OTHER FINANCIAL DATA - RECLASSIFICATION FROM ACCUMULATED OTHER COMPREHENSIVE INCOME (Details) - USD ($) $ in Millions		3 Months Ended
		Mar. 31, 2016	Mar. 31, 2015
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items]
Equity earnings, net of income tax.		$ 17	$ 15
Interest expense		(143)	(134)
Equity Earnings (Losses) Recorded Before Tax		(22)	19
Revenues - energy related businesses		180	260
Total before income tax		455	606
Income tax (expense) benefit		(142)	(163)
Earnings attributable to noncontrolling interest		(11)	(21)
Grand total reclassifications for the period, net of tax		(1)	0
San Diego Gas and Electric Company [Member]
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items]
Interest expense		(48)	(52)
Total before income tax		202	239
Income tax (expense) benefit		(72)	(88)
Earnings attributable to noncontrolling interest		(1)	(4)
Southern California Gas Company [Member]
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items]
Interest expense		(22)	(19)
Total before income tax		282	309
Income tax (expense) benefit		(87)	(95)
Accumulated Defined Benefit Plans Adjustment [Member]
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items]
Income tax (expense) benefit		(1)	(1)
Total reclassifications for the period, net of tax		1	1
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]	2	2
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		1	2
Income tax (expense) benefit		0	1
Net of Income Tax		1	3
Earnings attributable to noncontrolling interest		(3)	(4)
Total reclassifications for the period, net of tax		(2)	(1)
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)
Total reclassifications for the period, net of tax		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]
Equity earnings, net of income tax.		1	0
Interest expense		4	6
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]
Equity Earnings (Losses) Recorded Before Tax		3	3
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
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		$ (7)	$ (7)

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