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, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018
Balance			$ 7,390	$ 7,925	$ 7,925
Charge-offs			(696)	(487)	(689)
Recoveries			218	182	235
Provision for loan losses	$ 95	$ 223	350	93	(81)
Balance	7,262	7,713	7,262	7,713	7,390
Real Estate Construction Portfolio Segment[Member]
Balance			398	337	337
Charge-offs			0
Recoveries			0	0	0
Provision for loan losses			56	137	61
Balance	454	474	454	474	398
Consumer Real Estate Portfolio Segment [Member]
Balance			2,049	2,027	2,027
Charge-offs			(147)	(36)	(38)
Recoveries				2	3
Provision for loan losses			199	185	57
Balance	2,101	2,178	2,101	2,178	2,049
Commercial Real Estate Portfolio Segment [Member]
Balance			2,798	3,044	3,044
Charge-offs			(150)
Recoveries			37	37	49
Provision for loan losses			14	(42)	(295)
Balance	2,699	3,039	2,699	3,039	2,798
Commercial Non Real Estate Segment [Member]
Balance			602	1,072	1,072
Charge-offs				(107)	(107)
Recoveries				22	22
Provision for loan losses			(75)	(305)	(385)
Balance	527	682	527	682	602
Public Sector and IDA Portfolio Segment[Member]
Balance			583	419	419
Charge-offs			0	0	0
Recoveries			0	0	0
Provision for loan losses			(93)	151	164
Balance	490	570	490	570	583
Consumer Non Real Estate Portfolio Segment [Member]
Balance			750	707	707
Charge-offs			(399)	(344)	(544)
Recoveries			181	121	161
Provision for loan losses			156	240	426
Balance	688	724	688	724	750
Unallocated Financing Receivables [Member]
Balance			210	319	319
Charge-offs			0	0	0
Recoveries			0	0	0
Provision for loan losses			93	(273)	(109)
Balance	$ 303	$ 46	$ 303	$ 46	$ 210