Note 6 - Instruments and Risk Management - Foreign Exchange Contracts Statement of Financial Position (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Interest Rate Swap [Member]
Interest rate swap:	$ 129	$ 111	$ 113

Aggregate net gain (loss) on all derivative instruments recognized in earnings during the period, before tax effects.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 4A
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=109980867&loc=SL5618551-113959

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration