Leases - Supplemental cash flow information (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2020	Sep. 30, 2019
Cash paid for amounts included in the measurement of lease liabilities:
Operating cash flows from operating leases	$ 757
Operating cash flows from short-term leases	38
Operating cash flows from finance leases	30
Financing cash flows from finance leases	333	$ 276
Operating leases	216
Cash received from subleases	$ 451