Business Segments (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended										12 Months Ended
	Dec. 31, 2011		Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2010		Sep. 30, 2010	Jun. 30, 2010	Mar. 31, 2010	Dec. 31, 2011		Dec. 31, 2010		Dec. 31, 2009
Reportable Segments Information
Operating revenue	$ 3,013		$ 3,981	$ 2,983	$ 2,782	$ 3,069		$ 3,788	$ 2,741	$ 2,810	$ 12,760		$ 12,409		$ 12,361
Depreciation, decommissioning and amortization											1,737		1,522		1,418
Interest and dividend income											37		31		32
Equity in income from partnerships and unconsolidated subsidiaries - net											86		106		42
Interest expense - net of amounts capitalized											808		703		732
Income tax expense (benefit) - continuing operations											(288)		354		(98)
Income (loss) from continuing operations	(824)		441	192	216	178		527	356	243	24		1,303		952
Net income (loss) attributable to common shareholders	(839)		426	176	200	166		510	344	236	(37)		1,256		849
Total assets	48,039					45,530					48,039		45,530		41,444
Capital expenditures											4,808		4,543		3,282
Income (loss) from discontinued operations, net of tax	0		0	(1)	(2)	0		(4)	1	6	(3)		4		(7)
Electric Utility
Reportable Segments Information
Operating revenue											10,577		9,983		9,965
Depreciation, decommissioning and amortization											1,426		1,273		1,178
Interest and dividend income											5		7		11
Equity in income from partnerships and unconsolidated subsidiaries - net											0		0		0
Interest expense - net of amounts capitalized											463		429		420
Income tax expense (benefit) - continuing operations											601		440		249
Income (loss) from continuing operations											1,144		1,092		1,371
Net income (loss) attributable to common shareholders											1,085	[1]	1,040	[1]	1,226	[1]
Total assets	40,315					35,906					40,315		35,906		32,474
Capital expenditures											4,122		3,780		2,999
Earning benefits (losses)													95		306
Competitive Power Generation
Reportable Segments Information
Operating revenue											2,186		2,429		2,399
Depreciation, decommissioning and amortization											310		249		239
Interest and dividend income											32		30		30
Equity in income from partnerships and unconsolidated subsidiaries - net											86		106		89
Interest expense - net of amounts capitalized											324		264		306
Income tax expense (benefit) - continuing operations											(864)		(36)		(284)
Income (loss) from continuing operations											(1,087)		219		(391)
Net income (loss) attributable to common shareholders											(1,089)	[2],[3]	224	[2],[3]	(395)	[2],[3]
Total assets	8,392					9,597					8,392		9,597		9,543
Capital expenditures											686		763		283
Lease termination and earning (loss) benefits													52		(610)
Parent and Other
Reportable Segments Information
Operating revenue											(3)	[4]	(3)	[4]	(3)	[4]
Depreciation, decommissioning and amortization											1	[4]	0		1	[4]
Interest and dividend income											0	[4]	(6)	[4]	(9)	[4]
Equity in income from partnerships and unconsolidated subsidiaries - net											0	[4]	0		(47)	[4]
Interest expense - net of amounts capitalized											21	[4]	10	[4]	6	[4]
Income tax expense (benefit) - continuing operations											(25)	[4]	(50)	[4]	(63)	[4]
Income (loss) from continuing operations											(33)	[4]	(8)	[4]	(28)	[4]
Net income (loss) attributable to common shareholders											(33)	[4],[5]	(8)	[4],[5]	18	[4],[5]
Total assets	(668)	[4]				27	[4]				(668)	[4]	27	[4]	(573)	[4]
Capital expenditures											0	[4]	0		0
Earning benefits (losses)													$ 28		$ 50

[1] Includes earnings of $95 million and $306 million for the years ended December 31, 2010 and 2009, respectively, related to the federal and state impacts of the Global Settlement. See Note 7.

[2] Includes earnings (losses) of $52 million and $(610) million for the years ended December 31, 2010 and 2009, respectively, related to termination of Edison Capital's cross-border leases and the federal and state impacts of the Global Settlement on EMG. See Note 7.

[3] Includes earnings (losses) from discontinued operations of $(3) million, $4 million and $(7) million for the years ended December 31, 2011, 2010 and 2009, respectively.

[4] Includes amounts from Edison International (parent) and other Edison International subsidiaries that are not significant as a reportable segment, as well as intercompany eliminations.

[5] Includes earnings of $28 million and $50 million for the years ended December 31, 2010 and 2009, respectively, related to the federal and state impacts of the Global Settlement. See Note 7.