Derivative Instruments (Details 2)	Dec. 31, 2014 MWh
Power Contracts
Volume of First Energy's outstanding derivative transactions
Purchases (in MWH or mmBTUs)	21,000,000
Sales (in MWH or mmBTUs)	33,000,000
Net (in MWH or mmBTUs)	(12,000,000)
FTRs
Volume of First Energy's outstanding derivative transactions
Purchases (in MWH or mmBTUs)	43,000,000
Sales (in MWH or mmBTUs)	0
Net (in MWH or mmBTUs)	43,000,000
NUGs
Volume of First Energy's outstanding derivative transactions
Purchases (in MWH or mmBTUs)	6,000,000
Sales (in MWH or mmBTUs)	0
Net (in MWH or mmBTUs)	6,000,000
Natural Gas
Volume of First Energy's outstanding derivative transactions
Purchases (in MWH or mmBTUs)	40,000,000
Sales (in MWH or mmBTUs)	0
Net (in MWH or mmBTUs)	40,000,000