Note 7 - Financial Instruments and Fair Value Measurements (Details Textual) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Gain (Loss) from Components Excluded from Assessment of Cash Flow Hedge Effectiveness, Net, Total	$ 0
Cash Flow Hedge Gain (Loss) to be Reclassified within Twelve Months	1,200
Foreign Currency Transaction Gain (Loss), before Tax, Total	94	$ (2,175)	$ 1,144
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), before Reclassification, after Tax	(5,634)	(671)
Foreign Exchange Forward [Member] | AOCI Attributable to Parent [Member]
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), before Reclassification, after Tax	(3,400)
Reclassification out of Accumulated Other Comprehensive Income [Member] | Foreign Exchange Forward [Member] | Designated as Hedging Instrument [Member]
Foreign Currency Transaction Gain (Loss), before Tax, Total	(1,600)
Reclassification out of Accumulated Other Comprehensive Income [Member] | Foreign Exchange Forward [Member] | Not Designated as Hedging Instrument [Member]
Foreign Currency Transaction Gain (Loss), before Tax, Total	$ 1,700	$ 2,200	$ 1,100