FAIR VALUE MEASUREMENTS - Assets and Liabilities at Fair Value, Recurring (Details) - USD ($) $ in Millions	Sep. 30, 2024	Dec. 31, 2023
Fair Value Measurements
Assets at fair value	$ 0.2	$ 0.3
Derivative Asset, Statement of Financial Position [Extensible Enumeration]	Accounts and Other Receivables, Net, Current	Accounts and Other Receivables, Net, Current
Liabilities at fair value	$ (9.0)	$ (25.7)
Derivative Liability, Statement of Financial Position [Extensible Enumeration]	Accounts Payable, Current	Accounts Payable, Current
Total net derivative position	$ (8.9)	$ (27.0)
Assets at fair value, nonrecurring		3.2
Property Plant And Equipment At Fair Value | Boehlen Location
Fair Value Measurements
Assets at fair value, nonrecurring	3.3
Commodity Contract
Fair Value Measurements
Liabilities at fair value	(2.5)	(7.2)
Total net derivative position	(2.5)	(8.1)
Commodity Contract | Cash Flow Hedges
Fair Value Measurements
Liabilities at fair value	(2.9)	(13.7)
Total net derivative position	(2.9)	(14.4)
Not Designated as Hedging Instruments | Foreign exchange forward contracts
Fair Value Measurements
Assets at fair value	$ 0.2	0.3
Derivative Asset, Statement of Financial Position [Extensible Enumeration]	Accounts and Other Receivables, Net, Current
Liabilities at fair value	$ (3.6)	$ (4.8)
Derivative Liability, Statement of Financial Position [Extensible Enumeration]		Accounts Payable, Current
Total net derivative position	$ (3.5)	$ (4.5)
Not Designated as Hedging Instruments | Commodity Contract
Fair Value Measurements
Derivative Liability, Statement of Financial Position [Extensible Enumeration]	Accounts Payable, Current	Accounts Payable, Current
Not Designated as Hedging Instruments | Commodity Contract | Cash Flow Hedges
Fair Value Measurements
Derivative Liability, Statement of Financial Position [Extensible Enumeration]	Accounts Payable, Current	Accounts Payable, Current
Recurring
Fair Value Measurements
Total net derivative position	$ (8.9)	$ (27.0)
Recurring | Level 2
Fair Value Measurements
Total net derivative position	(8.9)	(27.0)
Recurring | Not Designated as Hedging Instruments | Foreign exchange forward contracts
Fair Value Measurements
Liabilities at fair value	(3.5)	(4.5)
Recurring | Not Designated as Hedging Instruments | Commodity Contract
Fair Value Measurements
Liabilities at fair value	(2.5)	(8.1)
Recurring | Not Designated as Hedging Instruments | Commodity Contract | Cash Flow Hedges
Fair Value Measurements
Liabilities at fair value	(2.9)	(14.4)
Recurring | Not Designated as Hedging Instruments | Level 2 | Foreign exchange forward contracts
Fair Value Measurements
Liabilities at fair value	(3.5)	(4.5)
Recurring | Not Designated as Hedging Instruments | Level 2 | Commodity Contract
Fair Value Measurements
Liabilities at fair value	(2.5)	(8.1)
Recurring | Not Designated as Hedging Instruments | Level 2 | Commodity Contract | Cash Flow Hedges
Fair Value Measurements
Liabilities at fair value	$ (2.9)	(14.4)
Nonrecurring
Fair Value Measurements
Assets at fair value, nonrecurring		0.0
Liabilities at fair value, nonrecurring		$ 0.0