Segment And Geographic Information (Summary Of Net Revenues By Product And Service) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Product Information [Line Items]
Total revenues	$ 253,227	$ 276,222	$ 262,841
Products [Member]
Product Information [Line Items]
Total revenues	179,299	197,246	187,394
BioGlue [Member]
Product Information [Line Items]
Total revenues	62,068	68,611	66,660
Aortic Stents And Stent Grafts [Member]
Product Information [Line Items]
Total revenues	61,663	64,974	63,341
On-X [Member]
Product Information [Line Items]
Total revenues	48,053	50,096	44,832
PhotoFix [Member]
Product Information [Line Items]
Total revenues	4,169	3,754	2,577
PerClot [Member]
Product Information [Line Items]
Total revenues	2,882	3,795	3,767
CardioGenesis Cardiac Laser Therapy [Member]
Product Information [Line Items]
Total revenues	464	6,016	6,217
Preservation Services [Member]
Product Information [Line Items]
Total revenues	73,928	78,976	75,447
Cardiac Tissues [Member]
Product Information [Line Items]
Total revenues	37,893	40,879	35,683
NeoPatch [Member]
Product Information [Line Items]
Total revenues	183
Vascular Tissues [Member]
Product Information [Line Items]
Total revenues	$ 35,852	$ 38,097	$ 39,764