Note 4 - Loans and the Allowance for Loan Losses - Credit Risk Profile by Internally Assigned Grade (Details) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Loans	$ 469,964	$ 461,123
Consumer Portfolio Segment [Member] | Performing Financial Instruments [Member]
Loans	57,050	56,985
Consumer Portfolio Segment [Member] | Nonperforming Financial Instruments [Member]
Loans	117	81
Consumer Portfolio Segment [Member] | Automobile Loan [Member]
Loans	53,639	53,553
Consumer Portfolio Segment [Member] | Automobile Loan [Member] | Performing Financial Instruments [Member]
Loans	53,523	53,474
Consumer Portfolio Segment [Member] | Automobile Loan [Member] | Nonperforming Financial Instruments [Member]
Loans	116	79
Consumer Portfolio Segment [Member] | Other Loans [Member]
Loans	3,528	3,513
Consumer Portfolio Segment [Member] | Other Loans [Member] | Performing Financial Instruments [Member]
Loans	3,527	3,511
Consumer Portfolio Segment [Member] | Other Loans [Member] | Nonperforming Financial Instruments [Member]
Loans	1	2
Consumer Portfolio Segment [Member] | Residential Portfolio Segment [Member]
Loans	$ 57,167
Consumer Portfolio Segment [Member] | Commercial Portfolio Segment [Member]
Loans		$ 57,066