Detail of Selected Balance Sheet Accounts - Activity in Allowance for Credit Losses (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2019
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Balance at beginning of period	$ 510	$ 301
Bad debt expense, net	48	258	$ 233
Uncollectible accounts written off, net of recoveries	(242)	(32)
Change due to foreign currency translation	17	(17)
Balance at end of period	$ 333	$ 510	$ 301