Note 9 - Allowance for Loan Losses and Credit Quality Information - Troubled Debt Restructurings (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Troubled debt restructurings	$ 997	$ 1,051
Performing Financial Instruments [Member]
Troubled debt restructurings	23	29
Nonperforming Financial Instruments [Member]
Troubled debt restructurings	974	1,022
Residential Portfolio Segment [Member]
Troubled debt restructurings	250	254
Residential Portfolio Segment [Member] | Performing Financial Instruments [Member]
Troubled debt restructurings	0	0
Residential Portfolio Segment [Member] | Nonperforming Financial Instruments [Member]
Troubled debt restructurings	250	254
Commercial Real Estate Portfolio Segment [Member]
Troubled debt restructurings	349	355
Commercial Real Estate Portfolio Segment [Member] | Performing Financial Instruments [Member]
Troubled debt restructurings	0	0
Commercial Real Estate Portfolio Segment [Member] | Nonperforming Financial Instruments [Member]
Troubled debt restructurings	349	355
Consumer Portfolio Segment [Member]
Troubled debt restructurings	398	442
Consumer Portfolio Segment [Member] | Performing Financial Instruments [Member]
Troubled debt restructurings	23	29
Consumer Portfolio Segment [Member] | Nonperforming Financial Instruments [Member]
Troubled debt restructurings	$ 375	$ 413