Consolidated Statements Of Operations And Comprehensive Loss - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Revenues:
Total revenues	$ 253,227	$ 276,222	$ 262,841
Cost of products and preservation services:
Total cost of products and preservation services	85,443	93,209	89,857
Gross margin	167,784	183,013	172,984
Operating expenses:
General, administrative, and marketing	141,136	143,011	140,574
Research and development	24,207	22,960	23,098
Total operating expenses	165,343	165,971	163,672
Operating income	2,441	17,042	9,312
Interest expense	16,698	14,886	15,788
Interest income	(217)	(738)	(226)
Other expense, net	3,134	1,250	141
(Loss) income before income taxes	(17,174)	1,644	(6,391)
Income tax benefit	(492)	(76)	(3,551)
Net (loss) income	$ (16,682)	$ 1,720	$ (2,840)
(Loss) income per common share:
Basic	$ (0.44)	$ 0.05	$ (0.08)
Diluted	$ (0.44)	$ 0.05	$ (0.08)
Weighted-average common shares outstanding:
Basic	37,861	37,118	36,412
Diluted	37,861	37,860	36,412
Net (loss) income	$ (16,682)	$ 1,720	$ (2,840)
Other comprehensive income (loss)	15,332	(2,517)	(7,929)
Comprehensive loss	(1,350)	(797)	(10,769)
Products [Member]
Revenues:
Total revenues	179,299	197,246	187,394
Cost of products and preservation services:
Total cost of products and preservation services	50,128	55,022	53,772
Preservation Services [Member]
Revenues:
Total revenues	73,928	78,976	75,447
Cost of products and preservation services:
Total cost of products and preservation services	$ 35,315	$ 38,187	$ 36,085