Income Taxes - Components of Loss Before Income Taxes (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Mar. 31, 2024	Mar. 31, 2023	Mar. 31, 2024	Mar. 31, 2023
Income Tax Disclosure [Abstract]
Domestic	$ (270,347)	$ (15,919)	$ (204,711)	$ (9,866)
Foreign	4,018	(6,464)	(3,420)	(13,425)
Loss before income taxes	$ (266,329)	$ (22,383)	$ (208,131)	$ (23,291)