Note 4 - Loans and the Allowance for Loan Losses - Credit Risk Profile by Internally Assigned Grade (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Loans	$ 601,756	$ 566,199
Consumer Portfolio Segment [Member] | Performing Financial Instruments [Member]
Loans	90,926	80,805
Consumer Portfolio Segment [Member] | Nonperforming Financial Instruments [Member]
Loans	268	410
Consumer Portfolio Segment [Member] | Automobile Loan [Member]
Loans	86,727	77,135
Consumer Portfolio Segment [Member] | Automobile Loan [Member] | Performing Financial Instruments [Member]
Loans	86,464	76,734
Consumer Portfolio Segment [Member] | Automobile Loan [Member] | Nonperforming Financial Instruments [Member]
Loans	263	401
Consumer Portfolio Segment [Member] | Other Loans [Member]
Loans	4,467	4,080
Consumer Portfolio Segment [Member] | Other Loans [Member] | Performing Financial Instruments [Member]
Loans	4,462	4,071
Consumer Portfolio Segment [Member] | Other Loans [Member] | Nonperforming Financial Instruments [Member]
Loans	5	9
Consumer Portfolio Segment [Member] | Residential Portfolio Segment [Member]
Loans	$ 91,194
Consumer Portfolio Segment [Member] | Commercial Portfolio Segment [Member]
Loans		$ 81,215