Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Revenues	$ 8,886	$ 17,607
Operating expenses:
Total cost of revenue	8,564	10,638
Gross profit	322	6,969
Research and development expense	18,661	24,666
Sales, marketing, general and administrative expense	8,133	9,523
Total operating expenses	26,794	34,189
Loss from operations	(26,472)	(27,220)
Other expense, net	(11)	(30)
Net loss	$ (26,483)	$ (27,250)
Net loss per share - basic and diluted	$ (0.24)	$ (0.31)
Weighted-average shares outstanding - basic and diluted	111,297	86,983
Product revenue
Revenue from Contract with Customer, Including Assessed Tax	$ 5,345	$ 0
Operating expenses:
Cost of Goods and Services Sold	6,692	5,468
License and royalty
Revenue from Contract with Customer, Including Assessed Tax	99	10,011
Contract
Revenue from Contract with Customer, Including Assessed Tax	3,442	7,596
Operating expenses:
Cost of Goods and Services Sold	$ 1,872	$ 5,170