Income Taxes - Summary of Components of Income Tax Expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2022
Current:
Federal	$ (424)	$ 16,184	$ 31,986
State	601	3,434	5,492
Foreign	0	0	6
Current total	177	19,618	37,484
Deferred:
Federal	(152)	(19,171)	5,376
State	(182)	(3,859)	365
Foreign	0	0	0
Deferred total	(334)	(23,030)	5,741
Income tax (benefit) expense	$ (157)	$ (3,412)	$ 43,225