Note 4 - Property and Equipment, Net (Details Textual) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021	Dec. 31, 2021
Property, Plant and Equipment, Net, Total	$ 53,935		$ 53,935		$ 61,854
Depreciation, Depletion And Amortization, Excluding Intangible Asset Amortization	6,700	$ 7,000	20,700	$ 21,200
Scanner Appliances and Other Computer Equipment Subject To Subscription [Member]
Property, Plant and Equipment, Net, Total	6,100		6,100		5,300
Scanner Appliances and Other Computer Equipment Not Placed In Service [Member]
Property, Plant and Equipment, Net, Total	$ 3,300		$ 3,300		$ 1,300