Segment Information and Major Customers Geographic revenue (Details) $ in Thousands	12 Months Ended
	Sep. 30, 2021 USD ($) customer	Sep. 30, 2020 USD ($) customer	Sep. 30, 2019 USD ($)
Segment Reporting Information [Line Items]
Revenue | $	$ 308,632	$ 279,271	$ 254,203
Number of customer representing over ten percent of revenue	0	0
Number of customer representing over ten percent of consolidated accounts receivable		1
Accounts Receivable | Customer Concentration Risk | Operating Segments
Segment Reporting Information [Line Items]
Percentage of concentration		17.20%
United States | U.S. Export Net Sales | Geographic Concentration Risk
Segment Reporting Information [Line Items]
Percentage of concentration	26.20%	25.10%	28.50%