Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Operating activities
Net (loss) income	$ (650,175)	$ 377,661	$ (348,865)
Reconciliation of net (loss) income to net cash used in operating activities:
Depreciation and amortization	24,172	17,953	9,184
Equity-based compensation	97,947	102,390	66,018
Other non-cash items, net	12,470	14,109	1,857
Changes in:
Accounts receivable	305	(161)	(45)
Prepaid expenses and other assets	1,598	(13,912)	17,338
Accounts payable and accrued expenses	5,164	37,514	25,747
Deferred revenue	(1,011)	(783)	1,381
Operating lease assets and liabilities	15,310	9,506	(473)
Other liabilities, net	(1,521)	(5,305)	(10,508)
Net cash (used in) provided by operating activities	(495,741)	538,972	(238,366)
Investing activities
Purchase of property, plant and equipment	(37,188)	(81,705)	(18,358)
Purchases of marketable securities	(1,417,800)	(1,509,327)	(593,998)
Maturities of marketable securities	1,196,333	555,602	71,186
Net cash used in investing activities	(258,655)	(1,035,430)	(541,170)
Financing activities
Proceeds from issuance of common shares, net of issuance costs	970	213,267	982,289
Proceeds from exercise of options and ESPP contributions, net of issuance costs	37,622	37,678	33,863
Net cash provided by financing activities	38,592	250,945	1,016,152
Effect of exchange rate changes on cash	(80)	(11)	40
(Decrease) increase in cash	(715,884)	(245,524)	236,656
Cash, cash equivalents and restricted cash, beginning of period	939,944	1,185,468	948,812
Cash, cash equivalents and restricted cash, end of period	224,060	939,944	1,185,468
Supplemental disclosure of non-cash investing and financing activities
Property and equipment purchases in accounts payable and accrued expenses	2,121	8,348	3,412
Equity issuance costs in accounts payable and accrued expenses	$ 99	$ 334	$ 9,590