Consolidated Statements of Operations (USD $) In Thousands, except Per Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012
Income Statement [Abstract]
Product revenue	$ 2,341	$ 6,782
Contract revenue	602	1,583
Development revenue	2,909	0
Total revenue	5,852	8,365
Cost of product revenue	1,518	6,085
Cost of contract revenue	283	839
Total cost of revenue	1,801	6,924
Gross margin	4,051	1,441
Research and development expense	10,267	12,851
Sales, marketing, general and administrative expense	8,792	11,252
Impairment of intangible assets	277	284
Gain on disposal of fixed assets	(35)	(79)
Gain on sale of previously reserved inventory	(156)	(212)
Total operating expenses	19,145	24,096
Loss from operations	(15,094)	(22,655)
Change in warrant liability	1,801	0
Other income (expense)	115	(38)
Net loss	$ (13,178)	$ (22,693)
Net loss per share - basic and diluted	$ (0.47)	$ (1.05)
Weighted-average shares outstanding - basic and diluted	28,025	21,595