Note 2 - Investment Securities - Schedule of Held-to-maturity Investment Securities with Credit Rating (Details) - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Held-to-maturity, Amortized cost	$ 16,016	$ 17,275
Standard & Poor's, AAA Rating [Member]
Held-to-maturity, Amortized cost	13,516	14,775
Not Rated - Non Agency [Member]
Held-to-maturity, Amortized cost	2,500	2,500
Nontaxable Municipal Bonds [Member]
Held-to-maturity, Amortized cost	13,516	14,775
Nontaxable Municipal Bonds [Member] | Standard & Poor's, AAA Rating [Member]
Held-to-maturity, Amortized cost	13,516	14,775
Nontaxable Municipal Bonds [Member] | Not Rated - Non Agency [Member]
Held-to-maturity, Amortized cost	0	0
Subordinated Debt [Member]
Held-to-maturity, Amortized cost	2,500	2,500
Subordinated Debt [Member] | Standard & Poor's, AAA Rating [Member]
Held-to-maturity, Amortized cost	0	0
Subordinated Debt [Member] | Not Rated - Non Agency [Member]
Held-to-maturity, Amortized cost	$ 2,500	$ 2,500