Note 4 - Loans and the Allowance for Loan Losses - Credit Risk Profile by Internally Assigned Grade (Details) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Loans	$ 476,091	$ 461,123
Consumer Portfolio Segment [Member] | Performing Financial Instruments [Member]
Loans	58,640	56,985
Consumer Portfolio Segment [Member] | Nonperforming Financial Instruments [Member]
Loans	310	81
Consumer Portfolio Segment [Member] | Automobile Loan [Member]
Loans	55,255	53,553
Consumer Portfolio Segment [Member] | Automobile Loan [Member] | Performing Financial Instruments [Member]
Loans	54,947	53,474
Consumer Portfolio Segment [Member] | Automobile Loan [Member] | Nonperforming Financial Instruments [Member]
Loans	308	79
Consumer Portfolio Segment [Member] | Other Loans [Member]
Loans	3,695	3,513
Consumer Portfolio Segment [Member] | Other Loans [Member] | Performing Financial Instruments [Member]
Loans	3,693	3,511
Consumer Portfolio Segment [Member] | Other Loans [Member] | Nonperforming Financial Instruments [Member]
Loans	2	2
Consumer Portfolio Segment [Member] | Residential Portfolio Segment [Member]
Loans	$ 58,950
Consumer Portfolio Segment [Member] | Commercial Portfolio Segment [Member]
Loans		$ 57,066