DERIVATIVE FINANCIAL INSTRUMENTS 4 (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended				9 Months Ended
	Sep. 30, 2012		Sep. 30, 2011		Sep. 30, 2012		Sep. 30, 2011
Cash Flow Hedges
Derivative Instruments, Gain (Loss) [Line Items]
Amount of pretax gain (loss) on derivative recognized in OCI (effective portion)	$ (15)		$ (48)		$ (36)		$ (66)
Gain (loss) reclassified from AOCI into earnings (effective portion)	(7)		2		(9)		(3)
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)	(6)	[1]	(21)	[1]	(21)	[1]	(32)	[1]
Gain (loss) reclassified from AOCI into earnings (effective portion)	(3)	[1]	4	[1]	(5)	[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)	(6)	[1]	(21)	[1]	(16)	[1]	(32)	[1]
Gain (loss) reclassified from AOCI into earnings (effective portion)	(2)	[1]	4	[1]	(3)	[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)		(3)
Cash Flow Hedges | Equity Earnings Before Income Tax [Member] | Interest Rate Instruments
Derivative Instruments, Gain (Loss) [Line Items]
Amount of pretax gain (loss) on derivative recognized in OCI (effective portion)	(6)		(27)		(12)		(34)
Gain (loss) reclassified from AOCI into earnings (effective portion)	(4)		(2)		(4)		(3)
Cash Flow Hedges | Cost of Natural Gas, Electric Fuel and Purchased Power [Member] | Commodity Contracts Not Subject To Rate Recovery
Derivative Instruments, Gain (Loss) [Line Items]
Amount of pretax gain (loss) on derivative recognized in OCI (effective portion)	(3)				(3)
Fair Value Hedges
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) on derivative recognized in earnings	5	[2]	15	[2]	11	[2]	23	[2]
Fair Value Hedges | Southern California Gas Company [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) on derivative recognized in earnings							(2)	[2]
Fair Value Hedges | Interest Expense | Interest Rate Instruments
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) on derivative recognized in earnings	1		2		5		7
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	4		13		6		16
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	38		(40)		40		(2)
Undesignated Derivatives | San Diego Gas and Electric Company and Subsidiary [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) on derivative recognized in earnings	41		(16)		32		(6)
Undesignated Derivatives | Southern California Gas Company [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) on derivative recognized in earnings	1		(3)				(1)
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		(26)		11		(14)
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	(5)		3		(3)		17
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	41		(15)		32		(6)
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	41		(15)		32		(6)
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)		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			(2)		(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			$ (2)		$ (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.

[2] There has been no hedge ineffectiveness on these swaps. Changes in the fair values of the interest rate swap agreements are exactly offset by changes in the fair value of the underlying long-term debt.