Income Taxes (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Income Tax Disclosure [Abstract]
Income tax provision	$ 13.1	$ 0.6	$ 25.7	$ 16.5
Earnings before income taxes	$ 53.9	$ 5.3	$ 98.6	$ 63.1
Effective tax rate	24.20%	11.90%	26.10%	26.10%