Segment Information (Summary Of Net Revenues By Product And Service) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Product Information [Line Items]
Total revenues	$ 71,139	$ 68,496	$ 138,644	$ 130,444
BioGlue And BioFoam [Member]
Product Information [Line Items]
Total revenues	17,933	17,069	35,155	33,039
JOTEC [Member]
Product Information [Line Items]
Total revenues	17,208	17,205	33,162	31,665
On-X [Member]
Product Information [Line Items]
Total revenues	12,410	11,888	24,141	22,197
CardioGenesis Cardiac Laser Therapy [Member]
Product Information [Line Items]
Total revenues	1,898	1,578	3,612	2,924
PerClot [Member]
Product Information [Line Items]
Total revenues	784	968	1,834	1,940
PhotoFix [Member]
Product Information [Line Items]
Total revenues	935	605	1,665	1,146
Cardiac Tissues [Member]
Product Information [Line Items]
Total revenues	10,500	9,055	19,430	17,158
Vascular Tissues [Member]
Product Information [Line Items]
Total revenues	9,471	10,128	19,645	20,375
Preservation Services [Member]
Product Information [Line Items]
Total revenues	19,971	19,183	39,075	37,533
Operating Segments [Member] | Total Products [Member]
Product Information [Line Items]
Total revenues	51,168	49,313	99,569	92,911
Operating Segments [Member] | Total Preservation Services [Member]
Product Information [Line Items]
Total revenues	$ 19,971	$ 19,183	$ 39,075	$ 37,533