Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016
Cash flows from operating activities:
Net income (loss)	$ 21,044	$ (122,071)
Adjustments to reconcile net income (loss) to cash flows from operating activities:
Gain from sale of Priority Review Voucher	(125,000)
Depreciation and amortization	3,409	2,873
Amortization of (discount) premium on available-for-sale securities and non-cash interest	(143)	394
Loss on abandonment of patents	604	24
Stock-based compensation	16,177	13,665
Changes in operating assets and liabilities, net:
Net increase in accounts receivable	(12,563)	(5)
Net increase in inventory	(28,941)
Net increase in other assets	(9,285)	(394)
Net (decrease) increase in accounts payable, accrued expenses, deferred revenue and other liabilities	(8,337)	1,542
Net cash used in operating activities	(143,035)	(103,972)
Cash flows from investing activities:
Purchase of property and equipment	(7,336)	(1,587)
Purchase of intangible assets	(1,601)	(768)
Purchase of available-for-sale securities	(100,348)
Proceeds from sale of Priority Review Voucher	125,000
Maturity of restricted investment	10,695
Maturity and sale of available-for-sale securities	163,521	100,712
Net cash provided by investing activities	189,931	98,357
Cash flows from financing activities:
Repayments of long-term debt and notes payable	(5,054)	(2,551)
Proceeds from sales of common stock, net of offering costs		37,500
Proceeds from exercise of options and purchase of stock under the Employee Stock Purchase Program	4,086	2,181
Net cash provided by (used in) financing activities	(968)	37,130
Increase (decrease) in cash and cash equivalents	45,928	31,515
Cash, cash equivalents and restricted cash:
Beginning of period	122,556	80,439
End of period	168,484	111,954
Supplemental disclosure of cash flow information:
Cash paid during the period for interest	538	828
Supplemental schedule of non-cash investing activities and financing activities:
Shares withheld for taxes	309	104
Intangible assets included in accrued expenses	265	259
Asset held for sale	1,529
Accrual for debt issuance costs related to the senior secured term loan	$ 400	400
Accrual for senior secured term loan principal payment		833
Accrual for offering costs related to the June 2016 equity offering		170
Property and equipment included in accrued expenses		$ 99