OTHER FINANCIAL DATA - PENSION AND OTHER POSTRETIREMENT BENEFITS (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
Mar. 31, 2015	Mar. 31, 2014
Pension Benefits
Net Periodic Benefit Cost
Service cost	$ 30	$ 26
Interest cost	39	41
Expected return on assets	(44)	(43)
Amortization of prior service cost	3	2
Amortization of actuarial loss	8	5
Settlement	0	3
Regulatory adjustment	(29)	(24)
Total net periodic benefit cost	7	10
Pension and Other Postretirement Benefit Contributions [Abstract]
Contributions to pension plans	15
Expected contributions to benefit plans	31
Pension Benefits \| San Diego Gas and Electric Company [Member]
Net Periodic Benefit Cost
Service cost	8	8
Interest cost	10	11
Expected return on assets	(14)	(14)
Amortization of prior service cost	0	0
Amortization of actuarial loss	2	1
Regulatory adjustment	(5)	(5)
Total net periodic benefit cost	1	1
Pension and Other Postretirement Benefit Contributions [Abstract]
Contributions to pension plans	1
Expected contributions to benefit plans	3
Pension Benefits \| Southern California Gas Company [Member]
Net Periodic Benefit Cost
Service cost	19	16
Interest cost	25	25
Expected return on assets	(27)	(26)
Amortization of prior service cost	2	2
Amortization of actuarial loss	5	2
Regulatory adjustment	(24)	(19)
Total net periodic benefit cost	0	0
Pension and Other Postretirement Benefit Contributions [Abstract]
Contributions to pension plans	1
Expected contributions to benefit plans	2
Other Postretirement Benefits
Net Periodic Benefit Cost
Service cost	7	6
Interest cost	12	12
Expected return on assets	(17)	(16)
Amortization of prior service cost	(1)	(1)
Amortization of actuarial loss	0	0
Settlement	0	0
Regulatory adjustment	0	0
Total net periodic benefit cost	1	1
Pension and Other Postretirement Benefit Contributions [Abstract]
Contributions to other postretirement benefit plans	1
Expected contributions to benefit plans	11
Other Postretirement Benefits \| San Diego Gas and Electric Company [Member]
Net Periodic Benefit Cost
Service cost	2	2
Interest cost	2	2
Expected return on assets	(3)	(3)
Amortization of prior service cost	1	1
Amortization of actuarial loss	0	0
Regulatory adjustment	(2)	(2)
Total net periodic benefit cost	0	0
Pension and Other Postretirement Benefit Contributions [Abstract]
Contributions to other postretirement benefit plans	0
Expected contributions to benefit plans	8
Other Postretirement Benefits \| Southern California Gas Company [Member]
Net Periodic Benefit Cost
Service cost	5	4
Interest cost	9	9
Expected return on assets	(14)	(13)
Amortization of prior service cost	(2)	(2)
Amortization of actuarial loss	0	0
Regulatory adjustment	2	2
Total net periodic benefit cost	0	0
Pension and Other Postretirement Benefit Contributions [Abstract]
Contributions to other postretirement benefit plans	0
Expected contributions to benefit plans	$ 0

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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Amount of the employer's best estimate of contributions expected to be paid to the plan in the current fiscal period.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 715

-SubTopic 20

-Section 50

-Paragraph 6

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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.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 715

-SubTopic 30

-Glossary Expected Return on 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 (loss), prior service cost or credit, transition asset or obligation, and gain (loss) due to settlements or curtailments.

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- Definition

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, but are not limited to, lump-sum cash payments to plan participants in exchange for their rights to receive specified benefits and purchasing nonparticipating annuity contracts to cover vested benefits.

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- Definition

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.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 715

-SubTopic 20

-Section 50

-Paragraph 1

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-Glossary Service Cost (Component of Net Periodic Pension Cost)

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The increase (decrease) during the reporting period in the value of other assets that are created when regulatory agencies permits public utilities to defer costs to the balance sheet.

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-Publisher FASB

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-Topic 230

-SubTopic 10

-Section 45

-Paragraph 28

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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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-Publisher FASB

-Name Accounting Standards Codification

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-Section 45

-Paragraph 25

-Subparagraph (g)

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

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