Segment Information (Summary Of Net Revenues By Product And Service) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Product Information [Line Items]
Total revenues	$ 76,148	$ 53,771	$ 147,235	$ 120,200
Products [Member]
Product Information [Line Items]
Total revenues	56,076	37,268	109,421	83,688
Aortic Stents And Stent Grafts [Member]
Product Information [Line Items]
Total revenues	21,064	13,174	41,269	28,642
Surgical Sealants [Member]
Product Information [Line Items]
Total revenues	17,864	12,437	35,692	29,174
On-X [Member]
Product Information [Line Items]
Total revenues	14,726	10,116	27,821	22,318
Other [Member]
Product Information [Line Items]
Total revenues	2,422	1,541	4,639	3,554
Preservation Services [Member]
Product Information [Line Items]
Total revenues	20,072	16,503	37,814	36,512
Operating Segments [Member] | Products [Member]
Product Information [Line Items]
Total revenues	$ 56,076	$ 37,268	$ 109,421	$ 83,688