Financial Instruments and Risk Management - Schedule of Derivative Instruments, Effect on Other Comprehensive Income (Loss) (Details) - Designated as Hedging Instrument - Cash Flow Hedging - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022	Sep. 30, 2022
Derivative Instruments, Gain (Loss) [Line Items]
Derivatives - Foreign Currency contracts	$ 66.6		$ 66.6		$ 96.6
(Loss)/Gain Recognized in OCI	9.2	$ 13.4	(4.0)	$ 56.8
Loss Reclassified From OCI into Income(Effective Portion)	6.9	3.7	26.0	7.5
Foreign currency contracts
Derivative Instruments, Gain (Loss) [Line Items]
Derivatives - Foreign Currency contracts	(3.0)		(3.0)		16.3
(Loss)/Gain Recognized in OCI	(1.6)	9.1
Loss Reclassified From OCI into Income(Effective Portion)	0.7	2.7
Interest rate swap
Derivative Instruments, Gain (Loss) [Line Items]
Derivatives - Foreign Currency contracts	77.1		77.1		86.4
(Loss)/Gain Recognized in OCI	15.7	12.0	9.0	48.8
Loss Reclassified From OCI into Income(Effective Portion)	7.1	(1.3)	18.3	(4.8)
Zinc contracts
Derivative Instruments, Gain (Loss) [Line Items]
Derivatives - Foreign Currency contracts	(7.5)		(7.5)		$ (6.1)
(Loss)/Gain Recognized in OCI	(4.9)	(7.7)	(2.0)	(1.7)
Loss Reclassified From OCI into Income(Effective Portion)	$ (0.9)	$ 2.3	(0.6)	6.8
Foreign currency contracts
Derivative Instruments, Gain (Loss) [Line Items]
(Loss)/Gain Recognized in OCI			(11.0)	9.7
Loss Reclassified From OCI into Income(Effective Portion)			$ 8.3	$ 5.5