Income Taxes - Schedule of Provision for Income Taxes Differed from the Amount Computed by Applying Federal Statutory Rate (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2022
Income Tax Disclosure [Abstract]
Federal tax provision at statutory rate	$ (122,768)	$ (7,633)	$ (41,738)
State tax, net of federal benefit	199	(890)	185
Foreign tax rate and other foreign related tax items	3,230	3,203	920
Uncertain tax positions	1,681	4,202	25
Stock-based compensation	1,953	4,734	(15,020)
Global intangible low-taxed income	(1,601)	7,464	(554)
Goodwill impairment	114,863		39,933
Change in valuation allowance	(1,763)	27,101	128,034
Executive compensation	183	991	885
Non-deductible expenditures	835	211	210
R&D credits	(1,531)	(588)	(805)
Intangible property transfers		(18,930)
Capital losses	8,187
Provision for income taxes	$ 3,468	$ 19,865	$ 112,075