Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Cash flows from operating activities:
Net loss	$ (52,501)	$ (13,297)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	2,910	2,833
Amortization of acquired intangible asset	420
Share-based compensation expense	7,279	6,806
Change in fair value of note hedge warrants	20,187	(7,135)
Change in fair value of convertible note hedges	(17,988)	8,778
Write-down of excess non-cancelable ZURAMPIC sample purchase commitments	1,353
(Gain) loss on facility subleases	(1,579)	3,480
Accretion of discount/premium on investment securities	105	340
Non-cash interest expense	3,877	3,572
Non-cash change in fair value of contingent consideration	1,614
Loss on extinguishment of debt	2,009
Changes in assets and liabilities:
Accounts receivable and related party accounts receivable	13,707	1,500
Prepaid expenses and other current assets	372	(1,093)
Inventory	71
Other assets	201	385
Accounts payable, related party accounts payable and accrued expenses	(5,238)	(8,104)
Accrued research and development costs	(1,831)	2,380
Deferred revenue	741	320
Deferred rent	(3,555)	(604)
Net cash (used in) provided by operating activities	(27,846)	161
Cash flows from investing activities:
Purchases of available-for-sale securities	(44,777)	(52,629)
Sales and maturities of available-for-sale securities	133,830	76,985
Purchases of property and equipment	(1,037)	(1,008)
Proceeds from sale of property and equipment	43
Net cash provided by investing activities	88,059	23,348
Cash flows from financing activities:
Proceeds from issuance of 2026 Notes, net of discount to lender	146,250
Costs associated with issuance of 2026 Notes	(209)
Proceeds from exercise of stock options and employee stock purchase plan	8,171	1,841
Payments on capital leases	(796)	(413)
Principal payments on PhaRMA notes	(134,258)	(5,298)
Payments on contingent purchase price consideration	(56)
Net cash provided by (used in) financing activities	19,102	(3,870)
Net increase in cash and cash equivalents	79,315	19,639
Cash and cash equivalents, beginning of period	54,004	261,287
Cash and cash equivalents, end of period	$ 133,319	$ 280,926