Note 4 - Premises and Equipment, Net - Summary of Premises and Equipment (Details) - USD ($)	Sep. 30, 2023	Dec. 31, 2022
Property, plant and equipment, gross	$ 94,806,000	$ 90,338,000
Less: accumulated depreciation	42,575,000	38,862,000
Premises and equipment, net	52,231,000	51,476,000
Land and Land Improvements [Member]
Property, plant and equipment, gross	13,072,000	13,532,000
Building [Member]
Property, plant and equipment, gross	57,076,000	53,865,000
Furniture and Fixtures [Member]
Property, plant and equipment, gross	$ 24,658,000	$ 22,941,000