Leases - Supplemental cash flow information (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Mar. 31, 2021	Mar. 31, 2020
Cash paid for amounts included in the measurement of lease liabilities:
Operating cash flows from operating leases	$ 185	$ 191	$ 376	$ 379
Operating cash flows from short-term leases	3	10	13	19
Operating cash flows from finance leases	3	12	8	25
Financing cash flows from finance leases	87	79	173	157
Operating leases				4
Cash received from subleases	$ 112	$ 112	$ 225	$ 225