COMMITMENTS AND CONTINGENCIES- Narrative (Details) $ in Millions	1 Months Ended	12 Months Ended
	Feb. 29, 2020 company	Dec. 31, 2025 USD ($)	Dec. 31, 2024 USD ($)	Dec. 31, 2023 USD ($)	Dec. 31, 2022 USD ($)
Loss Contingencies [Line Items]
Environment remediation expense, completion of certain remedial action activities				$ 20.6
Environmental activities expenses, construction bid costs			$ 19.8
Accrued probable future environmental expenditures		$ 141.2	$ 146.0	157.2	$ 118.3
Environmental loss contingency, statement of financial position		Accrued expenses and other current liabilities, Other non-current liabilities	Accrued expenses and other current liabilities, Other non-current liabilities
Gains from insurance recoveries		$ 2.0	$ 34.7	1.7
Cash received from insurance recoveries		36.0	$ 0.7	1.7
Calvert City
Loss Contingencies [Line Items]
Accrual for environmental loss contingencies, number of companies negotiating consent decree | company	3
Accrual for environmental loss contingencies, additional charge				$ 36.2
Environment remediation expense, charges recognized		$ 21.3
Environment remediation expense, extension period (in years)		2 years
Accrued probable future environmental expenditures		$ 133.2