Note 3 - Investments, Held To Maturity - Schedule of Credit Ratings for Held To Maturity Securities (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Debt Securities, Held-to-Maturity, Amortized Cost, after Allowance for Credit Loss	$ 163,072	$ 167,438
Private Label Taxable Municipal Securities [Member]
Debt Securities, Held-to-Maturity, Amortized Cost, after Allowance for Credit Loss	962
Private Label Taxable Municipal Securities [Member] | Moody's, Aa1 Rating [Member]
Debt Securities, Held-to-Maturity, Amortized Cost, after Allowance for Credit Loss	962
Private Label Mortgage Backed Securities [Member] | Moody's, Aaa Rating [Member]
Debt Securities, Held-to-Maturity, Amortized Cost, after Allowance for Credit Loss	9,259
Private Label Mortgage Backed Securities [Member] | Moody's, A1 Rating [Member]
Debt Securities, Held-to-Maturity, Amortized Cost, after Allowance for Credit Loss	1,663
Private Label Mortgage Backed Securities [Member] | Not Rated by Moodys [Member]
Debt Securities, Held-to-Maturity, Amortized Cost, after Allowance for Credit Loss	3,695
Private Label Investments [Member]
Debt Securities, Held-to-Maturity, Amortized Cost, after Allowance for Credit Loss	$ 14,617