OTHER FINANCIAL DATA - COMPREHENSIVE INCOME AND EQUITY 3 (Details) - USD ($) $ in Millions		3 Months Ended		9 Months Ended
		Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items]
Equity earnings, net of income tax.		$ 27	$ 7	$ 64	$ 22
Interest expense		(143)	(144)	(416)	(418)
Equity Earnings (Losses) Recorded Before Tax		33	22	79	62
Revenues - energy related businesses		268	352	762	970
Total before income tax		270	447	1,272	1,210
Income tax (expense) benefit		(15)	(71)	(276)	(291)
Earnings attributable to noncontrolling interest		(34)	(35)	(79)	(76)
Grand total reclassifications for the period, net of tax		6	4	9	26
San Diego Gas and Electric Company [Member]
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items]
Interest expense		(51)	(51)	(155)	(152)
Total before income tax		257	234	680	616
Income tax (expense) benefit		(75)	(65)	(217)	(217)
Earnings attributable to noncontrolling interest		(12)	(12)	(20)	(20)
Grand total reclassifications for the period, net of tax		0	1	0	2
Southern California Gas Company [Member]
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items]
Interest expense		(23)	(17)	(61)	(50)
Total before income tax		(28)	142	368	367
Income tax (expense) benefit		20	(44)	(91)	(110)
Grand total reclassifications for the period, net of tax		0	2	0	2
Accumulated Defined Benefit Plans Adjustment [Member]
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items]
Income tax (expense) benefit		(2)	(3)	(4)	(8)
Total reclassifications for the period, net of tax		5	5	7	13
Accumulated Defined Benefit Plans Adjustment [Member] | San Diego Gas and Electric Company [Member]
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items]
Income tax (expense) benefit		0	0	0	(1)
Total reclassifications for the period, net of tax		0	1	0	2
Accumulated Defined Benefit Plans Adjustment [Member] | Southern California Gas Company [Member]
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items]
Income tax (expense) benefit		0	(2)	0	(2)
Total reclassifications for the period, net of tax		0	2	0	2
Accumulated Defined Benefit Plans Adjustment [Member] | Amortization of Actuarial Loss [Member]
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items]
Pension and other postretirement benefit expense	[1]	7	8	11	21
Accumulated Defined Benefit Plans Adjustment [Member] | Amortization of Actuarial Loss [Member] | San Diego Gas and Electric Company [Member]
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items]
Pension and other postretirement benefit expense	[1]	0	1	0	3
Accumulated Defined Benefit Plans Adjustment [Member] | Amortization of Actuarial Loss [Member] | Southern California Gas Company [Member]
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items]
Pension and other postretirement benefit expense	[1]	0	4	0	4
Accumulated Net Gain Loss From Designated Or Qualifying Cash Flow Hedges [Member]
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items]
Total before income tax		5	3	13	29
Income tax (expense) benefit		(1)	(1)	1	(8)
Net of Income Tax		4	2	12	21
Earnings attributable to noncontrolling interest		(3)	(3)	(10)	(8)
Total reclassifications for the period, net of tax		1	(1)	2	13
Accumulated Net Gain Loss From Designated Or Qualifying Cash Flow Hedges [Member] | San Diego Gas and Electric Company [Member]
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items]
Earnings attributable to noncontrolling interest		(3)	(3)	(9)	(8)
Total reclassifications for the period, net of tax		0	0	0	0
Accumulated Net Gain Loss From Designated Or Qualifying Cash Flow Hedges [Member] | Interest Rate And Foreign Exchange Instruments [Member]
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items]
Interest expense		5	8	14	17
Accumulated Net Gain Loss From Designated Or Qualifying Cash Flow Hedges [Member] | Interest Rate Instruments [Member]
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items]
Gain on sale of equity interests and assets		0	5	0	(3)
Equity Earnings (Losses) Recorded Before Tax		3	2	(9)	(7)
Accumulated Net Gain Loss From Designated Or Qualifying Cash Flow Hedges [Member] | Interest Rate Instruments [Member] | San Diego Gas and Electric Company [Member]
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items]
Interest expense		3	3	9	8
Accumulated Net Gain Loss From Designated Or Qualifying Cash Flow Hedges [Member] | Commodity Contracts Not Subject To Rate Recovery [Member]
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items]
Revenues - energy related businesses		$ (3)	$ (2)	$ (10)	$ 8

[1] Amounts are included in the computation of net periodic benefit cost (see "Pension and Other Postretirement Benefits" above).