DERIVATIVE FINANCIAL INSTRUMENTS (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		12 Months Ended		3 Months Ended																																											3 Months Ended		12 Months Ended		3 Months Ended																					3 Months Ended
	Mar. 31, 2012		Dec. 31, 2011		Mar. 31, 2012 Cash Flow Hedges	Mar. 31, 2011 Cash Flow Hedges	Mar. 31, 2012 Cash Flow Hedges Interest Expense Interest Rate Instruments		Mar. 31, 2011 Cash Flow Hedges Interest Expense Interest Rate Instruments		Mar. 31, 2012 Cash Flow Hedges Equity Earnings Net Of Income Tax [Member] Interest Rate Instruments	Mar. 31, 2011 Cash Flow Hedges Equity Earnings Net Of Income Tax [Member] Interest Rate Instruments	Mar. 31, 2011 Fair Value Hedges		Mar. 31, 2012 Fair Value Hedges Interest Rate Instruments		Mar. 31, 2012 Fair Value Hedges Interest Expense Interest Rate Instruments	Mar. 31, 2011 Fair Value Hedges Interest Expense Interest Rate Instruments	Mar. 31, 2012 Fair Value Hedges Other Income, Net Interest Rate Instruments	Mar. 31, 2011 Fair Value Hedges Other Income, Net Interest Rate Instruments	Mar. 31, 2012 Undesignated Derivatives	Mar. 31, 2011 Undesignated Derivatives	Mar. 31, 2012 Undesignated Derivatives Other Income, Net Interest Rate And Foreign Exchange Instruments [Member]	Jun. 30, 2011 Undesignated Derivatives Other Income, Net Interest Rate And Foreign Exchange Instruments [Member]	Mar. 31, 2012 Undesignated Derivatives Revenues: Energy-Related Businesses [Member] Commodity Contracts Not Subject To Rate Recovery	Mar. 31, 2011 Undesignated Derivatives Revenues: Energy-Related Businesses [Member] Commodity Contracts Not Subject To Rate Recovery	Mar. 31, 2011 Undesignated Derivatives Cost of Natural Gas, Electric Fuel and Purchased Power [Member] Commodity Contracts Not Subject To Rate Recovery	Mar. 31, 2012 Undesignated Derivatives Cost of Electric Fuel and Purchased Power [Member] Commodity Contracts Subject To Rate Recovery [Member]	Mar. 31, 2011 Undesignated Derivatives Cost of Electric Fuel and Purchased Power [Member] Commodity Contracts Subject To Rate Recovery [Member]	Mar. 31, 2012 Undesignated Derivatives Other Operation And Maintenance [Member] Commodity Contracts Not Subject To Rate Recovery	Mar. 31, 2011 Undesignated Derivatives Other Operation And Maintenance [Member] Commodity Contracts Not Subject To Rate Recovery	Mar. 31, 2012 Fixed Price Contracts And Other Derivatives, Current Assets [Member]		Dec. 31, 2011 Fixed Price Contracts And Other Derivatives, Current Assets [Member]		Mar. 31, 2012 Fixed Price Contracts And Other Derivatives, Noncurrent Assets [Member]		Dec. 31, 2011 Fixed Price Contracts And Other Derivatives, Noncurrent Assets [Member]		Mar. 31, 2012 Fixed Price Contracts And Other Derivatives, Current Liabilities [Member]		Dec. 31, 2011 Fixed Price Contracts And Other Derivatives, Current Liabilities [Member]		Mar. 31, 2012 Fixed Price Contracts And Other Derivatives, Noncurrent Liabilities [Member]		Dec. 31, 2011 Fixed Price Contracts And Other Derivatives, Noncurrent Liabilities [Member]		Mar. 31, 2012 San Diego Gas and Electric Company and Subsidiary [Member]		Dec. 31, 2011 San Diego Gas and Electric Company and Subsidiary [Member]		Mar. 31, 2011 San Diego Gas and Electric Company and Subsidiary [Member] Cash Flow Hedges Interest Expense Interest Rate Instruments		Mar. 31, 2012 San Diego Gas and Electric Company and Subsidiary [Member] Undesignated Derivatives	Mar. 31, 2011 San Diego Gas and Electric Company and Subsidiary [Member] Undesignated Derivatives	Mar. 31, 2012 San Diego Gas and Electric Company and Subsidiary [Member] Undesignated Derivatives Cost of Electric Fuel and Purchased Power [Member] Commodity Contracts Subject To Rate Recovery [Member]	Mar. 31, 2011 San Diego Gas and Electric Company and Subsidiary [Member] Undesignated Derivatives Cost of Electric Fuel and Purchased Power [Member] Commodity Contracts Subject To Rate Recovery [Member]	Mar. 31, 2011 San Diego Gas and Electric Company and Subsidiary [Member] Undesignated Derivatives Other Operation And Maintenance [Member] Commodity Contracts Not Subject To Rate Recovery	Mar. 31, 2012 San Diego Gas and Electric Company and Subsidiary [Member] Fixed Price Contracts And Other Derivatives, Current Assets [Member]		Dec. 31, 2011 San Diego Gas and Electric Company and Subsidiary [Member] Fixed Price Contracts And Other Derivatives, Current Assets [Member]		Mar. 31, 2012 San Diego Gas and Electric Company and Subsidiary [Member] Fixed Price Contracts And Other Derivatives, Noncurrent Assets [Member]	Dec. 31, 2011 San Diego Gas and Electric Company and Subsidiary [Member] Fixed Price Contracts And Other Derivatives, Noncurrent Assets [Member]	Mar. 31, 2012 San Diego Gas and Electric Company and Subsidiary [Member] Fixed Price Contracts And Other Derivatives, Current Liabilities [Member]		Dec. 31, 2011 San Diego Gas and Electric Company and Subsidiary [Member] Fixed Price Contracts And Other Derivatives, Current Liabilities [Member]		Mar. 31, 2012 San Diego Gas and Electric Company and Subsidiary [Member] Fixed Price Contracts And Other Derivatives, Noncurrent Liabilities [Member]		Dec. 31, 2011 San Diego Gas and Electric Company and Subsidiary [Member] Fixed Price Contracts And Other Derivatives, Noncurrent Liabilities [Member]		Mar. 31, 2012 Southern California Gas Company [Member]	Mar. 31, 2012 Southern California Gas Company [Member] Cash Flow Hedges Interest Expense Interest Rate Instruments	Mar. 31, 2011 Southern California Gas Company [Member] Cash Flow Hedges Interest Expense Interest Rate Instruments	Mar. 31, 2011 Southern California Gas Company [Member] Fair Value Hedges Interest Rate Instruments		Mar. 31, 2011 Southern California Gas Company [Member] Fair Value Hedges Interest Expense Interest Rate Instruments	Mar. 31, 2011 Southern California Gas Company [Member] Fair Value Hedges Other Income, Net Interest Rate Instruments	Mar. 31, 2012 Southern California Gas Company [Member] Undesignated Derivatives	Mar. 31, 2011 Southern California Gas Company [Member] Undesignated Derivatives	Mar. 31, 2012 Southern California Gas Company [Member] Undesignated Derivatives Other Operation And Maintenance [Member] Commodity Contracts Not Subject To Rate Recovery	Mar. 31, 2011 Southern California Gas Company [Member] Undesignated Derivatives Other Operation And Maintenance [Member] Commodity Contracts Not Subject To Rate Recovery	Mar. 31, 2012 Southern California Gas Company [Member] Fixed Price Contracts And Other Derivatives, Current Assets [Member]		Dec. 31, 2011 Southern California Gas Company [Member] Fixed Price Contracts And Other Derivatives, Current Assets [Member]		Mar. 31, 2012 Southern California Gas Company [Member] Fixed Price Contracts And Other Derivatives, Current Liabilities [Member]		Dec. 31, 2011 Southern California Gas Company [Member] Fixed Price Contracts And Other Derivatives, Current Liabilities [Member]		Mar. 31, 2012 S D G E Segment [Member]		Dec. 31, 2011 S D G E Segment [Member]		Mar. 31, 2012 Sempra Mexico Segment [Member]		Dec. 31, 2011 Sempra Mexico Segment [Member]		Mar. 31, 2012 Sempra Natural Gas Segment [Member]		Dec. 31, 2011 Sempra Natural Gas Segment [Member]
Schedule Of Commodity Derivative Volumes [Line Items]
Commodity derivative volumes, natural gas (in millions of million British thermal units)																																																																																												32	[1]	35	[1]	1	[1]	1	[1]	15	[1]	20	[1]
Commodity derivative volumes, congestion revenue rights (in millions of megawatt hours)																																																																																												17	[2]	19	[2]
Commodity derivative volumes, electric power (in millions of megawatt hours)																																																																																																				4	[2]	5	[2]
Schedule Of Notional Amounts Of Interest Rate Derivatives [Line Items]
Notional amount of interest rate derivatives, minimum	$ 15	[3]	$ 15	[3]																																												$ 285	[3]	$ 285	[3]
Notional amount of interest rate derivatives, maximum	305	[3]	305	[3]																																												352	[3]	355	[3]
Maturities of interest rate derivatives, minimum	2013	[3]	2013	[3]
Maturities of interest rate derivatives, maximum	2019	[3]	2019	[3]
Maturities of interest rate derivatives																																																2019	[3]	2019	[3]
Derivative Instruments in Hedges, at Fair Value, Net [Abstract]
Interest rate instruments designated as hedging instruments																																7	[4],[5]	5	[4],[5]	12	[5]	11	[5]	(17)	[5],[6]	(17)	[5],[6]	(61)	[5]	(65)	[5]																		(17)	[5],[6]	(16)	[5],[6]	(61)	[5]	(65)	[5]
Other Derivatives Not Designated as Hedging Instruments at Fair Value, Net, Total [Abstract]
Interest rate interest rate instruments not designated as hedging instruments																																8	[4]	8	[4]	37		41		(8)	[6]	(7)	[6]	(31)		(36)
Commodity contracts not subject to rate recovery not designated as hedging instruments																																234	[4]	156	[4]	23		72		(232)	[6]	(148)	[6]	(40)		(94)																																						1	[4]
Associated offsetting commodity contracts not subject to rate recovery																																(208)	[4]	(120)	[4]	(19)		(68)		208	[6]	120	[6]	19		68
Derivative commodity contracts subject to rate recovery not designated as hedging instruments																																21	[4]	28	[4]	7		8		(69)	[6]	(62)	[6]	(23)		(24)													18	[4]	22	[4]	7	8	(66)	[6]	(55)	[6]	(23)		(24)													2	[4]	6	[4]	(3)	[6]	(7)	[6]
Associated offsetting commodity contracts subject to rate recovery																																(6)	[4]	(10)	[4]	(1)		(2)		6	[6]	10	[6]	1		2													(3)	[4]	(5)	[4]	(1)	(2)	3	[6]	5	[6]	1		2													(2)	[4]	(5)	[4]	2	[6]	5	[6]
Total derivatives not designated as hedging instruments																																49	[4]	62	[4]	47		51		(95)	[6]	(87)	[6]	(74)		(84)													15	[4]	17	[4]	6	6	(63)	[6]	(50)	[6]	(22)		(22)													1	[4]	1	[4]	(1)	[6]	(2)	[6]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) on derivative recognized in earnings													(2)	[7]	4	[7]	2	3	2	(5)	2	28	11	10	11	6	1	(21)	9	1	2																							(21)	10	(21)	9	1																		(2)	[7]	1	(3)	1	1	1	1
Amount of pretax gain (loss) on derivative recognized in OCI (effective portion)					4	1	3	[8]			1	1
Gain (loss) reclassified from AOCI into earnings (effective portion)					(3)	(3)	(1)	[8]	(2)	[8]	(2)	(1)																																								(1)	[8]																					(1)	(1)
Reclassification Of Cash Flow Hedge Gain (Loss) [Line Items]
Cash Flow Hedge Gain (Loss) to be Reclassified within Twelve Months	(14)																																															(5)																									(1)
Derivative Credit Risk Related Contingent Features [Line Items]
Derivative, Net Liability Position, Aggregate Fair Value	26																																															13
Additional Collateral Aggregate Fair Value	$ 26																																															$ 13

[1] Million British thermal units

[2] Megawatt hours

[3] Includes Otay Mesa VIE. All of SDG&E’s interest rate derivatives relate to Otay Mesa VIE.

[4] Included in Current Assets: Other for SoCalGas.

[5] Includes Otay Mesa VIE. All of SDG&E’s amounts relate to Otay Mesa VIE.

[6] Included in Current Liabilities: Other for SoCalGas.

[7] 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.

[8] 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.