Income Taxes - Summary of Income Tax Expense and Effective Income Tax Rate (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Jun. 30, 2025	Jun. 30, 2024	Jun. 30, 2025	Jun. 30, 2024
Income Tax Disclosure [Abstract]
Income before income taxes	$ 44.9	$ 33.4	$ 39.0	$ 58.3
Income tax expense	$ 12.6	$ 9.9	$ 10.7	$ 17.5
Effective income tax rate	28.10%	29.60%	27.40%	30.00%