Leases (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2021
Lessee, Lease, Description [Line Items]
Operating lease, renewal term	5 years
Operating lease right-of-use ("ROU") assets	$ 1,772	$ 1,980
Operating lease cost	354	371	$ 395
Short-term lease cost	0	0	0
Total lease cost	354	371	395
Operating cash flows from operating leases	$ 316	$ 342	$ 327
Weighted average remaining lease term-operating leases	6 years 8 months 8 days	7 years 8 months 1 day	8 years 5 months 8 days
Weighted average discount rate-operating leases	2.33%	2.25%	2.24%
Minimum
Lessee, Lease, Description [Line Items]
Operating leases, term of contract	2 years
Maximum
Lessee, Lease, Description [Line Items]
Operating leases, term of contract	8 years