OTHER FINANCIAL DATA - INCOME TAXES (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Income Tax Expense And Effective Income Tax Rates Disclosure [Line Items]
Income tax expense	$ 282	$ 15	$ 284	$ 276
Effective income tax rate	29.00%	6.00%	21.00%	22.00%
San Diego Gas and Electric Company [Member]
Income Tax Expense And Effective Income Tax Rates Disclosure [Line Items]
Income tax expense	$ 91	$ 75	$ 204	$ 217
Effective income tax rate	32.00%	29.00%	33.00%	32.00%
Southern California Gas Company [Member]
Income Tax Expense And Effective Income Tax Rates Disclosure [Line Items]
Income tax expense	$ 21	$ (20)	$ 75	$ 91
Effective income tax rate	100.00%	71.00%	27.00%	25.00%