Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Cash flows from operating activities:
Net loss	$ (95,792)	$ (63,866)
Adjustments to reconcile net loss to net cash used in operating activities:
Non-cash royalty revenue related to sale of future royalties	(6,920)	(6,663)
Non-cash interest expense on liability related to sale of future royalties	5,019	4,552
Stock-based compensation	19,949	8,184
Depreciation and amortization	2,541	4,033
Other non-cash transactions	(370)	(731)
Changes in operating assets and liabilities:
Accounts receivable, net	151	14,113
Inventory	51	(1,907)
Other assets	1,853	2,134
Accounts payable	6,492	4,117
Accrued compensation	6,867	(6,817)
Accrued clinical trial expenses	10,329	(515)
Other accrued expenses	605	1,798
Interest payable	(108)	(108)
Deferred revenue	(3,678)	9,619
Other liabilities	545	(2,509)
Net cash used in operating activities	(52,466)	(34,566)
Cash flows from investing activities:
Purchases of investments	0	(75,857)
Maturities of investments	37,232	58,053
Sales of investments	11,963	8,823
Purchases of property, plant and equipment	(985)	(4,089)
Net cash provided by (used in) investing activities	48,210	(13,070)
Cash flows from financing activities:
Payment of capital lease obligations	0	(613)
Proceeds from shares issued under equity compensation plans	34,352	11,792
Net cash provided by financing activities	34,352	11,179
Effect of exchange rates on cash and cash equivalents	(53)	297
Net increase (decrease) in cash and cash equivalents	30,043	(36,160)
Cash and cash equivalents at beginning of period	4,762	59,640
Cash and cash equivalents at end of period	34,805	23,480
Supplemental disclosure of cash flow information:
Cash paid for interest	$ 4,952	$ 5,067