Segment Information (Summary Of Net Revenues By Product And Service) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Product Information [Line Items]
Total revenues	$ 66,429	$ 67,505
BioGlue [Member]
Product Information [Line Items]
Total revenues	16,737	17,222
JOTEC [Member]
Product Information [Line Items]
Total revenues	15,268	15,954
On-X [Member]
Product Information [Line Items]
Total revenues	12,202	11,731
CardioGenesis Cardiac Laser Therapy [Member]
Product Information [Line Items]
Total revenues	111	1,714
PhotoFix [Member]
Product Information [Line Items]
Total revenues	1,042	730
PerClot [Member]
Product Information [Line Items]
Total revenues	860	1,050
NEXUS [Member]
Product Information [Line Items]
Total revenues	200
Cardiac Tissues [Member]
Product Information [Line Items]
Total revenues	10,033	8,930
Vascular Tissues [Member]
Product Information [Line Items]
Total revenues	9,976	10,174
Preservation Services [Member]
Product Information [Line Items]
Total revenues	20,009	19,104
Operating Segments [Member] | Total Products [Member]
Product Information [Line Items]
Total revenues	46,420	48,401
Operating Segments [Member] | Total Preservation Services [Member]
Product Information [Line Items]
Total revenues	$ 20,009	$ 19,104