Note 9 - Fair Value Measurements - Quantitative Information About Level 3 Fair Value Measurements for Financial Instruments Measured at Fair Value on a Non-recurring Basis (Details) - Fair Value, Nonrecurring [Member] $ in Thousands	6 Months Ended	12 Months Ended
Jun. 30, 2026 USD ($)	Dec. 31, 2025 USD ($)
Collateral dependent loans, fair value	$ 743	$ 1,988
Other Real Estate Owned and Receivables, Fair Value		226
Commercial Loans [Member]
Collateral dependent loans, fair value	0	84
Agricultural Loans [Member]
Collateral dependent loans, fair value	743	1,904
Real Estate Loan [Member] \| Residential Portfolio Segment [Member]
RE – Residential, fair value		91
Equity Lines of Credit [Member] \| Residential Portfolio Segment [Member]
Equity lines of credit, fair value	135	135
Fair Value, Inputs, Level 3 [Member]
Collateral dependent loans, fair value	743	1,988
Other Real Estate Owned and Receivables, Fair Value		226
Fair Value, Inputs, Level 3 [Member] \| Commercial Loans [Member]
Collateral dependent loans, fair value	0	84
Fair Value, Inputs, Level 3 [Member] \| Agricultural Loans [Member]
Collateral dependent loans, fair value	743	1,904
Fair Value, Inputs, Level 3 [Member] \| Real Estate Loan [Member]
RE – Residential, fair value		91
Fair Value, Inputs, Level 3 [Member] \| Equity Lines of Credit [Member] \| Residential Portfolio Segment [Member]
Equity lines of credit, fair value	135	135
Third Party Appraisals [Member] \| Fair Value, Inputs, Level 3 [Member]
Collateral dependent loans, fair value	743	1,988
Other Real Estate Owned and Receivables, Fair Value	135	226
Third Party Appraisals [Member] \| Fair Value, Inputs, Level 3 [Member] \| Commercial Loans [Member]
Collateral dependent loans, fair value	$ 0	$ 84
Third Party Appraisals [Member] \| Fair Value, Inputs, Level 3 [Member] \| Commercial Loans [Member] \| Measurement Input, Manager Adjustments [Member] \| Minimum [Member]
Collateral dependent loans, measurement input		14
Third Party Appraisals [Member] \| Fair Value, Inputs, Level 3 [Member] \| Commercial Loans [Member] \| Measurement Input, Manager Adjustments [Member] \| Maximum [Member]
Collateral dependent loans, measurement input		100
Third Party Appraisals [Member] \| Fair Value, Inputs, Level 3 [Member] \| Commercial Loans [Member] \| Measurement Input, Manager Adjustments [Member] \| Weighted Average [Member]
Collateral dependent loans, measurement input	100	45
Third Party Appraisals [Member] \| Fair Value, Inputs, Level 3 [Member] \| Agricultural Loans [Member]
Collateral dependent loans, fair value	$ 743	$ 1,904
Third Party Appraisals [Member] \| Fair Value, Inputs, Level 3 [Member] \| Agricultural Loans [Member] \| Measurement Input, Manager Adjustments [Member] \| Minimum [Member]
Collateral dependent loans, measurement input	18	2
Third Party Appraisals [Member] \| Fair Value, Inputs, Level 3 [Member] \| Agricultural Loans [Member] \| Measurement Input, Manager Adjustments [Member] \| Maximum [Member]
Collateral dependent loans, measurement input	100	100
Third Party Appraisals [Member] \| Fair Value, Inputs, Level 3 [Member] \| Agricultural Loans [Member] \| Measurement Input, Manager Adjustments [Member] \| Weighted Average [Member]
Collateral dependent loans, measurement input	73	43
Third Party Appraisals [Member] \| Fair Value, Inputs, Level 3 [Member] \| Real Estate Loan [Member]
RE – Residential, fair value	$ 0	$ 91
Third Party Appraisals [Member] \| Fair Value, Inputs, Level 3 [Member] \| Real Estate Loan [Member] \| Measurement Input, Manager Adjustments [Member] \| Weighted Average [Member]
Other Real Estate, measurement input	0	60
Third Party Appraisals [Member] \| Fair Value, Inputs, Level 3 [Member] \| Equity Lines of Credit [Member] \| Residential Portfolio Segment [Member]
Equity lines of credit, fair value	$ 135	$ 135
Third Party Appraisals [Member] \| Fair Value, Inputs, Level 3 [Member] \| Equity Lines of Credit [Member] \| Measurement Input, Manager Adjustments [Member] \| Weighted Average [Member] \| Residential Portfolio Segment [Member]
Equity lines of credit, measurement input	10	10

Note 9 - Fair Value Measurements - Quantitative Information About Level 3 Fair Value Measurements for Financial Instruments Measured at Fair Value on a Non-recurring Basis (Details) - Fair Value, Nonrecurring [Member]
$ in Thousands

6 Months Ended

12 Months Ended

Jun. 30, 2026

USD ($)

Dec. 31, 2025

USD ($)

Collateral dependent loans, fair value

$ 743

$ 1,988

Other Real Estate Owned and Receivables, Fair Value

226

Commercial Loans [Member]