Capitalization (Details Textuals) (USD $)	3 Months Ended							12 Months Ended							12 Months Ended								3 Months Ended
	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2012 Beaver Valley Unit 2	Dec. 31, 2012 Perry Plant	Dec. 31, 2012 OE	Dec. 31, 2011 OE	Dec. 31, 2012 OE PCRB	Dec. 31, 2012 TrAIL	Dec. 31, 2012 AGC	Dec. 31, 2012 FES	Dec. 31, 2011 FES	Dec. 31, 2012 JCP&L	Dec. 31, 2011 JCP&L	Dec. 31, 2012 JCP&L PCRB	Dec. 31, 2012 JCP&L Maximum series	Mar. 31, 2013 Dividend Paid
Debt Instrument [Line Items]
Retained earnings (accumulated deficit)	$ 2,888,000,000				$ 3,047,000,000			$ 2,888,000,000	$ 3,047,000,000			$ 17,000,000	$ (84,000,000)				$ 2,118,000,000	$ 1,931,000,000	$ 64,000,000	$ 121,000,000
Dividends declared								$ 2.2	$ 2.2
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			0	0
Preference shares outstanding	0				0			0	0
Remarketed Pollution Control Revenue Bond	493,000,000				513,000,000			493,000,000	513,000,000					0							0
Transition bond outstanding	243,000,000				287,000,000			243,000,000	287,000,000
Number of series of bonds																						2
Aggregate annual servicing fees receivable on transition bonds																						628,000
Annual sinking fund requirement for FMB								7,000,000
Current payable of long term pollution control revenue bonds	809,000,000							809,000,000									736,000,000
LOC Related To Sale And Lease Back										102,000,000	31,000,000
Principal default amount specified in debt covenants								$ 100,000,000