Derivative Instruments (Details 1)	Sep. 30, 2012 MWh
Power Contracts
Volume of First Energy's outstanding derivative transactions
Purchases, in ones	33,000,000
Sales, in ones	38,000,000
Net, in ones	(5,000,000)
FTRs
Volume of First Energy's outstanding derivative transactions
Purchases, in ones	67,000,000
Sales, in ones	0
Net, in ones	67,000,000
NUGs
Volume of First Energy's outstanding derivative transactions
Purchases, in ones	16,000,000
Sales, in ones	0
Net, in ones	16,000,000
LCAPP
Volume of First Energy's outstanding derivative transactions
Volume of Derivatives, Purchases, in ones	408,000,000
Volume of Derivatives, Sales, in ones	0
Volume of Derivatives, Net, in ones	408,000,000
Natural Gas Futures
Volume of First Energy's outstanding derivative transactions
Purchases, in ones	16,000,000
Sales, in ones	0
Net, in ones	16,000,000