Summary of Significant Accounting Policies - COGS (Details) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2021
Selling, general and administrative expenses
Cost of Goods Sold
Storage and other warehousing costs	$ 20.1	$ 16.6	$ 17.0