CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Current assets
Cash and cash equivalents	$ 342,283	$ 237,125
Marketable securities	32,897	167,408
Restricted cash (current)	1,032	1,032
Trade accounts receivable, net	855	476
Inventories	4,355	6,347
Prepaid expenses and other current assets	4,985	3,034
Total current assets	386,407	415,422
Property, plant and equipment, net	183,862	176,872
Restricted cash (non-current)	76,736	77,219
Operating right-of-use assets	1,285	1,331
Finance right-of-use assets	217	219
Intangible assets, net	7,400	7,691
Deposits and other assets	32,787	21,994
Total assets	688,694	700,748
Current liabilities
Accounts payable and accrued liabilities	24,931	24,760
Operating lease liabilities (current)	421	438
Finance lease liabilities (current)	59	79
Loans payable (current)	152	159
Total current liabilities	25,563	25,436
2021 Bonds payable, net	67,408	67,223
Loans payable (non-current)	126	159
Operating lease liabilities (non-current)	1,392	1,450
Finance lease liabilities (non-current)	184	183
Other liabilities (non-current)	560	820
Total liabilities	95,233	95,271
Stockholders' Equity
Common stock, $0.01 par value per share; 500,000,000 shares authorized; 237,261,164 and 237,166,625 shares issued and outstanding at March 31, 2023, and December 31, 2022, respectively.	2,373	2,372
Additional paid-in capital	1,264,203	1,259,527
Accumulated other comprehensive loss	(115)	(1,040)
Accumulated deficit	(673,000)	(655,382)
Total stockholders' equity	593,461	605,477
Total liabilities and stockholders' equity	$ 688,694	$ 700,748