COMMITMENTS, GUARANTEES AND CONTINGENCIES - Narrative (Details) $ in Thousands	Feb. 09, 2022 USD ($)	Jul. 21, 2021 USD ($)	Oct. 29, 2020 USD ($) review	Jun. 30, 2023 USD ($)	Mar. 11, 2022 director
Guarantor Obligations [Line Items]
Outstanding guarantees and other assurances aggregated				$ 796,000
Company posted collateral related to net liability positions				66,000
Collateral received				$ 33,000
Goal to reduce in GHG emissions				30.00%
Litigation settlement, number of voluntary compliance reports | review			2
Litigation settlement, amount awarded to other party, civil penalty			$ 3,860
United States v. Householder, et al.
Guarantor Obligations [Line Items]
Number of board members not seeking re-election | director					6
Number of board members on special committee | director					3
Shareholder Derivative Lawsuit
Guarantor Obligations [Line Items]
Amount awarded to other party	$ 36,000
Amount awarded from other party	$ 180,000
Regulation of Waste Disposal
Guarantor Obligations [Line Items]
Accrual for environmental loss contingencies				$ 97,000
Environmental liabilities former gas facilities				62,000
U.S. Attorney's Office | United States v. Householder, et al.
Guarantor Obligations [Line Items]
Term of DPA		3 years
Loss in period		$ 230,000
Term of payments		60 days
United States Treasury | United States v. Householder, et al.
Guarantor Obligations [Line Items]
Amount awarded to other party		$ 115,000
Ohio Development Service | United States v. Householder, et al.
Guarantor Obligations [Line Items]
Amount awarded to other party		$ 115,000
FE
Guarantor Obligations [Line Items]
Outstanding guarantees and other assurances aggregated				510,000
Other Assurances
Guarantor Obligations [Line Items]
Outstanding guarantees and other assurances aggregated				$ 286,000