INCOME TAXES - Schedule of Components of Deferred Tax Assets (Liabilities) (Details) - USD ($) $ in Millions	Dec. 31, 2025	Dec. 31, 2024
Deferred tax assets:
Employment costs	$ 21.3	$ 22.0
Environmental accruals	34.1	35.5
Net operating loss carryforwards	96.9	60.8
Operating leases	8.9	9.5
Research and development	62.7	53.0
Capitalized and carryforward interest	105.2	78.5
Financial derivatives	73.7	4.5
Other	26.5	32.7
Gross deferred tax assets	429.3	296.5
Valuation allowances	(76.3)	(30.3)
Total deferred tax assets, net of valuation allowances	353.0	266.2
Deferred tax liabilities:
Property, plant and equipment	(100.4)	(100.4)
Goodwill and intangibles	(325.7)	(318.5)
Operating leases	(9.0)	(9.7)
Other	(8.9)	(16.7)
Total deferred tax liabilities	(444.0)	(445.3)
Net deferred tax liabilities	(91.0)	(179.1)
Consolidated Balance Sheets:
Non-current deferred income tax assets	194.7	81.3
Non-current deferred income tax liabilities	$ (285.7)	$ (260.4)