Supplemental Information (Payables and Accrued Liabilities) (Details) - USD ($) $ in Millions	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2023
Restructuring Cost and Reserve [Line Items]
Trade creditors	$ 1,437.0	$ 1,451.6
Dividends payable	398.4	393.6
Accrued payroll and employee benefits	303.3	257.2
Contract liabilities	253.4	240.0
Accrued interest	138.8	120.6
Current lease obligations	91.8	100.3
Derivative instruments	35.9	44.6
Pension and postretirement benefits	15.8	11.3
Other	283.4	273.0
Payables and accrued liabilities	3,237.7	2,926.2
Project Exit Costs
Restructuring Cost and Reserve [Line Items]
Accrued restructuring	178.3	0.0
Global Cost Reduction Plan
Restructuring Cost and Reserve [Line Items]
Accrued restructuring	$ 101.6	$ 34.0	$ 19.8