Note 3 - Loans Receivable - Past Due and Non-accrual Status of Loans (Details) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Loans, nonaccrual loans	$ 3,352	$ 924
Loans, past due	3,445	1,926
Loans, current	431,056	417,065
Loans	434,501	418,991
Construction Loan Portfolio Segment [Member] | Residential [Member]
Loans, nonaccrual loans
Loans, past due
Loans, current	9,990	10,204
Loans	9,990	10,204
Construction Loan Portfolio Segment [Member] | Land Acquisition Development And Commercial [Member]
Loans, nonaccrual loans
Loans, past due	241
Loans, current	31,537	27,480
Loans	31,778	27,480
Real Estate Portfolio Segment [Member] | Residential [Member]
Loans, nonaccrual loans	577	577
Loans, past due	1,950	1,442
Loans, current	111,484	110,184
Loans	113,434	111,626
Real Estate Portfolio Segment [Member] | Commercial [Member]
Loans, nonaccrual loans	2,748	336
Loans, past due	817	115
Loans, current	179,304	172,133
Loans	180,121	172,248
Commercial Industrial and Agricultural Portfolio Segment [Member]
Loans, nonaccrual loans	27	11
Loans, past due	71	93
Loans, current	61,388	59,716
Loans	61,459	59,809
Equity Lines Portfolio Segment [Member]
Loans, nonaccrual loans
Loans, past due	329	258
Loans, current	30,190	29,698
Loans	30,519	29,956
Consumer Portfolio Segment [Member]
Loans, nonaccrual loans
Loans, past due	37	18
Loans, current	7,163	7,650
Loans	7,200	7,668
Financing Receivables, 30 to 59 Days Past Due [Member]
Loans, past due	2,541	1,113
Financing Receivables, 30 to 59 Days Past Due [Member] | Construction Loan Portfolio Segment [Member] | Residential [Member]
Loans, past due
Financing Receivables, 30 to 59 Days Past Due [Member] | Construction Loan Portfolio Segment [Member] | Land Acquisition Development And Commercial [Member]
Loans, past due	241
Financing Receivables, 30 to 59 Days Past Due [Member] | Real Estate Portfolio Segment [Member] | Residential [Member]
Loans, past due	1,183	672
Financing Receivables, 30 to 59 Days Past Due [Member] | Real Estate Portfolio Segment [Member] | Commercial [Member]
Loans, past due	817	115
Financing Receivables, 30 to 59 Days Past Due [Member] | Commercial Industrial and Agricultural Portfolio Segment [Member]
Loans, past due	45	60
Financing Receivables, 30 to 59 Days Past Due [Member] | Equity Lines Portfolio Segment [Member]
Loans, past due	225	258
Financing Receivables, 30 to 59 Days Past Due [Member] | Consumer Portfolio Segment [Member]
Loans, past due	30	8
Financing Receivables, 60 to 89 Days Past Due [Member]
Loans, past due	310	232
Financing Receivables, 60 to 89 Days Past Due [Member] | Construction Loan Portfolio Segment [Member] | Residential [Member]
Loans, past due
Financing Receivables, 60 to 89 Days Past Due [Member] | Construction Loan Portfolio Segment [Member] | Land Acquisition Development And Commercial [Member]
Loans, past due
Financing Receivables, 60 to 89 Days Past Due [Member] | Real Estate Portfolio Segment [Member] | Residential [Member]
Loans, past due	190	193
Financing Receivables, 60 to 89 Days Past Due [Member] | Real Estate Portfolio Segment [Member] | Commercial [Member]
Loans, past due
Financing Receivables, 60 to 89 Days Past Due [Member] | Commercial Industrial and Agricultural Portfolio Segment [Member]
Loans, past due	16	33
Financing Receivables, 60 to 89 Days Past Due [Member] | Equity Lines Portfolio Segment [Member]
Loans, past due	104
Financing Receivables, 60 to 89 Days Past Due [Member] | Consumer Portfolio Segment [Member]
Loans, past due		6
Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Loans, past due	594	581
Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Construction Loan Portfolio Segment [Member] | Residential [Member]
Loans, past due
Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Construction Loan Portfolio Segment [Member] | Land Acquisition Development And Commercial [Member]
Loans, past due
Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Real Estate Portfolio Segment [Member] | Residential [Member]
Loans, past due	577	577
Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Real Estate Portfolio Segment [Member] | Commercial [Member]
Loans, past due
Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Commercial Industrial and Agricultural Portfolio Segment [Member]
Loans, past due	10
Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Equity Lines Portfolio Segment [Member]
Loans, past due
Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Consumer Portfolio Segment [Member]
Loans, past due	$ 7	$ 4