Consolidated Statements Of Operations And Comprehensive Income - USD ($) shares in Thousands, $ in Thousands		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Revenues:
Products		$ 119,631	$ 113,992	$ 83,081
Preservation services		70,071	66,388	62,817
Total revenues		189,702	180,380	145,898
Cost of products and preservation services:
Products		29,798	28,033	18,663
Preservation services		31,262	33,448	36,516
Total cost of products and preservation services		61,060	61,481	55,179
Gross margin		128,642	118,899	90,719
Operating expenses:
General, administrative, and marketing		101,211	91,548	74,929
Research and development		19,461	13,446	10,436
Total operating expenses		120,672	104,994	85,365
Gain from sale of business components			(7,915)
Operating income		7,970	21,820	5,354
Interest expense		4,881	3,043	(62)
Interest income		(212)	(72)	(45)
Gain on sale of Medafor investment				(891)
Other (income) expense, net		(260)	437	484
Income before income taxes		3,561	18,412	5,868
Income tax (benefit) expense		(143)	7,634	1,863
Net income		$ 3,704	$ 10,778	$ 4,005
Income per common share:
Basic		$ 0.11	$ 0.33	$ 0.14
Diluted	[1]	0.11	0.32	0.14
Dividends declared per common share		$ 0	$ 0	$ 0.120
Weighted-average common shares outstanding:
Basic		33,008	31,855	27,744
Diluted		34,163	32,822	28,542
Other comprehensive income (loss)		$ 2,286	$ (353)	$ 45
Comprehensive income		$ 5,990	$ 10,425	$ 4,050

[1] We excluded stock options from the calculation of diluted weighted-average common shares outstanding if the per share value, including the sum of (i) the exercise price of the options and (ii) the amount of the compensation cost attributed to future services and not yet recognized, was greater than the average market price of the shares, because the inclusion of these stock options would be antidilutive to income per common share. Accordingly, stock options to purchase 227,000, 1,000, and 710,000 shares for the years ended December 31, 2017, 2016, and 2015, respectively, were excluded from the calculation of diluted weighted-average common shares outstanding.