Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Operating activities
Net loss	$ (58,464)	$ (83,400)
Adjustments to reconcile net loss to net cash used in operating activities:
Share-based compensation expense	8,947	10,965
Depreciation and amortization	639	270
Amortization of premiums and discounts on available-for-sale securities	214	80
Amortization of debt issuance costs	317	307
Change in fair value of contingent purchase consideration	0	1,049
Loss on disposal of property and equipment	0	169
Deferred income taxes	(60)	(4,145)
Changes in operating assets and liabilities:
Accounts receivable	(2,257)	0
Inventory	(6,504)	0
Prepaid and accrued research and development expenses	(10,047)	(7,601)
Other operating assets	(17,014)	(130)
Accounts payable	13,780	2,682
Other accrued expenses	(9,990)	(3,984)
Net cash used in operating activities	(80,439)	(83,738)
Investing activities
Purchases of property and equipment	(53)	(604)
Deposits for purchases of property and equipment	(2,515)	0
Purchases of available-for-sale securities	(133,000)	0
Maturities of available-for-sale securities	50,000	25,000
Acquired in-process research and development - milestone payment	(1,100)	0
Net cash (used in) provided by investing activities	(86,668)	24,396
Financing activities
Proceeds from the sale of common stock, net of issuance costs	221,224	0
Proceeds from the exercise of stock options	5,674	705
Net cash provided by financing activities	226,898	705
Effect of exchange rate changes on cash and cash equivalents	72	254
Increase (decrease) in cash and cash equivalents	59,863	(58,383)
Cash and cash equivalents at beginning of period	216,186	278,756
Cash and cash equivalents at end of period	276,049	220,373
Supplemental disclosure of cash flow information:
Cash paid for interest	3,594	3,594
Non-cash investing and financing activities:
Vesting of restricted stock units	$ 2,534	$ 0