Note 4 - Loans and Allowance for Loan Losses - Nonaccrual Loans and Loans Past Due 90 Days or More and Still Accruing (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Loans past due 90 days and still accruing	$ 1,983	$ 889
Nonaccrual	8,195	9,149
Residential Portfolio Segment [Member]
Loans past due 90 days and still accruing	360	255
Nonaccrual	5,867	6,119
Commercial Real Estate Portfolio Segment [Member] | Commercial Real Estate Owner Occupied [Member]
Loans past due 90 days and still accruing	60
Nonaccrual	348	863
Commercial Real Estate Portfolio Segment [Member] | Commercial Real Estate Nonowner Occupied [Member]
Loans past due 90 days and still accruing
Nonaccrual	724	804
Commercial Real Estate Portfolio Segment [Member] | Construction Loans [Member]
Loans past due 90 days and still accruing
Nonaccrual	237	229
Commercial and Industrial Portfolio Segment [Member]
Loans past due 90 days and still accruing	1,192
Nonaccrual	534	590
Consumer Portfolio Segment [Member] | Automobile Loan [Member]
Loans past due 90 days and still accruing	116	239
Nonaccrual	77	61
Consumer Portfolio Segment [Member] | Home Equity Loan [Member]
Loans past due 90 days and still accruing
Nonaccrual	359	392
Consumer Portfolio Segment [Member] | Other Consumer Loans [Member]
Loans past due 90 days and still accruing	255	395
Nonaccrual	$ 49	$ 91