Income Taxes (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Mar. 31, 2025	Mar. 31, 2024	Mar. 31, 2025	Mar. 31, 2024	Sep. 30, 2024
Income Tax Disclosure [Abstract]
Income tax expense	$ 9.1	$ 13.9	$ 14.5	$ 26.9
Effective Income Tax Rate Reconciliation, Percent	22.40%	23.60%	23.20%	24.40%
Deferred Tax Liabilities, Gross	$ 74.2		$ 74.2		$ 66.7
Deferred Tax Assets, Valuation Allowance	0.7		0.7		0.8
Deferred tax liability, net	$ 74.9		$ 74.9		$ 67.5