Note 11 - Derivatives and Hedging Activities - Effective Portion of the Gains and Losses on Derivative Instruments Designated (Details) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2019	Mar. 31, 2018
Changes in unrealized gains (losses)	$ 206	$ (24)
Derivatives Designated as Cash Flow Hedging Instruments [Member]
Changes in unrealized gains (losses)	206	(24)
Derivatives Designated as Cash Flow Hedging Instruments [Member] \| Foreign Exchange Option Contracts [Member]
Changes in unrealized gains (losses)	16	(19)
Derivatives Designated as Cash Flow Hedging Instruments [Member] \| Foreign Exchange Forward Contracts [Member]
Changes in unrealized gains (losses)	$ 190	$ (5)

Amount before tax of increase (decrease) in accumulated gain (loss) from derivative instruments designated and qualifying as the effective portion of cash flow hedges and an entity's share of an equity investee's increase (decrease) in deferred hedging gain (loss).

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 45
-Paragraph 11
-URI http://asc.fasb.org/extlink&oid=118930883&loc=d3e637-108580

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 30
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=109978405&loc=d3e80720-113993

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 45
-Paragraph 10A
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=118930883&loc=SL7669646-108580

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