Note 10 - Affordable Housing Tax Credit Limited Partnerships - Activity in Affordable Housing Program Obligation (Details) (Parentheticals)	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Investment Program, Proportional Amortization Method, Elected, Income Tax Credit and Other Income Tax Benefit, before Amortization, Statement of Income	Income Tax Expense (Benefit)	Income Tax Expense (Benefit)	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]	Deferred Income Tax Expense (Benefit)	Deferred Income Tax Expense (Benefit)	Deferred Income Tax Expense (Benefit)
Investment Program, Proportional Amortization Method, Applied, Amortization Expense, Statement of Cash Flows [Extensible Enumeration]	Depreciation, Amortization and Accretion, Net	Depreciation, Amortization and Accretion, Net	Depreciation, Amortization and Accretion, Net
Investment Program, Proportional Amortization Method, Applied, Amortization Expense, Statement of Income	Income Tax Expense (Benefit)	Income Tax Expense (Benefit)	Income Tax Expense (Benefit)