Note 2 - Summary of Significant Accounting Policies - Revenue From Unaffiliated Customers by Geographic Area (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Revenue	$ 1,795	$ 1,654	$ 3,436	$ 3,104
North America [Member]
Revenue	1,101	994	1,871	1,919
Asia Pacific [Member]
Revenue	694	658	1,562	1,177
Europe And Middle East [Member]
Revenue	$ 0	$ 2	$ 3	$ 8

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
-Publisher FASB
-Name Accounting Standards Codification
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-Section 50
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Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
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Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
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Reference 4: http://www.xbrl.org/2003/role/disclosureRef
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Reference 5: http://www.xbrl.org/2003/role/disclosureRef
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Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
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Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
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Reference 10: http://www.xbrl.org/2003/role/disclosureRef
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-Name Accounting Standards Codification
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+ Details