CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME AND CHANGES IN EQUITY (USD $) In Millions, unless otherwise specified	Total	San Diego Gas and Electric Company and Subsidiary [Member]	Southern California Gas Company [Member]	Preferred Stock Southern California Gas Company [Member]	Common Stock	Common Stock San Diego Gas and Electric Company and Subsidiary [Member]	Common Stock Southern California Gas Company [Member]	Retained Earnings	Retained Earnings San Diego Gas and Electric Company and Subsidiary [Member]	Retained Earnings Southern California Gas Company [Member]	Deferred Compensation E S O P [Member]	Accumulated Other Comprehensive Income (Loss)	Accumulated Other Comprehensive Income (Loss) San Diego Gas and Electric Company and Subsidiary [Member]	Accumulated Other Comprehensive Income (Loss) Southern California Gas Company [Member]	Total Shareholders' Equity	Total Shareholders' Equity San Diego Gas and Electric Company and Subsidiary [Member]	Noncontrolling Interests	Noncontrolling Interests San Diego Gas and Electric Company and Subsidiary [Member]
Equity, beginning of period at Dec. 31, 2008	$ 8,309	$ 2,670	$ 1,490	$ 22	$ 2,265	$ 1,138	$ 866	$ 6,235	$ 1,417	$ 630	$ (18)	$ (513)	$ (13)	$ (28)	$ 7,969	$ 2,542	$ 340	$ 128
Comprehensive income, net of income tax
Net income	1,122	373	274					1,129	349	274					1,129	349	(7)	24
Foreign currency translation adjustments	102											102			102
Financial instruments	35	(2)	3									38	1	3	38	1	(3)	(3)
Available-for-sale securities	7											7			7
Pension and other postretirement benefits	(3)	2										(3)	2		(3)	2
Comprehensive income (loss)	1,263	373	277									144	3	3	1,273	352	(10)	21
Share-based compensation expense	38				38										38
Common stock dividends declared	(383)	(150)						(383)	(150)						(383)	(150)
Preferred stock dividends declared		(5)	(1)						(5)	(1)						(5)
Preferred dividends of subsidiaries	(10)							(10)							(10)
Issuance of common stock	114				114										114
Tax benefit related to share-based compensation	23				23										23
Repurchases of common stock	(22)				(22)										(22)
Common stock released from ESOP	15				10						5				15
Equity contributed by noncontrolling interests	7	6															7	6
Distributions to noncontrolling interests	(9)	(9)															(9)	(9)
Purchase of noncontrolling interest in subsidiary	(94)				(10)										(10)		(84)
Equity, end of period at Dec. 31, 2009	9,251	2,885	1,766	22	2,418	1,138	866	6,971	1,611	903	(13)	(369)	(10)	(25)	9,007	2,739	244	146
Comprehensive income, net of income tax
Net income	733	358	287					749	374	287					749	374	(16)	(16)
Foreign currency translation adjustments	47											47			47
Financial instruments	(6)	7	3									(13)		3	(13)		7	7
Available-for-sale securities	(8)											(8)			(8)
Pension and other postretirement benefits	13											13			13
Comprehensive income (loss)	779	365	290									39		3	788	374	(9)	(9)
Share-based compensation expense	38				38										38
Common stock dividends declared	(381)		(100)					(381)		(100)					(381)
Preferred stock dividends declared		(5)	(1)						(5)	(1)						(5)
Preferred dividends of subsidiaries	(10)							(10)							(10)
Issuance of common stock	64				64										64
Tax benefit related to share-based compensation	5				5										5
Repurchases of common stock	(502)				(502)										(502)
Common stock released from ESOP	18				13						5				18
Distributions to noncontrolling interests	(24)	(24)															(24)	(24)
Equity, end of period at Dec. 31, 2010	9,238	3,221	1,955	22	2,036	1,138	866	7,329	1,980	1,089	(8)	(330)	(10)	(22)	9,027	3,108	211	113
Comprehensive income, net of income tax
Net income	1,407	455	288					1,365	436	288					1,365	436	42	19
Foreign currency translation adjustments	(70)											(76)			(76)		6
Reclassification to net income of foreign currency translation adjustment related to remeasurement of equity method investments	(54)											(54)			(54)
Financial instruments	(52)	(36)	2									(16)		2	(16)		(36)	(36)
Available-for-sale securities	(1)											(1)			(1)
Pension and other postretirement benefits	(12)		(1)									(12)		(1)	(12)
Comprehensive income (loss)	1,218	419	289									(159)		1	1,206	436	12	(17)
Share-based compensation expense	48				48										48
Common stock dividends declared	(461)		(50)					(461)		(50)					(461)
Preferred stock dividends declared		(5)	(1)						(5)	(1)						(5)
Preferred dividends of subsidiaries	(8)							(8)							(8)
Capital contribution		200				200										200
Issuance of common stock	28				28										28
Repurchases of common stock	(18)				(18)										(18)
Common stock released from ESOP	20				14						6				20
Acquisition of South American entities	279																279
Equity contributed by noncontrolling interests	36	6															36	6
Distributions to noncontrolling interests	(16)																(16)
Purchase of noncontrolling interest in subsidiary	(43)				(4)										(4)		(39)
Redemption of preferred stock of subidiary	(80)																(80)
Equity, end of period at Dec. 31, 2011	$ 10,241	$ 3,841	$ 2,193	$ 22	$ 2,104	$ 1,338	$ 866	$ 8,225	$ 2,411	$ 1,326	$ (2)	$ (489)	$ (10)	$ (21)	$ 9,838	$ 3,739	$ 403	$ 102