Note 2 - Revenue - Disaggregation of Revenues (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Revenue	$ 19,436	$ 21,219	$ 39,182	$ 55,596
UNITED STATES
Revenue	4,442	5,735	11,366	19,034
Europe and ROW [Member]
Revenue	1,701	2,709	5,833	7,670
Asia [Member]
Revenue	$ 13,293	$ 12,775	$ 21,983	$ 28,892

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