Document and Entity Information	9 Months Ended
Sep. 30, 2011	Oct. 31, 2011
Entity Registrant Name	FIRSTENERGY CORP
Entity Central Index Key	0001031296
Document Type	10-Q
Document Period End Date	Sep. 30, 2011
Amendment Flag	false
Document Fiscal Year Focus	2011
Document Fiscal Period Focus	Q3
Current Fiscal Year End Date	--12-31
Entity Well Known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Filer Category	Large Accelerated Filer
Entity Common Stock Shares Outstanding		418,216,437
FES
Entity Common Stock Shares Outstanding		7
OE
Entity Common Stock Shares Outstanding		60
CEI
Entity Common Stock Shares Outstanding		67,930,743
TE
Entity Common Stock Shares Outstanding		29,402,054
JCP&L
Entity Common Stock Shares Outstanding		13,628,447
Met-Ed
Entity Common Stock Shares Outstanding		740,905
Penelec
Entity Common Stock Shares Outstanding		4,427,577

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Reference 1: http://www.xbrl.org/2003/role/presentationRef

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