Leases (Details Textuals) $ in Millions		1 Months Ended	12 Months Ended
	Feb. 12, 2014 USD ($) MW	Nov. 30, 2014 USD ($) MW	Dec. 31, 2007	Dec. 30, 1987	Dec. 31, 2015
Leases (Textuals) [Abstract]
Period of lease terms on the portions sold by OE of its ownership interests in Perry Unit 1 and Beaver Valley Unit 2 in years				29 years
Period of lease terms on the portions sold by CEI and TE of their ownership interests in Beaver Valley Unit 2 and Bruce Mansfield Units				30 years
Beaver Valley Unit 2
Leases (Textuals) [Abstract]
Percentage leased					2.60%
Bruce Mansfield Unit 1
Leases (Textuals) [Abstract]
Percentage leased					93.83%
Perry Power Plant Unit 1
Leases (Textuals) [Abstract]
Percentage leased					3.75%
FGCO
Leases (Textuals) [Abstract]
Percentage of undivided interest of FGCO in Bruce Mansfield Unit 1			93.825%
FGCO | Bruce Mansfield Unit 1
Leases (Textuals) [Abstract]
Basic terms of operating lease			33 years
Nuclear Generation Corp | Beaver Valley Unit 2
Leases (Textuals) [Abstract]
Purchase of lessor equity interests in sale and leaseback (in MW) | MW	47.7
Purchase of lessor equity interests in sale and leaseback, value | $	$ 94
Nuclear Generation Corp | Perry Power Plant Unit 1
Leases (Textuals) [Abstract]
Purchase of lessor equity interests in sale and leaseback (in MW) | MW		55.3
Purchase of lessor equity interests in sale and leaseback, value | $		$ 87