Consolidated Statements of Operations - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Revenue:
Product sales	$ 41,695	$ 40,318	$ 27,533
Development revenue	10,095	10,235	8,892
Licensing revenue	1,076	166	7,242
Royalties	1,649	1,503	1,991
Total revenue	54,515	52,222	45,658
Cost of revenue:
Cost of product sales	22,317	23,909	12,925
Cost of development revenue	5,149	4,908	6,533
Total cost of revenue	27,466	28,817	19,458
Gross profit	27,049	23,405	26,200
Operating expenses:
Research and development	13,147	21,127	19,731
Selling, general and administrative	30,353	26,395	26,931
Total operating expenses	43,500	47,522	46,662
Operating loss	(16,451)	(24,117)	(20,462)
Other income (expense):
Gain on sale of assets	860
Interest expense	(1,423)
Other, net	271	(122)	(22)
Total other expense	(292)	(122)	(22)
Net loss before income taxes	(16,743)	(24,239)	(20,484)
Income tax provision		100	175
Net loss	$ (16,743)	$ (24,339)	$ (20,659)
Basic and diluted net loss per common share	$ (0.11)	$ (0.16)	$ (0.14)
Basic and diluted weighted average common shares outstanding	156,054,094	154,992,124	146,594,079