Income Taxes - Components of (Loss) Income Before Income Taxes (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2020
Income Tax Disclosure [Abstract]
Domestic	$ (168,452)	$ 20,933	$ (27,889)
Foreign	(30,299)	27,336	4,849
(Loss) income before income taxes	$ (198,751)	$ 48,269	$ (23,040)