Segment Information (Summary Of Net Revenues By Product And Service) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Product Information [Line Items]
Total revenues	$ 71,087	$ 66,429
Products [Member]
Product Information [Line Items]
Total revenues	53,345	46,420
Aortic Stents And Stent Grafts [Member]
Product Information [Line Items]
Total revenues	20,205	15,468
Surgical Sealants [Member]
Product Information [Line Items]
Total revenues	17,828	16,737
On-X [Member]
Product Information [Line Items]
Total revenues	13,095	12,202
Other [Member]
Product Information [Line Items]
Total revenues	2,217	2,013
Preservation Services [Member]
Product Information [Line Items]
Total revenues	17,742	20,009
Operating Segments [Member] | Products [Member]
Product Information [Line Items]
Total revenues	$ 53,345	$ 46,420