Variable Interest Entities (Details Textuals) (USD $)	3 Months Ended														3 Months Ended
	Mar. 31, 2012 contracts	Mar. 31, 2012 entities	Mar. 31, 2011	Mar. 31, 2012 Power Purchase Agreements agreements	Mar. 31, 2012 JCP&L contracts	Mar. 31, 2011 JCP&L	Mar. 31, 2012 JCP&L Power Purchase Agreements	Mar. 31, 2011 JCP&L Power Purchase Agreements	Mar. 31, 2012 PE Power Purchase Agreements	Mar. 31, 2011 PE Power Purchase Agreements	Mar. 31, 2012 WP Power Purchase Agreements	Mar. 31, 2011 WP Power Purchase Agreements	Mar. 31, 2012 Signal Peak FEV	Oct. 18, 2011 Signal Peak FEV	Mar. 31, 2012 Variable Interest Entity, Not Primary Beneficiary	Mar. 31, 2012 PATH-WV	Mar. 31, 2012 PATH-WV Allegheny	Mar. 31, 2012 Oyster Creek Nuclear Generating Station
Variable Interest Entities (Textuals) [Abstract]
Bondable stranded costs																		$ 270,000,000
Environmental control bond	504,000,000	504,000,000
Distributions to owners															3,000,000
Joint venture, ownership percentage by parent														50.00%
Ownership interest													33.33%
Percentage of high-voltage transmission line project owned by subsidiary of AE on the Allegheny Series																100.00%
Percentage of high-voltage transmission line project owned by subsidiary of AE on the West Virginia Series																50.00%
Maximum Exposure																	30,000,000
Number of long-term power purchase agreements maintained by FirstEnergy with NUG entities				22
Number of contracts that may contain variable interest	3	3			4
Equity or debt invested in non-VIE NUG entities	0	0
Purchased power		1,347,000,000	1,186,000,000		264,000,000	370,000,000	12,000,000	65,000,000	32,000,000	11,000,000	16,000,000	5,000,000
Reserve for adverse purchase power commitment											51,000,000
Current liability included in adverse purchase power commitment											11,000,000
Net present value of FirstEnergy's consolidated sale and leaseback operating lease commitments	$ 1,600,000,000	$ 1,600,000,000