Note 16 - Segment and Geographic Information - Product Revenue by Product Group (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Product revenue	$ 27,178	$ 25,783	$ 78,899	$ 74,636
Orthobiologics [Member]
Product revenue	23,990	22,428	68,686	65,319
Surgical [Member]
Product revenue	1,765	1,173	4,395	3,924
Dermal [Member]
Product revenue	358	594	1,235	1,558
Other [Member]
Product revenue	$ 1,065	$ 1,588	$ 4,583	$ 3,835