Condensed Consolidated Statements of Cash Flows (unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017
Cash flows from operating activities:
Net loss	$ (101,549)	$ (103,001)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	2,424	2,585
Stock-based compensation expense	8,659	11,710
Change in fair value of derivative liability		15,411
Amortization of debt discount	256	3,349
Deferred rent expense	329	640
(Gain) loss on disposal of assets and impairment charges	(62)	80
Research and development license purchased with convertible bond and stock	31,545	13,250
Interest incurred on converted bonds		2,759
Deferred income taxes	(316)	(108)
Changes in operating assets and liabilities:
Receivables, net	1,397	(3,682)
Prepaid expenses and other assets	(6,290)	(2,722)
Inventories	(8,670)	(7,395)
Accounts payable and accrued expenses	(3,038)	3,480
Net cash used in operating activities	(75,315)	(63,644)
Cash flows from investing activities:
Purchase of property and equipment	(2,501)	(4,384)
Receipt of deposit		80
Payments for licenses		(1,550)
Purchases of short-term investments	(110,605)	(55,282)
Sale of short-term investments	31,981	14,114
Net cash used in investing activities	(81,125)	(47,022)
Cash flows from financing activities:
Proceeds from sale of stock	122,666	75,900
Proceeds from issuance of debt	50,000	30,000
Costs incurred related to the sale of stock	(5,118)	(10,168)
Costs incurred related to the issuance of debt	(1,593)
Proceeds from exercise of stock options	2,960	1,208
Investment from non-controlling interest		49
Repayment of capital lease obligations and long-term debt	(551)	(896)
Net cash provided by financing activities	168,364	96,093
Net increase (decrease) in cash and cash equivalents	11,924	(14,573)
Cash and cash equivalents, beginning of period	39,284	33,125
Effect of exchange rate changes on cash and cash equivalents	(100)	710
Cash and cash equivalents, end of period	51,108	19,262
Non-cash investing and financing activities:
Accrued purchases of property and equipment	445	150
Cost of equity in accounts payable and accrued expenses	400
Convertible bond issued in lieu of licensing cash payment		7,000
Common stock issued for purchase of license (See Note 6)	$ 31,545	6,250
Common stock issued upon the conversion of bonds		98,929
Property and equipment financed under capital lease		$ 242