Note 3 - Loans and Allowance for Loan Losses - Troubled Debt Restructuring by Accrual Status (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Recorded investment in loans	$ 490,897	$ 508,879
Real Estate Mortgage Portfolio Segment [Member] \| Residential Loan [Member]
Recorded investment in loans	125,727	131,850
Real Estate Mortgage Portfolio Segment [Member] \| Commercial Real Estate Loan [Member]
Recorded investment in loans	133,777	135,484
Commercial Portfolio Segment [Member]
Recorded investment in loans	71,190	81,809
Consumer Portfolio Segment [Member] \| Home Equity and Second Mortgage [Member]
Recorded investment in loans	51,611	53,277
Nonperforming Financial Instruments [Member]
TDR accruing	1,412	1,732
TDR nonaccrual	290	0
Recorded investment in loans	1,702	1,732
TDR related allowance for loan losses	9	0
Nonperforming Financial Instruments [Member] \| Real Estate Mortgage Portfolio Segment [Member] \| Residential Loan [Member]
TDR accruing	551	556
TDR nonaccrual	0	0
Recorded investment in loans	551	556
TDR related allowance for loan losses	0	0
Nonperforming Financial Instruments [Member] \| Real Estate Mortgage Portfolio Segment [Member] \| Commercial Real Estate Loan [Member]
TDR accruing	610	621
TDR nonaccrual	0	0
Recorded investment in loans	610	621
TDR related allowance for loan losses	0	0
Nonperforming Financial Instruments [Member] \| Commercial Portfolio Segment [Member]
TDR accruing	201	210
TDR nonaccrual	0	0
Recorded investment in loans	201	210
TDR related allowance for loan losses	0	0
Nonperforming Financial Instruments [Member] \| Consumer Portfolio Segment [Member] \| Home Equity and Second Mortgage [Member]
TDR accruing	50	345
TDR nonaccrual	290	0
Recorded investment in loans	340	345
TDR related allowance for loan losses	$ 9	$ 0

Amount of allowance to cover probable credit losses on loans and leases. Includes carryover of or adjustments to the allowance for loan losses in connection with business combinations. Excludes allowance for loans and leases covered under loss sharing agreements.

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