Variable Interest Entities (Details Textuals) (USD $)	1 Months Ended	3 Months Ended		9 Months Ended					3 Months Ended		9 Months Ended		12 Months Ended		1 Months Ended
	Mar. 31, 2013	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013 entities	Sep. 30, 2012	Sep. 30, 2013 Power Purchase Agreements agreements	Sep. 30, 2013 OE	Sep. 30, 2013 Other FE subsidiaries	Sep. 30, 2013 Other FE subsidiaries Power Purchase Agreements	Sep. 30, 2012 Other FE subsidiaries Power Purchase Agreements	Sep. 30, 2013 Other FE subsidiaries Power Purchase Agreements	Sep. 30, 2012 Other FE subsidiaries Power Purchase Agreements	Dec. 31, 2012 Nuclear Generation Corp Beaver Valley Unit 2	Dec. 31, 2012 FGCO Bruce Mansfield Plant	Aug. 31, 2013 Ohio Funding Companies	Jun. 30, 2013 Ohio Funding Companies	Jun. 30, 2013 Ohio Funding Companies Existing Taxable Bonds	Jun. 30, 2013 Ohio Funding Companies Existing Taxable Bonds Year 2013	Jun. 30, 2013 Ohio Funding Companies Existing Taxable Bonds Year 2015	Jun. 30, 2013 Ohio Funding Companies Existing Taxable Bonds Year 2020	Jun. 30, 2013 Ohio Funding Companies Phase In Recovery Bonds	Sep. 30, 2013 Signal Peak FEV Global Holding	Sep. 30, 2013 Path-WV
Variable Interest Entities (Textuals) [Abstract]
Debt Instrument, Face Amount																	$ 410,000,000	$ 225,000,000	$ 150,000,000	$ 35,000,000	$ 445,000,000
Weighted average interest rate on debt																	5.71%				2.48%
Make-whole premiums paid on debt redemptions				181,000,000	0										120,000,000	30,000,000
Distributions to owners				6,000,000
Equity interest by unaffiliated third party in PNBV				3.00%
Equity interest by OES Ventures in PNBV							3.00%
Ownership interest								0.00%														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%
Number of long-term power purchase agreements maintained by FirstEnergy with NUG entities						21
Number of contracts that may contain variable interest				2
Purchased power		1,120,000,000	1,063,000,000	2,932,000,000	3,367,000,000				48,000,000	65,000,000	139,000,000	184,000,000
Purchase of lessor equity interests in sale and leaseback, value	221,000,000												129,000,000	262,000,000
Net present value of FirstEnergy's consolidated sale and leaseback operating lease commitments		$ 1,200,000,000		$ 1,200,000,000