CONSOLIDATED STATEMENTS OF OPERATIONS (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Income Statement [Abstract]
Operating Revenues	$ 2,180	$ 2,423	$ 2,377
Operating Expenses
Fuel	799	809	796
Plant operations	709	654	579
Plant operating leases	177	178	177
Depreciation and amortization	310	248	236
Asset impairments and other charges (Notes 1 and 13)	1,746	45	4
Administrative and general	180	182	196
Total operating expenses	3,921	2,116	1,988
Operating income (loss)	(1,741)	307	389
Other Income (Expense)
Equity in income from unconsolidated affiliates	86	104	100
Dividend income	30	19	12
Interest income	1	2	7
Interest expense	(323)	(263)	(296)
Other income (expense), net	15	9	5
Total other expense	(191)	(129)	(172)
Income (loss) from continuing operations before income taxes	(1,932)	178	217
Provision (benefit) for income taxes	(856)	19	16
Income (Loss) from Continuing Operations	(1,076)	159	201
Income (Loss) from Operations of Discontinued Subsidiaries, net of tax (Note 14)	(3)	4	(7)
Net Income (Loss)	(1,079)	163	194
Net Loss Attributable to Noncontrolling Interests	1	1	3
Net Income (Loss) Attributable to Edison Mission Energy Common Shareholder	(1,078)	164	197
Amounts Attributable to Edison Mission Energy Common Shareholder
Income (loss) from continuing operations, net of tax	(1,075)	160	204
Income (loss) from discontinued operations, net of tax	(3)	4	(7)
Net Income (Loss) Attributable to Edison Mission Energy Common Shareholder	$ (1,078)	$ 164	$ 197