Condensed Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Revenues	$ 1,190	$ 11,572	$ 4,281	$ 15,774
Operating expenses:
Total cost of revenue	2,072	2,645	5,138	6,199
Gross profit	(882)	8,927	(857)	9,575
Research and development expense	3,566	6,386	15,484	17,905
Sales, marketing, general and administrative expense	1,697	2,253	6,851	6,953
Total operating expenses	5,263	8,639	22,335	24,858
Income (loss) from operations	(6,145)	288	(23,192)	(15,283)
Other income (expense), net	4	1	(7)	(19)
Net income (loss)	$ (6,141)	$ 289	$ (23,199)	$ (15,302)
Net income (loss) per share - basic	$ (0.05)	$ 0.00	$ (0.21)	$ (0.18)
Net income (loss) per share - diluted	$ (0.05)	$ 0.00	$ (0.21)	$ (0.18)
Weighted-average shares outstanding - basic	114,874	93,073	107,953	84,388
Weighted-average shares outstanding - diluted	114,874	93,204	107,953	84,388
Product revenue
Revenue from Contract with Customer, Including Assessed Tax	$ 999	$ 0	$ 1,198	$ 0
Operating expenses:
Cost of Goods and Services Sold	2,039	1,434	3,352	1,998
License and royalty
Revenue from Contract with Customer, Including Assessed Tax	17	10,000	17	10,011
Contract
Revenue from Contract with Customer, Including Assessed Tax	174	1,572	3,066	5,763
Operating expenses:
Cost of Goods and Services Sold	$ 33	$ 1,211	$ 1,786	$ 4,201