Segment Information - Narrative (Details) mi² in Thousands, customer in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2019 USD ($) mi² customer company MW
Other/Corporate | OVEC
Segment Reporting Information [Line Items]
Megawatts of net demonstrated capacity of competitive segment (in MW's) | MW	67
Regulated Distribution
Segment Reporting Information [Line Items]
Number of existing utility operating companies | company	10
Number of customers served by utility operating companies | customer	6,000,000
Number of square miles in service area | mi²	65
Megawatts of net demonstrated capacity of competitive segment (in MW's) | MW	3,790
Regulated Distribution | Disposal Group, Held-for-sale | TMI-2
Segment Reporting Information [Line Items]
Assets held-for-sale | $	$ 882
FE | Other/Corporate
Segment Reporting Information [Line Items]
Long-term debt and other long-term obligations | $	$ 7,100