Note 4 - Loans and the Allowance for Credit Losses - Balance of Nonaccrual Loans By Loan Category (Details) - USD ($) $ in Thousands	Sep. 30, 2025	Dec. 31, 2024
Total nonaccrual	$ 15,029	$ 4,105
Past due 90 days or more and still accruing	0	0
Commercial Portfolio Segment [Member] \| Commercial Loans [Member]
Total nonaccrual	508	355
Past due 90 days or more and still accruing	0	0
Commercial Portfolio Segment [Member] \| Agricultural Loans [Member]
Total nonaccrual	10,540	567
Past due 90 days or more and still accruing	0	0
Commercial Portfolio Segment [Member] \| Real Estate Loan [Member]
Total nonaccrual	1,798	1,579
Past due 90 days or more and still accruing	0	0
Commercial Portfolio Segment [Member] \| Construction Loans [Member]
Total nonaccrual	0	0
Past due 90 days or more and still accruing	0	0
Residential Portfolio Segment [Member] \| Real Estate Loan [Member]
Total nonaccrual	258	83
Past due 90 days or more and still accruing	0	0
Residential Portfolio Segment [Member] \| Equity Lines of Credit [Member]
Total nonaccrual	1,090	650
Past due 90 days or more and still accruing	0	0
Consumer Portfolio Segment [Member] \| Automobile Loan [Member]
Total nonaccrual	823	792
Past due 90 days or more and still accruing	0	0
Consumer Portfolio Segment [Member] \| Other Loans [Member]
Total nonaccrual	12	79
Past due 90 days or more and still accruing	0	0
Nonperforming Financial Instruments [Member]
Nonaccrual with no allowance for credit losses	12,739	4,050
Total nonaccrual	15,029	4,105
Past due 90 days or more and still accruing	0	0
Nonperforming Financial Instruments [Member] \| Commercial Portfolio Segment [Member] \| Commercial Loans [Member]
Nonaccrual with no allowance for credit losses	257	302
Total nonaccrual	508	355
Past due 90 days or more and still accruing	0	0
Nonperforming Financial Instruments [Member] \| Commercial Portfolio Segment [Member] \| Agricultural Loans [Member]
Nonaccrual with no allowance for credit losses	8,501	567
Total nonaccrual	10,540	567
Past due 90 days or more and still accruing	0	0
Nonperforming Financial Instruments [Member] \| Commercial Portfolio Segment [Member] \| Real Estate Loan [Member]
Nonaccrual with no allowance for credit losses	1,798	1,579
Total nonaccrual	1,798	1,579
Past due 90 days or more and still accruing	0	0
Nonperforming Financial Instruments [Member] \| Commercial Portfolio Segment [Member] \| Construction Loans [Member]
Nonaccrual with no allowance for credit losses	0	0
Total nonaccrual	0	0
Past due 90 days or more and still accruing	0	0
Nonperforming Financial Instruments [Member] \| Residential Portfolio Segment [Member] \| Real Estate Loan [Member]
Nonaccrual with no allowance for credit losses	258	83
Total nonaccrual	258	83
Past due 90 days or more and still accruing	0	0
Nonperforming Financial Instruments [Member] \| Residential Portfolio Segment [Member] \| Equity Lines of Credit [Member]
Nonaccrual with no allowance for credit losses	1,090	650
Total nonaccrual	1,090	650
Past due 90 days or more and still accruing	0	0
Nonperforming Financial Instruments [Member] \| Consumer Portfolio Segment [Member] \| Automobile Loan [Member]
Nonaccrual with no allowance for credit losses	823	792
Total nonaccrual	823	792
Past due 90 days or more and still accruing	0	0
Nonperforming Financial Instruments [Member] \| Consumer Portfolio Segment [Member] \| Other Loans [Member]
Nonaccrual with no allowance for credit losses	12	77
Total nonaccrual	12	79
Past due 90 days or more and still accruing	$ 0	$ 0

Amortized cost of financing receivable on nonaccrual status with no allowance for credit losses. Excludes net investment in lease.

No definition available.

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- Definition

Amortized cost excluding accrued interest, of financing receivable 90 days or more past due and still accruing. Excludes net investment in lease.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 16
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479319/326-20-50-16

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- Definition

Amortized cost excluding accrued interest, of financing receivable on nonaccrual status. Excludes net investment in lease.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 16
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479319/326-20-50-16

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