Note 10 - Revenue - Product Revenue by Product Group (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Revenue	$ 38,145	$ 30,678	$ 72,437	$ 66,075
Joint Pain Management Therapies [Member]
Revenue	24,321	22,247	43,637	47,730
Joint Preservation and Restoration [Member]
Revenue	11,884	6,622	24,103	14,518
Manufactured Product, Other [Member]
Revenue	1,940	1,809	4,697	3,827
Product [Member]
Revenue	$ 38,145	$ 30,678	$ 72,437	$ 66,075