Income Taxes - Components of Provision for Income Taxes (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2021
Current:
Federal	$ 611	$ 12
State	38	15	$ 35
Foreign	11,619	14,761	6,760
Total current	12,268	14,788	6,795
Deferred:
Federal	7,941	(6,823)	5,437
State	(1,164)	218	5,001
Foreign	820	103,892	(14,857)
Total deferred	7,597	97,287	(4,419)
Provision for income taxes	$ 19,865	$ 112,075	$ 2,376
Effective income tax rate	(54.60%)	(56.40%)	4.90%