NUCLEAR PLANT 1 (Details) - USD ($) $ in Millions	3 Months Ended						6 Months Ended	9 Months Ended
	Sep. 30, 2015	Mar. 31, 2015	Dec. 31, 2014		Sep. 30, 2014	Mar. 31, 2014	Jun. 30, 2013	Sep. 30, 2015	Sep. 30, 2014
Nuclear Plant Investment [Line Items]
Plant closure (adjustment) loss	$ 0				$ 0			$ (21)	$ (13)
Loss (Adjustment) From Plant Closure, After Tax		$ (13)	$ 12			$ 9
Loss from plant closure, after-tax (cumulative)	127						$ 119
Charge To Reduce Certain Tax Regulatory Assets Attributable To Nuclear Plant									17
Regulatory Asset, Current, Nuclear Plant Closure	42							42
Regulatory Asset, Nuclear Plant Closure	272							272
Regulatory Asset, Noncurrent, Nuclear Plant Closure	230							230
Other Commitments [Line Items]
Five-year research funding commitment, annual amount	1							1
Nuclear Plant Decommissioning And Funding [Line Items]
Nuclear decommissioning trusts	1,060		1,131	[1]				1,060
Year 2013 [Member]
Nuclear Plant Decommissioning And Funding [Line Items]
Authorized Annuial Recovery Amount, Nuclear Decommissioning Trust Funding	55							55
Withdrawal From Nuclear Decommissioning Trust Funds	37
Amount funded to customers through Energy Resource Recovery Account	34
Amount Pending IRS Clarification	18
Amount To Refund Regulatory Assets	3
Year 2014 [Member]
Nuclear Plant Decommissioning And Funding [Line Items]
Withdrawal From Nuclear Decommissioning Trust Funds	23
Amount Pending IRS Clarification	13
Requested Annuial Recovery Amount, Nuclear Decommissioning Trust Funding	36							36
Nuclear Plant Entire Ownership [Member]
Nuclear Plant Settlement [Line Items]
Nuclear Plant, Insurance Recovery	400							400
Nuclear Plant SDGE Ownership [Member]
Nuclear Plant Settlement [Line Items]
Nuclear Plant, Insurance Recovery	$ 80							$ 80
Recovery Allocation Percentage	5.00%							5.00%
Customers [Member]
Nuclear Plant Settlement [Line Items]
Recovery Allocation Percentage	95.00%							95.00%
Nuclear Plant, SDGE [Member]
Nuclear Plant [Line Items]
Nuclear Plant, Ownership Percentage	20.00%							20.00%
San Diego Gas and Electric Company [Member]
Nuclear Plant Investment [Line Items]
Utility plant closure (adjustment) loss	$ 0				$ 0			$ (21)	(13)
Loss (Adjustment) From Plant Closure, After Tax		$ (13)	12			$ 9
Loss from plant closure, after-tax (cumulative)	127						$ 119
Charge To Reduce Certain Tax Regulatory Assets Attributable To Nuclear Plant									$ 17
Regulatory Asset, Current, Nuclear Plant Closure	42							42
Regulatory Asset, Nuclear Plant Closure	272							272
Regulatory Asset, Noncurrent, Nuclear Plant Closure	230							230
Other Commitments [Line Items]
Five-year research funding commitment, annual amount	1							1
Nuclear Plant Decommissioning And Funding [Line Items]
Nuclear decommissioning trusts	1,060		$ 1,131	[1]				1,060
San Diego Gas and Electric Company [Member] | Year 2013 [Member]
Nuclear Plant Decommissioning And Funding [Line Items]
Authorized Annuial Recovery Amount, Nuclear Decommissioning Trust Funding	55							55
Withdrawal From Nuclear Decommissioning Trust Funds	37
Amount funded to customers through Energy Resource Recovery Account	34
Amount Pending IRS Clarification	18
Amount To Refund Regulatory Assets	3
San Diego Gas and Electric Company [Member] | Year 2014 [Member]
Nuclear Plant Decommissioning And Funding [Line Items]
Withdrawal From Nuclear Decommissioning Trust Funds	23
Amount Pending IRS Clarification	13
Requested Annuial Recovery Amount, Nuclear Decommissioning Trust Funding	$ 36							$ 36

[1] Derived from audited financial statements.