Note 5 - Loans - Nonaccrual Loans (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Nonaccrual loans	$ 5,799	$ 11,386
Commercial Portfolio Segment [Member]
Nonaccrual loans	1,603	2,749
Commercial Real Estate Portfolio Segment [Member] | Commercial Non-owner Occupied [Member]
Nonaccrual loans		1,196
Commercial Real Estate Portfolio Segment [Member] | Commercial Owner Occupied Loan [Member]
Nonaccrual loans	600	784
Residential Portfolio Segment [Member] | Real Estate Loan [Member] | Individual Tax Identification Number Loan [Member]
Nonaccrual loans	2,909	3,576
Residential Portfolio Segment [Member] | Real Estate Loan [Member] | Mortgage Receivable [Member]
Nonaccrual loans	606	1,914
Residential Portfolio Segment [Member] | Home Equity Loan [Member]
Nonaccrual loans	45	917
Consumer Portfolio Segment [Member]
Nonaccrual loans	$ 36	$ 250