Income Taxes - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Sep. 30, 2021
Income Tax Disclosure [Abstract]
Income tax expense	$ 13.0	$ 7.1
Effective income tax rate, percent	24.30%	24.30%
Deferred Income Tax Liabilities, Net of Deferred Income Tax Assets	$ 23.0		$ 23.2
Valuation allowance, deferred tax asset, amount	1.2		1.2
Deferred tax liability, net	$ 24.2		$ 24.4