Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Revenue:
Product and service	$ 69,134	$ 56,639	$ 44,497
Collaboration	17,355	6,028	3,096
Total revenue	86,489	62,667	47,593
Costs and expenses:
Cost of product and service revenue	30,245	26,126	21,149
Research and development	34,720	24,597	21,404
Selling, general and administrative	62,700	53,186	51,063
Total costs and expenses	127,665	103,909	93,616
Loss from operations	(41,176)	(41,242)	(46,023)
Other income (expense):
Interest income	390	233	272
Interest expense	(5,672)	(4,017)	(4,140)
Other expense	(515)	(389)	(147)
Total other income (expense)	(5,797)	(4,173)	(4,015)
Net loss before provision for income taxes	(46,973)	(45,415)	(50,038)
Provision for income taxes	(116)	(166)	0
Net loss	$ (47,089)	$ (45,581)	$ (50,038)
Net loss per share-basic and diluted (in dollars per share)	$ (2.34)	$ (2.40)	$ (2.80)
Weighted average shares used in computing basic and diluted net loss per share (in shares)	20,116	19,027	17,839