ORGANIZATION AND BASIS OF PRESENTATION (Details) mi in Thousands, customer in Millions, $ in Millions		3 Months Ended		9 Months Ended
	May 31, 2022 USD ($)	Sep. 30, 2023 USD ($) company transmissionCenter MW	Sep. 30, 2022 USD ($)	Sep. 30, 2023 USD ($) company customer transmissionCenter mi MW	Sep. 30, 2022 USD ($)	Apr. 27, 2023 USD ($)	Feb. 02, 2023 USD ($) director	Dec. 31, 2022 USD ($)
Property, Plant and Equipment [Line Items]
Length of transmission lines | mi				24
Number of regional transmission centers | transmissionCenter		2		2
Capitalized cost of equity		$ 12	$ 15	$ 31	$ 39
Capitalized interest		14	8	38	20
Equity method investment earnings (Note 1)		43	57	134	134
Revision of Prior Period, Adjustment
Property, Plant and Equipment [Line Items]
Deferred tax assets, valuation allowance		$ 21		$ 21
Regulated Distribution
Property, Plant and Equipment [Line Items]
Number Of existing utility operating companies | company		10		10
Number of customers | customer				6
Plant capacity (in MW's) | MW		3,580		3,580
North American Transmission Company II LLC | FET
Property, Plant and Equipment [Line Items]
Sale of ownership interest by parent						30.00%	30.00%
Noncontrolling interest, ownership percentage by noncontrolling owners							49.90%
FET
Property, Plant and Equipment [Line Items]
Net of transaction costs	$ 37
Carrying value of the noncontrolling interest	$ 451
Number of directors | director							5
FET | FE
Property, Plant and Equipment [Line Items]
Number of directors | director							3
FET | North American Transmission Company II LLC
Property, Plant and Equipment [Line Items]
Sale of ownership interest by parent	19.90%
Sale price of ownership interest by parent	$ 2,375
Disposal group, including discontinued operation, consideration						$ 3,500	$ 3,500
Number of directors | director							2
Minimum ownership interest							30.00%
Global Holding | Variable Interest Entity, Not Primary Beneficiary
Property, Plant and Equipment [Line Items]
Equity method investments		$ 54		$ 54				$ 57
Global Holding | FEV
Property, Plant and Equipment [Line Items]
Investment ownership percentage		33.30%		33.30%
Global Holding | FEV | Variable Interest Entity, Not Primary Beneficiary
Property, Plant and Equipment [Line Items]
Proceeds from dividends received				$ 135	120
Global Holding | FEV | Corporate and Other | Other Nonoperating Income (Expense)
Property, Plant and Equipment [Line Items]
Equity method investment earnings (Note 1)		$ 43	$ 57	132	$ 133
Other Sundry Investments
Property, Plant and Equipment [Line Items]
Equity method investments		93		93				90
Path Wv | Variable Interest Entity, Not Primary Beneficiary
Property, Plant and Equipment [Line Items]
Equity method investments		$ 18		$ 18				$ 18
Variable interest entities percentage of high voltage transmission line project owned By variable interest entity one in joint venture party one		100.00%		100.00%
Variable interest entities percentage of high voltage transmission line project owned by variable interest entity one in joint venture party two		50.00%		50.00%