Note 4 - Loans - Nonaccrual Loans (Details) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Nonaccrual loans	$ 4,232	$ 5,799
Commercial Portfolio Segment [Member]
Nonaccrual loans	1,358	1,603
Commercial Real Estate Portfolio Segment [Member] | Commercial Non-owner Occupied [Member]
Nonaccrual loans		600
Residential Portfolio Segment [Member] | Real Estate Loan [Member] | Individual Tax Identification Number Loan [Member]
Nonaccrual loans	2,613	2,909
Residential Portfolio Segment [Member] | Real Estate Loan [Member] | Mortgage Receivable [Member]
Nonaccrual loans	184	606
Residential Portfolio Segment [Member] | Home Equity Loan [Member]
Nonaccrual loans	44	45
Consumer Portfolio Segment [Member]
Nonaccrual loans	$ 33	$ 36