Note 3 - Loans and Allowance for Credit Losses - Loans Past Due (Details) - USD ($) $ in Thousands	Jun. 30, 2024	Sep. 30, 2023	Jun. 30, 2023
Recorded investment	$ 759,114		$ 711,960
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing	84		50
Recorded investment	759,114		711,960
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing	84		50
Financial Asset, 30 to 59 Days Past Due [Member]
Recorded investment	1,180		455
Recorded investment	1,180		455
Financial Asset, 60 to 89 Days Past Due [Member]
Recorded investment	98		244
Recorded investment	98		244
Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Recorded investment	671		104
Recorded investment	671		104
Financial Asset, Past Due [Member]
Recorded investment	1,949		803
Recorded investment	1,949		803
Financial Asset, Not Past Due [Member]
Recorded investment	757,165		711,157
Recorded investment	757,165		711,157
Commercial Portfolio Segment [Member]
Recorded investment	127,811	$ 127,811	112,826
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing	0		0
Recorded investment	127,811	127,811	112,826
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing	0		0
Commercial Portfolio Segment [Member] | Financial Asset, 30 to 59 Days Past Due [Member]
Recorded investment	0		0
Recorded investment	0		0
Commercial Portfolio Segment [Member] | Financial Asset, 60 to 89 Days Past Due [Member]
Recorded investment	0		0
Recorded investment	0		0
Commercial Portfolio Segment [Member] | Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Recorded investment	308		0
Recorded investment	308		0
Commercial Portfolio Segment [Member] | Financial Asset, Past Due [Member]
Recorded investment	308		0
Recorded investment	308		0
Commercial Portfolio Segment [Member] | Financial Asset, Not Past Due [Member]
Recorded investment	127,503		112,826
Recorded investment	127,503		112,826
Commercial Real Estate Portfolio Segment [Member]
Recorded investment			342,701
Recorded investment			342,701
Commercial Real Estate Portfolio Segment [Member] | Construction Loans [Member]
Recorded investment			23,996
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing			0
Recorded investment			23,996
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing			0
Commercial Real Estate Portfolio Segment [Member] | Owner Occupied Loans [Member]
Recorded investment	163,543	163,543
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing	0
Recorded investment	163,543	163,543
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing	0
Commercial Real Estate Portfolio Segment [Member] | Other Commercial Real Estate Loans [Member]
Recorded investment			318,705
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing			0
Recorded investment			318,705
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing			0
Commercial Real Estate Portfolio Segment [Member] | Non-owner Occupied Loans [Member]
Recorded investment	146,529	146,529
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing	0
Recorded investment	146,529	146,529
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing	0
Commercial Real Estate Portfolio Segment [Member] | Financial Asset, 30 to 59 Days Past Due [Member] | Construction Loans [Member]
Recorded investment			0
Recorded investment			0
Commercial Real Estate Portfolio Segment [Member] | Financial Asset, 30 to 59 Days Past Due [Member] | Owner Occupied Loans [Member]
Recorded investment	311
Recorded investment	311
Commercial Real Estate Portfolio Segment [Member] | Financial Asset, 30 to 59 Days Past Due [Member] | Other Commercial Real Estate Loans [Member]
Recorded investment			0
Recorded investment			0
Commercial Real Estate Portfolio Segment [Member] | Financial Asset, 30 to 59 Days Past Due [Member] | Non-owner Occupied Loans [Member]
Recorded investment	0
Recorded investment	0
Commercial Real Estate Portfolio Segment [Member] | Financial Asset, 60 to 89 Days Past Due [Member] | Construction Loans [Member]
Recorded investment			0
Recorded investment			0
Commercial Real Estate Portfolio Segment [Member] | Financial Asset, 60 to 89 Days Past Due [Member] | Owner Occupied Loans [Member]
Recorded investment	0
Recorded investment	0
Commercial Real Estate Portfolio Segment [Member] | Financial Asset, 60 to 89 Days Past Due [Member] | Other Commercial Real Estate Loans [Member]
Recorded investment			0
Recorded investment			0
Commercial Real Estate Portfolio Segment [Member] | Financial Asset, 60 to 89 Days Past Due [Member] | Non-owner Occupied Loans [Member]
Recorded investment	0
Recorded investment	0
Commercial Real Estate Portfolio Segment [Member] | Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Construction Loans [Member]
Recorded investment			0
Recorded investment			0
Commercial Real Estate Portfolio Segment [Member] | Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Owner Occupied Loans [Member]
Recorded investment	189
Recorded investment	189
Commercial Real Estate Portfolio Segment [Member] | Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Other Commercial Real Estate Loans [Member]
Recorded investment			51
Recorded investment			51
Commercial Real Estate Portfolio Segment [Member] | Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Non-owner Occupied Loans [Member]
Recorded investment	0
Recorded investment	0
Commercial Real Estate Portfolio Segment [Member] | Financial Asset, Past Due [Member] | Construction Loans [Member]
Recorded investment			0
Recorded investment			0
Commercial Real Estate Portfolio Segment [Member] | Financial Asset, Past Due [Member] | Owner Occupied Loans [Member]
Recorded investment	500
Recorded investment	500
Commercial Real Estate Portfolio Segment [Member] | Financial Asset, Past Due [Member] | Other Commercial Real Estate Loans [Member]
Recorded investment			51
Recorded investment			51
Commercial Real Estate Portfolio Segment [Member] | Financial Asset, Past Due [Member] | Non-owner Occupied Loans [Member]
Recorded investment	0
Recorded investment	0
Commercial Real Estate Portfolio Segment [Member] | Financial Asset, Not Past Due [Member] | Construction Loans [Member]
Recorded investment			23,996
Recorded investment			23,996
Commercial Real Estate Portfolio Segment [Member] | Financial Asset, Not Past Due [Member] | Owner Occupied Loans [Member]
Recorded investment	163,043
Recorded investment	163,043
Commercial Real Estate Portfolio Segment [Member] | Financial Asset, Not Past Due [Member] | Other Commercial Real Estate Loans [Member]
Recorded investment			318,654
Recorded investment			318,654
Commercial Real Estate Portfolio Segment [Member] | Financial Asset, Not Past Due [Member] | Non-owner Occupied Loans [Member]
Recorded investment	146,529
Recorded investment	146,529
Residential Portfolio Segment [Member]
Recorded investment	197,143		190,839
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing	68
Recorded investment	197,143		190,839
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing	68
Residential Portfolio Segment [Member] | Construction Loans [Member]
Recorded investment			8,514
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing			0
Recorded investment			8,514
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing			0
Residential Portfolio Segment [Member] | Owner Occupied Loans [Member]
Recorded investment			158,437
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing			0
Recorded investment			158,437
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing			0
Residential Portfolio Segment [Member] | Non-owner Occupied Loans [Member]
Recorded investment			23,888
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing			0
Recorded investment			23,888
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing			0
Residential Portfolio Segment [Member] | Financial Asset, 30 to 59 Days Past Due [Member]
Recorded investment	294
Recorded investment	294
Residential Portfolio Segment [Member] | Financial Asset, 30 to 59 Days Past Due [Member] | Construction Loans [Member]
Recorded investment			0
Recorded investment			0
Residential Portfolio Segment [Member] | Financial Asset, 30 to 59 Days Past Due [Member] | Owner Occupied Loans [Member]
Recorded investment			17
Recorded investment			17
Residential Portfolio Segment [Member] | Financial Asset, 30 to 59 Days Past Due [Member] | Non-owner Occupied Loans [Member]
Recorded investment			0
Recorded investment			0
Residential Portfolio Segment [Member] | Financial Asset, 60 to 89 Days Past Due [Member]
Recorded investment	0
Recorded investment	0
Residential Portfolio Segment [Member] | Financial Asset, 60 to 89 Days Past Due [Member] | Construction Loans [Member]
Recorded investment			0
Recorded investment			0
Residential Portfolio Segment [Member] | Financial Asset, 60 to 89 Days Past Due [Member] | Owner Occupied Loans [Member]
Recorded investment			124
Recorded investment			124
Residential Portfolio Segment [Member] | Financial Asset, 60 to 89 Days Past Due [Member] | Non-owner Occupied Loans [Member]
Recorded investment			0
Recorded investment			0
Residential Portfolio Segment [Member] | Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Recorded investment	158
Recorded investment	158
Residential Portfolio Segment [Member] | Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Construction Loans [Member]
Recorded investment			0
Recorded investment			0
Residential Portfolio Segment [Member] | Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Owner Occupied Loans [Member]
Recorded investment			0
Recorded investment			0
Residential Portfolio Segment [Member] | Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Non-owner Occupied Loans [Member]
Recorded investment			3
Recorded investment			3
Residential Portfolio Segment [Member] | Financial Asset, Past Due [Member]
Recorded investment	452
Recorded investment	452
Residential Portfolio Segment [Member] | Financial Asset, Past Due [Member] | Construction Loans [Member]
Recorded investment			0
Recorded investment			0
Residential Portfolio Segment [Member] | Financial Asset, Past Due [Member] | Owner Occupied Loans [Member]
Recorded investment			141
Recorded investment			141
Residential Portfolio Segment [Member] | Financial Asset, Past Due [Member] | Non-owner Occupied Loans [Member]
Recorded investment			3
Recorded investment			3
Residential Portfolio Segment [Member] | Financial Asset, Not Past Due [Member]
Recorded investment	196,691
Recorded investment	196,691
Residential Portfolio Segment [Member] | Financial Asset, Not Past Due [Member] | Construction Loans [Member]
Recorded investment			8,514
Recorded investment			8,514
Residential Portfolio Segment [Member] | Financial Asset, Not Past Due [Member] | Owner Occupied Loans [Member]
Recorded investment			158,296
Recorded investment			158,296
Residential Portfolio Segment [Member] | Financial Asset, Not Past Due [Member] | Non-owner Occupied Loans [Member]
Recorded investment			23,885
Recorded investment			23,885
Farmland [Member]
Recorded investment	38,799	38,799
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing	0
Recorded investment	38,799	38,799
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing	0
Farmland [Member] | Financial Asset, 30 to 59 Days Past Due [Member]
Recorded investment	0
Recorded investment	0
Farmland [Member] | Financial Asset, 60 to 89 Days Past Due [Member]
Recorded investment	0
Recorded investment	0
Farmland [Member] | Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Recorded investment	0
Recorded investment	0
Farmland [Member] | Financial Asset, Past Due [Member]
Recorded investment	0
Recorded investment	0
Farmland [Member] | Financial Asset, Not Past Due [Member]
Recorded investment	38,799
Recorded investment	38,799
Consumer Portfolio Segment [Member]
Recorded investment	72,674		65,594
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing	16		50
Recorded investment	72,674		65,594
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing	16		50
Consumer Portfolio Segment [Member] | Financial Asset, 30 to 59 Days Past Due [Member]
Recorded investment	575		438
Recorded investment	575		438
Consumer Portfolio Segment [Member] | Financial Asset, 60 to 89 Days Past Due [Member]
Recorded investment	98		120
Recorded investment	98		120
Consumer Portfolio Segment [Member] | Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Recorded investment	16		50
Recorded investment	16		50
Consumer Portfolio Segment [Member] | Financial Asset, Past Due [Member]
Recorded investment	689		608
Recorded investment	689		608
Consumer Portfolio Segment [Member] | Financial Asset, Not Past Due [Member]
Recorded investment	71,985		64,986
Recorded investment	71,985		$ 64,986
Land Development [Member]
Recorded investment	12,615	12,615
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing	0
Recorded investment	12,615	$ 12,615
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing	0
Land Development [Member] | Financial Asset, 30 to 59 Days Past Due [Member]
Recorded investment	0
Recorded investment	0
Land Development [Member] | Financial Asset, 60 to 89 Days Past Due [Member]
Recorded investment	0
Recorded investment	0
Land Development [Member] | Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Recorded investment	0
Recorded investment	0
Land Development [Member] | Financial Asset, Past Due [Member]
Recorded investment	0
Recorded investment	0
Land Development [Member] | Financial Asset, Not Past Due [Member]
Recorded investment	12,615
Recorded investment	$ 12,615