Commitments, Guarantees and Contingencies (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2011
Guarantor Obligations [Line Items]
Guarantor Obligations, Maximum Exposure, Undiscounted	$ 636
FES
Guarantor Obligations [Line Items]
Guarantor Obligations, Maximum Exposure, Undiscounted	499
AE Supply
Guarantor Obligations [Line Items]
Guarantor Obligations, Maximum Exposure, Undiscounted	68
Utilities
Guarantor Obligations [Line Items]
Guarantor Obligations, Maximum Exposure, Undiscounted	69
Credit Rating Downgrade to Below Investment Grade [Member]
Guarantor Obligations [Line Items]
Guarantor Obligations, Maximum Exposure, Undiscounted	533	[1]
Credit Rating Downgrade to Below Investment Grade [Member] | FES
Guarantor Obligations [Line Items]
Guarantor Obligations, Maximum Exposure, Undiscounted	468	[1]
Potential Acceleration Payments or Funding Obligations Due to Credit Rating Downgrade	205
Credit Rating Downgrade to Below Investment Grade [Member] | AE Supply
Guarantor Obligations [Line Items]
Guarantor Obligations, Maximum Exposure, Undiscounted	8	[1]
Credit Rating Downgrade to Below Investment Grade [Member] | Utilities
Guarantor Obligations [Line Items]
Guarantor Obligations, Maximum Exposure, Undiscounted	57	[1]
Potential Acceleration Payments or Funding Obligations Due to Credit Rating Downgrade	47
Material Adverse Event [Member]
Guarantor Obligations [Line Items]
Guarantor Obligations, Maximum Exposure, Undiscounted	103	[2]
Material Adverse Event [Member] | FES
Guarantor Obligations [Line Items]
Guarantor Obligations, Maximum Exposure, Undiscounted	31	[2]
Potential Acceleration Payments or Funding Obligations Due to a Material Adverse Event	31
Material Adverse Event [Member] | AE Supply
Guarantor Obligations [Line Items]
Guarantor Obligations, Maximum Exposure, Undiscounted	60	[2]
Material Adverse Event [Member] | Utilities
Guarantor Obligations [Line Items]
Guarantor Obligations, Maximum Exposure, Undiscounted	$ 12	[2]

[1] Includes $205 million and $47 million that are also considered accelerations of payment or funding obligations for FES and the Utilities, respectively.

[2] Includes $31 million that is also considered an acceleration of payment or funding obligation at FES.