Note 2 - Revenue - Disaggregation of Revenues (Details) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2020	Mar. 31, 2019
Revenue	$ 13,911	$ 14,789
UNITED STATES
Revenue	5,728	5,531
Europe and ROW [Member]
Revenue	3,123	2,762
Asia [Member]
Revenue	$ 5,060	$ 6,496

Amount, including tax collected from customer, of revenue from satisfaction of performance obligation by transferring promised good or service to customer. Tax collected from customer is tax assessed by governmental authority that is both imposed on and concurrent with specific revenue-producing transaction, including, but not limited to, sales, use, value-added and excise.

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+ Details