Note 10 - Income Taxes - Difference In Statutory Federal Income Tax Rate and Effective Tax Rate (Details)	3 Months Ended
	Mar. 31, 2025	Mar. 31, 2024
Statutory tax rate	21.00%	21.00%
Tax exempt interest	(0.50%)	(1.20%)
Tax exempt income on bank-owned life insurance	(1.30%)	(3.00%)
Captive insurance premium income	(1.30%)	(3.30%)
Affordable housing tax credit limited partnerships	(1.60%)	(3.20%)
Nondeductible merger-related expenses	0.00%	3.30%
Other, net	0.10%	0.40%
Effective tax rate	16.40%	14.00%