Note 7 - Investments, Held to Maturity ("HTM") (Details Textual)	Mar. 31, 2024 USD ($)	Dec. 31, 2023 USD ($)
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss	$ 159,085,000	$ 163,072,000
Debt Securities, Held-to-Maturity, Fair Value	$ 154,938,000	$ 158,540,000
Debt Securities, Held-to-Maturity, Weighted Average Yield	4.81%
Debt Securities, Held to Maturity, Unrealized Loss Position, Number of Positions	49	55
Debt Securities, Held to Maturity, Continuous Unrealized Loss Position, 12 Months or Longer, Number of Positions	43	42
Debt Securities, Held-to-Maturity, Amortized Cost, after Allowance for Credit Loss	$ 159,085,000	$ 163,072,000
Debt Securities, Held-to-Maturity, Allowance for Credit Loss	0	0
Debt Securities, Held-to-Maturity, 90 Days or More Past Due, Still Accruing	0
Debt Securities, Held-to-Maturity, Nonaccrual		0
Debt Securities, Held-to-Maturity, Accrued Interest, after Allowance for Credit Loss	883,000
Commitments on Mortgage Loans [Member]
Debt Securities, Held-to-Maturity, Fair Value	13,800,000	14,300,000
Debt Securities, Held-to-Maturity, Amortized Cost, after Allowance for Credit Loss	14,100,000	14,600,000
Asset Pledged as Collateral [Member] | Deposit Accounts, FHLB Advances and Other Borrowings [Member]
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss	104,000,000	107,500,000
Debt Securities, Held-to-Maturity, Fair Value	$ 100,300,000	$ 103,800,000