Discontinued Operations (Details) (Edison Mission Energy, USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2014 installments	Feb. 18, 2014
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Liabilities For Joint Tax and Qualified Retirement Plans Resulting from Deconsolidation	$ 350
Percentage of Tax Benefits To Be Paid	50.00%
Tax Attributes Estimated Amount	1,191
Estimated Period for Updating Procedure	6 months
Cash Portion of Settlement Payment	225
Number of Installments	2
Interest Rate On Installments	5.00%
Tax Attribute Including Interest, Installment One	199
Tax Attribute Including Interest Installment Two	210
Amount Required for Escrow		50
Estimated Amount That Tax Benefits Will Exceed Liabilities	200
Deferred Tax Assets, Net of Valuation Allowance	198
Provision for losses	150
Cumulative impact of deconsolidation on earnings	48
Subsequent Event [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Estimated Income From Settlement Expected to Be Recorded	$ 152