Variable Interest Entities (Details) (USD $) In Millions, unless otherwise specified	Sep. 30, 2012
FES
Net exposure to loss based upon the casualty value provisions
Maximum Exposure	$ 1,339
Discounted Lease Payments, net	1,123	[1]
Variable Interest Entities Net Exposure	216
OE
Net exposure to loss based upon the casualty value provisions
Maximum Exposure	551
Discounted Lease Payments, net	390	[1]
Variable Interest Entities Net Exposure	161
Other FE Subsidiaries
Net exposure to loss based upon the casualty value provisions
Maximum Exposure	561
Discounted Lease Payments, net	326	[1]
Variable Interest Entities Net Exposure	$ 235

[1] The net present value of FirstEnergy’s consolidated sale and leaseback operating lease commitments is $1.4 billion.