Note 4 - Loans and Allowance for Loan Losses - Recorded Investment of Residential and Consumer Loans (Details) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Loans receivable	$ 756,905	$ 734,901
Consumer Portfolio Segment [Member]
Loans receivable	137,291	134,283
Consumer Portfolio Segment [Member] | Automobile Loan [Member]
Loans receivable	64,540	59,772
Consumer Portfolio Segment [Member] | Home Equity Loan [Member]
Loans receivable	21,300	20,861
Consumer Portfolio Segment [Member] | Other Consumer Loans [Member]
Loans receivable	51,451	53,650
Residential Portfolio Segment [Member]
Loans receivable	304,537	286,022
Consumer and Residential Portfolio Segment [Member]
Loans receivable	441,828	420,305
Performing Financial Instruments [Member] | Consumer Portfolio Segment [Member] | Automobile Loan [Member]
Loans receivable	64,400	59,646
Performing Financial Instruments [Member] | Consumer Portfolio Segment [Member] | Home Equity Loan [Member]
Loans receivable	21,048	20,827
Performing Financial Instruments [Member] | Consumer Portfolio Segment [Member] | Other Consumer Loans [Member]
Loans receivable	51,252	53,598
Performing Financial Instruments [Member] | Residential Portfolio Segment [Member]
Loans receivable	300,986	282,445
Performing Financial Instruments [Member] | Consumer and Residential Portfolio Segment [Member]
Loans receivable	437,686	416,516
Nonperforming Financial Instruments [Member] | Consumer Portfolio Segment [Member] | Automobile Loan [Member]
Loans receivable	140	126
Nonperforming Financial Instruments [Member] | Consumer Portfolio Segment [Member] | Home Equity Loan [Member]
Loans receivable	252	34
Nonperforming Financial Instruments [Member] | Consumer Portfolio Segment [Member] | Other Consumer Loans [Member]
Loans receivable	199	52
Nonperforming Financial Instruments [Member] | Residential Portfolio Segment [Member]
Loans receivable	3,551	3,577
Nonperforming Financial Instruments [Member] | Consumer and Residential Portfolio Segment [Member]
Loans receivable	$ 4,142	$ 3,789