Commitments, Guarantees and Contingencies (Details) (USD $)	3 Months Ended		9 Months Ended	12 Months Ended			1 Months Ended									9 Months Ended	12 Months Ended	9 Months Ended						9 Months Ended																					9 Months Ended						3 Months Ended		3 Months Ended	9 Months Ended		9 Months Ended
	Sep. 30, 2011	Jun. 30, 2011	Sep. 30, 2011 options years	Dec. 31, 2010 auctions	May 02, 2011	Mar. 31, 2011	Oct. 31, 2011 Nuclear Plant Matters Areas	Mar. 28, 2011 Nuclear Plant Matters Shortfall	Jun. 24, 2011 Nuclear Plant Matters Proposed Guarantee	Sep. 30, 2011 CEI Regulation of Waste Disposal	Sep. 30, 2011 TE Regulation of Waste Disposal	Sep. 30, 2011 JCP&L Regulation of Waste Disposal	Sep. 30, 2011 Regulation of Waste Disposal	Sep. 30, 2011 Regulation of Waste Disposal FE	Sep. 30, 2011 Regulation of Waste Disposal FGCO	Sep. 30, 2011 Monongahela River Water Quality	Dec. 31, 2010 Monongahela River Water Quality	Sep. 30, 2011 Clean Water Act	Sep. 30, 2011 Clean Water Act FGCO spills	Sep. 30, 2011 CAIR [Member] phases	Sep. 30, 2011 CSAPR [Member] phases	Sep. 30, 2011 Climate change celsius	Jan. 02, 2011 Climate change T	Sep. 30, 2011 Climate change Increase in funding	Sep. 30, 2011 National Ambient Air Quality Standards T	Sep. 30, 2011 State Air Quality Compliance	Sep. 30, 2011 Caa Compliance	Sep. 30, 2011 Caa Compliance FGCO plantiffs	Sep. 30, 2011 Class Action [Member]	Sep. 30, 2011 FES Additional Requirements	Sep. 30, 2011 Additional Requirements AE Supply	Sep. 30, 2011 Guarantees and other Assurances	Sep. 30, 2011 Guarantees and other Assurances Parental Guarantees	Sep. 30, 2011 Guarantees and other Assurances Energy and Energy-related Activities	Sep. 30, 2011 Guarantees and other Assurances Subsidiaries Guarantees	Sep. 30, 2011 Guarantees and other Assurances Surety Bonds and Lines Of Credit	Sep. 30, 2011 Normal Condition	Sep. 30, 2011 Normal Condition Below Investment Grade Credit Rating	Sep. 30, 2011 Normal Condition Material Adverse Event	Sep. 30, 2011 Normal Condition Acceleration of Payment	Sep. 30, 2011 Stress Condition	May 02, 2011 MP Supply	Sep. 30, 2011 FGCO	Dec. 31, 2010 FGCO	Sep. 30, 2011 JCP&L plantiffs lawsuits	Dec. 31, 2010 JCP&L	Sep. 30, 2011 OE	Dec. 31, 2010 OE	Sep. 30, 2011 TE	Dec. 31, 2010 TE	Sep. 30, 2011 FES	Dec. 31, 2010 FES	Sep. 30, 2011 AE Supply	Sep. 30, 2011 AE Supply	May 02, 2011 AE Supply	Sep. 30, 2011 2012	Sep. 30, 2011 2025
Commitments Guarantees and Contingencies [Line Items]
Outstanding guarantees and other assurances aggregated																																$ 3,800,000,000	$ 900,000,000	$ 300,000,000	$ 2,500,000,000	$ 400,000,000
Surety bonds and related guarantees	147,000,000		147,000,000
Reduction in air emissions and compliance						81.00%
Required reduction in mercury by the beginning of 2010																										80.00%
Number of RGGI auctions held				10
Number of phases under the EPA’s CAIR for reductions of Sulfur Dioxide and Mono-Nitrogen Oxides																				2	2
Days In Federal Register																					60 days
Capping of SO2 Emissions Under CSAPR																									2,400,000
Outstanding collateral payments																																																			123,000,000		1,000,000	1,000,000
Outstanding collateral payments additional requirement	48,000,000		48,000,000																											16,000,000	1,000,000
Signal Peak and Global Rail entered into a syndicated two-year senior secured term loan facility	350,000,000		350,000,000
Maximum exposure under collateral provisions																																					594,000,000	495,000,000	99,000,000	257,000,000	662,000,000
Number of complaints filed against FGCO																											3
Number of complaints seek enjoin plant			2
Number of individuals behalf of which complaint filed			21
Number of named plaintiffs as class representatives																												8																	9
Number of days required prior to the filing of a citizen suit under notice																											60 days
JCP&L former owning in Keystone Station (In Percentage)																											16.67%
Capping of SO2 emissions (In Tons)																									2,500,000
Capping of NOx emissions under CSAPR																									1,200,000
Pretax impairment for obsolete NOx emission allowances	6,000,000																																																		1,000,000		5,000,000
Capping of NOx emissions (In Tons)																									1,300,000
Electricity production from renewable sources																																																								10.00%	25.00%
Upper threshold limit for carbon di oxide emission (Tons per Year)																							75,000
Increase (Decrease) in Global Temperature																						2
Total environmental liabilities										1,000,000	1,000,000	69,000,000	103,000,000	31,000,000	1,000,000
Parental guarantee associated with the funding of decommissioning costs								92,500,000	95,000,000
Renewal length of operating license for Davis-Besse Nuclear Power Station			20 years
Contentions admitted by ASLB opposing Davis-Besse license renewal			2
Localized areas featuring sub-surface hairline cracks not associated with architectural elements							2
Percent confidence level																																																			95.00%
Funds provided for Copenhagen Green Climate Fund																						30,000,000,000		100,000,000,000
Emission allowance, current	26,000,000		26,000,000
Proposed Greenhouse Gas emissions reduction by Twenty Fifty																						80.00%
Environmental Liabilities Former Gas Facilities													63,000,000
Number of electric generation facilities																											10
Number of generation units																													22
Sulfate impairment designation for an approximately mile stretch of the river																	68
TMDL Limit Development Period			5 years
Options proposed by EPA for additional regulation of coal combustion residuals			2
Estimated clean up cost			59,000,000
Additional expenses recognized for clean up cost		29,000,000
Previously reserved clean up cost				30,000,000
Class action lawsuits no longer certified as class action																																													2
Decommissioning Fund Investments	2,060,000,000		2,060,000,000	1,973,000,000																																							0	0	194,000,000	182,000,000	136,000,000	127,000,000	78,214,000	75,558,000	1,187,000,000	1,146,000,000
Loss incurred in damages for replacement coal purchased																																																						80,000,000
Amount for replacement coal and interest					14,000,000
Annual percentage that fish impingement should be reduced to, per CWA																		12.00%
Extension of comment period			30 days															30 days
Number of petroleum spills for which prosecution is no longer being considered under the Clean Water and Migratory Bird Treaty Acts																			3
Additional damages incurred for future shortfalls																																																						150,000,000
Maximum Capital Investment Required To Install Technology To Meet Tds and Sulfate Limits																150,000,000
Amount for which verdict entered for future damages																																										$ 90,000,000													$ 104,000,000