Derivative Financial Instruments and Hedging (Gain) Loss recognized in Statement of Operations from derivative instruments (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Mar. 31, 2024	Mar. 31, 2023	Mar. 31, 2024	Mar. 31, 2023
Commodity contracts
Derivative Instruments, (Gain) Loss
Derivative, Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration]	Cost of goods sold	Cost of goods sold	Cost of goods sold	Cost of goods sold
Energy Contracts
Derivative Instruments, (Gain) Loss
Derivative, Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration]	Cost of goods sold	Cost of goods sold	Cost of goods sold	Cost of goods sold
Foreign Exchange Contract - Forward Contracts
Derivative Instruments, (Gain) Loss
Derivative, Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration]	Selling, general and administrative expenses	Selling, general and administrative expenses	Selling, general and administrative expenses	Selling, general and administrative expenses
PHPC Warrants
Derivative Instruments, (Gain) Loss
Derivative, Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration]	Other Nonoperating Income (Expense)	Other Nonoperating Income (Expense)	Other Nonoperating Income (Expense)	Other Nonoperating Income (Expense)
Derivatives Not Designated as Hedging Instruments | Commodity contracts
Derivative Instruments, (Gain) Loss
(Gain) Loss Recognized in Statement of Operations	$ 17.6	$ 7.8	$ 19.2	$ 5.7
Derivatives Not Designated as Hedging Instruments | Energy Contracts
Derivative Instruments, (Gain) Loss
(Gain) Loss Recognized in Statement of Operations	(1.8)	5.8	5.7	8.6
Derivatives Not Designated as Hedging Instruments | Foreign Exchange Contract - Forward Contracts
Derivative Instruments, (Gain) Loss
(Gain) Loss Recognized in Statement of Operations	0.0	0.1	0.0	0.0
Derivatives Not Designated as Hedging Instruments | Interest Rate Swap
Derivative Instruments, (Gain) Loss
(Gain) Loss Recognized in Statement of Operations	(13.3)	9.0	7.8	(3.3)
Derivatives Not Designated as Hedging Instruments | PHPC Warrants
Derivative Instruments, (Gain) Loss
(Gain) Loss Recognized in Statement of Operations	$ 0.0	$ 0.7	$ 0.0	$ 0.5