Variable Interest Entities (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2012
FES
Net exposure to loss based upon the casualty value provisions
Maximum Exposure	$ 1,324
Discounted Lease Payments, net	1,113	[1]
Variable Interest Entities Net Exposure	211
OE
Net exposure to loss based upon the casualty value provisions
Maximum Exposure	545
Discounted Lease Payments, net	353	[1]
Variable Interest Entities Net Exposure	192
Other FE subsidiaries
Net exposure to loss based upon the casualty value provisions
Maximum Exposure	303
Discounted Lease Payments, net	263	[1]
Variable Interest Entities Net Exposure	$ 40

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