Organization and Basis of Presentation (Details Textuals) mi in Thousands, MW in Thousands, customer in Millions, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2016 USD ($) transmission_center	Jun. 30, 2015 USD ($)	Jun. 30, 2016 USD ($) customer transmission_center company mi MW	Jun. 30, 2015 USD ($)	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		2
Capitalized cost of equity	$ 9	$ 14	$ 17	$ 30
Capitalized interest	17	19	34	37
Impairment of assets	1,447	16	$ 1,447	16
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
Impairment of assets	0	0	$ 0	0
FES
Property, Plant and Equipment [Line Items]
Impairment of assets	$ 540	$ 16	$ 540	$ 16
FES | New Accounting Pronouncement, Early Adoption, Effect | Deferred Charges and Other Assets
Property, Plant and Equipment [Line Items]
Debt issuance costs					$ 17