OTHER FINANCIAL DATA - PENSION AND OTHER POSTRETIREMENT BENEFITS (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
Southern California Gas Company [Member]
Remeasurement Due To Collective Bargaining Agreement [Line Items]
Discount Rate For Remeasurement	4.65%
Decrease In Recorded Liability From Remeasurement	$ 66
Pension Benefits
Net Periodic Benefit Cost
Service cost	23	22
Interest cost	41	43
Expected return on assets	(39)	(37)
Amortization of prior service cost	1	1
Amortization of actuarial loss	12	9
Regulatory adjustment	(30)	(29)
Total net periodic benefit cost	8	9
Pension and Other Postretirement Benefit Contributions [Abstract]
Contributions to pension plans	10
Expected contributions to pension and other postretirement benefit plans	218
Pension Benefits | San Diego Gas and Electric Company and Subsidiary [Member]
Net Periodic Benefit Cost
Service cost	7	7
Interest cost	12	13
Expected return on assets	(12)	(12)
Amortization of prior service cost		1
Amortization of actuarial loss	4	2
Regulatory adjustment	(10)	(9)
Total net periodic benefit cost	1	2
Pension and Other Postretirement Benefit Contributions [Abstract]
Expected contributions to pension and other postretirement benefit plans	67
Pension Benefits | Southern California Gas Company [Member]
Net Periodic Benefit Cost
Service cost	13	12
Interest cost	25	25
Expected return on assets	(24)	(22)
Amortization of prior service cost	1	1
Amortization of actuarial loss	6	4
Regulatory adjustment	(20)	(20)
Total net periodic benefit cost	1
Pension and Other Postretirement Benefit Contributions [Abstract]
Contributions to pension plans	2
Expected contributions to pension and other postretirement benefit plans	113
Other Postretirement Benefits
Net Periodic Benefit Cost
Service cost	8	7
Interest cost	14	17
Expected return on assets	(13)	(12)
Amortization of actuarial loss	3	4
Regulatory adjustment	3	2
Total net periodic benefit cost	15	18
Pension and Other Postretirement Benefit Contributions [Abstract]
Contributions to other postretirement benefit plans	15
Expected contributions to pension and other postretirement benefit plans	46
Other Postretirement Benefits | San Diego Gas and Electric Company and Subsidiary [Member]
Net Periodic Benefit Cost
Service cost	2	2
Interest cost	2	2
Expected return on assets	(1)	(2)
Amortization of prior service cost	1	1
Regulatory adjustment		1
Total net periodic benefit cost	4	4
Pension and Other Postretirement Benefit Contributions [Abstract]
Contributions to other postretirement benefit plans	4
Expected contributions to pension and other postretirement benefit plans	14
Other Postretirement Benefits | Southern California Gas Company [Member]
Net Periodic Benefit Cost
Service cost	5	5
Interest cost	11	13
Expected return on assets	(11)	(10)
Amortization of prior service cost	(1)	(1)
Amortization of actuarial loss	3	5
Regulatory adjustment	3	1
Total net periodic benefit cost	10	13
Pension and Other Postretirement Benefit Contributions [Abstract]
Contributions to other postretirement benefit plans	10
Expected contributions to pension and other postretirement benefit plans	$ 27