Note 4 - Fair Value Measurements - Assets and Liabilities Measured on Recurring Basis (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Securities available for sale	$ 218,167	$ 246,019
Fair Value, Recurring [Member]
Securities available for sale	218,167	246,019
Equity securities	309	225
Commitments to extend credit	(37)	(28)
Total	218,439	246,216
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Securities available for sale	0	0
Equity securities	0	0
Commitments to extend credit	0	0
Total	0	0
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Securities available for sale	218,167	246,019
Equity securities	309	225
Commitments to extend credit	(37)	(28)
Total	218,439	246,216
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]
Securities available for sale	0	0
Equity securities	0	0
Commitments to extend credit	0	0
Total	$ 0	$ 0