CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021
Current assets
Cash and cash equivalents	$ 172,984	$ 40,833
Marketable securities (current)	297,631	275,340
Restricted cash (current)	5,894	25,032
Accounts receivable, net	188	978
Inventories	2,649	2,751
Prepaid expenses and other current assets	5,275	3,607
Total current assets	484,621	348,541
Property, plant and equipment, net	176,054	139,141
Long-term marketable securities	0	64,396
Long-term restricted cash	70,256	70,168
Operating right-of-use assets	2,098	2,414
Finance right-of-use assets	27,477	27,297
Intangible assets, net	8,364	8,938
Deposits and other assets	5,741	5,581
Total assets	774,611	666,476
Current liabilities
Accounts payable and accrued liabilities	18,750	28,288
Operating lease liabilities (current)	423	772
Finance lease liabilities (current)	6,293	3,413
Loans payable - other (current)	158	158
Total current liabilities	25,624	32,631
2021 Bonds payable (long-term)	66,853	66,486
Loans payable - other (long-term)	238	318
Operating lease liabilities (long-term)	1,786	1,902
Finance lease liabilities (long-term)	16,342	17,797
Other long-term liabilities	0	87
Total liabilities	110,843	119,221
Stockholders' Equity
Common stock, $0.01 par value per share; 500,000,000 and 250,000,000 shares authorized at June 30, 2022, and December 31, 2021, respectively; 235,165,951 and 201,988,662 shares issued and outstanding at June 30, 2022, and December 31, 2021, respectively.	2,353	2,020
Additional paid-in capital	1,249,880	1,103,224
Accumulated other comprehensive loss	(2,256)	(614)
Accumulated deficit	(586,209)	(557,375)
Total stockholders' equity	663,768	547,255
Total liabilities and stockholders' equity	$ 774,611	$ 666,476