Note 3 - Allowance for Loan Losses, Nonperforming Assets and Impaired Loans - Allowance for Loan Losses (Details) - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2018
Balance	$ 7,390	$ 7,925	$ 7,925
Charge-offs	(328)	(139)	(689)
Recoveries	98	77	235
Provision for (recovery of) loan losses	200	(472)	(81)
Balance	7,360	7,391	7,390
Real Estate Construction Portfolio Segment[Member]
Balance	398	337	337
Charge-offs	0
Recoveries	0	0	0
Provision for (recovery of) loan losses	70	(42)	61
Balance	468	295	398
Consumer Real Estate Portfolio Segment [Member]
Balance	2,049	2,027	2,027
Charge-offs	(16)		(38)
Recoveries			3
Provision for (recovery of) loan losses	58	(98)	57
Balance	2,091	1,929	2,049
Commercial Real Estate Portfolio Segment [Member]
Balance	2,798	3,044	3,044
Charge-offs	(150)
Recoveries	12	12	49
Provision for (recovery of) loan losses	327	(266)	(295)
Balance	2,987	2,790	2,798
Commercial Non Real Estate Segment [Member]
Balance	602	1,072	1,072
Charge-offs			(107)
Recoveries		7	22
Provision for (recovery of) loan losses	(27)	(163)	(385)
Balance	575	916	602
Public Sector and IDA Portfolio Segment[Member]
Balance	583	419	419
Charge-offs	0	0	0
Recoveries	0	0	0
Provision for (recovery of) loan losses	(58)	13	164
Balance	525	432	583
Consumer Non Real Estate Portfolio Segment [Member]
Balance	750	707	707
Charge-offs	(162)	(139)	(544)
Recoveries	86	58	161
Provision for (recovery of) loan losses		54	426
Balance	674	680	750
Unallocated Financing Receivables [Member]
Balance	210	319	319
Charge-offs	0	0	0
Recoveries	0	0	0
Provision for (recovery of) loan losses	(170)	30	(109)
Balance	$ 40	$ 349	$ 210