Variable Interest Entities (Details) (USD $) In Millions, unless otherwise specified	Mar. 31, 2013
FES
Net exposure to loss based upon the casualty value provisions
Maximum Exposure	$ 1,345
Discounted Lease Payments, net	1,132	[1]
Net Exposure	213
Other FE subsidiaries
Net exposure to loss based upon the casualty value provisions
Maximum Exposure	811
Discounted Lease Payments, net	624	[1]
Net Exposure	$ 187

[1] The net present value of FirstEnergy’s consolidated sale and leaseback operating lease commitments is $1.2 billion.