Condensed Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Revenues:
Product revenue	$ 3,723	$ 6,600	$ 9,886	$ 12,186
Research and development revenue	9,815	3,747	17,694	6,131
Total revenues	13,538	10,347	27,580	18,317
Costs and operating expenses:
Cost of product revenue	2,611	3,790	6,436	6,792
Research and development	7,370	6,348	14,548	12,187
Selling, general and administrative	7,395	6,546	15,141	13,152
Total costs and operating expenses	17,376	16,684	36,125	32,131
Loss from operations	(3,838)	(6,337)	(8,545)	(13,814)
Interest income	174	49	245	68
Other expenses, net	(82)	(34)	(142)	(12)
Loss before income taxes	(3,746)	(6,322)	(8,442)	(13,758)
Benefit from income taxes	(11)	(42)	(13)	(18)
Net loss	$ (3,735)	$ (6,280)	$ (8,429)	$ (13,740)
Net loss per share, basic and diluted (usd per shares)	$ (0.07)	$ (0.13)	$ (0.17)	$ (0.31)
Weighted average common stock shares used in computing net income (loss) per share, basic (shares)	52,787	47,232	50,598	44,258