Note 1 - Significant Accounting Policies and Related Matters (Details Textual) $ in Thousands	1 Months Ended	9 Months Ended	12 Months Ended
	Dec. 31, 2021 USD ($)	Sep. 30, 2021	Dec. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)
Number of Operating Segments	1		1
Accounts Receivable, after Allowance for Credit Loss, Current, Total	$ 19,631		$ 19,631	$ 19,552
Goodwill, Impairment Loss			0	0	$ 0
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax			0	0	$ 0
Accumulated Other Comprehensive Income (Loss), Foreign Currency Translation Adjustment, Net of Tax, Ending Balance	3,100		3,100	$ 1,600
ITALY
Accounts Receivable, after Allowance for Credit Loss, Current, Total	1,000		1,000
SPAIN
Accounts Receivable, after Allowance for Credit Loss, Current, Total	700		700
Geographic Distribution, Foreign [Member]
Cash, Ending Balance	$ 9,400		$ 9,400
Minimum [Member]
Period of Payments Received from Customers (Day)		30 days
Finite-Lived Intangible Asset, Useful Life (Year)			2 years
Maximum [Member]
Period of Payments Received from Customers (Day)		60 days
Finite-Lived Intangible Asset, Useful Life (Year)			16 years