Revenue Recognition - Summary of Revenues Classified by Major Geographic Region (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2020
Revenues:
Total net revenues	$ 327,891	$ 387,182	$ 330,967
United States
Revenues:
Total net revenues	100,564	135,033	129,338
Other Americas
Revenues:
Total net revenues	99	175	16
Germany
Revenues:
Total net revenues	74,550	114,936	100,674
Other Europe, Middle East and Africa
Revenues:
Total net revenues	15,579	29,964	25,394
Japan
Revenues:
Total net revenues	74,480	62,840	50,936
Other Asia-Pacific
Revenues:
Total net revenues	$ 62,619	$ 44,234	$ 24,609