GENERAL INFORMATION AND OTHER FINANCIAL DATA - INCOME TAXES (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Income Tax Expense And Effective Income Tax Rates Disclosure [Line Items]
Income Tax Expense (Benefit)	$ 42	$ 242
Income from continuing operations before income taxes and equity earnings (losses) of unconsolidated entities	501	593
Equity (losses) earnings, before income tax	5	5
Pretax income	$ 506	$ 598
Effective income tax rate	8.00%	40.00%
Income tax expense related to outside basis differences existing prior to the January 25, 2019 approval of our plan to sell our South American businesses	$ 103
Income tax expense related to the increase in outside basis differences from 2019 earnings since January 25, 2019	13
San Diego Gas and Electric Company [Member]
Income Tax Expense And Effective Income Tax Rates Disclosure [Line Items]
Tax Cuts and Jobs Act of 2017, Change in Tax Rate, Deferred Tax Assets and Liabilities, Income Tax (Expense) Benefit, Recognized in Period	31
Income Tax Expense (Benefit)	5	$ 56
Income from continuing operations before income taxes and equity earnings (losses) of unconsolidated entities	182	225
Pretax income	$ 182	$ 225
Effective income tax rate	3.00%	25.00%
Southern California Gas Company [Member]
Income Tax Expense And Effective Income Tax Rates Disclosure [Line Items]
Tax Cuts and Jobs Act of 2017, Change in Tax Rate, Deferred Tax Assets and Liabilities, Income Tax (Expense) Benefit, Recognized in Period	$ 35
Income Tax Expense (Benefit)	19	$ 59
Income from continuing operations before income taxes and equity earnings (losses) of unconsolidated entities	283	284
Pretax income	$ 283	$ 284
Effective income tax rate	7.00%	21.00%