Note 10 - Accumulated Other Comprehensive Income (Loss) - Other Comprehensive Loss (Details) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2021	Mar. 31, 2020
Balance	$ 644,356	$ 585,790
Balance	813,431	587,740
Accumulated Foreign Currency Adjustment Attributable to Parent [Member]
Balance	(3,420)	(7,018)
Other comprehensive income (loss) before reclassifications	(6,842)	(2,980)
Amounts reclassified from accumulated other comprehensive loss	0	0
Net current-period other comprehensive income (loss)	(6,842)	(2,980)
AOCI, Accumulated Gain (Loss), Debt Securities, Available-for-sale, Parent [Member]
Balance	0	0
Other comprehensive income (loss) before reclassifications	166	0
Amounts reclassified from accumulated other comprehensive loss	0	0
Net current-period other comprehensive income (loss)	166	0
AOCI Attributable to Parent [Member]
Balance	(3,420)	(7,018)
Balance	$ (10,096)	$ (9,998)

Amount after tax, before reclassification adjustments, of other comprehensive income (loss), attributable to parent.

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