OTHER FINANCIAL DATA - CAPITALIZED FINANCING COSTS (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Schedule of Capitalization [Line Items]
AFUDC related to debt	$ 7	$ 6	$ 22	$ 19
AFUDC related to equity	29	26	86	84
Other capitalized interest	26	18	64	52
Total capitalized financing costs	62	50	172	155
San Diego Gas and Electric Company [Member]
Schedule of Capitalization [Line Items]
AFUDC related to debt	4	3	12	10
AFUDC related to equity	11	9	35	27
Total capitalized financing costs	15	12	47	37
Southern California Gas Company [Member]
Schedule of Capitalization [Line Items]
AFUDC related to debt	3	3	10	9
AFUDC related to equity	10	10	30	29
Other capitalized interest	1	1	1	1
Total capitalized financing costs	$ 14	$ 14	$ 41	$ 39