Note 2 - Summary of Significant Accounting Policies - Reclassification Adjustment (Details) - USD ($) $ in Thousands	3 Months Ended					12 Months Ended
	Mar. 31, 2022	Dec. 31, 2021	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Dec. 31, 2021
Revenues	$ 26,406				$ 22,597
Revision of Prior Period, Error Correction, Adjustment [Member]
Revenues		$ 0	$ 0	$ 0	0	$ 0
UNITED STATES | Revision of Prior Period, Error Correction, Adjustment [Member]
Revenues		(440)	(703)	(615)	(362)	(2,120)
Non-US [Member] | Revision of Prior Period, Error Correction, Adjustment [Member]
Revenues		$ 440	$ 703	$ 615	$ 362	$ 2,120