Segment Information (Summary Of Net Revenues By Product And Service) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Product Information [Line Items]
Total revenues	$ 65,131	$ 67,881	$ 185,331	$ 206,525
BioGlue [Member]
Product Information [Line Items]
Total revenues	15,811	15,679	44,985	50,834
JOTEC (including NEXUS) [Member]
Product Information [Line Items]
Total revenues	15,290	15,774	43,932	48,936
On-X [Member]
Product Information [Line Items]
Total revenues	12,067	12,610	34,385	36,751
CardioGenesis Cardiac Laser Therapy [Member]
Product Information [Line Items]
Total revenues	83	1,354	358	4,966
PhotoFix [Member]
Product Information [Line Items]
Total revenues	1,134	1,087	3,056	2,752
PerClot [Member]
Product Information [Line Items]
Total revenues	724	980	2,081	2,814
Cardiac Tissues [Member]
Product Information [Line Items]
Total revenues	10,679	11,304	28,758	30,734
Vascular Tissues [Member]
Product Information [Line Items]
Total revenues	9,285	9,093	27,657	28,738
NeoPatch [Member]
Product Information [Line Items]
Total revenues	58		119
Preservation Services [Member]
Product Information [Line Items]
Total revenues	20,022	20,397	56,534	59,472
Operating Segments [Member] | Total Products [Member]
Product Information [Line Items]
Total revenues	45,109	47,484	128,797	147,053
Operating Segments [Member] | Total Preservation Services [Member]
Product Information [Line Items]
Total revenues	$ 20,022	$ 20,397	$ 56,534	$ 59,472