Leases - Supplemental cash flow information (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2023	Sep. 30, 2022
Cash paid for amounts included in the measurement of lease liabilities:
Operating cash flows from operating leases	$ 628	$ 633
Operating cash flows from short-term leases	43	137
Operating cash flows from finance leases	1	4
Financing cash flows from finance leases	4	47
Lease assets obtained in exchange for new lease liabilities, Operating leases	392	352
Cash received from subleases	$ (20)	$ (49)