Short-Term Borrowings and Bank Lines of Credit (Details 1)	Dec. 31, 2016 USD ($)
FE
Borrowing sub-limits for each borrower and limitations on short-term indebtedness
Revolving Credit Facility Sub-Limits	$ 4,000,000,000
Regulatory and Other Short-Term Debt Limitations	0
FET
Borrowing sub-limits for each borrower and limitations on short-term indebtedness
Revolving Credit Facility Sub-Limits	1,000,000,000
Regulatory and Other Short-Term Debt Limitations	0
OE
Borrowing sub-limits for each borrower and limitations on short-term indebtedness
Revolving Credit Facility Sub-Limits	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-Limits	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-Limits	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-Limits	600,000,000
Regulatory and Other Short-Term Debt Limitations	500,000,000
ME
Borrowing sub-limits for each borrower and limitations on short-term indebtedness
Revolving Credit Facility Sub-Limits	300,000,000
Regulatory and Other Short-Term Debt Limitations	500,000,000
PN
Borrowing sub-limits for each borrower and limitations on short-term indebtedness
Revolving Credit Facility Sub-Limits	300,000,000
Regulatory and Other Short-Term Debt Limitations	300,000,000
WP
Borrowing sub-limits for each borrower and limitations on short-term indebtedness
Revolving Credit Facility Sub-Limits	200,000,000
Regulatory and Other Short-Term Debt Limitations	200,000,000
MP
Borrowing sub-limits for each borrower and limitations on short-term indebtedness
Revolving Credit Facility Sub-Limits	500,000,000
Regulatory and Other Short-Term Debt Limitations	500,000,000
PE
Borrowing sub-limits for each borrower and limitations on short-term indebtedness
Revolving Credit Facility Sub-Limits	150,000,000
Regulatory and Other Short-Term Debt Limitations	150,000,000
ATSI
Borrowing sub-limits for each borrower and limitations on short-term indebtedness
Revolving Credit Facility Sub-Limits	500,000,000
Regulatory and Other Short-Term Debt Limitations	500,000,000
Penn
Borrowing sub-limits for each borrower and limitations on short-term indebtedness
Revolving Credit Facility Sub-Limits	50,000,000
Regulatory and Other Short-Term Debt Limitations	100,000,000
TrAIL
Borrowing sub-limits for each borrower and limitations on short-term indebtedness
Revolving Credit Facility Sub-Limits	400,000,000
Regulatory and Other Short-Term Debt Limitations	400,000,000
MAIT
Borrowing sub-limits for each borrower and limitations on short-term indebtedness
Revolving Credit Facility Sub-Limits	400,000,000
Regulatory and Other Short-Term Debt Limitations	$ 400,000,000