Income Taxes (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended					9 Months Ended		12 Months Ended
	Sep. 30, 2011	Sep. 30, 2010	Jun. 30, 2010	Mar. 31, 2010	Dec. 31, 2009	Sep. 30, 2011	Sep. 30, 2010	Dec. 31, 2011		Dec. 31, 2010		Dec. 31, 2009
Pretax Income from Continuing Operations Excluding Income Attributable to Noncontrolling Interest [Abstract]
Income from continuing operations before income taxes								$ (264)		$ 1,657		$ 854
Discontinued operations before income taxes								1		13		(7)
Income before income tax								(263)		1,670		847
Current Income Tax Expense (Benefit), Continuing Operations [Abstract]
Federal								(223)		(432)		1,211
State								36		(86)		361
Current Income Tax Expense (Benefit)								(187)		(518)		1,572
Deferred Income Tax Expense (Benefit), Continuing Operations [Abstract]
Federal								(9)		892		(1,638)
State								(92)		(20)		(32)
Deferred Income Tax Expense (Benefit)								(101)		872		(1,670)
Discontinued operations								4		9		(2)
Total								(284)		363		(100)
Components of Deferred Tax Assets [Abstract]
Property and software related								728		655
Unrealized gains and losses								385		400
Loss and credit carryforwards								689		97
Regulatory balancing accounts								89		230
Pension and PBOPs								179		183
Other								1,028		890
Total								3,098		2,455
Deferred Tax Liabilities [Abstract]
Property-related								7,140		6,637
Leveraged leases								150		177
Capitalized software costs								324		293
Regulatory balancing accounts								301		293
Unrealized gains and losses								374		389
Other								296		315
Total								8,585		8,104
Accumulated deferred income tax liability – net								5,487		5,649
Deferred Tax Assets (Liabilities), Net [Abstract]
Included in deferred credits and other liabilities								5,396		5,625
Included in current liabilities								91		24
Effective Tax Rate
Income from continuing operations before income taxes								(264)		1,657		854
Net income attributable to noncontrolling interests in the Big 4 projects								0		0		(48)
Adjusted income from continuing operations before income taxes								(264)		1,657		806
Federal statutory rate (as a percent)	35.00%	35.00%				35.00%	35.00%
Provision for income tax at federal statutory rate								(92)		580		282
Items presented with related state income tax, net
Global Settlement related								0	[1]	(175)	[1]	(318)	[1]
Change in tax accounting method for asset removal costs			(40)					0	[2]	(40)	[2]	0	[2]
State tax - net of federal benefit								(19)		60		48
Employee benefits								(16)		0		0
Health care legislation								0	[3]	39	[3]	0	[3]
Production and housing credits								(68)		(66)		(63)
Property-related and other								(76)		(47)		(57)
Other								(17)		3		10
Total income tax expense from continuing operations								(288)		354		(98)
Effective tax rate										21.40%
Non-cash charge to reverse previously recognized federal tax benefits				39
Asset removal costs relating to prior periods			(28)
Unrecognized Tax Benefits
Unrecognized tax benefits, beginning balance				664		565	664	565		664		2,237
Unrecognized tax benefits, increases resulting from current period tax positions								39		42		102
Unrecognized tax benefits, increases resulting from prior period tax positions								102		273		201
Unrecognized tax benefits, decreases resulting from prior period tax positions								(75)		(332)		(224)
Unrecognized tax benefits, decreases resulting from settlements with taxing authorities								0		(82)		(1,652)
Unrecognized tax benefits, ending balance					664			631		565		664
Unrecognized tax benefits that would impact effective tax rate								532		455
Accrued Interest and Penalties
Accrued interest and penalties								242		213
Net after-tax interest income and penalties recognized in income tax expense (benefit)								18		153		80
Change in tax accounting method, cash benefit					192
Edison Capital
Items presented with related state income tax, net
After-tax earnings charge (benefit) relating to Global Settlement										254
Proceeds from Termination of Cross Border Leases before Tax										1,385
IRS Examination
Components of Deferred Tax Assets [Abstract]
Credit carryforwards								217
Operating loss carryforwards								476
Settlement of Tax Disputes
Estimated potential future federal tax payment as of the balance sheet date, including interest and penalties, based on a proposed adjustment								193
Penalty for understatement of tax liability (as a percent)								40.00%
IRS Examination | Southern California Edison Company
Settlement of Tax Disputes
Estimated potential future federal tax payment as of the balance sheet date, including interest and penalties, based on a proposed adjustment								93
IRS Examination | Expire Between 2029 and 2031 [Member]
Components of Deferred Tax Assets [Abstract]
Credit carryforwards								194
California Franchise Tax Board and other state tax authorities
Items presented with related state income tax, net
Resolution of State Tax Issues with California Franchise Tax Board								(175)
California Franchise Tax Board and other state tax authorities | Expire Between 2016 and 2023 [Member]
Components of Deferred Tax Assets [Abstract]
Operating loss carryforwards								$ 20

[1] Edison International and the IRS finalized the terms of a Global Settlement on May 5, 2009. The Global Settlement resolved federal tax disputes related to Edison Capital's cross-border, leveraged leases through 2009, and all other outstanding federal tax disputes and affirmative claims for tax years 1986 through 2002. Pursuant to the Global Settlement, Edison Capital terminated its interests in the cross-border leases and received net proceeds of $1.385 billion. The Global Settlement and termination of the Edison Capital cross-border leases resulted in a consolidated after-tax earnings charge of $254 million recorded in 2009. During 2010, Edison International recognized a $175 million earnings benefit from the acceptance by the California Franchise Tax Board of the IRS tax positions finalized in 2009 and receipt of the final interest determination from the Franchise Tax Board.

[2] During the second quarter of 2010, the IRS approved Edison International's request to change its tax accounting method for asset removal costs primarily related to SCE's infrastructure replacement program. As a result, Edison International recognized a $40 million earnings benefit (of which $28 million relates to asset removal costs incurred prior to 2010) from deducting asset removal costs earlier in the construction cycle. These deductions were recorded on a flow-through basis as required by the CPUC.

[3] During the first quarter of 2010, Edison International recorded a $39 million non-cash charge to reverse previously recognized federal tax benefits eliminated by the federal health care legislation enacted in March 2010. The health care law eliminated the federal tax deduction for retiree health care costs to the extent those costs are eligible for federal Medicare Part D subsidies.