OTHER FINANCIAL DATA - PENSION AND OTHER POSTRETIREMENT BENEFITS (Details) (USD $) In Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2011	Jun. 30, 2010
San Diego Gas and Electric Company and Subsidiary [Member] | Pension Benefits
Net Periodic Benefit Cost
Service cost	$ 8	$ 7	$ 15	$ 14
Interest cost	12	12	25	24
Expected return on assets	(13)	(11)	(25)	(21)
Amortization of prior service cost			1	1
Amortization of actuarial loss	3	3	5	6
Settlement	1		1
Regulatory adjustment	7	7	(2)	(5)
Total net periodic benefit cost	18	18	20	19
Pension and Other Postretirement Benefit Contributions [Abstract]
Contributions to pension plans	17
Expected contributions to pension and other postretirement benefit plans	81		81
Southern California Gas Company [Member] | Pension Benefits
Net Periodic Benefit Cost
Service cost	12	11	24	23
Interest cost	25	24	50	49
Expected return on assets	(21)	(22)	(43)	(45)
Amortization of prior service cost			1	1
Amortization of actuarial loss	4	2	8	5
Settlement	1		1
Regulatory adjustment	(3)	3	(23)	(14)
Total net periodic benefit cost	18	18	18	19
Pension and Other Postretirement Benefit Contributions [Abstract]
Contributions to pension plans	22
Expected contributions to pension and other postretirement benefit plans	120		120
Pension Benefits
Net Periodic Benefit Cost
Service cost	21	20	43	42
Interest cost	42	41	85	84
Expected return on assets	(36)	(36)	(73)	(72)
Amortization of prior service cost	1	1	2	2
Amortization of actuarial loss	9	7	18	15
Settlement	10		10
Regulatory adjustment	4	10	(25)	(19)
Total net periodic benefit cost	51	43	60	52
Pension and Other Postretirement Benefit Contributions [Abstract]
Contributions to pension plans	70
Expected contributions to pension and other postretirement benefit plans	249		249
San Diego Gas and Electric Company and Subsidiary [Member] | Other Postretirement Benefits
Net Periodic Benefit Cost
Service cost	2	1	4	3
Interest cost	3	3	5	5
Expected return on assets	(2)	(1)	(4)	(3)
Amortization of prior service cost	1	1	2	2
Regulatory adjustment			1	1
Total net periodic benefit cost	4	4	8	8
Pension and Other Postretirement Benefit Contributions [Abstract]
Contributions to other postretirement benefit plans	8
Expected contributions to pension and other postretirement benefit plans	16		16
Southern California Gas Company [Member] | Other Postretirement Benefits
Net Periodic Benefit Cost
Service cost	5	5	10	10
Interest cost	14	11	27	23
Expected return on assets	(10)	(10)	(20)	(20)
Amortization of prior service cost	(1)	(1)	(2)	(2)
Amortization of actuarial loss	4	2	9	4
Regulatory adjustment	2	2	3	3
Total net periodic benefit cost	14	9	27	18
Pension and Other Postretirement Benefit Contributions [Abstract]
Contributions to other postretirement benefit plans	28
Expected contributions to pension and other postretirement benefit plans	55		55
Other Postretirement Benefits
Net Periodic Benefit Cost
Service cost	8	8	15	15
Interest cost	16	14	33	29
Expected return on assets	(12)	(11)	(24)	(23)
Amortization of prior service cost		(1)		(1)
Amortization of actuarial loss	5	2	9	4
Regulatory adjustment	2	2	4	4
Total net periodic benefit cost	19	14	37	28
Pension and Other Postretirement Benefit Contributions [Abstract]
Contributions to other postretirement benefit plans	37
Expected contributions to pension and other postretirement benefit plans	$ 76		$ 76