Discontinued Operations (Details) (USD $) In Millions, unless otherwise specified	9 Months Ended		1 Months Ended	9 Months Ended				3 Months Ended	9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Apr. 30, 2014 Edison Mission Energy	Sep. 30, 2014 Edison Mission Energy installment	Aug. 31, 2014 Edison Mission Energy	Apr. 01, 2014 Edison Mission Energy	Dec. 31, 2013 Edison Mission Energy	Sep. 30, 2014 Edison Mission Energy Discontinued Operations	Sep. 30, 2014 Edison Mission Energy Discontinued Operations
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						$ 342
Percentage of Tax Benefits To Be Paid				50.00%
Tax Attributes Estimated Amount							1,191
Cash Portion of Settlement Payment	225	0	225
Tax Attributes					1,206
Number of Installments				2
Tax Attribute Including Interest, Installment One				204
Tax Attribute Including Interest Installment Two				214
Gain (Loss) Related to EME Settlement								$ (16)	$ 168