OTHER FINANCIAL DATA - CAPITALIZED FINANCING COSTS (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Capitalized Financing Costs Disclosure [Line Items]
AFUDC related to debt	$ 5	$ 10	$ 32	$ 27
AFUDC related to equiity	13	26	80	67
Other capitalized financing costs	13	6	40	20
Total capitalized financing costs	31	42	152	114
San Diego Gas and Electric Company and Subsidiary [Member]
Capitalized Financing Costs Disclosure [Line Items]
AFUDC related to debt	3	8	26	22
AFUDC related to equiity	6	21	61	54
Total capitalized financing costs	9	29	87	76
Southern California Gas Company [Member]
Capitalized Financing Costs Disclosure [Line Items]
AFUDC related to debt	2	2	6	5
AFUDC related to equiity	7	5	19	13
Total capitalized financing costs	$ 9	$ 7	$ 25	$ 18