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Organization and Basis of Presentation (Details Textuals) mi in Thousands, MW in Thousands, customer in Millions, $ in Millions	3 Months Ended
	Mar. 31, 2016 USD ($) customer transmission_center company mi MW	Mar. 31, 2015 USD ($)	Dec. 31, 2015 USD ($)
Property, Plant and Equipment [Line Items]
Aggregate amount of capacity \| MW	17
Length of transmission lines \| mi	24
Number of regional transmission centers \| transmission_center	2
Capitalized cost of equity	$ 8	$ 16
Capitalized interest	$ 17	$ 18
New Accounting Pronouncement, Early Adoption, Effect \| Deferred Charges and Other Assets
Property, Plant and Equipment [Line Items]
Debt issuance costs			$ 93
Regulated Distribution
Property, Plant and Equipment [Line Items]
Number of existing utility operating companies \| company	10
Number of customers served by utility operating companies \| customer	6
FES \| New Accounting Pronouncement, Early Adoption, Effect \| Deferred Charges and Other Assets
Property, Plant and Equipment [Line Items]
Debt issuance costs			$ 17