Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Income Statement [Abstract]
Product revenue	$ 2,182	$ 1	$ 2,923	$ 2
Royalty revenue	324	18	468	26
Contract revenue	1,537	324	1,553	341
Development revenue	0	268	0	1,461
Total revenue	4,043	611	4,944	1,830
Cost of product revenue	2,074	33	3,111	23
Cost of contract revenue	782	135	789	144
Total cost of revenue	2,856	168	3,900	167
Gross profit	1,187	443	1,044	1,663
Research and development expense	2,011	2,236	3,909	4,779
Sales, marketing, general and administrative expense	1,946	1,841	3,867	3,800
Gain on sale of previously reserved inventory	0	(228)	0	(455)
Total operating expenses	3,957	3,849	7,776	8,124
Loss from operations	(2,770)	(3,406)	(6,732)	(6,461)
Loss on warrant exchange	0	0		(4,967)
Other income, net	1	5	1	9
Net loss	$ (2,769)	$ (3,401)	$ (6,731)	$ (11,419)
Net loss per share - basic and diluted	$ (0.06)	$ (0.08)	$ (0.15)	$ (0.29)
Weighted-average shares outstanding - basic and diluted	46,663	43,015	45,818	38,951