Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income (loss)	$ 515,837	$ 528,584	$ (298,665)
Adjustments to reconcile net loss to net cash used in operating activities:
Changes in estimated constraint on profit-sharing amount	369,535	0	0
Depreciation and amortization	6,251	5,278	4,400
Amortization of intangible assets	532	533	1,042
Impairment of intangible assets	0	0	832
(Accretion of discounts) amortization of premiums on investments, net	(8,943)	(244)	1,548
Noncash lease expense	8,709	6,172	3,371
Change in fair value of equity investments	111,140	(138,049)	0
Change in estimated fair value of contingent consideration	2,115	91,848	38,394
Payment of contingent consideration in excess of acquisition date fair value	(93,803)	(8,140)	(15,752)
Change in estimated fair value of derivative liability	0	0	16,796
Stock-based compensation	102,082	83,784	27,600
Change in deferred income taxes	(15,186)	15,186	(52)
Gain from a sublease termination	0	(4,844)	0
Other	(383)	697	23
Changes in operating assets and liabilities:
Receivable from collaboration	770,038	(773,079)	0
Prepaid expenses and other current assets	(39,358)	(3,665)	(4,475)
Other assets	(11,795)	(1,483)	(1,100)
Accounts payable	797	(171)	(790)
Accrued liabilities and other long-term liabilities	(15,513)	58,498	46,614
Operating lease liabilities	(5,502)	(535)	(3,684)
Deferred revenue	(33,300)	92,041	(7,043)
Net cash used in operating activities	1,663,253	(47,589)	(190,941)
CASH FLOWS FROM INVESTING ACTIVITIES:
Proceeds from sale of an equipment	22	0	0
Purchases of property and equipment	(68,028)	(21,817)	(6,549)
Purchases of investments	(1,476,965)	(420,240)	(403,841)
Maturities of investments	351,510	301,243	400,348
Proceeds from disposal of an asset held for sale	0	0	180
Net cash used in investing activities	(1,193,461)	(140,814)	(9,862)
CASH FLOWS FROM FINANCING ACTIVITIES:
Proceeds from issuance of common stock, net of issuance costs	0	0	323,214
Proceeds from issuance of common stock in connection with a collaboration agreement	0	85,213	206,699
Proceeds from issuance of common stock in connection with a grant agreement	28,462	0	0
Payment of contingent consideration	(1,197)	0	(4,248)
Payment of principal on financing lease obligations	(260)	(259)	(250)
Proceeds from exercise of stock options	4,534	13,077	4,059
Proceeds from issuance of common stock under the employee stock purchase plan	3,222	2,300	0
Net cash provided by financing activities	34,761	100,331	529,474
Net (decrease) increase in cash, cash equivalents and restricted cash and cash equivalents	504,553	(88,072)	328,671
Cash, cash equivalents and restricted cash and cash equivalents at beginning of period	363,415	451,487	122,816
Cash, cash equivalents and restricted cash and cash equivalents at end of period	867,968	363,415	451,487
NONCASH INVESTING AND FINANCING ACTIVITIES:
Property and equipment purchases included in accounts payable and accrued liabilities	1,020	8,731	382
Common stock issued for payment of contingent consideration	0	1,860	0
Operating lease liabilities obtained in exchange of right-of-use asset	4,046	77,187	48,495
Reclassification of derivative liability to additional paid-in capital	0	0	29,245
SUPPLEMENTAL DISCLOSURE OF CASHFLOW INFORMATION:
Cash paid during the period for income tax	252,030	0	0
RECONCILIATION OF CASH, CASH EQUIVALENTS AND RESTRICTED CASH TO THE CONSOLIDATED BALANCE SHEETS:
Cash and cash equivalents	848,631	347,815	436,575
Restricted cash and cash equivalents, current	12,681	8,594	7,993
Restricted cash and cash equivalents, noncurrent	6,656	7,006	6,919
Total cash, cash equivalents and restricted cash	$ 867,968	$ 363,415	$ 451,487