Note 10 - Accumulated Other Comprehensive Loss - Other Comprehensive Loss (Details) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2019	Mar. 31, 2018
Balance	$ 541,497	$ 461,215
Balance	542,795	487,676
Accumulated Foreign Currency Adjustment Attributable to Parent [Member]
Balance	(8,492)	(5,234)
Other comprehensive income before reclassifications	476	2,393
Amounts reclassified from accumulated other comprehensive income
Net current-period other comprehensive income	476	2,393
Balance	$ (8,016)	$ (2,841)

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

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Amount after tax and reclassification adjustments of other comprehensive income (loss).

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Amount after tax of reclassification adjustments of other comprehensive income (loss).

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Total of all stockholders' equity (deficit) items, net of receivables from officers, directors, owners, and affiliates of the entity which are attributable to the parent. The amount of the economic entity's stockholders' equity attributable to the parent excludes the amount of stockholders' equity which is allocable to that ownership interest in subsidiary equity which is not attributable to the parent (noncontrolling interest, minority interest). This excludes temporary equity and is sometimes called permanent equity.

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