Note 4 - Property and Equipment, Net (Details Textual) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2022	Mar. 31, 2021	Dec. 31, 2021
Property, Plant and Equipment, Net, Total	$ 63,377		$ 61,854
Depreciation, Depletion And Amortization, Excluding Intangible Asset Amortization	7,100	$ 7,300
Scanner Appliances and Other Computer Equipment Subject To Subscription [Member]
Property, Plant and Equipment, Net, Total	7,000		5,300
Scanner Appliances and Other Computer Equipment Not Placed In Service [Member]
Property, Plant and Equipment, Net, Total	$ 3,500		$ 1,300

Amount after accumulated depreciation, depletion and amortization of physical assets used in the normal conduct of business to produce goods and services and not intended for resale. Examples include, but are not limited to, land, buildings, machinery and equipment, office equipment, and furniture and fixtures.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 360
-SubTopic 10
-Section 50
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Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
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-Subparagraph (SX 210.7-03(a)(8))
-URI https://asc.fasb.org/extlink&oid=126734703&loc=d3e572229-122910

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 360
-Section 50
-Paragraph 1
-URI https://asc.fasb.org/extlink&oid=124429447&loc=SL124453093-239630

Reference 4: http://www.xbrl.org/2003/role/exampleRef
-Publisher FASB
-Name Accounting Standards Codification
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-SubTopic 10
-Section 55
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