Long-term and Short-term Debt - Narrative (Details) $ in Millions		12 Months Ended
	Jun. 29, 2022 USD ($)	Sep. 30, 2025 USD ($)	Sep. 30, 2024 USD ($)	Sep. 30, 2023 USD ($)	May 31, 2025 USD ($)	Apr. 30, 2025 USD ($)
Debt Instrument [Line Items]
Short-term debt		$ 608.0	$ 771.0
Interest payments		157.0	153.0	$ 133.0
Notes Payable, Other Payables | $250.0 Million Dollar Note Due 2028
Debt Instrument [Line Items]
Total debt		250.0
Notes Payable, Other Payables | $425.0 Million Dollar Note Due 2029
Debt Instrument [Line Items]
Total debt		425.0
Notes Payable, Other Payables | Unsecured Revolving Credit Facility Expiring in 2027
Debt Instrument [Line Items]
Borrowing capacity					$ 1,500.0
Line of Credit | Revolving Credit Facility
Debt Instrument [Line Items]
Borrowing capacity	$ 750.0
Maximum ratio of EBITDA to interest expense under credit facility	3.0
Notes Payable to Banks | Senior Unsecured 364-Day Term Loan
Debt Instrument [Line Items]
Debt instrument, face amount					$ 500.0
Commercial Paper
Debt Instrument [Line Items]
Short-term debt		$ 522.0	$ 657.0
Debt, weighted average interest rate (in percent)		4.24%	5.14%
Debt instrument, term		16 days	24 days
Line of Credit
Debt Instrument [Line Items]
Short-term debt		$ 70.0	$ 70.0
Borrowing capacity		$ 75.0
Stated interest rate (in percent)		5.18%	6.17%
Sensia loans from SLB, payable in October 2026
Debt Instrument [Line Items]
Short-term debt		$ 14.0	$ 42.0			$ 14.0
Foreign Line of Credit
Debt Instrument [Line Items]
Borrowing capacity		275.0
Letter of Credit
Debt Instrument [Line Items]
Borrowing capacity		$ 34.0