Note 16 - Amounts Reclassified Out of Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items]
Income before income taxes	$ 3,012	$ 3,113	$ 2,800	$ 3,053	$ 2,514	$ 2,935	$ 2,517	$ 2,837	$ 11,978	$ 10,803	$ 11,642
Tax effect	(743)	(821)	(702)	(788)	(571)	(715)	(583)	(701)	(3,054)	(2,570)	(2,644)
Net income	$ 2,269	$ 2,292	$ 2,098	$ 2,265	$ 1,943	$ 2,220	$ 1,934	$ 2,136	8,924	8,233	8,998
Reclassification out of Accumulated Other Comprehensive Income (Loss) [Member]
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items]
Unrealized net holding gains on available-for-sale securities									866	838	1,112
Other-than-temporary impairment losses on investment securities									(192)	(55)
Income before income taxes									674	783	1,112
Tax effect									(229)	(266)	(378)
Net income									$ 445	$ 517	$ 734