Note 9 - Allowance for Loan Losses and Credit Quality Information - Classified and Unclassified Loans (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Loans receivable	$ 607,644	$ 594,856
Classified [Member]
Loans receivable	31,815	32,591
Classified [Member] | Special Mention [Member]
Loans receivable	19,512	17,240
Classified [Member] | Substandard [Member]
Loans receivable	12,067	15,164
Classified [Member] | Doubtful [Member]
Loans receivable	131	81
Classified [Member] | Unlikely to be Collected Financing Receivable [Member]
Loans receivable	105	106
Unclassified [Member]
Loans receivable	575,829	562,265
Residential Portfolio Segment [Member]
Loans receivable	109,210	110,698
Residential Portfolio Segment [Member] | Classified [Member]
Loans receivable	1,818	1,961
Residential Portfolio Segment [Member] | Classified [Member] | Special Mention [Member]
Loans receivable	571	150
Residential Portfolio Segment [Member] | Classified [Member] | Substandard [Member]
Loans receivable	1,152	1,771
Residential Portfolio Segment [Member] | Classified [Member] | Doubtful [Member]
Loans receivable	95	40
Residential Portfolio Segment [Member] | Classified [Member] | Unlikely to be Collected Financing Receivable [Member]
Loans receivable	0	0
Residential Portfolio Segment [Member] | Unclassified [Member]
Loans receivable	107,392	108,737
Commercial Real Estate Portfolio Segment [Member]
Loans receivable	349,864	336,130
Commercial Real Estate Portfolio Segment [Member] | Real Estate Loan [Member]
Loans receivable	198,379	195,564
Commercial Real Estate Portfolio Segment [Member] | Commercial Real Estate Other [Member]
Loans receivable	151,485	140,566
Commercial Real Estate Portfolio Segment [Member] | Classified [Member] | Real Estate Loan [Member]
Loans receivable	10,831	10,369
Commercial Real Estate Portfolio Segment [Member] | Classified [Member] | Commercial Real Estate Other [Member]
Loans receivable	10,240	9,997
Commercial Real Estate Portfolio Segment [Member] | Classified [Member] | Special Mention [Member] | Real Estate Loan [Member]
Loans receivable	8,101	5,564
Commercial Real Estate Portfolio Segment [Member] | Classified [Member] | Special Mention [Member] | Commercial Real Estate Other [Member]
Loans receivable	5,201	4,879
Commercial Real Estate Portfolio Segment [Member] | Classified [Member] | Substandard [Member] | Real Estate Loan [Member]
Loans receivable	2,730	4,805
Commercial Real Estate Portfolio Segment [Member] | Classified [Member] | Substandard [Member] | Commercial Real Estate Other [Member]
Loans receivable	5,039	5,118
Commercial Real Estate Portfolio Segment [Member] | Classified [Member] | Doubtful [Member] | Real Estate Loan [Member]
Loans receivable	0	0
Commercial Real Estate Portfolio Segment [Member] | Classified [Member] | Doubtful [Member] | Commercial Real Estate Other [Member]
Loans receivable	0	0
Commercial Real Estate Portfolio Segment [Member] | Classified [Member] | Unlikely to be Collected Financing Receivable [Member] | Real Estate Loan [Member]
Loans receivable	0	0
Commercial Real Estate Portfolio Segment [Member] | Classified [Member] | Unlikely to be Collected Financing Receivable [Member] | Commercial Real Estate Other [Member]
Loans receivable	0	0
Commercial Real Estate Portfolio Segment [Member] | Unclassified [Member] | Real Estate Loan [Member]
Loans receivable	187,548	185,195
Commercial Real Estate Portfolio Segment [Member] | Unclassified [Member] | Commercial Real Estate Other [Member]
Loans receivable	141,245	130,569
Consumer Portfolio Segment [Member]
Loans receivable	73,085	72,532
Consumer Portfolio Segment [Member] | Classified [Member]
Loans receivable	617	856
Consumer Portfolio Segment [Member] | Classified [Member] | Special Mention [Member]
Loans receivable	0	0
Consumer Portfolio Segment [Member] | Classified [Member] | Substandard [Member]
Loans receivable	476	709
Consumer Portfolio Segment [Member] | Classified [Member] | Doubtful [Member]
Loans receivable	36	41
Consumer Portfolio Segment [Member] | Classified [Member] | Unlikely to be Collected Financing Receivable [Member]
Loans receivable	105	106
Consumer Portfolio Segment [Member] | Unclassified [Member]
Loans receivable	72,468	71,676
Commercial Portfolio Segment [Member]
Loans receivable	75,485	75,496
Commercial Portfolio Segment [Member] | Classified [Member]
Loans receivable	8,309	9,408
Commercial Portfolio Segment [Member] | Classified [Member] | Special Mention [Member]
Loans receivable	5,639	6,647
Commercial Portfolio Segment [Member] | Classified [Member] | Substandard [Member]
Loans receivable	2,670	2,761
Commercial Portfolio Segment [Member] | Classified [Member] | Doubtful [Member]
Loans receivable	0	0
Commercial Portfolio Segment [Member] | Classified [Member] | Unlikely to be Collected Financing Receivable [Member]
Loans receivable	0	0
Commercial Portfolio Segment [Member] | Unclassified [Member]
Loans receivable	$ 67,176	$ 66,088