OTHER FINANCIAL DATA - PENSION AND OTHER POSTRETIREMENT BENEFITS (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Remeasurement Due To Collective Bargaining Agreement [Line Items]
Decrease In Recorded Liability From Remeasurement			$ 66
Southern California Gas Company [Member]
Remeasurement Due To Collective Bargaining Agreement [Line Items]
Discount Rate For Remeasurement			4.65%
Pension Benefits
Net Periodic Benefit Cost
Service cost	22	21	45	43
Interest cost	41	42	82	85
Expected return on assets	(39)	(36)	(78)	(73)
Amortization of prior service cost	1	1	2	2
Amortization of actuarial loss	11	9	23	18
Settlement	7	10	7	10
Regulatory adjustment	12	4	(18)	(25)
Total net periodic benefit cost	55	51	63	60
Pension and Other Postretirement Benefit Contributions [Abstract]
Contributions to pension plans			70
Expected contributions to pension and other postretirement benefit plans	218		218
Pension Benefits | San Diego Gas and Electric Company and Subsidiary [Member]
Net Periodic Benefit Cost
Service cost	7	8	14	15
Interest cost	11	12	23	25
Expected return on assets	(12)	(13)	(24)	(25)
Amortization of prior service cost	1		1	1
Amortization of actuarial loss	3	3	7	5
Settlement	2	1	2	1
Regulatory adjustment	10	7		(2)
Total net periodic benefit cost	22	18	23	20
Pension and Other Postretirement Benefit Contributions [Abstract]
Contributions to pension plans			20
Expected contributions to pension and other postretirement benefit plans	67		67
Pension Benefits | Southern California Gas Company [Member]
Net Periodic Benefit Cost
Service cost	14	12	27	24
Interest cost	25	25	50	50
Expected return on assets	(25)	(21)	(49)	(43)
Amortization of prior service cost			1	1
Amortization of actuarial loss	5	4	11	8
Settlement	1	1	1	1
Regulatory adjustment	2	(3)	(18)	(23)
Total net periodic benefit cost	22	18	23	18
Pension and Other Postretirement Benefit Contributions [Abstract]
Contributions to pension plans			24
Expected contributions to pension and other postretirement benefit plans	113		113
Other Postretirement Benefits
Net Periodic Benefit Cost
Service cost	7	8	15	15
Interest cost	14	16	28	33
Expected return on assets	(14)	(12)	(27)	(24)
Amortization of prior service cost	(2)		(2)
Amortization of actuarial loss	4	5	7	9
Regulatory adjustment	2	2	5	4
Total net periodic benefit cost	11	19	26	37
Pension and Other Postretirement Benefit Contributions [Abstract]
Contributions to other postretirement benefit plans			25
Expected contributions to pension and other postretirement benefit plans	46		46
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	3	4	5
Expected return on assets	(3)	(2)	(4)	(4)
Amortization of prior service cost	1	1	2	2
Regulatory adjustment	1		1	1
Total net periodic benefit cost	3	4	7	8
Pension and Other Postretirement Benefit Contributions [Abstract]
Contributions to other postretirement benefit plans			8
Expected contributions to pension and other postretirement benefit plans	14		14
Other Postretirement Benefits | Southern California Gas Company [Member]
Net Periodic Benefit Cost
Service cost	5	5	10	10
Interest cost	11	14	22	27
Expected return on assets	(12)	(10)	(23)	(20)
Amortization of prior service cost	(3)	(1)	(4)	(2)
Amortization of actuarial loss	4	4	7	9
Regulatory adjustment	1	2	4	3
Total net periodic benefit cost	6	14	16	27
Pension and Other Postretirement Benefit Contributions [Abstract]
Contributions to other postretirement benefit plans			16
Expected contributions to pension and other postretirement benefit plans	$ 27		$ 27