Income Taxes (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Mar. 31, 2026	Mar. 31, 2025	Mar. 31, 2026	Mar. 31, 2025	Sep. 30, 2025
Income Tax Disclosure [Abstract]
Effective income tax rate	25.70%	23.70%	22.80%	13.20%
Unrecognized tax benefits, uncertain tax positions	$ 21.1		$ 21.1		$ 19.5
Unrecognized tax benefits, accrued interest	$ 2.5		$ 2.5		$ 1.9