Note 4 - Loans and the Allowance for Credit Losses - Allocation of the Allowance for Credit Losses (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
Mar. 31, 2024	Mar. 31, 2023	Dec. 31, 2023
Beginning balance	$ 12,867	$ 10,717	$ 10,717
Charge-offs	(680)		(1,802)
Recoveries	70		848
Provision	900		2,575
Ending balance	13,157		12,867
Provision	821	1,525
Accounting Standards Update 2016-13 [Member] \| Cumulative Effect, Period of Adoption, Adjustment [Member]
Beginning balance	0	529	529
Ending balance			0
Loans, Net of Unfunded Commitments [Member]
Beginning balance	12,867	10,717	10,717
Charge-offs	(680)	(308)
Recoveries	70	142
Provision	900
Ending balance	13,157	12,330	12,867
Provision		1,250
Loans, Net of Unfunded Commitments [Member] \| Accounting Standards Update 2016-13 [Member] \| Cumulative Effect, Period of Adoption, Adjustment [Member]
Beginning balance		529	529
Commercial Portfolio Segment [Member] \| Commercial Loans [Member]
Beginning balance	1,134	892	892
Charge-offs	(43)	0	(123)
Recoveries	9	6
Provision	211
Ending balance	1,311	1,475	1,134
Provision		223
Commercial Portfolio Segment [Member] \| Commercial Loans [Member] \| Accounting Standards Update 2016-13 [Member] \| Cumulative Effect, Period of Adoption, Adjustment [Member]
Beginning balance		354	354
Commercial Portfolio Segment [Member] \| Agricultural Loans [Member]
Beginning balance	1,738	1,086	1,086
Charge-offs	0	0	0
Recoveries	0	0
Provision	(86)
Ending balance	1,652	1,307	1,738
Provision		73
Commercial Portfolio Segment [Member] \| Agricultural Loans [Member] \| Accounting Standards Update 2016-13 [Member] \| Cumulative Effect, Period of Adoption, Adjustment [Member]
Beginning balance		148	148
Commercial Portfolio Segment [Member] \| Real Estate Loan [Member]
Beginning balance	6,678	4,980	4,980
Charge-offs	0	0	0
Recoveries	0	1
Provision	239
Ending balance	6,917	6,740	6,678
Provision		271
Commercial Portfolio Segment [Member] \| Real Estate Loan [Member] \| Accounting Standards Update 2016-13 [Member] \| Cumulative Effect, Period of Adoption, Adjustment [Member]
Beginning balance		1,488	1,488
Commercial Portfolio Segment [Member] \| Construction Loans [Member]
Beginning balance	797	1,500	1,500
Charge-offs	0	0	0
Recoveries	0	0
Provision	121
Ending balance	918	763	797
Provision		214
Commercial Portfolio Segment [Member] \| Construction Loans [Member] \| Accounting Standards Update 2016-13 [Member] \| Cumulative Effect, Period of Adoption, Adjustment [Member]
Beginning balance		(951)	(951)
Residential Portfolio Segment [Member] \| Real Estate Loan [Member]
Beginning balance	137	138	138
Charge-offs	0	0	0
Recoveries	1	1
Provision	(4)
Ending balance	134	162	137
Provision		21
Residential Portfolio Segment [Member] \| Real Estate Loan [Member] \| Accounting Standards Update 2016-13 [Member] \| Cumulative Effect, Period of Adoption, Adjustment [Member]
Beginning balance		2	2
Residential Portfolio Segment [Member] \| Equity Lines of Credit [Member]
Beginning balance	439	687	687
Charge-offs	0	0	0
Recoveries	0	0
Provision	(2)
Ending balance	437	330	439
Provision		64
Residential Portfolio Segment [Member] \| Equity Lines of Credit [Member] \| Accounting Standards Update 2016-13 [Member] \| Cumulative Effect, Period of Adoption, Adjustment [Member]
Beginning balance		(421)	(421)
Consumer Portfolio Segment [Member] \| Automobile Loan [Member]
Beginning balance	1,865	1,289	1,289
Charge-offs	(633)	(293)	(1,550)
Recoveries	57	131
Provision	411
Ending balance	1,700	1,504	1,865
Provision		368
Consumer Portfolio Segment [Member] \| Automobile Loan [Member] \| Accounting Standards Update 2016-13 [Member] \| Cumulative Effect, Period of Adoption, Adjustment [Member]
Beginning balance		9	9
Consumer Portfolio Segment [Member] \| Other Loans [Member]
Beginning balance	79	145	145
Charge-offs	(4)	(15)	(129)
Recoveries	3	3
Provision	10
Ending balance	$ 88	49	79
Provision		16
Consumer Portfolio Segment [Member] \| Other Loans [Member] \| Accounting Standards Update 2016-13 [Member] \| Cumulative Effect, Period of Adoption, Adjustment [Member]
Beginning balance		$ (100)	$ (100)

Amount of allowance for credit loss on financing receivable. Excludes allowance for financing receivable covered under loss sharing agreement.

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