Note 7 - Loans and Related Allowance for Credit Losses (Details Textual)		3 Months Ended			12 Months Ended
		Mar. 31, 2025 USD ($)		Mar. 31, 2024 USD ($)	Dec. 31, 2024 USD ($)		Dec. 31, 2023 USD ($)
Financing Receivable, Accrued Interest, after Allowance for Credit Loss		$ 5,500,000			$ 5,500,000
Financing Receivable, Deferred Commitment Fee		7,700,000			8,200,000
Financing Receivable, Allowance for Credit Loss, Period Increase (Decrease)		$ 46,000
Financing Receivable, Allowance for Credit Loss, Period Increase (Decrease), Percentage		0.20%
Financing Receivable, before Allowance for Credit Loss, Total	[1],[2]	$ 1,550,349,000			1,519,614,000
Mortgage Loans in Process of Foreclosure, Amount		959,000			352,000
Financing Receivable, Nonaccrual, Interest Income		417,000			$ 1,100,000
Financing Receivable, Modified, Commitment to Lend		$ 111,000
Financing Receivable, Troubled Debt Restructuring, Subsequent Default, Number of Contracts		0			0
Financing Receivable, Allowance for Credit Loss		$ 22,401,000	[1],[2]	$ 21,069,000	$ 22,447,000	[1],[2]	$ 21,693,000
Provision for Loan, Lease, and Other Losses		$ (255,000)		(692,000)
Financing Receivable, Accrued Interest, after Allowance for Credit Loss, Statement of Financial Position [Extensible Enumeration]		Interest Receivable and Other Assets			Interest Receivable and Other Assets
Threshold For Loans Evaluated For Impairment [Member]
Financing Receivable, before Allowance for Credit Loss, Total		$ 750,000
Threshold For Loans Evaluated For Impairment [Member] | Criticized Relationships [Member]
Financing Receivable, before Allowance for Credit Loss, Total		150,000
Unfunded Loan Commitment [Member]
Financing Receivable, Allowance for Credit Loss		2,000,000			$ 1,600,000
Provision for Loan, Lease, and Other Losses		$ 350,000		$ 556,000

[1] Accrued interest of $5.5 million and $5.5 million at March 31, 2025 and December 31, 2024, respectively, is excluded from amortized cost and presented in "accrued interest receivable and other assets" on the Consolidated Balance Sheets.

[2] Unearned income, including net deferred loan fees and costs and unamortized premiums and discounts, totaled $7.7 million and $8.2 million at March 31, 2025 and December 31, 2024, respectively.