Note 14 - Fair Value Measurements (Details Textual) $ in Thousands	12 Months Ended
Dec. 31, 2018 USD ($)
Fair Value Measurements [Line Items]
Percentage of equity investment acquired	19.90%
Investment in equity securities	$ 13,048
Initial Public Offering [Member]
Fair Value Measurements [Line Items]
Percentage of equity investment acquired	16.30%

Fair value portion of investments accounted under the equity method.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 323
-SubTopic 10
-Section 25
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=66022186&loc=d3e32014-111567

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