Goodwill and Intangible Assets -Goodwill - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Goodwill [Line Items]
Goodwill impairment charge	$ 0.0
Goodwill	$ 922.4	$ 922.4	$ 923.5