Segment Information (Summary Of Net Revenues By Product And Service) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Product Information [Line Items]
Total revenues	$ 67,881	$ 64,598	$ 206,525	$ 195,042
BioGlue And BioFoam [Member]
Product Information [Line Items]
Total revenues	15,679	15,646	50,834	48,685
JOTEC [Member]
Product Information [Line Items]
Total revenues	15,774	15,004	48,936	46,669
On-X [Member]
Product Information [Line Items]
Total revenues	12,610	11,298	36,751	33,495
CardioGenesis Cardiac Laser Therapy [Member]
Product Information [Line Items]
Total revenues	1,354	1,590	4,966	4,514
PerClot [Member]
Product Information [Line Items]
Total revenues	980	882	2,814	2,822
PhotoFix [Member]
Product Information [Line Items]
Total revenues	1,087	732	2,752	1,878
Cardiac Tissues [Member]
Product Information [Line Items]
Total revenues	11,304	9,502	30,734	26,660
Vascular Tissues [Member]
Product Information [Line Items]
Total revenues	9,093	9,944	28,738	30,319
Preservation Services [Member]
Product Information [Line Items]
Total revenues	20,397	19,446	59,472	56,979
Operating Segments [Member] | Total Products [Member]
Product Information [Line Items]
Total revenues	47,484	45,152	147,053	138,063
Operating Segments [Member] | Total Preservation Services [Member]
Product Information [Line Items]
Total revenues	$ 20,397	$ 19,446	$ 59,472	$ 56,979