Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020
Cash flows from operating activities:
Net loss	$ (296,799)	$ (364,811)
Adjustments to reconcile net loss to cash flows from operating activities:
(Gain) loss on contingent consideration, net	(7,200)	45,000
Gain from sale of Priority Review Voucher, net of commission	(102,000)	(108,069)
Depreciation and amortization	27,872	19,623
Reduction in the carrying amounts of the right of use assets	10,112	8,749
Non-cash interest expense	5,617	18,532
Stock-based compensation	84,161	78,543
Impairment of equity investment	4,488
Other	3,964	(2,031)
Changes in operating assets and liabilities, net:
Net increase in accounts receivable	(48,447)	(30,948)
Net increase in inventory	(56,508)	(48,739)
Net decrease (increase) in other assets	74,155	(114,127)
Net (decrease) increase in deferred revenue	(66,750)	771,923
Net (decrease) increase in accounts payable, accrued expenses and other liabilities	(46,511)	8,356
Net cash (used in) provided by operating activities	(413,846)	282,001
Cash flows from investing activities:
Purchase of property and equipment	(36,284)	(53,592)
Proceeds from sale of Priority Review Voucher, net of commission	102,000	108,069
Purchase of available-for-sale securities	(29,988)	(897,691)
Maturity and sale of available-for-sale securities	466,000	847,980
Other	(3,738)	(2,596)
Net cash provided by investing activities	497,990	2,170
Cash flows from financing activities:
Proceeds from exercise of stock options and purchase of stock under the Employee Stock Purchase Program	18,654	48,131
Taxes paid related to net share settlement of equity awards	(6,333)	(4,798)
Net cash provided by financing activities	12,321	355,386
Increase in cash, cash equivalents and restricted cash	96,465	639,557
Cash, cash equivalents and restricted cash:
Beginning of period	1,511,713	843,645
End of period	1,608,178	1,483,202
Reconciliation of cash, cash equivalents and restricted cash:
Cash and cash equivalents	1,599,113	1,474,637
Restricted cash in other assets	$ 9,065	$ 8,565
Restricted Cash, Noncurrent, Statement of Financial Position [Extensible Enumeration]	us-gaap:OtherNoncurrentAssetsMember	us-gaap:OtherNoncurrentAssetsMember
Total cash, cash equivalents and restricted cash	$ 1,608,178	$ 1,483,202
Supplemental disclosure of cash flow information:
Cash paid during the period for interest	39,727	20,462
Supplemental schedule of non-cash investing activities and financing activities:
Intangible assets and property and equipment included in accounts payable and accrued expenses	4,644	8,292
Shares withheld for tax included in accrued expenses	1,432	0
Lease liabilities arising from obtaining right of use assets	13,148	37,647
Lease liabilities terminated	$ 19,967	0
Roche
Cash flows from financing activities:
Proceeds from issuance of common stock to Roche, net of offering costs		$ 312,053