Note 13 - Other Comprehensive Income - Reclassifications Out of Accumulated Other Comprehensive Income (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Net gains on sale of securities reclassified into net income	$ (367)		$ (1,338)	$ (960)
Income tax expense	827	724	2,543	1,611
Net of tax amount	242		883	634
Reclassification out of Accumulated Other Comprehensive Income [Member]
Net gains on sale of securities reclassified into net income	(367)		(1,338)	(960)
Income tax expense	125		455	326
Net of tax amount	$ (242)		$ (883)	$ (634)