Debt - Schedule of Carrying Value of Individual Components of Debt (Details) - USD ($) $ in Millions	Dec. 31, 2023	Sep. 30, 2023
Debt Instrument [Line Items]
Total debt	$ 8,698.2	$ 8,583.9
Less: current portion of debt	462.3	533.0
Long-term debt due after one year	8,235.9	8,050.9
Commercial Paper [Member]
Debt Instrument [Line Items]
Total debt	249.2	283.9
Notes Due Fiscal 2025 To 2028 [Member] | Unsecured Debt [Member]
Debt Instrument [Line Items]
Total debt	2,939.4	2,938.6
Notes Due Fiscal 2029 to 2033 [Member] | Unsecured Debt [Member]
Debt Instrument [Line Items]
Total debt	2,735.9	2,739.5
Notes Due Fiscal 2037 to 2047 [Member] | Unsecured Debt [Member]
Debt Instrument [Line Items]
Total debt	177.2	177.3
Term Loan Facilities [Member] | Unsecured Debt [Member]
Debt Instrument [Line Items]
Total debt	1,347.7	1,347.4
Revolving Credit and Swing Facilities [Member] | Unsecured Debt [Member]
Debt Instrument [Line Items]
Total debt	43.6	32.0
Receivables Securitization [Member] | Secured Debt [Member]
Debt Instrument [Line Items]
Total debt	525.0	425.0
Finance Lease Obligations [Member] | Secured Debt [Member]
Debt Instrument [Line Items]
Total debt	521.2	472.6
Vendor Financing and Commercial Card Programs [Member] | Unsecured Debt [Member]
Debt Instrument [Line Items]
Total debt	110.6	105.7
International and Other Debt [Member]
Debt Instrument [Line Items]
Total debt	$ 48.4	$ 61.9