Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($)	6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017
Cash flows from operating activities:
Net income (loss)	$ 875,668,000	$ (123,737,000)
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	(15,965,000)	(13,301,000)
Non-cash interest expense on liability related to sale of future royalties	9,994,000	9,064,000
Stock-based compensation	40,608,000	16,283,000
Depreciation and amortization	5,115,000	8,287,000
Other non-cash transactions	(3,991,000)	(1,089,000)
Changes in operating assets and liabilities:
Accounts receivable, net	(19,557,000)	11,564,000
Inventory	(1,158,000)	101,000
Other assets	(14,282,000)	2,280,000
Accounts payable	5,791,000	3,221,000
Accrued compensation	10,717,000	(3,934,000)
Accrued clinical trial expenses	10,567,000	(1,275,000)
Other accrued expenses	4,904,000	2,388,000
Interest payable	(54,000)	(54,000)
Deferred revenue	(6,249,000)	(3,887,000)
Other liabilities	5,068,000	1,000,000
Net cash provided by (used in) operating activities	907,176,000	(93,089,000)
Cash flows from investing activities:
Purchases of investments	(989,850,000)	(121,135,000)
Maturities of investments	132,779,000	147,558,000
Sales of investments	11,963,000	8,823,000
Purchases of property, plant and equipment	(3,730,000)	(6,344,000)
Sales of property, plant and equipment	2,633,000	0
Net cash (used in) provided by investing activities	(846,205,000)	28,902,000
Cash flows from financing activities:
Payment of capital lease obligations	0	(1,369,000)
Issuance of common stock	790,231,000	0
Proceeds from shares issued under equity compensation plans	55,208,000	22,016,000
Net cash provided by financing activities	845,439,000	20,647,000
Effect of exchange rates on cash and cash equivalents	(47,000)	49,000
Net increase (decrease) in cash and cash equivalents	906,363,000	(43,491,000)
Cash and cash equivalents at beginning of period	4,762,000	59,640,000
Cash and cash equivalents at end of period	911,125,000	16,149,000
Supplemental disclosure of cash flow information:
Cash paid for interest	$ 9,795,000	$ 10,010,000