Segment and Geographic Information - Revenue By Geographic Segment (Parenthetical) (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2020
Total revenue	$ 1,933,347	$ 1,807,159	$ 1,458,415
United States
Total revenue	864,700	741,300	621,800
Germany
Total revenue	$ 318,500	$ 290,700	$ 198,700