Debt (Eurobond Issuance - Narrative) (Details) € in Millions, $ in Millions	3 Months Ended	6 Months Ended
	Mar. 31, 2025 EUR (€)	Mar. 31, 2025 USD ($)	Mar. 31, 2024 USD ($)	Feb. 28, 2025 USD ($)	Feb. 28, 2025 EUR (€)
Debt Instrument [Line Items]
Repayment of debt | $		$ 332.3	$ 64.7
2025 Eurobonds | Bonds
Debt Instrument [Line Items]
Debt instrument, face amount | €					€ 1,000
Debt issuance costs | $				$ 8.0
Eurobonds One Percent | Bonds
Debt Instrument [Line Items]
Repayment of debt | €	€ 300
Interest rate	1.00%	1.00%