NUCLEAR PLANT - DECOMMISSIONING AND FUNDING (Details) - USD ($) $ in Millions	3 Months Ended
	Dec. 31, 2015		Sep. 30, 2015	Mar. 31, 2016
Nuclear Plant Decommissioning And Funding [Line Items]
Nuclear decommissioning trusts	$ 1,063	[1]		$ 1,082
San Diego Gas and Electric Company [Member]
Nuclear Plant Decommissioning And Funding [Line Items]
Nuclear decommissioning trusts	1,063	[1]		$ 1,082
Year 2013 [Member]
Nuclear Plant Decommissioning And Funding [Line Items]
Authorized Annuial Recovery Amount, Nuclear Decommissioning Trust Funding			$ 55
Amount Pending IRS Clarification			18
Year 2013 [Member] | San Diego Gas and Electric Company [Member]
Nuclear Plant Decommissioning And Funding [Line Items]
Authorized Annuial Recovery Amount, Nuclear Decommissioning Trust Funding			55
Amount Pending IRS Clarification			$ 18
Year 2014 [Member]
Nuclear Plant Decommissioning And Funding [Line Items]
Authorized Annuial Recovery Amount, Nuclear Decommissioning Trust Funding	36
Amount Pending IRS Clarification	13
Year 2014 [Member] | San Diego Gas and Electric Company [Member]
Nuclear Plant Decommissioning And Funding [Line Items]
Authorized Annuial Recovery Amount, Nuclear Decommissioning Trust Funding	36
Amount Pending IRS Clarification	$ 13

[1] Derived from audited financial statements.