Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021
Current Assets
Cash and cash equivalents	$ 108,075	$ 78,229
Short-term investments	316,383	426,181
Prepaid expenses and other assets	7,135	3,546
Total Current Assets	431,593	507,956
Property and equipment, net	101,154	100,938
Operating lease right-of-use assets	70,845	68,983
Long-term investments	0	91,588
Restricted cash	6,430	6,084
Long-term assets	856	1,784
Total Assets	610,878	777,333
Current Liabilities
Accounts payable	20,009	27,377
Accrued expenses	37,700	56,766
Operating lease liabilities	6,483	5,057
Total Current Liabilities	64,192	89,200
Non-Current Liabilities
Operating lease liabilities - noncurrent	72,996	65,474
Long-term note payable	1,000	1,000
Total Non-Current Liabilities	73,996	66,474
Total Liabilities	138,188	155,674
Commitments and contingencies
Stockholders' Equity
Common stock, $0.000041666 par value; 300,000,000 shares authorized, 157,800,581 and 157,004,742 shares issued and outstanding as of June 30, 2022 and December 31, 2021, respectively	7	7
Accumulated other comprehensive loss	(2,697)	(601)
Additional paid-in capital	1,838,778	1,794,695
Accumulated deficit	(1,363,401)	(1,172,445)
Total Stockholders' Equity	472,690	621,659
Total Liabilities and Stockholders' Equity	610,878	777,333
Series A Convertible Preferred Stock
Stockholders' Equity
Preferred stock, Value	0	0
Series B Convertible Preferred Stock
Stockholders' Equity
Preferred stock, Value	$ 3	$ 3