Income Taxes, Composition of Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Sep. 30, 2020
Deferred tax assets [Abstract]
Allowance for loan losses	$ 2,602	$ 2,468
Organizational costs	76	46
Start-up and other costs	77	115
Net operating loss carryforwards	2,443	1,887
Accrued SERP	1,288	1,462
Purchase accounting fair value adjustments	2,034	0
Other assets	1,984	1,134
Total deferred tax assets	10,504	7,112
Deferred tax liabilities [Abstract]
Depreciation	(771)	(734)
Deferred loan fees/costs	(883)	(651)
Purchase accounting fair value adjustments	0	(670)
Tax bad debt reserve	(204)	(124)
Mortgage servicing rights	(1,122)	(49)
Unrealized gain on securities AFS	(70)	(41)
Total deferred tax liabilities	(3,050)	(2,269)
Total	7,454	4,843
Valuation allowance	(3,896)	(2,765)
Net deferred tax asset	$ 3,558	$ 2,078