Note 3 - Allowance for Loan Losses, Nonperforming Assets and Impaired Loans - Allowance for Loan Losses (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019
Balance			$ 6,863	$ 7,390	$ 7,390
Charge-offs			(639)	(696)	(920)
Recoveries			219	218	267
Provision for loan losses	$ 154	$ 95	1,985	350	126
Balance	8,428	7,262	8,428	7,262	6,863
Real Estate Construction Portfolio Segment[Member]
Balance			400	398	398
Provision for loan losses			24	56	2
Balance	424	454	424	454	400
Consumer Real Estate Portfolio Segment [Member]
Balance			1,895	2,049	2,049
Charge-offs			(62)	(147)	(192)
Recoveries			18
Provision for loan losses			311	199	38
Balance	2,162	2,101	2,162	2,101	1,895
Commercial Real Estate Portfolio Segment [Member]
Balance			2,559	2,798	2,798
Charge-offs			(15)	(150)	(150)
Recoveries			53	37	49
Provision for loan losses			1,047	14	(138)
Balance	3,644	2,699	3,644	2,699	2,559
Commercial Non Real Estate Segment [Member]
Balance			555	602	602
Charge-offs			(372)		(47)
Recoveries			6		1
Provision for loan losses			510	(75)	(1)
Balance	699	527	699	527	555
Public Sector and IDA Portfolio Segment[Member]
Balance			478	583	583
Provision for loan losses			53	(93)	(105)
Balance	531	490	531	490	478
Consumer Non Real Estate Portfolio Segment [Member]
Balance			650	750	750
Charge-offs			(190)	(399)	(531)
Recoveries			142	181	217
Provision for loan losses			(5)	156	214
Balance	597	688	597	688	650
Unallocated Financing Receivables [Member]
Balance			326	210	210
Provision for loan losses			45	93	116
Balance	$ 371	$ 303	$ 371	$ 303	$ 326