Note 5 - Loans and Allowance for Loan Losses - Recorded Investment of Residential and Consumer Loans (Details) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Performing Financial Instruments [Member] | Consumer Portfolio Segment [Member] | Automobile Loan [Member]
Loans receivable	$ 58,290	$ 44,521
Performing Financial Instruments [Member] | Consumer Portfolio Segment [Member] | Home Equity Loan [Member]
Loans receivable	20,124	20,745
Performing Financial Instruments [Member] | Consumer Portfolio Segment [Member] | Other Consumer Loans [Member]
Loans receivable	56,792	45,218
Performing Financial Instruments [Member] | Residential Portfolio Segment [Member]
Loans receivable	269,796	221,807
Performing Financial Instruments [Member] | Consumer and Residential Portfolio Segment [Member]
Loans receivable	405,002	332,291
Nonperforming Financial Instruments [Member] | Consumer Portfolio Segment [Member] | Automobile Loan [Member]
Loans receivable	69	45
Nonperforming Financial Instruments [Member] | Consumer Portfolio Segment [Member] | Home Equity Loan [Member]
Loans receivable	35	96
Nonperforming Financial Instruments [Member] | Consumer Portfolio Segment [Member] | Other Consumer Loans [Member]
Loans receivable	129	4
Nonperforming Financial Instruments [Member] | Residential Portfolio Segment [Member]
Loans receivable	3,539	2,068
Nonperforming Financial Instruments [Member] | Consumer and Residential Portfolio Segment [Member]
Loans receivable	3,772	2,213
Consumer Portfolio Segment [Member] | Automobile Loan [Member]
Loans receivable	58,359	44,566
Consumer Portfolio Segment [Member] | Home Equity Loan [Member]
Loans receivable	20,159	20,841
Consumer Portfolio Segment [Member] | Other Consumer Loans [Member]
Loans receivable	56,921	45,222
Consumer Portfolio Segment [Member]
Loans receivable	135,439	110,629
Residential Portfolio Segment [Member]
Loans receivable	273,335	223,875
Consumer and Residential Portfolio Segment [Member]
Loans receivable	408,774	334,504
Loans receivable	$ 721,587	$ 585,752