Note 9 - Derivatives and Hedging Activities - Effective Portion of the Gains and Losses on Derivative Instruments Designated (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Gain (loss) recognized in other comprehensive income (loss), Effective portion, Net, Total	$ (431)	$ 183	$ 158
Derivatives Designated as Cash Flow Hedging Instruments [Member]
Gain (loss) recognized in other comprehensive income (loss), Effective portion, Net, Total	(431)	183	158
Derivatives Designated as Cash Flow Hedging Instruments [Member] | Foreign Exchange Option Contracts [Member]
Gain (loss) recognized in other comprehensive income (loss), Effective portion, Net, Total	(146)	90	67
Derivatives Designated as Cash Flow Hedging Instruments [Member] | Foreign Exchange Forward Contracts [Member]
Gain (loss) recognized in other comprehensive income (loss), Effective portion, Net, Total	$ (285)	$ 93	$ 91