Taxes (Details 1) (USD $) In Millions, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Reconciliation of federal income tax expense at the federal statutory rate to the total provision for income taxes
Book income (loss) before provision for income taxes									$ 1,323	$ 1,459	$ 1,204
Federal income tax expense at statutory rate									463	511	421
Increases (reductions) in taxes resulting from-
Amortization of investment tax credits									(11)	(11)	(9)
State income taxes, net of federal tax benefit									69	28	40
State unitary tax adjustments										33
Manufacturing deduction										16
Medicare Part D									32	36	17
Effectively settled tax items									(20)	(11)	(34)
State valuation allowance									60	(19)
Income Tax Reconciliation, Change in Deferred State Apportionment Tax Assets Valuation Allowance									(50)
Other, net									10	(9)	27
Total provision for income taxes	(105)	309	127	222	24	325	114	111	553	574	462
FES
Reconciliation of federal income tax expense at the federal statutory rate to the total provision for income taxes
Book income (loss) before provision for income taxes									298	(70)	356
Federal income tax expense at statutory rate									104	(25)	125
Increases (reductions) in taxes resulting from-
Amortization of investment tax credits									(4)	(4)	(4)
State income taxes, net of federal tax benefit									18	4	7
State unitary tax adjustments										0
Manufacturing deduction										13
Medicare Part D									1	4	1
Effectively settled tax items									(11)	(2)	(2)
State valuation allowance									0	2
Income Tax Reconciliation, Change in Deferred State Apportionment Tax Assets Valuation Allowance									0
Other, net									3	(3)	(2)
Total provision for income taxes	(34)	68	1	76	(125)	78	10	26	111	(11)	125
OE
Reconciliation of federal income tax expense at the federal statutory rate to the total provision for income taxes
Book income (loss) before provision for income taxes									175	206	233
Federal income tax expense at statutory rate									61	72	82
Increases (reductions) in taxes resulting from-
Amortization of investment tax credits									(1)	(1)	(1)
State income taxes, net of federal tax benefit									7	1	1
State unitary tax adjustments										0
Manufacturing deduction										3
Medicare Part D									6	6	2
Effectively settled tax items									(1)	(3)	(9)
State valuation allowance									0	0
Income Tax Reconciliation, Change in Deferred State Apportionment Tax Assets Valuation Allowance									0
Other, net									2	0	3
Total provision for income taxes	(2)	34	21	21	6	34	18	20	74	78	78
JCP&L
Reconciliation of federal income tax expense at the federal statutory rate to the total provision for income taxes
Book income (loss) before provision for income taxes									240	261	330
Federal income tax expense at statutory rate									84	91	116
Increases (reductions) in taxes resulting from-
Amortization of investment tax credits									0	0	0
State income taxes, net of federal tax benefit									17	18	24
State unitary tax adjustments										0
Manufacturing deduction										0
Medicare Part D									5	6	4
Effectively settled tax items									0	0	0
State valuation allowance									0	0
Income Tax Reconciliation, Change in Deferred State Apportionment Tax Assets Valuation Allowance									0
Other, net									1	2	3
Total provision for income taxes	$ (7)	$ 62	$ 30	$ 22	$ 4	$ 61	$ 32	$ 20	$ 107	$ 117	$ 147