Note 5 - Derivative Instruments and Hedging Activities - Effects of Derivative Instruments on Income and Other Comprehensive Income (OCI) (Details) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2020	Mar. 31, 2019
Operating Expense [Member]
Amount of Gain or (Loss) Recognized in OCI, Net of Tax, on Derivative (Effective Portion)
Amount of Gain or (Loss) Reclassified from Accumulated OCI into Income (Effective Portion)	(45)	(64)
Cost of Sales [Member]
Amount of Gain or (Loss) Recognized in OCI, Net of Tax, on Derivative (Effective Portion)	(1,191)	610
Amount of Gain or (Loss) Reclassified from Accumulated OCI into Income (Effective Portion)	$ (13)	$ (15)

Amount after 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 10A
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=121641772&loc=SL7669646-108580

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=121558989&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 11
-URI http://asc.fasb.org/extlink&oid=121641772&loc=d3e637-108580

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration