Consolidated Statements of Comprehensive Loss - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2021	Sep. 30, 2020
Statement Of Income And Comprehensive Income [Abstract]
Net loss	$ (14,056)	$ (19,242)
Other comprehensive loss:
Change in unrealized losses on available-for-sale securities, net of tax	(15)
Foreign currency translation adjustments	393	(941)
Total other comprehensive income (loss)	378	(941)
Total comprehensive loss	$ (13,678)	$ (20,183)