Detail of Selected Balance Sheet Accounts - Activity in Allowance for Doubtful Accounts (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2018
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Balance at beginning of period	$ 301	$ 157
Bad debt expense	258	233	$ 111
Uncollectible accounts written off, net of recoveries	(32)	(81)
Change due to foreign currency translation	(17)	(8)
Balance at end of period	$ 510	$ 301	$ 157