Note 3 - Loans and Allowance for Loan Losses - Allowance for Loan Losses (Details) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2021	Mar. 31, 2020	Mar. 31, 2021	Dec. 31, 2020
Individually evaluated for impairment			$ 9	$ 0
Collectively evaluated for impairment			6,587	6,594
Allowance for loan losses	$ 6,625	$ 5,307	6,628	6,625
Beginning balance	6,625	5,061
Provision for loan losses	75	351
Charge-offs	(130)	(159)
Recoveries	58	54
Ending balance	6,628	5,307
Provision for Loan and Lease Losses, Total	75	351
Financial Asset Acquired with Credit Deterioration [Member]
Allowance for loan losses	31		32	31
Beginning balance	31
Ending balance	32
Real Estate Mortgage Portfolio Segment [Member] \| Residential Loan [Member]
Individually evaluated for impairment			0	0
Collectively evaluated for impairment			1,189	1,208
Allowance for loan losses	1,239	929	1,221	1,239
Beginning balance	1,239	867
Provision for loan losses	(14)	62
Charge-offs	(4)	0
Recoveries	0	0
Ending balance	1,221	929
Provision for Loan and Lease Losses, Total	(14)	62
Real Estate Mortgage Portfolio Segment [Member] \| Residential Loan [Member] \| Financial Asset Acquired with Credit Deterioration [Member]
Allowance for loan losses	31		32	31
Beginning balance	31
Ending balance	32
Real Estate Mortgage Portfolio Segment [Member] \| Land Loan [Member]
Individually evaluated for impairment			0	0
Collectively evaluated for impairment			209	209
Allowance for loan losses	209	163	209	209
Beginning balance	209	163
Provision for loan losses	3	0
Charge-offs	(3)	0
Recoveries	0	0
Ending balance	209	163
Provision for Loan and Lease Losses, Total	3	0
Real Estate Mortgage Portfolio Segment [Member] \| Land Loan [Member] \| Financial Asset Acquired with Credit Deterioration [Member]
Allowance for loan losses	0		0	0
Beginning balance	0
Ending balance	0
Real Estate Mortgage Portfolio Segment [Member] \| Construction Loans [Member]
Individually evaluated for impairment			0	0
Collectively evaluated for impairment			348	292
Allowance for loan losses	292	353	348	292
Beginning balance	292	350
Provision for loan losses	56	3
Charge-offs	0	0
Recoveries	0	0
Ending balance	348	353
Provision for Loan and Lease Losses, Total	56	3
Real Estate Mortgage Portfolio Segment [Member] \| Construction Loans [Member] \| Financial Asset Acquired with Credit Deterioration [Member]
Allowance for loan losses	0		0	0
Beginning balance	0
Ending balance	0
Real Estate Mortgage Portfolio Segment [Member] \| Commercial Real Estate Loan [Member]
Individually evaluated for impairment			0	0
Collectively evaluated for impairment			2,355	2,358
Allowance for loan losses	2,358	1,735	2,355	2,358
Beginning balance	2,358	1,623
Provision for loan losses	(3)	112
Charge-offs	0	0
Recoveries	0	0
Ending balance	2,355	1,735
Provision for Loan and Lease Losses, Total	(3)	112
Real Estate Mortgage Portfolio Segment [Member] \| Commercial Real Estate Loan [Member] \| Financial Asset Acquired with Credit Deterioration [Member]
Allowance for loan losses	0		0	0
Beginning balance	0
Ending balance	0
Commercial Portfolio Segment [Member]
Individually evaluated for impairment			0	0
Collectively evaluated for impairment			816	843
Allowance for loan losses	843	620	816	843
Beginning balance	843	595
Provision for loan losses	(27)	25
Charge-offs	0	0
Recoveries	0	0
Ending balance	816	620
Provision for Loan and Lease Losses, Total	(27)	25
Commercial Portfolio Segment [Member] \| Financial Asset Acquired with Credit Deterioration [Member]
Allowance for loan losses	0		0	0
Beginning balance	0
Ending balance	0
Consumer Portfolio Segment [Member] \| Home Equity and Second Mortgage [Member]
Individually evaluated for impairment			9	0
Collectively evaluated for impairment			613	617
Allowance for loan losses	617	550	622	617
Beginning balance	617	515
Provision for loan losses	14	33
Charge-offs	(9)	0
Recoveries	0	2
Ending balance	622	550
Provision for Loan and Lease Losses, Total	14	33
Consumer Portfolio Segment [Member] \| Home Equity and Second Mortgage [Member] \| Financial Asset Acquired with Credit Deterioration [Member]
Allowance for loan losses	0		0	0
Beginning balance	0
Ending balance	0
Consumer Portfolio Segment [Member] \| Other Consumer Loan [Member]
Allowance for loan losses	1,057	957	1,057	1,067
Beginning balance	1,067	948
Provision for loan losses	46	116
Charge-offs	(114)	(159)
Recoveries	58	52
Ending balance	1,057	957
Provision for Loan and Lease Losses, Total	46	$ 116
Consumer Portfolio Segment [Member] \| All Other Consumer Excluding Home Equity and Second Mortgage [Member]
Individually evaluated for impairment			0	0
Collectively evaluated for impairment			1,057	1,067
Allowance for loan losses	1,067		1,057	1,067
Beginning balance	1,067
Ending balance	1,057
Consumer Portfolio Segment [Member] \| All Other Consumer Excluding Home Equity and Second Mortgage [Member] \| Financial Asset Acquired with Credit Deterioration [Member]
Allowance for loan losses	0		$ 0	$ 0
Beginning balance	0
Ending balance	$ 0

Amount of allowance for credit loss on financing receivable. Excludes allowance for financing receivable covered under loss sharing agreement.

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