OTHER FINANCIAL DATA - COMPREHENSIVE INCOME AND EQUITY (Details) In Millions, except Share data, unless otherwise specified	0 Months Ended		3 Months Ended		9 Months Ended																							3 Months Ended		9 Months Ended			3 Months Ended		9 Months Ended			3 Months Ended		9 Months Ended			3 Months Ended		9 Months Ended		3 Months Ended		9 Months Ended			3 Months Ended		9 Months Ended
	Mar. 31, 2013 USD ($)	Mar. 31, 2013 MXN	Sep. 30, 2013 USD ($)	Sep. 30, 2012 USD ($)	Sep. 30, 2013 USD ($)		Sep. 30, 2012 USD ($)		Dec. 31, 2012 USD ($)	Sep. 30, 2013 Ownership Interests Held By Others, Bay Gas Storage Company [Member] USD ($)	Dec. 31, 2012 Ownership Interests Held By Others, Bay Gas Storage Company [Member] USD ($)	Sep. 30, 2013 Ownership Interests Held By Others, Southern Gas Transmission [Member] USD ($)	Dec. 31, 2012 Ownership Interests Held By Others, Southern Gas Transmission [Member] USD ($)	Sep. 30, 2013 Ownership Interests Held By Others, Liberty Gas Storage [Member] USD ($)	Dec. 31, 2012 Ownership Interests Held By Others, Liberty Gas Storage [Member] USD ($)	Sep. 30, 2013 Ownership Interests Held By Others, Tecsur [Member] USD ($)	Dec. 31, 2012 Ownership Interests Held By Others, Tecsur [Member] USD ($)	Sep. 30, 2013 Ownership Interests Held By Others, Luz Del Sur [Member] USD ($)	Dec. 31, 2012 Ownership Interests Held By Others, Luz Del Sur [Member] USD ($)	Sep. 30, 2013 Ownership Interests Held By Others, Chilquinta Energia [Member] USD ($)		Dec. 31, 2012 Ownership Interests Held By Others, Chilquinta Energia [Member] USD ($)		Sep. 30, 2013 Ownership Interests Held By Others, Otay Mesa VIE [Member] USD ($)	Dec. 31, 2012 Ownership Interests Held By Others, Otay Mesa VIE [Member] USD ($)	Sep. 30, 2013 Ownership Interests Held By Others IEnova [Member] USD ($)	Dec. 31, 2012 Ownership Interests Held By Others IEnova [Member] USD ($)	Sep. 30, 2013 San Diego Gas and Electric Company and Subsidiary [Member] USD ($)	Sep. 30, 2012 San Diego Gas and Electric Company and Subsidiary [Member] USD ($)	Sep. 30, 2013 San Diego Gas and Electric Company and Subsidiary [Member] USD ($)		Sep. 30, 2012 San Diego Gas and Electric Company and Subsidiary [Member] USD ($)	Sep. 30, 2013 Southern California Gas Company [Member] USD ($)	Sep. 30, 2012 Southern California Gas Company [Member] USD ($)	Sep. 30, 2013 Southern California Gas Company [Member] USD ($)		Sep. 30, 2012 Southern California Gas Company [Member] USD ($)	Sep. 30, 2013 Total Shareholders' Equity USD ($)	Sep. 30, 2012 Total Shareholders' Equity USD ($)	Sep. 30, 2013 Total Shareholders' Equity USD ($)	Sep. 30, 2012 Total Shareholders' Equity USD ($)		Sep. 30, 2013 Total Shareholders' Equity San Diego Gas and Electric Company and Subsidiary [Member] USD ($)	Sep. 30, 2012 Total Shareholders' Equity San Diego Gas and Electric Company and Subsidiary [Member] USD ($)	Sep. 30, 2013 Total Shareholders' Equity San Diego Gas and Electric Company and Subsidiary [Member] USD ($)	Sep. 30, 2012 Total Shareholders' Equity San Diego Gas and Electric Company and Subsidiary [Member] USD ($)	Sep. 30, 2013 Noncontrolling Interests USD ($)	Sep. 30, 2012 Noncontrolling Interests USD ($)	Sep. 30, 2013 Noncontrolling Interests USD ($)	Sep. 30, 2012 Noncontrolling Interests USD ($)		Sep. 30, 2013 Noncontrolling Interests San Diego Gas and Electric Company and Subsidiary [Member] USD ($)	Sep. 30, 2012 Noncontrolling Interests San Diego Gas and Electric Company and Subsidiary [Member] USD ($)	Sep. 30, 2013 Noncontrolling Interests San Diego Gas and Electric Company and Subsidiary [Member] USD ($)	Sep. 30, 2012 Noncontrolling Interests San Diego Gas and Electric Company and Subsidiary [Member] USD ($)
Comprehensive Income And Equity Disclosure [Line Items]
Equity, beginning of period					$ 10,683	[1]	$ 10,178																							$ 4,298	[1]	$ 3,841			$ 2,235	[1]				$ 10,282	$ 9,775				$ 4,222	$ 3,739			$ 401	$ 403				$ 76	$ 102
Comprehensive income			325	361	921		713																					139	184	309		388	102	71	268		192	305	337	888	671		135	176	294	378	20	24	33	42		4	8	15	10
Share-based compensation expense					30		33																																	30	33								0	0
Call premium on preferred stock of subsidiary			(3)	0	(3)		0																																	(3)									0
Call premium on preferred stock			(3)		(3)		0																					(3)	0	(3)		0													(3)									0
Common stock dividends declared					(460)		(435)																																	(460)	(435)								0	0
Preferred dividend requirements																												(2)	(2)	(4)		(4)	0	0	(1)		(1)								(4)	(4)								0	0
Preferred dividends of subsidiaries			(2)	(2)	(5)		(5)																															(2)	(2)	(5)	(5)						0	0	0
Issuance of common stock					57		50																																	57	50								0	0
Tax benefit related to share-based compensation					30																																			30									0
Repurchases of common stock					(45)		(16)																																	(45)	(16)								0	0
Common stock released from ESOP							9	[2]																																	9	[2]								0	[2]
Sale of noncontrolling interests, net of offering costs					574																																			135									439
Equity contributed by noncontrolling interests							5																																		0									5
Distributions to noncontrolling interests					(28)		(36)																							(12)		(22)								0	0				0	0			(28)	(36)				(12)	(22)
Equity, end of period			11,754	10,496	11,754		10,496																					4,588	4,203	4,588		4,203	2,452		2,452			10,909	10,082	10,909	10,082		4,509	4,113	4,509	4,113	845	414	845	414		79	90	79	90
Ownership Interests Held By Others [Line Items]
Percent of ownership held by others										9.10%		49.00%		25.00%		9.80%		20.20%						100.00%		18.90%
Percent of ownership held by others, minimum																				24.40%	[3]
Percent of ownership held by others, maximum																				43.40%	[3]
Amount of ownership interests held by others			825		825				381	21	20	1	1	15	15	3	4	222	236	27	[3]	29	[3]	79	76	457	0
Sale Of Noncontrolling Interests [Abstract]
Proceeds From Sale Of Noncontrolling Interests Net	$ 574	7,100			$ 574		$ 0
Common stock shares issued	218,110,500	218,110,500
Share price	$ 2.75	34
Minority interest ownership percentage by parent	81.10%	81.10%
Foreign currency exchange rate pesos to US dollars	12.3841	12.3841

[1] Derived from audited financial statements.

[2] Employee Stock Ownership Plan

[3] Chilquinta Energía has four subsidiaries with noncontrolling interests held by others. Percentage range reflects the highest and lowest ownership percentages amongst these subsidiaries.