Note 4 - Loans - Nonaccrual Loans (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Nonaccrual loans	$ 5,243	$ 5,616
Commercial Portfolio Segment [Member]
Nonaccrual loans	39	61
Commercial Real Estate Portfolio Segment [Member] | Commercial Non-owner Occupied [Member]
Nonaccrual loans	3,103	3,103
Residential Portfolio Segment [Member] | Real Estate Loan [Member] | Individual Tax Identification Number Loan [Member]
Nonaccrual loans	1,878	2,221
Residential Portfolio Segment [Member] | Real Estate Loan [Member] | Mortgage Receivable [Member]
Nonaccrual loans	184	191
Consumer Portfolio Segment [Member]
Nonaccrual loans	$ 39	$ 40