Provision for Income Taxes - Components of Income Tax Expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2023	Sep. 30, 2022
Income Tax Disclosure [Abstract]
Current expense	$ 3,823	$ 7,351
Deferred expense	(4,464)	424
Income tax (benefit) expense	$ (641)	$ 7,775