Note 9 - Share-based Compensation - Schedule of Stock-based Compensation (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Total stock-based compensation	$ 655	$ 537	$ 2,095	$ 1,794
Cost of Sales [Member]
Total stock-based compensation	75	61	233	209
Selling and Marketing Expense [Member]
Total stock-based compensation	155	155	459	429
General and Administrative Expense [Member]
Total stock-based compensation	356	266	1,194	967
Research and Development Expense [Member]
Total stock-based compensation	$ 69	$ 55	$ 209	$ 189

Amount of expense for award under share-based payment arrangement. Excludes amount capitalized.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
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-URI http://asc.fasb.org/extlink&oid=116856206&loc=d3e5047-113901

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
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-Paragraph 1
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Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
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