CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2026	Sep. 30, 2025
Cash flows from operating activities:
Net income (loss)	$ 297,608	$ (301,184)
Adjustments to reconcile net income (loss) to net cash used in operating activities
Stock-based compensation	80,614	93,380
Depreciation and amortization	26,903	39,268
Non-cash interest expense	28,926	5,810
Non-cash inventory write-downs for obsolescence	11,599	0
Reduction in the carrying amounts of the right of use assets	9,614	11,326
Loss on strategic investments	2,683	17,268
Accretion of investment discount, net	(2,464)	(4,911)
In-kind milestone payment to Arrowhead Pharmaceuticals, Inc.	0	50,000
Non-cash write-off of prepaid deposits	0	17,041
Gain on debt extinguishment	0	(3,761)
Other	1,379	549
Changes in operating assets and liabilities, net:
Decrease in accounts receivable	29,055	206,249
Decrease in manufacturing-related deposits and prepaids	53,384	67,072
Decrease (increase) in inventory	29,793	(319,568)
Decrease (increase) in other assets	87,158	(100,070)
(Decrease) increase in deferred revenue	(338,510)	30,193
Decrease in accounts payable	(236,564)	(89,860)
Decrease in accrued expenses, lease liabilities and other liabilities	(26,825)	(55,487)
Net cash used in operating activities	54,353	(336,685)
Cash flows from investing activities:
Purchase of investments	(557,299)	(45,316)
Maturity and sales of available-for-sale securities	180,953	195,935
Purchase of property and equipment	(5,570)	(98,381)
Purchase of intangible assets	(4,200)	(7,080)
Acquisition of strategic investments	0	(245,819)
Proceeds from sale of investment in Arrowhead Pharmaceuticals, Inc.	0	174,095
Net cash provided by investing activities	(386,116)	(26,566)
Cash flows from financing activities:
Proceeds from exercise of stock options and purchase of stock under the Employee Stock Purchase Program	241	18,395
Proceeds from borrowings under the Revolving Credit Facility	425,000	0
Repayments of borrowings under the Revolving Credit Facility	(425,000)	0
Repayment of 2027 Notes	0	(123,333)
Debt issuance costs for the August 2025 Exchange	0	(12,787)
Proceeds from issuance of common stock	0	20,000
Common stock issuance costs	0	(2,276)
Repurchases of common stock	0	(25,013)
Payments related to obtaining Revolving Credit Facility	0	(4,122)
Net cash provided by financing activities	241	(129,136)
Decrease in cash, cash equivalents and restricted cash	(331,522)	(492,387)
Cash, cash equivalents and restricted cash:
Beginning of period	814,407	1,118,589
End of period	482,885	626,202
Reconciliation of cash, cash equivalents and restricted cash:
Cash and cash equivalents	472,760	613,077
Restricted cash in other assets	10,125	13,125
Total cash, cash equivalents and restricted cash	482,885	626,202
Supplemental disclosure of cash flow information:
Cash paid during the period for income taxes	11,862	21,249
Cash paid during the period for interest	46,940	13,962
Supplemental schedule of non-cash activities:
Intangible assets and property and equipment included in accounts payable and accrued expenses	3,523	5,697
Capitalized stock-based compensation and depreciation as inventory	18,802	18,253
Lease liabilities arising from obtaining right of use assets	155	5,232
Issuance of 2030 Notes in exchange for 2027 Notes	0	602,002
Non-cash settlement of 2027 Notes	0	(602,002)
Common stock issued for conversion or exchange of 2027 Notes	0	107,320
Accrued debt issuance costs for the August 2025 Exchange	0	618
Accrued common stock issuance costs	0	110
Contingent consideration liabilities derecognized in connection with adoption of ASU 2025-07	$ 0	$ 47,400