Note 11 - Recent Accounting Pronouncements (Details Textual)	Sep. 30, 2021 USD ($)
Commercial Portfolio Segment [Member]
Loans Receivable with Variable Rates of Interest	$ 615,000
Number of Tax-exempt Loans Tied to LIBOR Reference Rate	1
National Syndicated Credits [Member]
Loans Receivable with Variable Rates of Interest	$ 7,400,000
Number of Purchased Participation Loans Tied to LIBOR Reference Rate	2
Financial Asset Acquired and No Credit Deterioration [Member]
Number of Loans Receivable with Variable Rates of Interest	13
Loans Receivable with Variable Rates of Interest	$ 50,000,000.0