Taxes (Details) (Textuals) (USD $)	3 Months Ended		12 Months Ended					12 Months Ended				12 Months Ended				12 Months Ended
	Sep. 30, 2009	Jun. 30, 2009	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009	Dec. 31, 2011 Federal	Dec. 31, 2011 State and Local	Dec. 31, 2011 FE	Dec. 31, 2010 FE	Dec. 31, 2009 FE	Dec. 31, 2008 FE	Dec. 31, 2011 OE	Dec. 31, 2010 OE	Dec. 31, 2009 OE	Dec. 31, 2008 OE	Dec. 31, 2011 TE	Dec. 31, 2010 TE	Dec. 31, 2009 TE	Dec. 31, 2008 TE
Income Taxes (Textuals) [Abstract]
Reduction in income tax expense due to reversal of valuation allowance			$ 27,000,000
Change to FirstEnergy's earnings resulting from retiree healthcare liabilities and related tax impact already reflected in consolidated financial statements				13,000,000
Increase due to merger with AE								97,000,000				0				0
Recognized tax benefits			30,000,000
Tax benefits favorably affecting effective tax rate			5,000,000
Decrease in unrecognized tax benefits				78,000,000	100,000,000
Tax benefits favorably affecting effective tax rate				21,000,000	161,000,000
Offsetting primarily related to tax items					61,000,000
Unrecognized tax benefits expected to resolved within the next twelve month			44,000,000					117,000,000	45,000,000	191,000,000	219,000,000	0	2,000,000	77,000,000	(30,000,000)	0	0	6,000,000	(4,000,000)
Unrecognized benefits (if recognized) affecting effective tax rate			10,000,000
Repair deduction cost		281,000,000		325,000,000
Reduction in effective tax rate			7,000,000	6,000,000	56,000,000
Adjustment that increased income tax expense				8,000,000
Increase in unrecognized tax benefits	34,000,000								10,000,000	41,000,000			2,000,000	4,000,000			0	0
Increase in accrued interest			6,000,000
Reversal of accrued interest affecting effective tax rate				12,000,000
Reversal of accrued interest associated with the recognized tax benefits	161,000,000
Deferred tax assets, Operating loss carryforward included in deferred income tax expense			344,000,000
Gross deferred income tax assets, Federal net operating loss carryforwards subject to expiration						286,000,000	301,000,000
Gross deferred income tax assets, Federal AMT credits not subject to expiration			25,000,000
Pre-tax net operating loss carryforwards for state and local income tax purposes								12,863,000,000
Pre-tax net operating loss carryforwards expected to utilized			11,800,000,000
Deferred tax assets, operating loss carryforward, net			267,000,000
Credit adjustments related to prior periods														$ 7,000,000				$ 3,000,000