior to the January 25, 2019 approval of our plan to sell our South American businesses	$ (192)	$ 103		$ (89)
Income tax expense related to the increase in outside basis differences from 2019 earnings since January 25, 2019				32
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	71		$ 53	111	$ 151
Income (loss) from continuing operations before income taxes and equity earnings	$ 337		$ 269	$ 700	$ 682
Effective income tax rate	21.00%		20.00%	16.00%	22.00%
Income tax benefit for release of a regulatory liability				$ 31
Southern California Gas Company [Member]
Income Tax Expense And Effective Income Tax Rates Disclosure [Line Items]
Income tax expense (benefit) from continuing operations	$ 35		$ (7)	50	$ 75
Income (loss) from continuing operations before income taxes and equity earnings	$ 178		$ (21)	$ 488	$ 320
Effective income tax rate	20.00%		33.00%	10.00%	23.00%
Income tax benefit for release of a regulatory liability				$ 38