Note 3 - Loans and Allowance for Loan Losses - Allowance for Loan Losses (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Dec. 31, 2019
Individually evaluated for impairment					$ 168	$ 16
Collectively evaluated for impairment					5,873	5,033
Allowance for loan losses	$ 5,307	$ 4,609	$ 5,061	$ 4,065	6,064	5,061
Beginning balance	5,307	4,339	5,061	4,065
Provision for loan losses	825	300	1,176	750
Charge-offs	(177)	(213)	(336)	(432)
Recoveries	109	183	163	226
Ending balance	6,064	4,609	6,064	4,609
Financial Asset Acquired with Credit Deterioration [Member]
Allowance for loan losses	23		12		23	12
Beginning balance			12
Ending balance	23		23
Real Estate Mortgage Portfolio Segment [Member] \| Residential Loan [Member]
Individually evaluated for impairment					0	16
Collectively evaluated for impairment					1,032	839
Allowance for loan losses	929	754	867	693	1,055	867
Beginning balance	929	727	867	693
Provision for loan losses	150	4	213	75
Charge-offs	(71)	(92)	(72)	(130)
Recoveries	47	115	47	116
Ending balance	1,055	754	1,055	754
Real Estate Mortgage Portfolio Segment [Member] \| Residential Loan [Member] \| Financial Asset Acquired with Credit Deterioration [Member]
Allowance for loan losses	23		12		23	12
Beginning balance			12
Ending balance	23		23
Real Estate Mortgage Portfolio Segment [Member] \| Land Loan [Member]
Individually evaluated for impairment					0	0
Collectively evaluated for impairment					196	163
Allowance for loan losses	163	170	163	162	196	163
Beginning balance	163	164	163	162
Provision for loan losses	33	6	33	8
Charge-offs	0	0	0	0
Recoveries	0	0	0	0
Ending balance	196	170	196	170
Real Estate Mortgage Portfolio Segment [Member] \| Land Loan [Member] \| Financial Asset Acquired with Credit Deterioration [Member]
Allowance for loan losses	0		0		0	0
Beginning balance			0
Ending balance	0		0
Real Estate Mortgage Portfolio Segment [Member] \| Construction Loans [Member]
Individually evaluated for impairment					0	0
Collectively evaluated for impairment					369	350
Allowance for loan losses	353	316	350	224	369	350
Beginning balance	353	291	350	224
Provision for loan losses	16	25	19	92
Charge-offs	0	0	0	0
Recoveries	0	0	0	0
Ending balance	369	316	369	316
Real Estate Mortgage Portfolio Segment [Member] \| Construction Loans [Member] \| Financial Asset Acquired with Credit Deterioration [Member]
Allowance for loan losses	0		0		0	0
Beginning balance			0
Ending balance	0		0
Real Estate Mortgage Portfolio Segment [Member] \| Commercial Real Estate Loan [Member]
Individually evaluated for impairment					0	0
Collectively evaluated for impairment					1,902	1,623
Allowance for loan losses	1,735	1,452	1,623	1,401	1,902	1,623
Beginning balance	1,735	1,391	1,623	1,401
Provision for loan losses	167	61	279	51
Charge-offs	0	0	0	0
Recoveries	0	0	0	0
Ending balance	1,902	1,452	1,902	1,452
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	0
Beginning balance			0
Ending balance	0		0
Commercial Portfolio Segment [Member]
Individually evaluated for impairment					168	0
Collectively evaluated for impairment					700	595
Allowance for loan losses	620	596	595	459	868	595
Beginning balance	620	541	595	459
Provision for loan losses	248	55	273	137
Charge-offs	0	0	0	0
Recoveries	0	0	0	0
Ending balance	868	596	868	596
Commercial Portfolio Segment [Member] \| Financial Asset Acquired with Credit Deterioration [Member]
Allowance for loan losses	0		0		0	0
Beginning balance			0
Ending balance	0		0
Consumer Portfolio Segment [Member] \| Home Equity and Second Mortgage [Member]
Individually evaluated for impairment					0	0
Collectively evaluated for impairment					604	515
Allowance for loan losses	550	472	515	443	604	515
Beginning balance	550	450	515	443
Provision for loan losses	45	20	79	25
Charge-offs	0	(2)	0	(2)
Recoveries	9	4	10	6
Ending balance	604	472	604	472
Consumer Portfolio Segment [Member] \| Home Equity and Second Mortgage [Member] \| Financial Asset Acquired with Credit Deterioration [Member]
Allowance for loan losses	0		0		0	0
Beginning balance			0
Ending balance	0		0
Consumer Portfolio Segment [Member] \| All Other Consumer Excluding Home Equity and Second Mortgage [Member]
Individually evaluated for impairment					0	0
Collectively evaluated for impairment					1,070	948
Allowance for loan losses	1,070		948		1,070	948
Beginning balance			948
Ending balance	1,070		1,070
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	0
Beginning balance			0
Ending balance	0		0
Consumer Portfolio Segment [Member] \| Other Consumer Loan [Member]
Allowance for loan losses	1,070	849	948	683	$ 1,070	$ 948
Beginning balance	957	775	948	683
Provision for loan losses	166	129	280	362
Charge-offs	(106)	(119)	(264)	(300)
Recoveries	53	64	106	104
Ending balance	$ 1,070	$ 849	$ 1,070	$ 849

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

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