Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Operating activities
Net (loss) income	$ (153,610)	$ (650,175)	$ 377,661
Reconciliation of net (loss) income to net cash used in operating activities:
Depreciation and amortization	19,837	24,172	17,953
Equity-based compensation	81,028	97,947	102,390
Other non-cash items, net	(16,545)	12,470	14,109
Acquired in-process research and development	2,500	0	0
Changes in:
Accounts receivable	(200,000)	305	(161)
Prepaid expenses and other assets	23,219	1,598	(13,912)
Accounts payable and accrued expenses	(20,247)	5,164	37,514
Deferred revenue	5,794	(1,011)	(783)
Operating lease assets and liabilities	(2,461)	15,310	9,506
Other liabilities, net	110	(1,521)	(5,305)
Net cash (used in) provided by operating activities	(260,375)	(495,741)	538,972
Investing activities
Purchase of property, plant and equipment	(9,470)	(37,188)	(81,705)
Purchase of in-process research and development	(2,500)	0	0
Purchases of marketable securities	(1,065,911)	(1,417,800)	(1,509,327)
Maturities of marketable securities	1,452,528	1,196,333	555,602
Net cash provided by (used in) investing activities	374,647	(258,655)	(1,035,430)
Financing activities
Proceeds from issuance of common shares, net of issuance costs	32,721	970	213,267
Proceeds from exercise of options and ESPP contributions, net of issuance costs	29,943	37,622	37,678
Net cash provided by financing activities	62,664	38,592	250,945
Effect of exchange rate changes on cash	73	(80)	(11)
Increase (decrease) in cash	177,009	(715,884)	(245,524)
Cash, cash equivalents and restricted cash, beginning of period	224,060	939,944	1,185,468
Cash, cash equivalents and restricted cash, end of period	401,068	224,060	939,944
Supplemental disclosure of non-cash investing and financing activities
Property and equipment purchases in accounts payable and accrued expenses	725	2,121	8,348
Equity issuance costs in accounts payable and accrued expenses	$ 417	$ 99	$ 334