Income Taxes - Schedule of Reconciliation Difference of Income Taxes (Detail) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2021
Income Tax Disclosure [Abstract]
Amount at statutory U.S. federal income tax rate	$ 522	$ (4,724)	$ 1,333
Change because of the following items:
State income taxes, net of federal benefit	(632)	(897)	(273)
Foreign and state rate differential	495	628	596
U.S. federal and foreign R&D credits	(1,544)	(1,511)	(920)
Valuation allowance change	4,083	10,978	1,059
Stock-based compensation	1,003	481	(544)
U.S. Federal and state rate change	(152)		(35)
Tax reserve change	734	(123)	(150)
Foreign-derived income deduction	(403)
Contingent consideration	(164)	13	3
Impact of CARES Act			735
Acquisition-related transaction costs			187
Other	81	(64)	118
Total income tax expense	$ 4,023	$ 4,781	$ 2,109