Variable Interest Entities (Details Textuals) (USD $)	3 Months Ended		6 Months Ended				3 Months Ended		6 Months Ended		3 Months Ended		6 Months Ended		3 Months Ended		6 Months Ended		3 Months Ended		6 Months Ended				6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012 contracts	Jun. 30, 2012 entities	Jun. 30, 2011	Jun. 30, 2012 Power Purchase Agreements agreements	Jun. 30, 2012 JCP&L	Jun. 30, 2011 JCP&L	Jun. 30, 2012 JCP&L	Jun. 30, 2011 JCP&L contracts	Jun. 30, 2012 JCP&L Power Purchase Agreements	Jun. 30, 2011 JCP&L Power Purchase Agreements	Jun. 30, 2012 JCP&L Power Purchase Agreements	Jun. 30, 2011 JCP&L Power Purchase Agreements	Jun. 30, 2012 PE Power Purchase Agreements	Jun. 30, 2011 PE Power Purchase Agreements	Jun. 30, 2012 PE Power Purchase Agreements	Jun. 30, 2011 PE Power Purchase Agreements	Jun. 30, 2012 WP Power Purchase Agreements	Jun. 30, 2011 WP Power Purchase Agreements	Jun. 30, 2012 WP Power Purchase Agreements	Jun. 30, 2011 WP Power Purchase Agreements	Jun. 30, 2012 Signal Peak FEV	Oct. 18, 2011 Signal Peak FEV	Jun. 30, 2012 Variable Interest Entity, Not Primary Beneficiary	Jun. 30, 2012 PATH-WV	Jun. 30, 2012 PATH-WV Allegheny	Jun. 30, 2012 Oyster Creek Nuclear Generating Station
Variable Interest Entities (Textuals) [Abstract]
Bondable stranded costs																												$ 262,000,000
Environmental control bond	503,000,000		503,000,000	503,000,000
Income (loss) attributable to noncontrolling interest	1,000,000	(10,000,000)		1,000,000	(15,000,000)																				1,000,000
Distributions to owners																									5,000,000
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																											31,000,000
Number of long-term power purchase agreements maintained by FirstEnergy with NUG entities						21
Number of contracts that may contain variable interest			3	3						4
Purchased power	1,156,000,000	1,220,000,000		2,503,000,000	2,406,000,000		254,000,000	328,000,000	518,000,000	698,000,000	14,000,000	55,000,000	26,000,000	120,000,000	27,000,000	47,000,000	59,000,000	58,000,000	17,000,000	21,000,000	33,000,000	26,000,000
Reserve for adverse purchase power commitment																			48,000,000		48,000,000
Current liability included in adverse purchase power commitment																			11,000,000		11,000,000
Net present value of FirstEnergy's consolidated sale and leaseback operating lease commitments	$ 1,500,000,000		$ 1,500,000,000	$ 1,500,000,000