Income Taxes - Reconciliation of Unrecognized Tax Benefits (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2020
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Gross unrecognized tax benefits at the beginning of the year	$ 2,114	$ 1,810	$ 1,607
Additions from tax positions taken in the current year	484	268	203
Additions from tax positions taken in prior years	66	36	0
Gross unrecognized tax benefits at end of the year	$ 2,664	$ 2,114	$ 1,810