Note 1 - Significant Accounting Policies and Related Matters (Details Textual) $ in Thousands	6 Months Ended	12 Months Ended
	Jun. 30, 2020	Dec. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)
Accounts Receivable, after Allowance for Credit Loss, Current, Total		$ 19,552	$ 16,572
Number of Operating Segments	1	1
Goodwill, Impairment Loss		$ 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		1,600	$ 4,000
ITALY
Accounts Receivable, after Allowance for Credit Loss, Current, Total		900
SPAIN
Accounts Receivable, after Allowance for Credit Loss, Current, Total		600
Geographic Distribution, Foreign [Member]
Cash, Ending Balance		$ 13,700
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