Note 2 - Summary of Significant Accounting Policies - Revenue From Unaffiliated Customers by Geographic Area (Details) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2020	Mar. 31, 2019
Revenue	$ 1,304	$ 3,012
North America [Member]
Revenue	688	1,792
Asia Pacific [Member]
Revenue	597	967
Europe And Middle East [Member]
Revenue	5	246
Latin America [Member]
Revenue	14
Other [Member]
Revenue		$ 7

Amount, excluding 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.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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Reference 2: http://www.xbrl.org/2003/role/disclosureRef
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+ Details