Note 3 - 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]	12 Months Ended
Dec. 31, 2025 USD ($)	Dec. 31, 2024 USD ($)
Collateral dependent loans, fair value	$ 1,988
Total	226
Commercial Loans [Member]
Collateral dependent loans, fair value	84	$ 24
Agricultural Loans [Member]
Collateral dependent loans, fair value	1,904
Real Estate Loan [Member] \| Residential Portfolio Segment [Member]
RE – Residential, fair value	91	91
Equity Lines of Credit [Member] \| Residential Portfolio Segment [Member]
Equity lines of credit, fair value	135
Fair Value, Inputs, Level 3 [Member]
Collateral dependent loans, fair value	1,988
Total	226
Fair Value, Inputs, Level 3 [Member] \| Commercial Loans [Member]
Collateral dependent loans, fair value	84	24
Fair Value, Inputs, Level 3 [Member] \| Agricultural Loans [Member]
Collateral dependent loans, fair value	1,904
Fair Value, Inputs, Level 3 [Member] \| Real Estate Loan [Member]
RE – Residential, fair value	91	91
Fair Value, Inputs, Level 3 [Member] \| Equity Lines of Credit [Member] \| Residential Portfolio Segment [Member]
Equity lines of credit, fair value	135
Third Party Appraisals [Member] \| Fair Value, Inputs, Level 3 [Member]
Collateral dependent loans, fair value	1,988	24
Total	226	91
Third Party Appraisals [Member] \| Fair Value, Inputs, Level 3 [Member] \| Commercial Loans [Member]
Collateral dependent loans, fair value	$ 84	$ 24
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	0.14
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	1
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		0.45
Third Party Appraisals [Member] \| Fair Value, Inputs, Level 3 [Member] \| Agricultural Loans [Member]
Collateral dependent loans, fair value	$ 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	0.02
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	1
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	0.43
Third Party Appraisals [Member] \| Fair Value, Inputs, Level 3 [Member] \| Real Estate Loan [Member]
RE – Residential, fair value	$ 91	$ 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	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	$ 0
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	0.10

Note 3 - 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]

12 Months Ended

Dec. 31, 2025

USD ($)

Dec. 31, 2024

USD ($)

Collateral dependent loans, fair value

$ 1,988

Total

226

Commercial Loans [Member]

Collateral dependent loans, fair value

$ 24