Note 19 - Tax Credit Investments (Details Textual) - USD ($)	3 Months Ended	12 Months Ended
Mar. 31, 2026	Mar. 31, 2025	Dec. 31, 2025
Investment, Proportional Amortization Method, Elected, Amount	$ 32,037,000		$ 29,256,000
Investment Program, Proportional Amortization Method, Elected, Income Tax Credit and Other Income Tax Benefit, after Amortization Expense	661,000	$ 564,000
Affordable Housing Tax Credits [Member]
Investment, Proportional Amortization Method, Elected, Amount	29,000,000		26,000,000
Investment Program, Proportional Amortization Method, Elected, Commitment	14,100,000		13,200,000
Investment Program, Proportional Amortization Method, Applied, Amortization Expense	537,000	473,000
Investment Program, Proportional Amortization Method, Elected, Impairment Loss	$ 0	$ 0
Investment Program, Proportional Amortization Method, Applied, Amortization Expense, Statement of Income or Comprehensive Income [Extensible Enumeration]	Income Tax Expense (Benefit)
Investment Program, Proportional Amortization Method, Applied, Amortization Expense, Statement of Cash Flows [Extensible Enumeration]	Increase (Decrease) in Other Operating Assets and Liabilities, Net
Solar Investment Tax Credit [Member]
Investment, Proportional Amortization Method, Elected, Amount	$ 2,900,000		3,300,000
Investment Program, Proportional Amortization Method, Elected, Commitment			$ 1,700,000
Investment Program, Proportional Amortization Method, Applied, Amortization Expense	569,000
Investment Program, Proportional Amortization Method, Elected, Income Tax Credit and Other Income Tax Benefit, after Amortization Expense	$ 730,000
Investment Program, Proportional Amortization Method, Elected, Income Tax Credit and Other Income Tax Benefit, before Amortization, Statement of Income or Comprehensive Income [Extensible Enumeration]			Income Tax Expense (Benefit)
Investment Program, Proportional Amortization Method, Elected, Income Tax Credit and Other Income Tax Benefit, before Amortization, Statement of Cash Flows [Extensible Enumeration]			Increase (Decrease) in Other Operating Assets and Liabilities, Net

Amount of impairment loss for investment that generates income tax credit and other income tax benefit under tax credit program elected to be accounted for using proportional amortization method. Includes, but is not limited to, investment under tax credit program not meeting condition for accounting under proportional amortization method.

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