Consolidated Balance Sheets - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Current assets:
Cash and cash equivalents	$ 64,579	$ 140,517
Investments	266,505	215,877
Prepaid expenses and other current assets	6,949	7,666
Total current assets	338,033	364,060
Property and equipment, net	30,588	29,009
Goodwill	39,154	39,154
Intangible assets	25,724	25,724
Restricted cash	1,340	1,340
Deposits	459	608
Investments	28,957	43,276
Operating lease right-of-use assets	4,369	1,972
Finance lease right-of-use asset	46,133	46,664
Total assets	514,757	551,807
Current liabilities:
Accounts payable and accrued expenses	28,609	36,660
Operating lease liabilities, current	849	773
Finance lease liability, current	1,748	1,736
Total current liabilities	31,206	39,169
Operating lease liabilities, non-current	3,506	1,088
Finance lease liability, non-current	19,294	19,269
Other liabilities	1,875	2,595
Total liabilities	55,881	62,121
Commitments and contingencies (Note 12)
Stockholders' equity:
Common stock, $0.01 par value, 120,000,000 shares authorized; 80,412,194 and 79,123,312 shares issued and 80,409,623 and 79,120,741 shares outstanding at March 31, 2023 and December 31, 2022, respectively	804	791
Treasury stock, at cost, 2,571 common shares at March 31, 2023 and December 31, 2022, respectively	(47)	(47)
Additional paid-in capital	1,230,319	1,203,074
Accumulated other comprehensive loss	(90)	(357)
Accumulated deficit	(772,110)	(713,775)
Total stockholders' equity	458,876	489,686
Total liabilities and stockholders' equity	514,757	551,807
Series A Convertible Preferred Shares [Member]
Stockholders' equity:
Preferred stock	0	0
Series B Convertible Preferred Shares [Member]
Stockholders' equity:
Preferred stock	$ 0	$ 0