Note 5 - Allowance for Loan Losses, Nonperforming Assets and Impaired Loans - Allowance for Loan Losses (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Balance	$ 8,297	$ 8,263	$ 8,227
Charge-offs	(1,806)	(2,120)	(1,860)
Recoveries	159	145	255
Provision for loan losses	1,650	2,009	1,641
Balance	8,300	8,297	8,263
Real Estate Construction Portfolio Segment[Member]
Balance	576	612	863
Charge-offs	(29)	0	(2)
Recoveries	0	0	0
Provision for loan losses	(109)	(36)	(249)
Balance	438	576	612
Consumer Real Estate Portfolio Segment [Member]
Balance	1,866	1,662	1,697
Charge-offs	(133)	(205)	(222)
Recoveries	2	2	0
Provision for loan losses	95	407	187
Balance	1,830	1,866	1,662
Commercial Real Estate Portfolio Segment [Member]
Balance	4,109	3,537	3,685
Charge-offs	(488)	(1,114)	(1,201)
Recoveries	83	49	50
Provision for loan losses	34	1,637	1,003
Balance	3,738	4,109	3,537
Commercial Non Real Estate Segment [Member]
Balance	655	1,475	989
Charge-offs	(883)	(490)	(89)
Recoveries	10	1	132
Provision for loan losses	1,281	(331)	443
Balance	1,063	655	1,475
Public Sector and IDA Portfolio Segment[Member]
Balance	436	327	132
Charge-offs	0	0	0
Recoveries	0	0	0
Provision for loan losses	(106)	109	195
Balance	330	436	327
Consumer Non Real Estate Portfolio Segment [Member]
Balance	627	602	576
Charge-offs	(273)	(311)	(346)
Recoveries	64	93	73
Provision for loan losses	226	243	299
Balance	644	627	602
Unallocated Financing Receivables [Member]
Balance	28	48	285
Charge-offs	0	0	0
Recoveries	0	0	0
Provision for loan losses	229	(20)	(237)
Balance	$ 257	$ 28	$ 48