Short-Term Borrowings and Bank Lines of Credit (Details 1) (USD $)	Dec. 31, 2012
Borrowing sub-limits for each borrower and limitations on short-term indebtedness
Revolving Credit Facility Sub-Limit	$ 5,550,000,000
FE
Borrowing sub-limits for each borrower and limitations on short-term indebtedness
Revolving Credit Facility Sub-Limit	2,000,000,000
Regulatory and Other Short-Term Debt Limitations	0	[1]
FES
Borrowing sub-limits for each borrower and limitations on short-term indebtedness
Revolving Credit Facility Sub-Limit	1,500,000,000
Regulatory and Other Short-Term Debt Limitations	0	[2]
AE Supply
Borrowing sub-limits for each borrower and limitations on short-term indebtedness
Revolving Credit Facility Sub-Limit	1,000,000,000
Regulatory and Other Short-Term Debt Limitations	0	[2]
FET
Borrowing sub-limits for each borrower and limitations on short-term indebtedness
Revolving Credit Facility Sub-Limit	1,000,000,000
Regulatory and Other Short-Term Debt Limitations	0	[1]
OE
Borrowing sub-limits for each borrower and limitations on short-term indebtedness
Revolving Credit Facility Sub-Limit	500,000,000
Regulatory and Other Short-Term Debt Limitations	500,000,000
CEI
Borrowing sub-limits for each borrower and limitations on short-term indebtedness
Revolving Credit Facility Sub-Limit	500,000,000
Regulatory and Other Short-Term Debt Limitations	500,000,000
TE
Borrowing sub-limits for each borrower and limitations on short-term indebtedness
Revolving Credit Facility Sub-Limit	500,000,000
Regulatory and Other Short-Term Debt Limitations	500,000,000
JCP&L
Borrowing sub-limits for each borrower and limitations on short-term indebtedness
Revolving Credit Facility Sub-Limit	425,000,000
Regulatory and Other Short-Term Debt Limitations	850,000,000	[3]
ME
Borrowing sub-limits for each borrower and limitations on short-term indebtedness
Revolving Credit Facility Sub-Limit	300,000,000
Regulatory and Other Short-Term Debt Limitations	500,000,000	[3]
PN
Borrowing sub-limits for each borrower and limitations on short-term indebtedness
Revolving Credit Facility Sub-Limit	300,000,000
Regulatory and Other Short-Term Debt Limitations	300,000,000	[3]
WP
Borrowing sub-limits for each borrower and limitations on short-term indebtedness
Revolving Credit Facility Sub-Limit	200,000,000
Regulatory and Other Short-Term Debt Limitations	200,000,000	[3]
MP
Borrowing sub-limits for each borrower and limitations on short-term indebtedness
Revolving Credit Facility Sub-Limit	150,000,000
Regulatory and Other Short-Term Debt Limitations	150,000,000	[3]
PE
Borrowing sub-limits for each borrower and limitations on short-term indebtedness
Revolving Credit Facility Sub-Limit	150,000,000
Regulatory and Other Short-Term Debt Limitations	150,000,000	[3]
ATSI
Borrowing sub-limits for each borrower and limitations on short-term indebtedness
Revolving Credit Facility Sub-Limit	100,000,000
Regulatory and Other Short-Term Debt Limitations	100,000,000
Penn
Borrowing sub-limits for each borrower and limitations on short-term indebtedness
Revolving Credit Facility Sub-Limit	50,000,000
Regulatory and Other Short-Term Debt Limitations	50,000,000	[3]
TrAIL
Borrowing sub-limits for each borrower and limitations on short-term indebtedness
Revolving Credit Facility Sub-Limit	200,000,000
Regulatory and Other Short-Term Debt Limitations	$ 400,000,000

[1] No limitations.

[2] No limitation based upon blanket financing authorization from the FERC under existing open market tariffs.

[3] Excluding amounts which may be borrowed under the regulated companies' money pool.