Note 3 - Loans and Allowance for Loan Losses - Recorded Investment in Loans by Risk Category (Details) - USD ($)	Jun. 30, 2017	Dec. 31, 2016
Loans	$ 399,152,000	$ 385,764,000
Pass [Member]
Loans	387,668	372,497,000
Special Mention [Member]
Loans	4,051,000	3,087,000
Substandard [Member]
Loans	4,396,000	6,863,000
Doubtful [Member]
Loans	3,037,000	3,317,000
Unlikely to be Collected Financing Receivable [Member]
Loans	0	0
Real Estate Mortgage Portfolio Segment [Member] | Residential Loan [Member]
Loans	135,240,000	138,377,000
Real Estate Mortgage Portfolio Segment [Member] | Residential Loan [Member] | Pass [Member]
Loans	131,490	135,328,000
Real Estate Mortgage Portfolio Segment [Member] | Residential Loan [Member] | Special Mention [Member]
Loans	437,000	403,000
Real Estate Mortgage Portfolio Segment [Member] | Residential Loan [Member] | Substandard [Member]
Loans	886,000	721,000
Real Estate Mortgage Portfolio Segment [Member] | Residential Loan [Member] | Doubtful [Member]
Loans	2,427,000	1,925,000
Real Estate Mortgage Portfolio Segment [Member] | Residential Loan [Member] | Unlikely to be Collected Financing Receivable [Member]
Loans	0	0
Real Estate Mortgage Portfolio Segment [Member] | Land Loan [Member]
Loans	17,943,000	13,951,000
Real Estate Mortgage Portfolio Segment [Member] | Land Loan [Member] | Pass [Member]
Loans	17,738	13,795,000
Real Estate Mortgage Portfolio Segment [Member] | Land Loan [Member] | Special Mention [Member]
Loans	85,000	86,000
Real Estate Mortgage Portfolio Segment [Member] | Land Loan [Member] | Substandard [Member]
Loans	120,000	70,000
Real Estate Mortgage Portfolio Segment [Member] | Land Loan [Member] | Doubtful [Member]
Loans	0	0
Real Estate Mortgage Portfolio Segment [Member] | Land Loan [Member] | Unlikely to be Collected Financing Receivable [Member]
Loans	0	0
Real Estate Mortgage Portfolio Segment [Member] | Construction Loans [Member]
Loans	25,135,000	19,489,000
Real Estate Mortgage Portfolio Segment [Member] | Construction Loans [Member] | Pass [Member]
Loans	25,135	19,489,000
Real Estate Mortgage Portfolio Segment [Member] | Construction Loans [Member] | Special Mention [Member]
Loans	0	0
Real Estate Mortgage Portfolio Segment [Member] | Construction Loans [Member] | Substandard [Member]
Loans	0	0
Real Estate Mortgage Portfolio Segment [Member] | Construction Loans [Member] | Doubtful [Member]
Loans	0	0
Real Estate Mortgage Portfolio Segment [Member] | Construction Loans [Member] | Unlikely to be Collected Financing Receivable [Member]
Loans	0	0
Real Estate Mortgage Portfolio Segment [Member] | Commercial Real Estate Loan [Member]
Loans	93,843,000	96,669,000
Real Estate Mortgage Portfolio Segment [Member] | Commercial Real Estate Loan [Member] | Pass [Member]
Loans	87,606	87,782,000
Real Estate Mortgage Portfolio Segment [Member] | Commercial Real Estate Loan [Member] | Special Mention [Member]
Loans	2,725,000	1,892,000
Real Estate Mortgage Portfolio Segment [Member] | Commercial Real Estate Loan [Member] | Substandard [Member]
Loans	3,309,000	5,991,000
Real Estate Mortgage Portfolio Segment [Member] | Commercial Real Estate Loan [Member] | Doubtful [Member]
Loans	203,000	1,004,000
Real Estate Mortgage Portfolio Segment [Member] | Commercial Real Estate Loan [Member] | Unlikely to be Collected Financing Receivable [Member]
Loans	0	0
Commercial Portfolio Segment [Member]
Loans	28,170,000	24,126,000
Commercial Portfolio Segment [Member] | Pass [Member]
Loans	27,182	23,246,000
Commercial Portfolio Segment [Member] | Special Mention [Member]
Loans	789,000	661,000
Commercial Portfolio Segment [Member] | Substandard [Member]
Loans	78,000	77,000
Commercial Portfolio Segment [Member] | Doubtful [Member]
Loans	121,000	142,000
Commercial Portfolio Segment [Member] | Unlikely to be Collected Financing Receivable [Member]
Loans	0	0
Consumer Portfolio Segment [Member] | Home Equity and Second Mortgage [Member]
Loans	47,139,000	43,831,000
Consumer Portfolio Segment [Member] | Home Equity and Second Mortgage [Member] | Pass [Member]
Loans	46,894	43,601,000
Consumer Portfolio Segment [Member] | Home Equity and Second Mortgage [Member] | Special Mention [Member]
Loans	0	0
Consumer Portfolio Segment [Member] | Home Equity and Second Mortgage [Member] | Substandard [Member]
Loans	3,000	4,000
Consumer Portfolio Segment [Member] | Home Equity and Second Mortgage [Member] | Doubtful [Member]
Loans	242,000	226,000
Consumer Portfolio Segment [Member] | Home Equity and Second Mortgage [Member] | Unlikely to be Collected Financing Receivable [Member]
Loans	0	0
Consumer Portfolio Segment [Member] | Other Consumer Loan [Member]
Loans	51,682,000	49,321,000
Consumer Portfolio Segment [Member] | Other Consumer Loan [Member] | Pass [Member]
Loans	51,623	49,256,000
Consumer Portfolio Segment [Member] | Other Consumer Loan [Member] | Special Mention [Member]
Loans	15,000	45,000
Consumer Portfolio Segment [Member] | Other Consumer Loan [Member] | Substandard [Member]
Loans	0	0
Consumer Portfolio Segment [Member] | Other Consumer Loan [Member] | Doubtful [Member]
Loans	44,000	20,000
Consumer Portfolio Segment [Member] | Other Consumer Loan [Member] | Unlikely to be Collected Financing Receivable [Member]
Loans	$ 0	$ 0