Note 9 - Accumulated Other Comprehensive Income (Loss) - Significant Amounts Reclassified Out of Each Component of Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Provision for income taxes	$ 243	$ 456
Total reclassifications for the period	1,190	2,082
Reclassification out of Accumulated Other Comprehensive Income [Member]
Provision for income taxes	16
Total reclassifications for the period	(62)	(2)
Reclassification out of Accumulated Other Comprehensive Income [Member] | AOCI, Accumulated Gain (Loss), Debt Securities, Available-for-sale, Parent [Member]
Unrealized gains and losses on available-for-sale securities	$ (78)	$ (2)