Revenue from Contracts with Customers - Revenue By Geographic Segment (Parenthetical) (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2022
Total revenue	$ 2,298,472	$ 2,097,053	$ 1,933,347
United States
Total revenue	1,057,300	993,800	864,700
Germany
Total revenue	$ 330,500	$ 292,000	$ 318,500