Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Current assets:
Cash and cash equivalents	$ 102,698	$ 15,508
Prepaid expenses and other current assets (including related parties)	4,664	4,105
Marketable debt securities, available-for-sale	7,925	36,144
Total current assets	115,287	55,757
Marketable debt securities, noncurrent	0	1,497
Property, plant and equipment, net	58,615	60,501
Operating lease right-of-use assets, net (including related parties)	10,407	11,729
Equity investment	9,253	9,253
Other assets (including related parties)	2,602	4,386
Total assets	196,164	143,123
Current liabilities:
Accounts payable	3,971	1,749
Accrued expenses	7,449	5,343
Due to related parties	2,228	486
Other current liabilities (including related parties)	3,401	3,981
Total current liabilities	17,049	11,559
Operating lease liability, less current portion (including related parties)	9,462	10,885
Total liabilities	26,511	22,444
Commitments and contingencies (Note 8)	0	0
Stockholders’ equity:
Common stock, $0.0001 par value; 500,000,000 shares authorized; 107,764,158 and 98,460,404 issued and outstanding as of June 30, 2020 and December 31, 2019	11	10
Additional paid-in capital	870,408	782,965
Accumulated other comprehensive loss	(100)	(105)
Accumulated deficit	(700,666)	(662,191)
Total stockholders’ equity	169,653	120,679
Total liabilities and stockholders’ equity	$ 196,164	$ 143,123