Note 4 - Loans and Allowance for Credit Losses - Schedule of Modified Financing Receivables (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2026	Jun. 30, 2025	Jun. 30, 2026	Jun. 30, 2025
Financing Receivable, Excluding Accrued Interest, Modified in Period, to Total Financing Receivables, Percentage	0.13%	0.23%	0.37%	0.25%
Financing Receivable, Modified, Weighted Average Interest Rate Decrease from Modification	0.00%	0.00%	0.00%	0.00%
Financing Receivable, Modified, Weighted Average Term Increase from Modification (Month)	10 months	4 months	8 months	6 months
Extended Maturity [Member]
Financing Receivable, Excluding Accrued Interest, Modified in Period, Amount	$ 1,415	$ 2,491	$ 3,161	$ 2,577
Payment Deferral [Member]
Financing Receivable, Excluding Accrued Interest, Modified in Period, Amount	$ 73		$ 961	$ 73
Extended Maturity and Payment Deferral [Member]
Financing Receivable, Excluding Accrued Interest, Modified in Period, Amount		$ 0
Commercial Portfolio Segment [Member]
Financing Receivable, Excluding Accrued Interest, Modified in Period, to Total Financing Receivables, Percentage	0.69%	0.82%	0.91%	0.93%
Financing Receivable, Modified, Weighted Average Interest Rate Decrease from Modification	0.00%	0.00%	0.00%	0.00%
Financing Receivable, Modified, Weighted Average Term Increase from Modification (Month)	10 months	5 months	9 months	10 months
Commercial Portfolio Segment [Member] \| Extended Maturity [Member]
Financing Receivable, Excluding Accrued Interest, Modified in Period, Amount	$ 1,415	$ 1,157	$ 1,870	$ 1,243
Commercial Portfolio Segment [Member] \| Payment Deferral [Member]
Financing Receivable, Excluding Accrued Interest, Modified in Period, Amount	$ 73		$ 73	$ 73
Commercial Portfolio Segment [Member] \| Extended Maturity and Payment Deferral [Member]
Financing Receivable, Excluding Accrued Interest, Modified in Period, Amount		$ 0
Commercial Real Estate Portfolio Segment [Member]
Financing Receivable, Excluding Accrued Interest, Modified in Period, to Total Financing Receivables, Percentage	0.00%	0.19%	0.13%	0.19%
Financing Receivable, Modified, Weighted Average Interest Rate Decrease from Modification	0.00%	0.00%	0.00%	0.00%
Financing Receivable, Modified, Weighted Average Term Increase from Modification (Month)	0 months	3 months	0 months	3 months
Commercial Real Estate Portfolio Segment [Member] \| Extended Maturity [Member]
Financing Receivable, Excluding Accrued Interest, Modified in Period, Amount	$ 0	$ 1,334	$ 0	$ 1,334
Commercial Real Estate Portfolio Segment [Member] \| Payment Deferral [Member]
Financing Receivable, Excluding Accrued Interest, Modified in Period, Amount	$ 0		$ 888	$ 0
Commercial Real Estate Portfolio Segment [Member] \| Extended Maturity and Payment Deferral [Member]
Financing Receivable, Excluding Accrued Interest, Modified in Period, Amount		$ 0
Agricultural Portfolio Segment [Member]
Financing Receivable, Excluding Accrued Interest, Modified in Period, to Total Financing Receivables, Percentage	0.00%	0.00%	1.49%	0.00%
Financing Receivable, Modified, Weighted Average Interest Rate Decrease from Modification	0.00%	0.00%	0.00%	0.00%
Financing Receivable, Modified, Weighted Average Term Increase from Modification (Month)	0 months	0 months	6 months	0 months
Agricultural Portfolio Segment [Member] \| Extended Maturity [Member]
Financing Receivable, Excluding Accrued Interest, Modified in Period, Amount	$ 0	$ 0	$ 1,291	$ 0
Agricultural Portfolio Segment [Member] \| Payment Deferral [Member]
Financing Receivable, Excluding Accrued Interest, Modified in Period, Amount	$ 0		$ 0	$ 0
Agricultural Portfolio Segment [Member] \| Extended Maturity and Payment Deferral [Member]
Financing Receivable, Excluding Accrued Interest, Modified in Period, Amount		$ 0
Residential Mortgage [Member]
Financing Receivable, Excluding Accrued Interest, Modified in Period, to Total Financing Receivables, Percentage	0.00%	0.00%	0.00%	0.00%
Financing Receivable, Modified, Weighted Average Interest Rate Decrease from Modification	0.00%	0.00%	0.00%	0.00%
Financing Receivable, Modified, Weighted Average Term Increase from Modification (Month)	0 months	0 months	0 months	0 months
Residential Mortgage [Member] \| Extended Maturity [Member]
Financing Receivable, Excluding Accrued Interest, Modified in Period, Amount	$ 0	$ 0	$ 0	$ 0
Residential Mortgage [Member] \| Payment Deferral [Member]
Financing Receivable, Excluding Accrued Interest, Modified in Period, Amount	$ 0		$ 0	$ 0
Residential Mortgage [Member] \| Extended Maturity and Payment Deferral [Member]
Financing Receivable, Excluding Accrued Interest, Modified in Period, Amount		$ 0
Residential Portfolio Segment [Member]
Financing Receivable, Excluding Accrued Interest, Modified in Period, to Total Financing Receivables, Percentage	0.00%	0.00%	0.00%	0.00%
Financing Receivable, Modified, Weighted Average Interest Rate Decrease from Modification	0.00%	0.00%	0.00%	0.00%
Financing Receivable, Modified, Weighted Average Term Increase from Modification (Month)	0 months	0 months	0 months	0 months
Residential Portfolio Segment [Member] \| Extended Maturity [Member]
Financing Receivable, Excluding Accrued Interest, Modified in Period, Amount	$ 0	$ 0	$ 0	$ 0
Residential Portfolio Segment [Member] \| Payment Deferral [Member]
Financing Receivable, Excluding Accrued Interest, Modified in Period, Amount	$ 0		$ 0	$ 0
Residential Portfolio Segment [Member] \| Extended Maturity and Payment Deferral [Member]
Financing Receivable, Excluding Accrued Interest, Modified in Period, Amount		$ 0
Consumer Portfolio Segment [Member]
Financing Receivable, Excluding Accrued Interest, Modified in Period, to Total Financing Receivables, Percentage	0.00%	0.00%	0.00%	0.00%
Financing Receivable, Modified, Weighted Average Interest Rate Decrease from Modification	0.00%	0.00%	0.00%	0.00%
Financing Receivable, Modified, Weighted Average Term Increase from Modification (Month)	0 months	0 months	0 months	0 months
Consumer Portfolio Segment [Member] \| Extended Maturity [Member]
Financing Receivable, Excluding Accrued Interest, Modified in Period, Amount	$ 0	$ 0	$ 0	$ 0
Consumer Portfolio Segment [Member] \| Payment Deferral [Member]
Financing Receivable, Excluding Accrued Interest, Modified in Period, Amount	$ 0		$ 0	$ 0
Consumer Portfolio Segment [Member] \| Extended Maturity and Payment Deferral [Member]
Financing Receivable, Excluding Accrued Interest, Modified in Period, Amount		$ 0

Note 4 - Loans and Allowance for Credit Losses - Schedule of Modified Financing Receivables (Details) - USD ($)
$ in Thousands

3 Months Ended

6 Months Ended

Jun. 30, 2026

Jun. 30, 2025

Jun. 30, 2026

Jun. 30, 2025

Financing Receivable, Excluding Accrued Interest, Modified in Period, to Total Financing Receivables, Percentage

0.13%

0.23%

0.37%

0.25%