CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015
Operating activities
Net loss	$ (123,336)	$ (137,393)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	1,944	2,292
Share-based compensation	31,129	42,539
Inventory write-down	119	79
Excess tax benefits from share-based compensation	0	(206)
Non-cash revenue from collaboration arrangements	0	(8,000)
Changes in operating assets and liabilities:
Accounts receivable	1,049	(494)
Receivables from collaborative arrangements	12,519	(17,800)
Prepaid taxes	9,596	(3,118)
Other prepaid and current assets	796	(503)
Inventories	(1,838)	118
Other assets	(3,705)	(415)
Accounts payable	(12,838)	(3,489)
Accrued personnel-related expenses, accrued clinical and development expenses, and other accrued liabilities	8,190	(9,927)
Deferred rent	(439)	(404)
Income taxes payable	0	1,305
Deferred revenue	482	222
Other long-term liabilities	5,456	83
Net cash used in operating activities	(70,876)	(135,111)
Investing activities
Purchases of property, equipment, and capitalized software	(1,735)	(2,041)
Purchases of marketable securities	(168,559)	(11,059)
Maturities of marketable securities	68,264	158,642
Net cash (used in) provided by investing activities	(102,030)	145,542
Financing activities
Net proceeds from sale of ordinary shares	145,241	27,262
Proceeds from ESPP purchases	1,944	0
Proceeds from option exercise	2,436	0
Excess tax benefits from share-based compensation	0	206
Repurchase of shares to satisfy tax withholding	(2,850)	0
Net cash provided by financing activities	146,771	27,468
Net (decrease) increase in cash and cash equivalents	(26,135)	37,899
Cash and cash equivalents at beginning of period	112,707	89,215
Cash and cash equivalents at end of period	86,572	127,114
Supplemental disclosure of cash flow information
Cash (received) paid for income taxes, net	$ (9,488)	$ 10,392