Note 2 - Investments, Available for Sale (Details Textual)	12 Months Ended
	Dec. 31, 2023 USD ($)	Dec. 31, 2022 USD ($)
Debt Securities, Available-for-Sale, Allowance for Credit Loss	$ 0
Debt Securities, Available-for-Sale, Amortized Cost	584,287,000	$ 604,157,000
Debt Securities, Available-for-Sale	537,640,000	550,148,000
Proceeds from Sale of Debt Securities, Available-for-Sale	0	22,375,000
Debt Securities, Available-for-Sale, Realized Gain	0	159,000
Debt Securities, Available-for-Sale, Realized Loss	$ 0	161,000
Debt Securities, Available-for-Sale, Unrealized Loss Position, Number of Positions	416
Debt Securities, Available-for-Sale, Accrued Interest, after Allowance for Credit Loss	$ 2,900,000
Asset Pledged as Collateral [Member] | Deposit Accounts, FHLB Advances and Other Borrowings [Member]
Debt Securities, Available-for-Sale, Amortized Cost	533,700,000	318,000,000
Debt Securities, Available-for-Sale	490,500,000	297,000,000
Mortgage-Backed Securities, Issued by Private Enterprises [Member]
Debt Securities, Available-for-Sale, Amortized Cost	83,300,000	60,100,000
Debt Securities, Available-for-Sale	76,700,000	53,800,000
Small Business Administration Bonds [Member]
Debt Securities, Available-for-Sale, Amortized Cost	79,014,000	102,293,000
Debt Securities, Available-for-Sale	$ 76,753,000	99,630,000
Debt Securities, Available-for-Sale, Unrealized Loss Position, Number of Positions	67
Collateralized Mortgage-Backed Securities [Member]
Debt Securities, Available-for-Sale, Amortized Cost	$ 368,081,000	353,222,000
Debt Securities, Available-for-Sale	$ 336,170,000	319,280,000
Debt Securities, Available-for-Sale, Unrealized Loss Position, Number of Positions	194
Commitments on Mortgage Loans [Member]
Debt Securities, Available-for-Sale, Amortized Cost	$ 83,300,000
Debt Securities, Available-for-Sale	$ 76,700,000
Debt Securities, Available-for-Sale, Unrealized Loss Position, Number of Positions	49
Commitments on Mortgage Loans [Member] | Moody's, Aa1 Rating [Member]
Debt Securities, Available-for-Sale, Unrealized Loss Position, Number of Positions	36
Tax Exempt Municipal Bonds [Member]
Debt Securities, Available-for-Sale, Unrealized Loss Position, Number of Positions	12
Taxable Municipal Bonds [Member]
Debt Securities, Available-for-Sale, Amortized Cost	$ 64,669,000	65,250,000
Debt Securities, Available-for-Sale	$ 53,115,000	$ 50,770,000
Debt Securities, Available-for-Sale, Unrealized Loss Position, Number of Positions	59