Income Taxes - Summary of Income Tax Benefit and Effective Income Tax Rate (Details) - USD ($) $ in Millions	3 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Income Tax Disclosure [Abstract]
(Loss) before income taxes	$ (24.4)	$ (17.4)
Income tax (benefit)	$ (5.5)	$ (4.6)
Effective income tax rate	22.50%	26.40%