Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Current assets
Cash and cash equivalents	$ 15,736	$ 3,169
Investment securities	62,207	72,453
Prepaid expenses and other current assets	859	1,310
Total current assets	78,802	76,932
Property, plant and equipment, net	134,591	92,070
Operating lease right-of-use assets, net	1,054
Other non current assets	6,748
Total assets	221,195	169,002
Current liabilities
Accounts payable	11,912	719
Share-based compensation liability	182	3,018
Accrued liabilities and other current liabilities	8,751	8,353
Current operating lease liabilities	698
Total current liabilities	21,543	12,090
Non-current Common Stock Warrant liabilities	12,034	7,441
Non-current operating lease liabilities	3
Total liabilities	33,580	19,531
Commitments and contingencies (Note 13)
Stockholders’ equity
Common stock, $0.0001 par value Authorized: 480.0 million shares at December 31, 2019 and December 31, 2018, Issued and outstanding: 117.3 million shares and 106.9 million shares at December 31, 2019 and December 31, 2018, respectively	12	11
Treasury stock: 137,860 shares and 6,425 shares at December 31, 2019 and December 31, 2018, respectively, at cost	(685)	(35)
Preferred stock, $0.0001 par value Authorized: 0.9 million, after designation of the Series A and Series B Convertible Preferred Stock, Issued and outstanding: none at December 31, 2019 and December 31, 2018, respectively
Additional paid-in-capital	224,091	180,862
Accumulated deficit	(133,701)	(97,617)
Total stockholders’ equity	89,717	83,221
Total liabilities, Series A and Series B Convertible Preferred Stock and stockholders’ equity	221,195	169,002
Series A Convertible Preferred Stock [Member]
Current liabilities
Convertible Preferred Stock	48,084	40,091
Series B Convertible Preferred Stock [Member]
Current liabilities
Convertible Preferred Stock	$ 49,814	$ 26,159