Capitalization (Details Textuals) (USD $)	3 Months Ended							12 Months Ended																		3 Months Ended
	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2010	Sep. 30, 2010	Jun. 30, 2010	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2011 Perry Plant [Member]	Dec. 31, 2011 Beaver Valley Unit 2 [Member]	Dec. 31, 2011 TrAIL	Dec. 31, 2011 AGC	Dec. 31, 2011 Met-Ed	Dec. 31, 2011 Penelec	Dec. 31, 2010 Penelec	Dec. 31, 2011 FES	Dec. 31, 2010 FES	Dec. 31, 2011 TE	Dec. 31, 2010 TE	Dec. 31, 2011 OE	Dec. 31, 2010 OE	Dec. 31, 2011 JCP&L	Dec. 31, 2010 JCP&L	Dec. 31, 2011 JCP&L Maximum	Mar. 31, 2012 Dividend Paid [Member]	Dec. 31, 2011 PCRB [Member] Met-Ed	Dec. 31, 2011 PCRB [Member] Penelec	Dec. 31, 2011 PCRB [Member] FES	Dec. 31, 2011 PCRB [Member] OE	Dec. 31, 2011 PCRB [Member] JCP&L
Debt Instrument [Line Items]
Retained Earnings (Accumulated Deficit)	$ 3,047,000,000				$ 3,084,000,000			$ 3,047,000,000	$ 3,084,000,000						$ (97,806,000)	$ (90,879,000)	$ 1,931,000,000	$ 1,990,000,000	$ 43,220,000	$ 42,500,000	$ (84,000,000)	$ (112,000,000)	$ 121,000,000	$ (23,000,000)
Dividends declared								$ 2.20	$ 2.20
Common Stock Dividends Per Share Paid	$ 0.55	$ 0.55	$ 0.55	$ 0.55	$ 0.55	$ 0.55	$ 0.55																			$ 0.55
Minimum Equity To Total Capitalization Ratio To Be Maintained for Payment of Capital Dividend								35.00%				50.00%	45.00%
Preferred shares shares outstanding	0							0
Preference shares outstanding	0							0
Remarketed Pollution Control Revenue Bond	513,000,000							513,000,000																						0	0
Transition bond outstanding	287,000,000							287,000,000
Aggregate annual servicing fees receivable on transition bonds																									628,000
Annual sinking fund requirement for FMB	6,000,000							6,000,000
Current payable of long term pollution control revenue bonds	632,000,000							632,000,000						29,000,000	45,000,000		558,000,000
Long-term Debt, Maturities, Repayments of Principal in Next Twelve Months														29,000,000	45,000,000		896,000,000		0		0		34,000,000				28,000,000	45,000,000	828,000,000
Long-term Debt, Maturing in Years Two and Three																			0
Long-term Debt, Maturing in Years Four and Five																			0
LOC Related To Sale And Lease Back										37,000,000	116,000,000
Principal Default Amount Specified In Debt Covenants								$ 100,000,000