Note 4 - Premises and Equipment, Net - Summary of Premises and Equipment (Details) - USD ($)	Mar. 31, 2023	Dec. 31, 2022
Property, plant and equipment, gross	$ 91,641,000	$ 90,338,000
Less: accumulated depreciation	40,131,000	38,862,000
Premises and equipment, net	51,510,000	51,476,000
Land and Land Improvements [Member]
Property, plant and equipment, gross	13,050,000	13,532,000
Building [Member]
Property, plant and equipment, gross	55,527,000	53,865,000
Furniture and Fixtures [Member]
Property, plant and equipment, gross	$ 23,064,000	$ 22,941,000