CAPITALIZATION - Narrative (Details) $ / shares in Units, $ in Millions					1 Months Ended	2 Months Ended	3 Months Ended							12 Months Ended
	Dec. 01, 2023 $ / shares	May 04, 2023 USD ($) tradingDay	May 01, 2023	Nov. 06, 2021 USD ($) $ / shares shares	Sep. 30, 2023 $ / shares	Dec. 31, 2021 USD ($)	Dec. 31, 2023 USD ($) $ / shares shares	Jun. 30, 2023 $ / shares	Mar. 31, 2023 $ / shares	Dec. 31, 2022 USD ($) $ / shares shares	Sep. 30, 2022 $ / shares	Jun. 30, 2022 $ / shares	Mar. 31, 2022 $ / shares	Dec. 31, 2024 USD ($)	Dec. 31, 2023 USD ($) subsidiary $ / shares shares	Dec. 31, 2022 USD ($) $ / shares shares	Dec. 31, 2021 $ / shares shares	Apr. 30, 2023	Jun. 30, 2013 USD ($)
Debt Instrument [Line Items]
Accumulated deficit							$ (97)			$ (1,199)					$ (97)	$ (1,199)
Dividends declared (in dollars per share) | $ / shares					$ 0.02		$ 0.41	$ 0.39	$ 0.39	$ 0.39	$ 0.39	$ 0.39	$ 0.39		$ 1.60	$ 1.56	$ 1.56
Dividends paid (in dollars per share) | $ / shares	$ 0.41
Increase in dividend percentage	0.05
FERC-defined equity to total capitalization ratio															35.00%
Common Stock, Par or Stated Value Per Share | $ / shares							$ 0.10			$ 0.10					$ 0.10	$ 0.10
Preference shares outstanding (in shares) | shares							0			0					0	0
Preferred shares, outstanding (in shares) | shares							0			0					0	0
Number of subsidiaries that issued environmental control bonds | subsidiary															2
Environmental control bonds outstanding							$ 218			$ 247					$ 218	$ 247
Principal default amount specified in debt covenants															$ 100
Common Stock Purchase Agreement
Debt Instrument [Line Items]
Number of shares issued in transaction | shares				25,588,535
Common Stock, Par or Stated Value Per Share | $ / shares				$ 0.10
Sale of stock, price per share (in dollars per share) | $ / shares				$ 39.08
Investment amount				$ 1,000
Transaction costs						$ 26
Registered Shareholders, Directors and Employees of Subsidiaries
Debt Instrument [Line Items]
Consolidated tax benefit allocation (in shares) | shares															2,000,000	2,000,000	1,000,000
AGC
Debt Instrument [Line Items]
FERC-defined equity to total capitalization ratio															45.00%
FET | Brookfield II | Forecast
Debt Instrument [Line Items]
Discontinued Operation, Tax Effect of Gain (Loss) from Disposal of Discontinued Operation														$ 7,000
4.00%, $1,500 Million Notes Maturity 2026
Debt Instrument [Line Items]
Proceeds from issuance of debt		$ 1,480
4.00%, $1,500 Million Notes Maturity 2026 | FE | Promissory Notes
Debt Instrument [Line Items]
Face amount of loan		$ 1,500
Debt instrument, convertible, threshold trading days | tradingDay		20
Debt instrument, convertible, threshold consecutive trading days | tradingDay		30
Debt instrument, convertible, threshold percentage of stock price trigger		130.00%
Debt instrument, convertible, business days | tradingDay		5
Threshold trading days measurement period | tradingDay		10
Debt instrument, measurement period percentage		98.00%
Debt instrument, conversation price (in dollars per share) | $ / shares							$ 46.81								$ 46.81
Debt instrument convertible premium			0.20
Repurchase price, percentage			1
Phase In Recovery Bonds
Debt Instrument [Line Items]
Long-term debt and other long-term obligations							$ 191			$ 206					$ 191	$ 206
Phase In Recovery Bonds | Ohio Funding Companies
Debt Instrument [Line Items]
Face amount of loan																			$ 445
2026 Convertible Notes
Debt Instrument [Line Items]
Debt instrument, convertible, conversion ratio															0.021362
2026 Convertible Notes | Unsecured Debt
Debt Instrument [Line Items]
Interest Rate																		4.00%