Transactions With Affiliated Companies (Details) T in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2017 USD ($) T	Dec. 31, 2016 USD ($) T	Dec. 31, 2015 USD ($) T
MP | FES
REVENUES:
Revenues		$ 31
Interest Expense:
Amount of coal sold under purchase agreement (in T) | T		0.7
AE Supply and MP | FES
REVENUES:
Revenues			$ 0
AE Supply | FES
REVENUES:
Revenues	$ 41	$ 16
Interest Expense:
Amount of coal sold under purchase agreement (in T) | T	1.1	0.4
FES
Investment Income:
Interest income from FE	$ 13	$ 2	2
Interest Expense:
Interest expense to affiliates	0	5	4
Interest expense to FE	19	2	3
FES | AE Supply
REVENUES:
Revenues	$ 15	$ 80	$ 63
Interest Expense:
Amount of coal sold under purchase agreement (in T) | T	0.4	1.5	1.2
FES | Electric sales to affiliates
REVENUES:
Revenues	$ 366	$ 459	$ 666
FES | Other
REVENUES:
Revenues	11	11	14
FES | Purchased power from affiliates
Expenses:
Expenses	201	622	353
FES | Fuel
Expenses:
Expenses	4	4	1
FES | Support services
Expenses:
Expenses	$ 775	$ 748	$ 705