Detail of Selected Balance Sheet Accounts - Activity in Allowance for Doubtful Accounts (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2017
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Balance at beginning of period	$ 157	$ 179
Bad debt expense	233	111	$ (160)
Uncollectible accounts written off, net of recoveries	(81)	(125)
Change due to foreign currency translation	(8)	(8)
Balance at end of period	$ 301	$ 157	$ 179