Income Taxes - Schedule of Income Tax Expense and Effective 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 tax expense	$ 20.0	$ 17.0	$ 65.9	$ 42.9
Effective tax rate percentage	26.00%	26.10%	25.80%	25.50%

Amount of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.

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+ Details