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Segment Information - Major customers (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended		12 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Mar. 31, 2021	Mar. 31, 2020	Sep. 30, 2020
Segment Reporting Information [Line Items]
Customer Revenues	$ 14,088	$ 16,883	$ 25,476	$ 33,741
Customer A \| Sales Revenue, Net \| Customer Concentration Risk
Segment Reporting Information [Line Items]
Customer Revenues	$ 1,200	$ 2,000	$ 1,800	$ 3,800
Concentration risk percentage	8.00%	12.00%	7.00%	11.00%
Customer A \| Accounts Receivable \| Customer Concentration Risk
Segment Reporting Information [Line Items]
Accounts receivable, gross	$ 13,000		$ 13,000		$ 4,700
Concentration risk percentage			56.00%		28.00%