Income Taxes - Income Tax Provision (Benefit) (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2023
Current:
Federal	$ 21,440	$ 148	$ 1,074
State	(56)	375	1,710
Foreign	35	(3,290)	0
Total current tax	21,419	(2,767)	2,784
Deferred:
Federal	0	0	0
State	0	0	0
Foreign	0	0	0
Total deferred tax	0	0	0
Income tax provision	$ 21,419	$ (2,767)	$ 2,784