Income Taxes - Summary of Reconciliation of Unrecognized Tax Benefits (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2021
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Balance at beginning of the year	$ 1,004	$ 949	$ 1,225
Additions related to tax positions taken in prior years		55
Reductions due to resolution of uncertain tax position	$ (1,004)		(276)
Balance at the end of the year		$ 1,004	$ 949