Income Taxes - Schedule of Income Taxes (Detail) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2021
Current expense (benefit):
U.S. Federal	$ 3,363	$ (510)	$ 263
U.S. State	591	(143)	108
International	250	166	87
Total current expense (benefit)	4,204	(487)	458
Deferred (benefit) expense:
U.S. Federal		5,200	1,851
U.S. State		515	(62)
International	(181)	(447)	(138)
Total deferred (benefit) expense	(181)	5,268	1,651
Total income tax expense	$ 4,023	$ 4,781	$ 2,109