Transactions With Affiliated Companies (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
FES
Investment Income:
Interest income from affiliates	$ 0	$ 0	$ 0
Interest income from FirstEnergy	2	3	4
Interest Expense:
Interest expense to affiliates	5	9	6
Interest expense to FirstEnergy	1	0	4
OE
Investment Income:
Interest income from affiliates	0	0	15
Interest income from FirstEnergy	0	0	1
Interest Expense:
Interest expense to affiliates	4	3	5
Interest expense to FirstEnergy	0	0	1
CEI
Investment Income:
Interest income from affiliates	0	0	0
Interest income from FirstEnergy	0	0	0
Interest Expense:
Interest expense to affiliates	10	14	17
Interest expense to FirstEnergy	0	1	1
TE
Investment Income:
Interest income from affiliates	9	12	17
Interest income from FirstEnergy	0	0	0
Interest Expense:
Interest expense to affiliates	1	1	2
Interest expense to FirstEnergy	0	0	1
JCP&L
Investment Income:
Interest income from affiliates	0	0	0
Interest income from FirstEnergy	0	0	0
Interest Expense:
Interest expense to affiliates	4	4	4
Interest expense to FirstEnergy	1	0	0
Met-Ed
Investment Income:
Interest income from affiliates	0	0	0
Interest income from FirstEnergy	0	0	1
Interest Expense:
Interest expense to affiliates	3	2	3
Interest expense to FirstEnergy	1	0	0
Penelec
Investment Income:
Interest income from affiliates	0	0	0
Interest income from FirstEnergy	0	0	0
Interest Expense:
Interest expense to affiliates	2	2	2
Interest expense to FirstEnergy	1	0	1
Electric Sales [Member] | FES
REVENUES:
Related Party Transaction, Revenues from Transactions with Related Party	752	2,227	2,826
Electric Sales [Member] | OE
REVENUES:
Related Party Transaction, Revenues from Transactions with Related Party	200	190	189
Electric Sales [Member] | CEI
REVENUES:
Related Party Transaction, Revenues from Transactions with Related Party	2	2	2
Electric Sales [Member] | TE
REVENUES:
Related Party Transaction, Revenues from Transactions with Related Party	55	46	38
Electric Sales [Member] | JCP&L
REVENUES:
Related Party Transaction, Revenues from Transactions with Related Party	0	0	0
Electric Sales [Member] | Met-Ed
REVENUES:
Related Party Transaction, Revenues from Transactions with Related Party	0	73	0
Electric Sales [Member] | Penelec
REVENUES:
Related Party Transaction, Revenues from Transactions with Related Party	0	65	0
Ground Lease [Member] | FES
REVENUES:
Related Party Transaction, Revenues from Transactions with Related Party	0	0	0
Ground Lease [Member] | OE
REVENUES:
Related Party Transaction, Revenues from Transactions with Related Party	12	12	12
Ground Lease [Member] | CEI
REVENUES:
Related Party Transaction, Revenues from Transactions with Related Party	7	7	7
Ground Lease [Member] | TE
REVENUES:
Related Party Transaction, Revenues from Transactions with Related Party	2	2	2
Ground Lease [Member] | JCP&L
REVENUES:
Related Party Transaction, Revenues from Transactions with Related Party	0	0	0
Ground Lease [Member] | Met-Ed
REVENUES:
Related Party Transaction, Revenues from Transactions with Related Party	0	0	0
Ground Lease [Member] | Penelec
REVENUES:
Related Party Transaction, Revenues from Transactions with Related Party	0	0	0
Other Revenue [Member] | FES
REVENUES:
Related Party Transaction, Revenues from Transactions with Related Party	80	88	30
Other Revenue [Member] | OE
REVENUES:
Related Party Transaction, Revenues from Transactions with Related Party	1	1	1
Other Revenue [Member] | CEI
REVENUES:
Related Party Transaction, Revenues from Transactions with Related Party	3	7	6
Other Revenue [Member] | TE
REVENUES:
Related Party Transaction, Revenues from Transactions with Related Party	0	1	1
Other Revenue [Member] | JCP&L
REVENUES:
Related Party Transaction, Revenues from Transactions with Related Party	0	0	0
Other Revenue [Member] | Met-Ed
REVENUES:
Related Party Transaction, Revenues from Transactions with Related Party	10	10	10
Other Revenue [Member] | Penelec
REVENUES:
Related Party Transaction, Revenues from Transactions with Related Party	0	0	0
Purchased Power [Member] | FES
EXPENSES:
Related Party Transaction, Expenses from Transactions with Related Party	252	371	222
Purchased Power [Member] | OE
EXPENSES:
Related Party Transaction, Expenses from Transactions with Related Party	287	522	993
Purchased Power [Member] | CEI
EXPENSES:
Related Party Transaction, Expenses from Transactions with Related Party	143	361	735
Purchased Power [Member] | TE
EXPENSES:
Related Party Transaction, Expenses from Transactions with Related Party	94	181	393
Purchased Power [Member] | JCP&L
EXPENSES:
Related Party Transaction, Expenses from Transactions with Related Party	0	0	0
Purchased Power [Member] | Met-Ed
EXPENSES:
Related Party Transaction, Expenses from Transactions with Related Party	143	612	365
Purchased Power [Member] | Penelec
EXPENSES:
Related Party Transaction, Expenses from Transactions with Related Party	208	643	342
Fuel [Member] | FES
EXPENSES:
Related Party Transaction, Expenses from Transactions with Related Party	37	46	15
Fuel [Member] | OE
EXPENSES:
Related Party Transaction, Expenses from Transactions with Related Party	0	0	0
Fuel [Member] | CEI
EXPENSES:
Related Party Transaction, Expenses from Transactions with Related Party	0	0	0
Fuel [Member] | TE
EXPENSES:
Related Party Transaction, Expenses from Transactions with Related Party	0	0	0
Fuel [Member] | JCP&L
EXPENSES:
Related Party Transaction, Expenses from Transactions with Related Party	0	0	0
Fuel [Member] | Met-Ed
EXPENSES:
Related Party Transaction, Expenses from Transactions with Related Party	0	0	0
Fuel [Member] | Penelec
EXPENSES:
Related Party Transaction, Expenses from Transactions with Related Party	0	0	0
Support Services [Member] | FES
EXPENSES:
Related Party Transaction, Expenses from Transactions with Related Party	655	620	584
Support Services [Member] | OE
EXPENSES:
Related Party Transaction, Expenses from Transactions with Related Party	130	128	141
Support Services [Member] | CEI
EXPENSES:
Related Party Transaction, Expenses from Transactions with Related Party	51	64	62
Support Services [Member] | TE
EXPENSES:
Related Party Transaction, Expenses from Transactions with Related Party	53	52	59
Support Services [Member] | JCP&L
EXPENSES:
Related Party Transaction, Expenses from Transactions with Related Party	90	94	91
Support Services [Member] | Met-Ed
EXPENSES:
Related Party Transaction, Expenses from Transactions with Related Party	53	59	54
Support Services [Member] | Penelec
EXPENSES:
Related Party Transaction, Expenses from Transactions with Related Party	$ 54	$ 58	$ 57