Segment Information (Summary Of Net Revenues By Product And Service) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Product Information [Line Items]
Total revenues	$ 72,207	$ 65,131	$ 219,442	$ 185,331
Products [Member]
Product Information [Line Items]
Total revenues	53,107	45,109	162,528	128,797
Aortic Stents And Stent Grafts [Member]
Product Information [Line Items]
Total revenues	20,896	15,290	62,165	43,932
Surgical Sealants [Member]
Product Information [Line Items]
Total revenues	16,544	15,811	52,236	44,985
On-X [Member]
Product Information [Line Items]
Total revenues	14,022	12,067	41,843	34,385
Other [Member]
Product Information [Line Items]
Total revenues	1,645	1,941	6,284	5,495
Preservation Services [Member]
Product Information [Line Items]
Total revenues	19,100	20,022	56,914	56,534
Operating Segments [Member] | Products [Member]
Product Information [Line Items]
Total revenues	$ 53,107	$ 45,109	$ 162,528	$ 128,797