Note 9 - Allowance for Loan Losses and Credit Quality Information - Classified and Unclassified Loans (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Loans receivable	$ 680,817	$ 604,435
Classified [Member]
Loans receivable	28,540	34,427
Classified [Member] | Special Mention [Member]
Loans receivable	14,580	14,768
Classified [Member] | Substandard [Member]
Loans receivable	13,846	19,490
Classified [Member] | Doubtful [Member]
Loans receivable	94	104
Classified [Member] | Unlikely to be Collected Financing Receivable [Member]
Loans receivable	20	65
Unclassified [Member]
Loans receivable	652,277	570,008
Residential Portfolio Segment [Member]
Loans receivable	130,843	120,064
Residential Portfolio Segment [Member] | Classified [Member]
Loans receivable	2,618	2,918
Residential Portfolio Segment [Member] | Classified [Member] | Special Mention [Member]
Loans receivable	274	1,118
Residential Portfolio Segment [Member] | Classified [Member] | Substandard [Member]
Loans receivable	2,313	1,765
Residential Portfolio Segment [Member] | Classified [Member] | Doubtful [Member]
Loans receivable	31	35
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	128,225	117,146
Commercial Real Estate Portfolio Segment [Member]
Loans receivable	383,907	350,195
Commercial Real Estate Portfolio Segment [Member] | Real Estate Loan [Member]
Loans receivable	213,696	192,502
Commercial Real Estate Portfolio Segment [Member] | Commercial Real Estate Other [Member]
Loans receivable	170,211	157,693
Commercial Real Estate Portfolio Segment [Member] | Classified [Member] | Real Estate Loan [Member]
Loans receivable	8,645	12,603
Commercial Real Estate Portfolio Segment [Member] | Classified [Member] | Commercial Real Estate Other [Member]
Loans receivable	11,111	9,704
Commercial Real Estate Portfolio Segment [Member] | Classified [Member] | Special Mention [Member] | Real Estate Loan [Member]
Loans receivable	5,194	3,489
Commercial Real Estate Portfolio Segment [Member] | Classified [Member] | Special Mention [Member] | Commercial Real Estate Other [Member]
Loans receivable	5,537	4,451
Commercial Real Estate Portfolio Segment [Member] | Classified [Member] | Substandard [Member] | Real Estate Loan [Member]
Loans receivable	3,451	9,114
Commercial Real Estate Portfolio Segment [Member] | Classified [Member] | Substandard [Member] | Commercial Real Estate Other [Member]
Loans receivable	5,574	5,253
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	205,051	179,899
Commercial Real Estate Portfolio Segment [Member] | Unclassified [Member] | Commercial Real Estate Other [Member]
Loans receivable	159,100	147,989
Consumer Portfolio Segment [Member]
Loans receivable	59,271	69,949
Consumer Portfolio Segment [Member] | Classified [Member]
Loans receivable	707	976
Consumer Portfolio Segment [Member] | Classified [Member] | Special Mention [Member]
Loans receivable	0	0
Consumer Portfolio Segment [Member] | Classified [Member] | Substandard [Member]
Loans receivable	624	842
Consumer Portfolio Segment [Member] | Classified [Member] | Doubtful [Member]
Loans receivable	63	69
Consumer Portfolio Segment [Member] | Classified [Member] | Unlikely to be Collected Financing Receivable [Member]
Loans receivable	20	65
Consumer Portfolio Segment [Member] | Unclassified [Member]
Loans receivable	58,564	68,973
Commercial Portfolio Segment [Member]
Loans receivable	106,796	64,227
Commercial Portfolio Segment [Member] | Classified [Member]
Loans receivable	5,459	8,226
Commercial Portfolio Segment [Member] | Classified [Member] | Special Mention [Member]
Loans receivable	3,575	5,710
Commercial Portfolio Segment [Member] | Classified [Member] | Substandard [Member]
Loans receivable	1,884	2,516
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	$ 101,337	$ 56,001