Note 10 - Revenue - Total Revenue by Geographic Location (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Revenue	$ 34,292	$ 35,397
Percentage of Revenue	100.00%	100.00%
UNITED STATES
Revenue	$ 25,005	$ 26,306
Percentage of Revenue	73.00%	74.00%
Europe [Member]
Revenue	$ 5,480	$ 5,276
Percentage of Revenue	16.00%	15.00%
Other Location [Member]
Revenue	$ 3,807	$ 3,815
Percentage of Revenue	11.00%	11.00%