Note 5 - Fair Value Measurements - Impaired Loans and Other Real Estate Owned Measured at Fair Value on Nonrecurring Basis (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Other real estate owned net of valuation allowance	$ 662	$ 662
Fair Value, Inputs, Level 1 [Member]
Other real estate owned net of valuation allowance	0	0
Fair Value, Inputs, Level 2 [Member]
Other real estate owned net of valuation allowance	0	0
Fair Value, Inputs, Level 3 [Member]
Other real estate owned net of valuation allowance	$ 662	$ 662