Variable Interest Entities (Details) (USD $) In Millions, unless otherwise specified	Jun. 30, 2012
FES
Net exposure to loss based upon the casualty value provisions
Maximum Exposure	$ 1,318
Discounted Lease Payments, net	1,111	[1]
Variable Interest Entities Net Exposure	207
OE
Net exposure to loss based upon the casualty value provisions
Maximum Exposure	574
Discounted Lease Payments, net	384	[1]
Variable Interest Entities Net Exposure	190
Other First Energy Subsidiaries
Net exposure to loss based upon the casualty value provisions
Maximum Exposure	599
Discounted Lease Payments, net	333	[1]
Variable Interest Entities Net Exposure	$ 266

[1] The net present value of FirstEnergy’s consolidated sale and leaseback operating lease commitments is $1.5 billion.