Consolidated Statements Of Operations And Comprehensive (Loss) Income - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Revenues:
Total revenues	$ 71,139	$ 68,496	$ 138,644	$ 130,444
Cost of products and preservation services:
Total cost of products and preservation services	24,173	22,645	47,405	45,365
Gross margin	46,966	45,851	91,239	85,079
Operating expenses:
General, administrative, and marketing	34,623	34,727	71,143	72,075
Research and development	5,841	5,719	11,389	11,089
Total operating expenses	40,464	40,446	82,532	83,164
Operating income	6,502	5,405	8,707	1,915
Interest expense	3,811	4,103	7,705	7,759
Interest income	(233)	(30)	(349)	(89)
Other expense, net	185	1,466	262	1,285
Income (loss) before income taxes	2,739	(134)	1,089	(7,040)
Income tax benefit	(93)	(360)	(1,446)	(3,411)
Net income (loss)	$ 2,832	$ 226	$ 2,535	$ (3,629)
Income (loss) per common share:
Basic	$ 0.08	$ 0.01	$ 0.07	$ (0.10)
Diluted	$ 0.07	$ 0.01	$ 0.07	$ (0.10)
Weighted-average common shares outstanding:
Basic	37,156	36,318	36,968	36,233
Diluted	37,838	37,249	37,789	36,233
Net income (loss)	$ 2,832	$ 226	$ 2,535	$ (3,629)
Foreign currency translation adjustments	2,995	(11,765)	(786)	(4,626)
Comprehensive income (loss)	5,827	(11,539)	1,749	(8,255)
Products [Member]
Revenues:
Total revenues	51,168	49,313	99,569	92,911
Cost of products and preservation services:
Total cost of products and preservation services	14,489	13,550	28,315	27,707
Preservation Services [Member]
Revenues:
Total revenues	19,971	19,183	39,075	37,533
Cost of products and preservation services:
Total cost of products and preservation services	$ 9,684	$ 9,095	$ 19,090	$ 17,658