Variable Interest Entities (Details Textuals) (USD $)	12 Months Ended											12 Months Ended					3 Months Ended
	Dec. 31, 2011 entities agreements	Dec. 31, 2010	Dec. 31, 2009	Dec. 31, 2011 OE	Dec. 31, 2011 JCP&L	Dec. 31, 2010 JCP&L	Dec. 31, 2009 JCP&L	Dec. 31, 2011 Variable Interest Entity, Not Primary Beneficiary [Member]	Dec. 31, 2011 PATH-WV	Dec. 31, 2011 PATH-WV Allegheny	Dec. 31, 2011 Oyster Creek Nuclear Generating Station	Dec. 31, 2011 Power Purchase Agreements JCP&L	Dec. 31, 2010 Power Purchase Agreements JCP&L	Dec. 31, 2009 Power Purchase Agreements JCP&L	Dec. 31, 2011 Power Purchase Agreements PE	Dec. 31, 2011 Power Purchase Agreements WP	Dec. 31, 2011 Signal Peak	Dec. 31, 2011 Signal Peak FEV [Member]	Sep. 30, 2011 Signal Peak FEV [Member]	Dec. 31, 2008 Signal Peak FEV [Member]
Variable Interest Entities (Textuals) [Abstract]
Bondable stranded costs											$ 287,000,000
Environmental control bond	513,000,000
Change in Noncontrolling interest, Equity contributions from owners								27,000,000
Deconsolidation of Signal Peak								45,000,000									569,000,000
Gain (loss) on divestiture, net of tax																	370,000,000
Income (loss) attributable to noncontrolling interest	(16,000,000)	(24,000,000)	(16,000,000)					(16,000,000)
Distributions to owners								5,000,000
Equity investments																				133,500,000
Joint venture, ownership percentage by parent																			50.00%
Proceeds from deconsolidation																	257,500,000
Gain on remeasurement of retained interest																	378,600,000
Ownership interest																		33.33%
Equity interest by unaffiliated third party in PNBV	3.00%
Equity interest by OES Ventures in PNBV				3.00%
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				606,000,000						29,000,000
Purchased power	4,986,000,000	4,624,000,000	4,730,000,000		1,382,000,000	1,736,000,000	1,783,000,000					176,000,000	243,000,000	225,000,000	101,600,000	48,900,000
Reserve for adverse purchase power commitment																53,000,000
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
Equity or debt invested in non-VIE NUG entities	$ 0
Number of contracts that may contain variable interest	4
Number of long-term power purchase agreements maintained by FirstEnergy with NUG entities	23