OTHER FINANCIAL DATA - PENSION AND OTHER POSTRETIREMENT BENEFITS (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Pension Benefits
Net Periodic Benefit Cost
Service cost	$ 27	$ 22	$ 54	$ 45
Interest cost	39	41	76	82
Expected return on assets	(42)	(39)	(82)	(78)
Amortization of prior service cost	1	1	2	2
Amortization of actuarial loss	15	11	30	23
Settlement		7		7
Regulatory adjustment	(19)	12	(51)	(18)
Total net periodic benefit cost	21	55	29	63
Pension and Other Postretirement Benefit Contributions [Abstract]
Contributions to pension plans			26
Expected contributions to pension and other postretirement benefit plans	139		139
Pension Benefits | San Diego Gas and Electric Company and Subsidiary [Member]
Net Periodic Benefit Cost
Service cost	8	7	16	14
Interest cost	11	11	21	23
Expected return on assets	(13)	(12)	(26)	(24)
Amortization of prior service cost	1	1	1	1
Amortization of actuarial loss	3	3	7	7
Settlement		2		2
Regulatory adjustment	2	10	(6)
Total net periodic benefit cost	12	22	13	23
Pension and Other Postretirement Benefit Contributions [Abstract]
Contributions to pension plans			11
Expected contributions to pension and other postretirement benefit plans	53		53
Pension Benefits | Southern California Gas Company [Member]
Net Periodic Benefit Cost
Service cost	17	14	33	27
Interest cost	23	25	46	50
Expected return on assets	(24)	(25)	(49)	(49)
Amortization of prior service cost			1	1
Amortization of actuarial loss	8	5	17	11
Settlement		1		1
Regulatory adjustment	(21)	2	(45)	(18)
Total net periodic benefit cost	3	22	3	23
Pension and Other Postretirement Benefit Contributions [Abstract]
Contributions to pension plans			3
Expected contributions to pension and other postretirement benefit plans	60		60
Other Postretirement Benefits
Net Periodic Benefit Cost
Service cost	6	7	13	15
Interest cost	12	14	23	28
Expected return on assets	(14)	(14)	(29)	(27)
Amortization of prior service cost	(1)	(2)	(2)	(2)
Amortization of actuarial loss	3	4	5	7
Regulatory adjustment	2	2	4	5
Total net periodic benefit cost	8	11	14	26
Pension and Other Postretirement Benefit Contributions [Abstract]
Contributions to other postretirement benefit plans			14
Expected contributions to pension and other postretirement benefit plans	23		23
Other Postretirement Benefits | San Diego Gas and Electric Company and Subsidiary [Member]
Net Periodic Benefit Cost
Service cost	2	2	4	4
Interest cost	2	2	4	4
Expected return on assets	(2)	(3)	(4)	(4)
Amortization of prior service cost	1	1	2	2
Regulatory adjustment		1		1
Total net periodic benefit cost	3	3	6	7
Pension and Other Postretirement Benefit Contributions [Abstract]
Contributions to other postretirement benefit plans			6
Expected contributions to pension and other postretirement benefit plans	11		11
Other Postretirement Benefits | Southern California Gas Company [Member]
Net Periodic Benefit Cost
Service cost	4	5	8	10
Interest cost	9	11	18	22
Expected return on assets	(12)	(12)	(24)	(23)
Amortization of prior service cost	(2)	(3)	(4)	(4)
Amortization of actuarial loss	2	4	4	7
Regulatory adjustment	2	1	4	4
Total net periodic benefit cost	3	6	6	16
Pension and Other Postretirement Benefit Contributions [Abstract]
Contributions to other postretirement benefit plans			6
Expected contributions to pension and other postretirement benefit plans	$ 7		$ 7