Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($)	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017
Cash flows from operating activities:
Net income (loss)	$ 779,525,000	$ (62,866,000)
Adjustments to reconcile net income (loss) to net cash provided by (used in) operating activities:
Non-cash royalty revenue related to sale of future royalties	(24,337,000)	(21,367,000)
Non-cash interest expense on liability related to sale of future royalties	14,808,000	13,535,000
Stock-based compensation	63,895,000	25,118,000
Depreciation and amortization	7,799,000	12,081,000
Other non-cash transactions	(8,136,000)	(1,370,000)
Changes in operating assets and liabilities:
Accounts receivable, net	(16,179,000)	12,364,000
Inventory	(2,570,000)	(2,545,000)
Other assets	(22,087,000)	(2,036,000)
Accounts payable	2,611,000	5,729,000
Accrued compensation	19,659,000	808,000
Accrued clinical trial expenses	12,505,000	(958,000)
Other accrued expenses	14,098,000	4,971,000
Deferred revenue	(10,931,000)	15,477,000
Other liabilities	5,104,000	1,046,000
Net cash provided by (used in) operating activities	835,764,000	(13,000)
Cash flows from investing activities:
Purchases of investments	(1,944,178,000)	(314,439,000)
Maturities of investments	467,658,000	261,112,000
Sales of investments	11,963,000	8,823,000
Purchases of property, plant and equipment	(5,552,000)	(7,283,000)
Sales of property, plant and equipment	2,633,000	0
Net cash used in investing activities	(1,467,476,000)	(51,787,000)
Cash flows from financing activities:
Payment of capital lease obligations	0	(2,159,000)
Issuance of common stock	790,231,000	0
Proceeds from shares issued under equity compensation plans	59,067,000	32,275,000
Net cash provided by financing activities	849,298,000	30,116,000
Effect of exchange rates on cash and cash equivalents	(87,000)	11,000
Net increase (decrease) in cash and cash equivalents	217,499,000	(21,673,000)
Cash and cash equivalents at beginning of period	4,762,000	59,640,000
Cash and cash equivalents at end of period	222,261,000	37,967,000
Supplemental disclosure of cash flow information:
Cash paid for interest	$ 14,701,000	$ 14,989,000