Note 3 - Loans Receivable - Past Due and Non-accrual Status of Loans (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Loans, past due	$ 2,747	$ 4,141
Loans, current	468,715	440,054
Loans	471,462	444,195
Loans, nonaccrual loans	1,683	1,144
Construction Loan Portfolio Segment [Member] | Residential [Member]
Loans, past due	507
Loans, current	16,725	15,221
Loans	17,232	15,221
Loans, nonaccrual loans
Construction Loan Portfolio Segment [Member] | Land Acquisition Development And Commercial [Member]
Loans, past due	243	317
Loans, current	28,660	35,284
Loans	28,903	35,601
Loans, nonaccrual loans	125	274
Real Estate Portfolio Segment [Member] | Residential [Member]
Loans, past due	513	2,005
Loans, current	142,872	119,644
Loans	143,385	121,649
Loans, nonaccrual loans	532	173
Real Estate Portfolio Segment [Member] | Commercial [Member]
Loans, past due	856	506
Loans, current	184,133	173,493
Loans	184,989	173,999
Loans, nonaccrual loans	463	209
Commercial Industrial and Agricultural Portfolio Segment [Member]
Loans, past due	206	665
Loans, current	60,059	60,532
Loans	60,265	61,197
Loans, nonaccrual loans	162	403
Equity Lines Portfolio Segment [Member]
Loans, past due	398	593
Loans, current	28,571	28,242
Loans	28,969	28,835
Loans, nonaccrual loans	400	49
Consumer Portfolio Segment [Member]
Loans, past due	24	55
Loans, current	7,695	7,638
Loans	7,719	7,693
Loans, nonaccrual loans	1	36
Financing Receivables, 30 to 59 Days Past Due [Member]
Loans, past due	2,744	1,601
Financing Receivables, 30 to 59 Days Past Due [Member] | Construction Loan Portfolio Segment [Member] | Residential [Member]
Loans, past due	507
Financing Receivables, 30 to 59 Days Past Due [Member] | Construction Loan Portfolio Segment [Member] | Land Acquisition Development And Commercial [Member]
Loans, past due	243	43
Financing Receivables, 30 to 59 Days Past Due [Member] | Real Estate Portfolio Segment [Member] | Residential [Member]
Loans, past due	513	589
Financing Receivables, 30 to 59 Days Past Due [Member] | Real Estate Portfolio Segment [Member] | Commercial [Member]
Loans, past due	856	278
Financing Receivables, 30 to 59 Days Past Due [Member] | Commercial Industrial and Agricultural Portfolio Segment [Member]
Loans, past due	206	130
Financing Receivables, 30 to 59 Days Past Due [Member] | Equity Lines Portfolio Segment [Member]
Loans, past due	398	544
Financing Receivables, 30 to 59 Days Past Due [Member] | Consumer Portfolio Segment [Member]
Loans, past due	21	17
Financing Receivables, 60 to 89 Days Past Due [Member]
Loans, past due	3	1,083
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		870
Financing Receivables, 60 to 89 Days Past Due [Member] | Real Estate Portfolio Segment [Member] | Commercial [Member]
Loans, past due		19
Financing Receivables, 60 to 89 Days Past Due [Member] | Commercial Industrial and Agricultural Portfolio Segment [Member]
Loans, past due		143
Financing Receivables, 60 to 89 Days Past Due [Member] | Equity Lines Portfolio Segment [Member]
Loans, past due		49
Financing Receivables, 60 to 89 Days Past Due [Member] | Consumer Portfolio Segment [Member]
Loans, past due	3	2
Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Loans, past due		1,457
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		274
Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Real Estate Portfolio Segment [Member] | Residential [Member]
Loans, past due		546
Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Real Estate Portfolio Segment [Member] | Commercial [Member]
Loans, past due		209
Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Commercial Industrial and Agricultural Portfolio Segment [Member]
Loans, past due		392
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		$ 36