DERIVATIVE FINANCIAL INSTRUMENTS 4 (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended				6 Months Ended
	Jun. 30, 2012		Jun. 30, 2011		Jun. 30, 2012		Jun. 30, 2011
Cash Flow Hedges
Derivative Instruments, Gain (Loss) [Line Items]
Amount of pretax gain (loss) on derivative recognized in OCI (effective portion)	$ (25)		$ (19)		$ (21)		$ (18)
Gain (loss) reclassified from AOCI into earnings (effective portion)	1		(2)		(2)		(5)
Cash Flow Hedges | Interest Expense | Interest Rate Instruments
Derivative Instruments, Gain (Loss) [Line Items]
Amount of pretax gain (loss) on derivative recognized in OCI (effective portion)	(18)	[1]	(11)	[1]	(15)	[1]	(11)	[1]
Gain (loss) reclassified from AOCI into earnings (effective portion)	(1)	[1]	(2)	[1]	(2)	[1]	(4)	[1]
Cash Flow Hedges | Interest Expense | Interest Rate Instruments | San Diego Gas and Electric Company and Subsidiary [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of pretax gain (loss) on derivative recognized in OCI (effective portion)	(10)	[1]	(11)	[1]	(10)	[1]	(11)	[1]
Gain (loss) reclassified from AOCI into earnings (effective portion)	(1)	[1]	(1)	[1]	(1)	[1]	(2)	[1]
Cash Flow Hedges | Interest Expense | Interest Rate Instruments | Southern California Gas Company [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) reclassified from AOCI into earnings (effective portion)			(1)		(1)		(2)
Cash Flow Hedges | Equity Earnings Net Of Income Tax [Member] | Interest Rate Instruments
Derivative Instruments, Gain (Loss) [Line Items]
Amount of pretax gain (loss) on derivative recognized in OCI (effective portion)	(7)		(8)		(6)		(7)
Gain (loss) reclassified from AOCI into earnings (effective portion)	2						(1)
Fair Value Hedges
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) on derivative recognized in earnings	2		10		6		8
Fair Value Hedges | Southern California Gas Company [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) on derivative recognized in earnings							(2)
Fair Value Hedges | Interest Expense | Interest Rate Instruments
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) on derivative recognized in earnings	2		2		4		5
Fair Value Hedges | Interest Expense | Interest Rate Instruments | Southern California Gas Company [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) on derivative recognized in earnings							1
Fair Value Hedges | Other Income, Net | Interest Rate Instruments
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) on derivative recognized in earnings			8		2		3
Fair Value Hedges | Other Income, Net | Interest Rate Instruments | Southern California Gas Company [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) on derivative recognized in earnings							(3)
Undesignated Derivatives
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) on derivative recognized in earnings			10		2		38
Undesignated Derivatives | San Diego Gas and Electric Company and Subsidiary [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) on derivative recognized in earnings	12				(9)		10
Undesignated Derivatives | Southern California Gas Company [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) on derivative recognized in earnings	(2)		1		(1)		2
Undesignated Derivatives | Other Income, Net | Interest Rate And Foreign Exchange Instruments [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) on derivative recognized in earnings	(1)		2		10		12
Undesignated Derivatives | Revenues: Energy-Related Businesses [Member] | Commodity Contracts Not Subject To Rate Recovery
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) on derivative recognized in earnings	(9)		8		2		14
Undesignated Derivatives | Cost of Natural Gas, Electric Fuel and Purchased Power [Member] | Commodity Contracts Not Subject To Rate Recovery
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) on derivative recognized in earnings							1
Undesignated Derivatives | Cost of Electric Fuel and Purchased Power [Member] | Commodity Contracts Subject To Rate Recovery [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) on derivative recognized in earnings	12				(9)		9
Undesignated Derivatives | Cost of Electric Fuel and Purchased Power [Member] | Commodity Contracts Subject To Rate Recovery [Member] | San Diego Gas and Electric Company and Subsidiary [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) on derivative recognized in earnings	12				(9)		9
Undesignated Derivatives | Other Operation And Maintenance [Member] | Commodity Contracts Not Subject To Rate Recovery
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) on derivative recognized in earnings	(1)		(1)				1
Undesignated Derivatives | Other Operation And Maintenance [Member] | Commodity Contracts Not Subject To Rate Recovery | San Diego Gas and Electric Company and Subsidiary [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) on derivative recognized in earnings							1
Undesignated Derivatives | Other Operation And Maintenance [Member] | Commodity Contracts Not Subject To Rate Recovery | Southern California Gas Company [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) on derivative recognized in earnings	(1)						1
Undesignated Derivatives | Cost of Natural Gas [Member] | Commodity Contracts Subject To Rate Recovery [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) on derivative recognized in earnings	(1)		1		(1)		1
Undesignated Derivatives | Cost of Natural Gas [Member] | Commodity Contracts Subject To Rate Recovery [Member] | Southern California Gas Company [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) on derivative recognized in earnings	$ (1)		$ 1		$ (1)		$ 1

[1] Amounts include Otay Mesa VIE. All of SDG&E’s interest rate derivative activity relates to Otay Mesa VIE. There has been a negligible amount of ineffectiveness related to these swaps.