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	12 Months Ended
	Sep. 30, 2023	Sep. 30, 2022
Derivative Instruments, Gain (Loss) [Line Items]
Estimated Fair Value Asset	$ 82.4	$ 96.6
Pre-Tax Gain/(Loss) Recognized in OCI	16.9	94.7
Pre-Tax Gain/(Loss) Reclassified From OCI into Income (Effective Portion)	31.1	16.5
Foreign currency contracts
Derivative Instruments, Gain (Loss) [Line Items]
Estimated Fair Value Asset	3.3	16.3
Pre-Tax Gain/(Loss) Recognized in OCI	(5.5)	20.9
Pre-Tax Gain/(Loss) Reclassified From OCI into Income (Effective Portion)	$ 7.5	$ 9.6
Derivative Instrument, Gain (Loss) Reclassified from AOCI into Income, Effective Portion, Statement of Income or Comprehensive Income [Extensible Enumeration]	Cost of products sold	Cost of products sold
Interest rate swaps
Derivative Instruments, Gain (Loss) [Line Items]
Estimated Fair Value Asset	$ 79.8	$ 86.4
Pre-Tax Gain/(Loss) Recognized in OCI	19.4	75.2
Pre-Tax Gain/(Loss) Reclassified From OCI into Income (Effective Portion)	$ 26.0	$ (2.5)
Derivative Instrument, Gain (Loss) Reclassified from AOCI into Income, Effective Portion, Statement of Income or Comprehensive Income [Extensible Enumeration]	Interest expense	Interest expense
Zinc contracts
Derivative Instruments, Gain (Loss) [Line Items]
Estimated Fair Value Asset	$ (0.7)	$ (6.1)
Pre-Tax Gain/(Loss) Recognized in OCI	3.0	(1.4)
Pre-Tax Gain/(Loss) Reclassified From OCI into Income (Effective Portion)	$ (2.4)	$ 9.4
Derivative Instrument, Gain (Loss) Reclassified from AOCI into Income, Effective Portion, Statement of Income or Comprehensive Income [Extensible Enumeration]	Cost of products sold	Cost of products sold