Consolidated Statements of Cash Flows - USD ($)		12 Months Ended
		Dec. 31, 2018	Dec. 31, 2017		Dec. 31, 2016
Operating activities:
Net (loss) income		$ (123,914,000)	$ (126,817,000)		$ (69,707,000)
Adjustments to reconcile net (loss) income to net cash used in operating activities:
Stock-based compensation		15,492,000	6,155,000		7,353,000
Depreciation		155,000	425,000		1,402,000
Amortization of debt issuance costs and debt discount		0	887,000		991,000
Net accretion and amortization of investments in marketable securities		(1,998,000)	0		0
Change in fair value of common stock warrant liabilities		(169,000)	(297,000)		(5,387,000)
Change in fair value of contingent consideration		1,300,000	24,100,000		1,800,000
Inventory write-down		0	2,232,000		0
Impairment charges		0	1,116,000		8,431,000
Loss on extinguishment of debt		0	4,876,000		0
Changes in operating assets and liabilities:
Trade accounts receivable		0	9,356,000		(11,181,000)
Inventory		0	2,583,000		4,983,000
Prepaid expenses and other current assets		(9,335,000)	(801,000)		(3,394,000)
Other assets		266,000	(2,784,000)		471,000
Accounts payable, accrued expenses and other liabilities		6,545,000	4,340,000		(1,778,000)
Deferred revenue		0	(1,245,000)		(5,839,000)
Deferred tax liability		0	0		(1,025,000)
Net cash used in operating activities		(111,658,000)	(75,874,000)		(72,880,000)
Investing activities:
Payments to acquire marketable securities		(569,515,000)	0		0
Proceeds from maturities of marketable securities		125,783,000	0		0
Purchases of property and equipment		(1,018,000)	(76,000)		(103,000)
Net cash (used in) provided by investing activities		(444,750,000)	(76,000)		(103,000)
Financing activities:
Proceeds from borrowings		0	0		2,167,000
Principal repayments of long-term debt		0	(20,000,000)		(3,334,000)
Payment of fees to extinguish long-term debt		0	(1,865,000)		0
Proceeds from issuance of common stock under equity incentive plans		9,654,000	9,176,000		350,000
Taxes paid related to net share settlement of equity awards		(1,430,000)	0		0
Proceeds from issuance of common stock, net of offering costs		323,135,000	290,591,000		0
Net cash provided by (used in) financing activities		331,359,000	277,902,000		(817,000)
Net (decrease) increase in cash, cash equivalents and restricted cash	[1]	(225,049,000)	201,952,000		(73,800,000)
Cash, cash equivalents and restricted cash at beginning of period	[1]	293,503,000	91,551,000		165,351,000
Cash, cash equivalents and restricted cash at end of period		68,454,000	293,503,000	[1]	91,551,000	[1]
Supplemental disclosure of cash flow information:
Cash paid for interest		0	1,475,000		1,470,000
Noncash Investing and Financing Items [Abstract]
Purchases of property and equipment in accounts payable and accrued liabilities		1,762,000	0		0
Extinguishment of Endo working capital advance note payable through net settlement of balances owed to the Company	[2]	$ 0	$ 7,000,000		$ 0

[1] Amounts in 2016 have been retrospectively adjusted to reflect the adoption of new accounting guidance that was effective January 1, 2018. See Note 2 for further information.

[2] See Notes 3 and 8 for further information.