Note 4 - Loans and Allowance for Loan Losses - Aging Analysis of the Recorded Investment of past Due Loans (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Past due	$ 1,913	$ 2,265
Current	532,233	516,451
Total loans (Note 4)	534,146	518,716
Recorded investment greater than 90 days and accruing	0	0
Financial Asset, 30 to 59 Days Past Due [Member]
Past due	8	44
Financial Asset, 60 to 89 Days Past Due [Member]
Past due	436	239
Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Past due	1,469	1,982
Commercial Portfolio Segment [Member]
Past due	890	1,153
Current	122,513	98,711
Total loans (Note 4)	123,403	99,864
Recorded investment greater than 90 days and accruing	0	0
Commercial Portfolio Segment [Member] | Financial Asset, 30 to 59 Days Past Due [Member]
Past due	0	1
Commercial Portfolio Segment [Member] | Financial Asset, 60 to 89 Days Past Due [Member]
Past due	0	0
Commercial Portfolio Segment [Member] | Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Past due	890	1,152
Commercial Real Estate Portfolio Segment [Member]
Past due	397	253
Current	303,007	301,831
Total loans (Note 4)	303,404	302,084
Recorded investment greater than 90 days and accruing	0	0
Commercial Real Estate Portfolio Segment [Member] | Financial Asset, 30 to 59 Days Past Due [Member]
Past due	0	0
Commercial Real Estate Portfolio Segment [Member] | Financial Asset, 60 to 89 Days Past Due [Member]
Past due	276	0
Commercial Real Estate Portfolio Segment [Member] | Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Past due	121	253
Residential Portfolio Segment [Member]
Past due	455	673
Current	79,353	86,499
Total loans (Note 4)	79,808	87,172
Recorded investment greater than 90 days and accruing	0	0
Residential Portfolio Segment [Member] | Financial Asset, 30 to 59 Days Past Due [Member]
Past due	0	5
Residential Portfolio Segment [Member] | Financial Asset, 60 to 89 Days Past Due [Member]
Past due	52	214
Residential Portfolio Segment [Member] | Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Past due	403	454
Consumer Portfolio Segment [Member]
Total loans (Note 4)	303,404	302,084
Consumer Portfolio Segment [Member] | Home Equity Loan [Member]
Past due	163	172
Current	23,586	25,684
Total loans (Note 4)	23,749	25,856
Recorded investment greater than 90 days and accruing	0	0
Consumer Portfolio Segment [Member] | Other Loan [Member]
Past due	8	14
Current	3,774	3,726
Total loans (Note 4)	3,782	3,740
Recorded investment greater than 90 days and accruing	0	0
Consumer Portfolio Segment [Member] | Financial Asset, 30 to 59 Days Past Due [Member] | Home Equity Loan [Member]
Past due	0	24
Consumer Portfolio Segment [Member] | Financial Asset, 30 to 59 Days Past Due [Member] | Other Loan [Member]
Past due	8	14
Consumer Portfolio Segment [Member] | Financial Asset, 60 to 89 Days Past Due [Member] | Home Equity Loan [Member]
Past due	108	25
Consumer Portfolio Segment [Member] | Financial Asset, 60 to 89 Days Past Due [Member] | Other Loan [Member]
Past due	0	0
Consumer Portfolio Segment [Member] | Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Home Equity Loan [Member]
Past due	55	123
Consumer Portfolio Segment [Member] | Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Other Loan [Member]
Past due	$ 0	$ 0