Note 9 - Allowance for Loan Losses and Credit Quality Information - Classified and Unclassified Loans (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Loans receivable	$ 626,265	$ 604,435
Classified [Member]
Loans receivable	38,349	34,427
Classified [Member] | Special Mention [Member]
Loans receivable	19,520	14,768
Classified [Member] | Substandard [Member]
Loans receivable	18,660	19,490
Classified [Member] | Doubtful [Member]
Loans receivable	108	104
Classified [Member] | Unlikely to be Collected Financing Receivable [Member]
Loans receivable	61	65
Unclassified [Member]
Loans receivable	587,916	570,008
Residential Portfolio Segment [Member]
Loans receivable	125,141	120,064
Residential Portfolio Segment [Member] | Classified [Member]
Loans receivable	3,133	2,918
Residential Portfolio Segment [Member] | Classified [Member] | Special Mention [Member]
Loans receivable	1,371	1,118
Residential Portfolio Segment [Member] | Classified [Member] | Substandard [Member]
Loans receivable	1,728	1,765
Residential Portfolio Segment [Member] | Classified [Member] | Doubtful [Member]
Loans receivable	34	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	122,008	117,146
Commercial Real Estate Portfolio Segment [Member]
Loans receivable	363,559	350,195
Commercial Real Estate Portfolio Segment [Member] | Real Estate Loan [Member]
Loans receivable	201,847	192,502
Commercial Real Estate Portfolio Segment [Member] | Commercial Real Estate Other [Member]
Loans receivable	161,712	157,693
Commercial Real Estate Portfolio Segment [Member] | Classified [Member] | Real Estate Loan [Member]
Loans receivable	14,231	12,603
Commercial Real Estate Portfolio Segment [Member] | Classified [Member] | Commercial Real Estate Other [Member]
Loans receivable	11,872	9,704
Commercial Real Estate Portfolio Segment [Member] | Classified [Member] | Special Mention [Member] | Real Estate Loan [Member]
Loans receivable	5,197	3,489
Commercial Real Estate Portfolio Segment [Member] | Classified [Member] | Special Mention [Member] | Commercial Real Estate Other [Member]
Loans receivable	6,399	4,451
Commercial Real Estate Portfolio Segment [Member] | Classified [Member] | Substandard [Member] | Real Estate Loan [Member]
Loans receivable	9,034	9,114
Commercial Real Estate Portfolio Segment [Member] | Classified [Member] | Substandard [Member] | Commercial Real Estate Other [Member]
Loans receivable	5,473	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	187,616	179,899
Commercial Real Estate Portfolio Segment [Member] | Unclassified [Member] | Commercial Real Estate Other [Member]
Loans receivable	149,840	147,989
Consumer Portfolio Segment [Member]
Loans receivable	68,080	69,949
Consumer Portfolio Segment [Member] | Classified [Member]
Loans receivable	802	976
Consumer Portfolio Segment [Member] | Classified [Member] | Special Mention [Member]
Loans receivable	0	0
Consumer Portfolio Segment [Member] | Classified [Member] | Substandard [Member]
Loans receivable	667	842
Consumer Portfolio Segment [Member] | Classified [Member] | Doubtful [Member]
Loans receivable	74	69
Consumer Portfolio Segment [Member] | Classified [Member] | Unlikely to be Collected Financing Receivable [Member]
Loans receivable	61	65
Consumer Portfolio Segment [Member] | Unclassified [Member]
Loans receivable	67,278	68,973
Commercial Portfolio Segment [Member]
Loans receivable	69,485	64,227
Commercial Portfolio Segment [Member] | Classified [Member]
Loans receivable	8,311	8,226
Commercial Portfolio Segment [Member] | Classified [Member] | Special Mention [Member]
Loans receivable	6,553	5,710
Commercial Portfolio Segment [Member] | Classified [Member] | Substandard [Member]
Loans receivable	1,758	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	$ 61,174	$ 56,001