Note 9 - Allowance for Credit Losses and Credit Quality Information - Aging of Past Due Loans (Details) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Loans receivable	$ 797,825	$ 787,887
Loans 90 days or more past due and still accruing	0	0
Residential Portfolio Segment [Member]
Loans receivable	208,321	205,890
Loans 90 days or more past due and still accruing	0	0
Commercial Real Estate Portfolio Segment [Member]
Loans receivable	474,723	471,345
Commercial Real Estate Portfolio Segment [Member] | Real Estate Loan [Member]
Loans receivable	252,339	249,783
Loans 90 days or more past due and still accruing	0	0
Commercial Real Estate Portfolio Segment [Member] | Commercial Real Estate Other [Member]
Loans receivable	222,384	221,562
Loans 90 days or more past due and still accruing	0	0
Consumer Portfolio Segment [Member]
Loans receivable	47,852	44,817
Loans 90 days or more past due and still accruing	0	0
Commercial Portfolio Segment [Member]
Loans receivable	66,929	65,835
Loans 90 days or more past due and still accruing	0	0
Financial Asset, 30 to 59 Days Past Due [Member]
Loans receivable	610	1,352
Financial Asset, 30 to 59 Days Past Due [Member] | Residential Portfolio Segment [Member]
Loans receivable	340	380
Financial Asset, 30 to 59 Days Past Due [Member] | Commercial Real Estate Portfolio Segment [Member] | Real Estate Loan [Member]
Loans receivable	0	0
Financial Asset, 30 to 59 Days Past Due [Member] | Commercial Real Estate Portfolio Segment [Member] | Commercial Real Estate Other [Member]
Loans receivable	0	578
Financial Asset, 30 to 59 Days Past Due [Member] | Consumer Portfolio Segment [Member]
Loans receivable	270	394
Financial Asset, 30 to 59 Days Past Due [Member] | Commercial Portfolio Segment [Member]
Loans receivable	0	0
Financial Asset, 60 to 89 Days Past Due [Member]
Loans receivable	0	268
Financial Asset, 60 to 89 Days Past Due [Member] | Residential Portfolio Segment [Member]
Loans receivable	0	145
Financial Asset, 60 to 89 Days Past Due [Member] | Commercial Real Estate Portfolio Segment [Member] | Real Estate Loan [Member]
Loans receivable	0	0
Financial Asset, 60 to 89 Days Past Due [Member] | Commercial Real Estate Portfolio Segment [Member] | Commercial Real Estate Other [Member]
Loans receivable	0	0
Financial Asset, 60 to 89 Days Past Due [Member] | Consumer Portfolio Segment [Member]
Loans receivable	0	123
Financial Asset, 60 to 89 Days Past Due [Member] | Commercial Portfolio Segment [Member]
Loans receivable	0	0
Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Loans receivable	616	569
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Residential Portfolio Segment [Member]
Loans receivable	453	481
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Commercial Real Estate Portfolio Segment [Member] | Real Estate Loan [Member]
Loans receivable	0	0
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Commercial Real Estate Portfolio Segment [Member] | Commercial Real Estate Other [Member]
Loans receivable	0	0
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Consumer Portfolio Segment [Member]
Loans receivable	163	88
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Commercial Portfolio Segment [Member]
Loans receivable	0	0
Financial Asset, Past Due [Member]
Loans receivable	1,226	2,189
Financial Asset, Past Due [Member] | Residential Portfolio Segment [Member]
Loans receivable	793	1,006
Financial Asset, Past Due [Member] | Commercial Real Estate Portfolio Segment [Member] | Real Estate Loan [Member]
Loans receivable	0	0
Financial Asset, Past Due [Member] | Commercial Real Estate Portfolio Segment [Member] | Commercial Real Estate Other [Member]
Loans receivable	0	578
Financial Asset, Past Due [Member] | Consumer Portfolio Segment [Member]
Loans receivable	433	605
Financial Asset, Past Due [Member] | Commercial Portfolio Segment [Member]
Loans receivable	0	0
Financial Asset, Not Past Due [Member]
Loans receivable	796,599	785,698
Financial Asset, Not Past Due [Member] | Residential Portfolio Segment [Member]
Loans receivable	207,528	204,884
Financial Asset, Not Past Due [Member] | Commercial Real Estate Portfolio Segment [Member] | Real Estate Loan [Member]
Loans receivable	252,339	249,783
Financial Asset, Not Past Due [Member] | Commercial Real Estate Portfolio Segment [Member] | Commercial Real Estate Other [Member]
Loans receivable	222,384	220,984
Financial Asset, Not Past Due [Member] | Consumer Portfolio Segment [Member]
Loans receivable	47,419	44,212
Financial Asset, Not Past Due [Member] | Commercial Portfolio Segment [Member]
Loans receivable	$ 66,929	$ 65,835