Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022
CASH FLOWS FROM OPERATING ACTIVITIES:
Net loss	$ (349,031)	$ (360,779)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	6,510	5,541
Loss (gain) on disposal of property and equipment	5	(162)
Equity-based compensation	99,007	66,774
(Accretion) amortization of investment discounts and premiums	(19,590)	5,252
Loss from equity method investment	10,905	7,831
Deferral of equity method investment intra-entity profit on sales	6,624	8,530
Change in fair value of contingent consideration	100	8,059
In-process research and development expense	0	55,990
Changes in operating assets and liabilities:
Accounts receivable	(2,723)	(1,992)
Prepaid expenses and other current assets	(11,806)	(228)
Operating lease right-of-use assets	14,148	8,516
Other assets	(836)	(982)
Accounts payable	(1,419)	(5,334)
Accrued expenses	(3,008)	12,852
Deferred revenue	(37,705)	(46,739)
Operating lease liabilities	(12,213)	(6,547)
Net cash used in operating activities	(301,032)	(243,418)
CASH FLOWS FROM INVESTING ACTIVITIES:
Purchases of property and equipment	(12,465)	(9,646)
Purchases of marketable securities	(754,689)	(192,598)
Maturities of marketable securities	689,868	437,387
Proceeds from sale of property and equipment	0	150
Acquired in-process research and development, net of cash acquired of $287	0	(44,832)
Net cash (used in) provided by investing activities	(77,286)	190,461
CASH FLOWS FROM FINANCING ACTIVITIES:
Proceeds from options exercised	5,604	13,984
Issuance of shares through employee stock purchase plan	2,051	1,068
Net cash provided by financing activities	23,839	77,192
Net (decrease) increase in cash, cash equivalents and restricted cash equivalents	(354,479)	24,235
Cash, cash equivalents and restricted cash equivalents, beginning of period	535,463	125,486
Cash, cash equivalents and restricted cash equivalents, end of period	180,984	149,721
Reconciliation of cash, cash equivalents and restricted cash equivalents to condensed consolidated balance sheet:
Cash and cash equivalents	168,027	141,194
Restricted cash equivalents, included in investments and other assets	12,957	8,527
Total cash, cash equivalents and restricted cash equivalents	180,984	149,721
SUPPLEMENTAL DISCLOSURES OF CASH FLOW INFORMATION:
Purchases of property and equipment unpaid at period end	1,552	2,180
Shares issued for Rewrite contingent consideration	24,126	0
Right-of-use asset acquired under operating lease	0	30,663
Contingent consideration liability assumed in asset acquisition	0	10,541
Proceeds from at-the-market offerings unpaid at period end	0	8,255
Non-cash trade-in of property and equipment	0	200
At The Market Offerings [Member]
CASH FLOWS FROM FINANCING ACTIVITIES:
Net proceeds from issuance of common stock	$ 16,184	$ 62,140