Segment Information (Summary Of Net Revenues By Product And Service) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Product Information [Line Items]
Total revenues	$ 53,771	$ 71,139	$ 120,200	$ 138,644
BioGlue [Member]
Product Information [Line Items]
Total revenues	12,437	17,933	29,174	35,155
JOTEC (including NEXUS) [Member]
Product Information [Line Items]
Total revenues	13,174	17,208	28,642	33,162
On-X [Member]
Product Information [Line Items]
Total revenues	10,116	12,410	22,318	24,141
CardioGenesis Cardiac Laser Therapy [Member]
Product Information [Line Items]
Total revenues	164	1,898	275	3,612
PhotoFix [Member]
Product Information [Line Items]
Total revenues	880	935	1,922	1,665
PerClot [Member]
Product Information [Line Items]
Total revenues	497	784	1,357	1,834
Cardiac Tissues [Member]
Product Information [Line Items]
Total revenues	8,061	10,500	18,079	19,430
Preservation Services [Member]
Product Information [Line Items]
Total revenues	16,503	19,971	36,512	39,075
Operating Segments [Member] | Total Products [Member]
Product Information [Line Items]
Total revenues	37,268	51,168	83,688	99,569
Operating Segments [Member] | Total Preservation Services [Member]
Product Information [Line Items]
Total revenues	$ 16,503	$ 19,971	$ 36,512	$ 39,075