NUCLEAR PLANT 1 (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended				6 Months Ended
	Mar. 31, 2015	Dec. 31, 2014		Mar. 31, 2014	Jun. 30, 2013
Nuclear Plant [Line Items]
Nuclear decommissioning trusts	$ 1,150	$ 1,131	[1]
Nuclear Plant Investment [Line Items]
Plant closure (adjustment) loss	(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	41
Regulatory Asset, Nuclear Plant Closure	294
Regulatory Asset, Noncurrent, Nuclear Plant Closure	253
Other Commitments [Line Items]
Five-year research funding commitment, annual amount	1
San Diego Gas and Electric Company [Member]
Nuclear Plant [Line Items]
Nuclear decommissioning trusts	1,150	1,131	[1]
Nuclear Plant Investment [Line Items]
Utility plant closure (adjustment) loss	(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	41
Regulatory Asset, Nuclear Plant Closure	294
Regulatory Asset, Noncurrent, Nuclear Plant Closure	253
Other Commitments [Line Items]
Five-year research funding commitment, annual amount	$ 1
Nuclear Plant, SDGE [Member]
Nuclear Plant [Line Items]
Nuclear Plant, Ownership Percentage	20.00%

[1] Derived from audited financial statements.