OTHER FINANCIAL DATA - PENSION AND OTHER POSTRETIREMENT BENEFITS (Details) (USD $) In Millions	3 Months Ended	9 Months Ended
Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2011	Sep. 30, 2010
San Diego Gas and Electric Company and Subsidiary [Member] \| Pension Benefits
Net Periodic Benefit Cost
Service cost	$ 6	$ 7	$ 21	$ 21
Interest cost	12	12	37	36
Expected return on assets	(10)	(11)	(35)	(32)
Amortization of prior service cost			1	1
Amortization of actuarial loss	2	3	7	9
Settlement			1
Regulatory adjustment	15	3	13	(2)
Total net periodic benefit cost	25	14	45	33
Pension and Other Postretirement Benefit Contributions [Abstract]
Contributions to pension plans	42
Expected contributions to pension and other postretirement benefit plans	68		68
Southern California Gas Company [Member] \| Pension Benefits
Net Periodic Benefit Cost
Service cost	10	11	34	34
Interest cost	24	25	74	74
Expected return on assets	(21)	(23)	(64)	(68)
Amortization of prior service cost	1	1	2	2
Amortization of actuarial loss	4	2	12	7
Settlement			1
Regulatory adjustment	16	2	(7)	(12)
Total net periodic benefit cost	34	18	52	37
Pension and Other Postretirement Benefit Contributions [Abstract]
Contributions to pension plans	56
Expected contributions to pension and other postretirement benefit plans	95		95
Pension Benefits
Net Periodic Benefit Cost
Service cost	20	20	63	62
Interest cost	41	41	126	125
Expected return on assets	(36)	(36)	(109)	(108)
Amortization of prior service cost	1	1	3	3
Amortization of actuarial loss	8	8	26	23
Settlement	1		11
Regulatory adjustment	31	5	6	(14)
Total net periodic benefit cost	66	39	126	91
Pension and Other Postretirement Benefit Contributions [Abstract]
Contributions to pension plans	136
Expected contributions to pension and other postretirement benefit plans	211		211
San Diego Gas and Electric Company and Subsidiary [Member] \| Other Postretirement Benefits
Net Periodic Benefit Cost
Service cost	1	2	5	5
Interest cost	2	2	7	7
Expected return on assets	(1)	(2)	(5)	(5)
Amortization of prior service cost	1	1	3	3
Regulatory adjustment	1		2	1
Total net periodic benefit cost	4	3	12	11
Pension and Other Postretirement Benefit Contributions [Abstract]
Contributions to other postretirement benefit plans	12
Expected contributions to pension and other postretirement benefit plans	15		15
Southern California Gas Company [Member] \| Other Postretirement Benefits
Net Periodic Benefit Cost
Service cost	7	3	17	13
Interest cost	12	11	39	34
Expected return on assets	(10)	(9)	(30)	(29)
Amortization of prior service cost	(1)	(1)	(3)	(3)
Amortization of actuarial loss	4	2	13	6
Regulatory adjustment	1	1	4	4
Total net periodic benefit cost	13	7	40	25
Pension and Other Postretirement Benefit Contributions [Abstract]
Contributions to other postretirement benefit plans	42
Expected contributions to pension and other postretirement benefit plans	55		55
Other Postretirement Benefits
Net Periodic Benefit Cost
Service cost	8	5	23	20
Interest cost	16	14	49	43
Expected return on assets	(12)	(12)	(36)	(35)
Amortization of prior service cost				(1)
Amortization of actuarial loss	4	2	13	6
Regulatory adjustment	2	1	6	5
Total net periodic benefit cost	18	10	55	38
Pension and Other Postretirement Benefit Contributions [Abstract]
Contributions to other postretirement benefit plans	56
Expected contributions to pension and other postretirement benefit plans	$ 74		$ 74

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The amount of gains or losses recognized in net periodic benefit cost

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The amount of the prior service cost or credit recognized in net periodic benefit cost relating to benefit changes attributable to plan participants' prior service pursuant to a plan amendment or a plan initiation.

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The employer's best estimate, as soon as it can be reasonably determined, of contributions expected to be paid to the plan during the next fiscal year beginning after the date of the latest statement of financial position. Estimated contributions may be presented in the aggregate combining (1) contributions required by funding regulations or laws, (2) discretionary contributions, and (3) noncash contributions.

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An amount calculated as a basis for determining the extent of delayed recognition of the effects of changes in the fair value of assets. The expected return on plan assets is determined based on the expected long-term rate of return on plan assets and the market-related value of plan assets.

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The increase in a defined benefit pension plan's projected benefit obligation or a defined benefit postretirement plan's accumulated postretirement benefit obligation due to the passage of time.

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The total amount of net periodic benefit cost for defined benefit plans for the period. Periodic benefit costs include the following components: service cost, interest cost, expected return on plan assets, gain or loss, prior service cost or credit, transition asset or obligation, and gain or loss due to settlements or curtailments).

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The amount of net (gain) loss recognized in net periodic benefit cost as a result of an irrevocable action that relieves the employer (or the plan) of primary responsibility for a benefit obligation and eliminates significant risks related to the obligation and the assets used to effect the settlement. Examples of transactions that constitute a settlement include (a) making lump-sum cash payments to plan participants in exchange for their rights to receive specified benefits and (b) purchasing nonparticipating annuity contracts to cover vested benefits.

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The actuarial present value of benefits attributed by the pension benefit formula to services rendered by employees during the period. The portion of the expected postretirement benefit obligation attributed to employee service during the period. The service cost component is a portion of the benefit obligation and is unaffected by the funded status of the plan.

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The amount of cash or cash equivalents contributed during the reporting period by the entity to fund non-pension postretirement benefits.

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The amount of cash or cash equivalents contributed by the entity to fund its pension plans.

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