Note 9 - Allowance for Credit Losses and Credit Quality Information - Aging of Past Due Loans (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Loans receivable	$ 868,730	$ 858,108
Loans 90 days or more past due and still accruing	0	0
Residential Portfolio Segment [Member]
Loans receivable	260,602	264,303
Loans 90 days or more past due and still accruing	0	0
Commercial Real Estate Portfolio Segment [Member]
Loans receivable	503,339	489,953
Commercial Real Estate Portfolio Segment [Member] | Real Estate Loan [Member]
Loans receivable	276,751	271,531
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	226,588	218,422
Loans 90 days or more past due and still accruing	0	0
Consumer Portfolio Segment [Member]
Loans receivable	41,110	42,734
Loans 90 days or more past due and still accruing	0	0
Commercial Portfolio Segment [Member]
Loans receivable	63,679	61,118
Loans 90 days or more past due and still accruing	0	0
Financial Asset, 30 to 59 Days Past Due [Member]
Loans receivable	1,692	814
Financial Asset, 30 to 59 Days Past Due [Member] | Residential Portfolio Segment [Member]
Loans receivable	842	453
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	0
Financial Asset, 30 to 59 Days Past Due [Member] | Consumer Portfolio Segment [Member]
Loans receivable	210	361
Financial Asset, 30 to 59 Days Past Due [Member] | Commercial Portfolio Segment [Member]
Loans receivable	640	0
Financial Asset, 60 to 89 Days Past Due [Member]
Loans receivable	1,466	472
Financial Asset, 60 to 89 Days Past Due [Member] | Residential Portfolio Segment [Member]
Loans receivable	103	71
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	619	0
Financial Asset, 60 to 89 Days Past Due [Member] | Consumer Portfolio Segment [Member]
Loans receivable	42	92
Financial Asset, 60 to 89 Days Past Due [Member] | Commercial Portfolio Segment [Member]
Loans receivable	702	309
Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Loans receivable	407	1,631
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Residential Portfolio Segment [Member]
Loans receivable	318	363
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	399
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Consumer Portfolio Segment [Member]
Loans receivable	43	57
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Commercial Portfolio Segment [Member]
Loans receivable	46	812
Financial Asset, Past Due [Member]
Loans receivable	3,565	2,917
Financial Asset, Past Due [Member] | Residential Portfolio Segment [Member]
Loans receivable	1,263	887
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	619	399
Financial Asset, Past Due [Member] | Consumer Portfolio Segment [Member]
Loans receivable	295	510
Financial Asset, Past Due [Member] | Commercial Portfolio Segment [Member]
Loans receivable	1,388	1,121
Financial Asset, Not Past Due [Member]
Loans receivable	865,165	855,191
Financial Asset, Not Past Due [Member] | Residential Portfolio Segment [Member]
Loans receivable	259,339	263,416
Financial Asset, Not Past Due [Member] | Commercial Real Estate Portfolio Segment [Member] | Real Estate Loan [Member]
Loans receivable	276,751	271,531
Financial Asset, Not Past Due [Member] | Commercial Real Estate Portfolio Segment [Member] | Commercial Real Estate Other [Member]
Loans receivable	225,969	218,023
Financial Asset, Not Past Due [Member] | Consumer Portfolio Segment [Member]
Loans receivable	40,815	42,224
Financial Asset, Not Past Due [Member] | Commercial Portfolio Segment [Member]
Loans receivable	$ 62,291	$ 59,997