Note 14 - Accumulated Other Comprehensive Loss - Changes in Accumulated Other Comprehensive Income (Details) - USD ($) $ in Thousands	3 Months Ended
	Jun. 30, 2020	Mar. 31, 2020
Balance	$ 813,190	$ 773,491
Balance	848,945	813,190
AOCI, Accumulated Gain (Loss), Debt Securities, Available-for-sale, Parent [Member]
Balance	(1,518)	135
Other comprehensive loss before reclassifications	5,386	(1,680)
Amounts reclassified from accumulated other comprehensive loss	(71)	(28)
Tax effect	(406)	55
Net current period other comprehensive loss	4,909	(1,653)
Balance	3,391	(1,518)
Accumulated Foreign Currency Adjustment Attributable to Parent [Member]
Balance	(8,493)	(5,611)
Other comprehensive loss before reclassifications	1,018	(2,882)
Amounts reclassified from accumulated other comprehensive loss	0	0
Tax effect	0	0
Net current period other comprehensive loss	1,018	(2,882)
Balance	(7,475)	(8,493)
AOCI Attributable to Parent [Member]
Balance	(10,011)	(5,476)
Other comprehensive loss before reclassifications	6,404	(4,562)
Amounts reclassified from accumulated other comprehensive loss	(71)	(28)
Tax effect	(406)	55
Net current period other comprehensive loss	5,927	(4,535)
Balance	$ (4,084)	$ (10,011)