Note 5 - Derivative Instruments and Hedging Activities (Details Textual) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Dec. 31, 2019
Derivative, Notional Amount	$ 61,751
Forward Contracts [Member]
Derivative, Notional Amount	61,800	$ 30,500
Forward Contracts [Member] | Designated as Hedging Instrument [Member]
Derivative, Notional Amount	$ 51,000	$ 26,100
Forward Contracts [Member] | Minimum [Member]
Derivative, Term of Contract (Month)	30 days
Forward Contracts [Member] | Maximum [Member]
Derivative, Term of Contract (Month)	1 year 180 days