Note 17 - Shareholders' Equity and Stock Plans - Summary of Cash Dividends Paid to Common Shareholders (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Cash dividends paid to common shareholders	$ 2,274	$ 1,776	$ 1,603
Dividend on common stock (in dollars per share)	$ 0.14	$ 0.12	$ 0.12

Amount of cash outflow in the form of ordinary dividends to common shareholders of the parent entity.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 15
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=109223946&loc=d3e3291-108585

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