Note 15 - Revenue by Product Group, by Significant Customer and by Geographic Region; Geographic Information - Product Revenue by Product Group (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Product Revenue	$ 28,296	$ 25,783	$ 26,575	$ 22,278	$ 25,607	$ 23,676	$ 22,898	$ 15,515	$ 102,932	$ 87,696	$ 75,474
Concentration risk, percentage									100.00%	100.00%	100.00%
Orthobiologics [Member]
Product Revenue									$ 89,695	$ 73,247	$ 61,957
Concentration risk, percentage									87.00%	84.00%	82.00%
Dermal [Member]
Product Revenue									$ 2,759	$ 2,266	$ 1,334
Concentration risk, percentage									3.00%	2.00%	2.00%
Surgical [Member]
Product Revenue									$ 5,427	$ 5,812	$ 5,855
Concentration risk, percentage									5.00%	7.00%	8.00%
Other [Member]
Product Revenue									$ 5,051	$ 6,371	$ 6,328
Concentration risk, percentage									5.00%	7.00%	8.00%