Condensed Consolidated Balance Sheets (Unaudited) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Current assets:
Cash and cash equivalents	$ 171,979	$ 226,748
Marketable securities	619,315	685,475
Accounts receivable	36,427	36,456
Prepaid expenses and other current assets	56,322	49,651
Total current assets	884,043	998,330
Marketable securities - noncurrent	162,090	99,864
Property and equipment, net	32,075	32,760
Operating lease right-of-use assets	110,424	115,375
Equity method investment	0	11,765
Investments and other assets	70,957	42,883
Total assets	1,259,589	1,300,977
Current liabilities:
Accounts payable	13,689	7,452
Accrued expenses	43,276	67,017
Current portion of operating lease liability	18,763	18,599
Current portion of deferred revenue	22,184	22,140
Total current liabilities	97,912	115,208
Deferred revenue, net of current portion	33,440	38,853
Long-term operating lease liability	92,100	96,747
Total liabilities	223,452	250,808
Commitments and contingencies (Note 6)
Stockholders' equity:
Common stock, $0.0001 par value; 240,000,000 shares authorized at March 31, 2024 and December 31, 2023; 96,333,373 and 92,997,158 shares issued and outstanding at March 31, 2024 and December 31, 2023, respectively	10	9
Additional paid-in capital	2,802,889	2,710,797
Accumulated other comprehensive loss	(947)	(2,258)
Accumulated deficit	(1,765,815)	(1,658,379)
Total stockholders’ equity	1,036,137	1,050,169
Total liabilities and stockholders' equity	$ 1,259,589	$ 1,300,977