Note 3 - Loans and Allowance for Loan Losses - Aging of Recorded Investment in Loans (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Past Due	$ 5,503	$ 5,282
Current	399,622	379,852
Loans	405,561	385,764
Receivables Acquired with Deteriorated Credit Quality [Member]
Loans	436	630
Real Estate Mortgage Portfolio Segment [Member] | Residential Loan [Member]
Past Due	3,989	4,172
Current	132,441	133,815
Loans	136,813	138,377
Real Estate Mortgage Portfolio Segment [Member] | Residential Loan [Member] | Receivables Acquired with Deteriorated Credit Quality [Member]
Loans	383	390
Real Estate Mortgage Portfolio Segment [Member] | Land Loan [Member]
Past Due	152	52
Current	17,585	13,899
Loans	17,737	13,951
Real Estate Mortgage Portfolio Segment [Member] | Land Loan [Member] | Receivables Acquired with Deteriorated Credit Quality [Member]
Loans	0	0
Real Estate Mortgage Portfolio Segment [Member] | Construction Loans [Member]
Past Due	0	0
Current	23,019	19,489
Loans	23,019	19,489
Real Estate Mortgage Portfolio Segment [Member] | Construction Loans [Member] | Receivables Acquired with Deteriorated Credit Quality [Member]
Loans	0	0
Real Estate Mortgage Portfolio Segment [Member] | Commercial Real Estate Loan [Member]
Past Due	33	27
Current	95,426	96,402
Loans	95,512	96,669
Real Estate Mortgage Portfolio Segment [Member] | Commercial Real Estate Loan [Member] | Receivables Acquired with Deteriorated Credit Quality [Member]
Loans	53	240
Commercial Portfolio Segment [Member]
Past Due	716	238
Current	27,882	23,888
Loans	28,598	24,126
Commercial Portfolio Segment [Member] | Receivables Acquired with Deteriorated Credit Quality [Member]
Loans	0	0
Consumer Portfolio Segment [Member] | Home Equity and Second Mortgage [Member]
Past Due	297	365
Current	49,782	43,466
Loans	50,079	43,831
Consumer Portfolio Segment [Member] | Home Equity and Second Mortgage [Member] | Receivables Acquired with Deteriorated Credit Quality [Member]
Loans	0	0
Consumer Portfolio Segment [Member] | Other Consumer Loan [Member]
Past Due	316	428
Current	53,487	48,893
Loans	53,803	49,321
Consumer Portfolio Segment [Member] | Other Consumer Loan [Member] | Receivables Acquired with Deteriorated Credit Quality [Member]
Loans	0	0
Financing Receivables, 30 to 59 Days Past Due [Member]
Past Due	2,783	3,270
Financing Receivables, 30 to 59 Days Past Due [Member] | Real Estate Mortgage Portfolio Segment [Member] | Residential Loan [Member]
Past Due	1,635	2,444
Financing Receivables, 30 to 59 Days Past Due [Member] | Real Estate Mortgage Portfolio Segment [Member] | Land Loan [Member]
Past Due	147	0
Financing Receivables, 30 to 59 Days Past Due [Member] | Real Estate Mortgage Portfolio Segment [Member] | Construction Loans [Member]
Past Due	0	0
Financing Receivables, 30 to 59 Days Past Due [Member] | Real Estate Mortgage Portfolio Segment [Member] | Commercial Real Estate Loan [Member]
Past Due	0	0
Financing Receivables, 30 to 59 Days Past Due [Member] | Commercial Portfolio Segment [Member]
Past Due	651	155
Financing Receivables, 30 to 59 Days Past Due [Member] | Consumer Portfolio Segment [Member] | Home Equity and Second Mortgage [Member]
Past Due	78	352
Financing Receivables, 30 to 59 Days Past Due [Member] | Consumer Portfolio Segment [Member] | Other Consumer Loan [Member]
Past Due	272	319
Financing Receivables, 60 to 89 Days Past Due [Member]
Past Due	1,059	825
Financing Receivables, 60 to 89 Days Past Due [Member] | Real Estate Mortgage Portfolio Segment [Member] | Residential Loan [Member]
Past Due	905	707
Financing Receivables, 60 to 89 Days Past Due [Member] | Real Estate Mortgage Portfolio Segment [Member] | Land Loan [Member]
Past Due	5	52
Financing Receivables, 60 to 89 Days Past Due [Member] | Real Estate Mortgage Portfolio Segment [Member] | Construction Loans [Member]
Past Due	0	0
Financing Receivables, 60 to 89 Days Past Due [Member] | Real Estate Mortgage Portfolio Segment [Member] | Commercial Real Estate Loan [Member]
Past Due	0	0
Financing Receivables, 60 to 89 Days Past Due [Member] | Commercial Portfolio Segment [Member]
Past Due	65	0
Financing Receivables, 60 to 89 Days Past Due [Member] | Consumer Portfolio Segment [Member] | Home Equity and Second Mortgage [Member]
Past Due	40	0
Financing Receivables, 60 to 89 Days Past Due [Member] | Consumer Portfolio Segment [Member] | Other Consumer Loan [Member]
Past Due	44	66
Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Past Due	1,661	1,187
Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Real Estate Mortgage Portfolio Segment [Member] | Residential Loan [Member]
Past Due	1,449	1,021
Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Real Estate Mortgage Portfolio Segment [Member] | Land Loan [Member]
Past Due	0	0
Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Real Estate Mortgage Portfolio Segment [Member] | Construction Loans [Member]
Past Due	0	0
Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Real Estate Mortgage Portfolio Segment [Member] | Commercial Real Estate Loan [Member]
Past Due	33	27
Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Commercial Portfolio Segment [Member]
Past Due	0	83
Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Consumer Portfolio Segment [Member] | Home Equity and Second Mortgage [Member]
Past Due	179	13
Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Consumer Portfolio Segment [Member] | Other Consumer Loan [Member]
Past Due	$ 0	$ 43