Note 6 - Financial Instruments and Fair Value Measurements (Details Textual) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Gain (Loss) from Components Excluded from Assessment of Cash Flow Hedge Effectiveness, Net, Total			$ 0
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), Reclassification, after Tax	$ (0)	$ (1,624)	(5,326)	$ (1,624)
Cash Flow Hedge Gain (Loss) to be Reclassified within Twelve Months			6,900
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), before Reclassification, after Tax	1,745	(7,393)	(7,724)	(8,654)
Foreign Currency Transaction Gain (Loss), before Tax, Total	989	(2,338)	(6,334)	(1,181)
Foreign Exchange Forward [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member] | Designated as Hedging Instrument [Member]
Foreign Currency Transaction Gain (Loss), before Tax, Total		(1,600)	(5,300)	(1,600)
Foreign Exchange Forward [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member] | Not Designated as Hedging Instrument [Member]
Foreign Currency Transaction Gain (Loss), before Tax, Total	1,000	700	1,000	400
AOCI Attributable to Parent [Member] | Foreign Exchange Forward [Member]
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), before Reclassification, after Tax	$ 1,700	$ 5,500	$ 7,600	$ 6,400