Note 4 - Fair Value of Financial Instruments - Amounts of Gain (Loss) Recognized in Condensed Consolidated Statements on Derivative Instruments Not Designated as Hedges (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Amount of gain (loss) recognized	$ 1,435	$ 616	$ 2,525	$ 1,699
Foreign Currency Gain (Loss) [Member] | Currency Forward Contracts [Member]
Amount of gain (loss) recognized	$ 1,435	$ 616	$ 2,525	$ 1,699