Note 11 - Recent Accounting Pronouncements (Details Textual) $ in Millions	Mar. 31, 2022 USD ($)
Commercial Portfolio Segment [Member]
Loans Receivable with Variable Rates of Interest	$ 1.1
Number of Tax-exempt Loans Tied to LIBOR Reference Rate	1
National Syndicated Credits [Member]
Loans Receivable with Variable Rates of Interest	$ 7.5
Number of Purchased Participation Loans Tied to LIBOR Reference Rate	2
Financial Asset Acquired and No Credit Deterioration [Member]
Loans Receivable with Variable Rates of Interest	$ 48.1