Condensed Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013
Operating activities
Net income (loss)	$ 19,142	$ (20,253)
Adjustments to reconcile net income (loss) to cash provided by (used in) operating activities:
Depreciation and amortization	357	284
Share-based compensation	2,781	1,082
Excess tax benefit from share-based award exercises	(252)	0
Deferred income taxes	(483)	(406)
Gain on disposal of fixed asset	0	(29)
Changes in operating assets and liabilities:
Receivable from Roche	(1,491)	0
Receivable from related party	12	168
Other assets	(138)	(274)
Accounts payable, accruals and other liabilities	4,177	7,470
Net cash provided by (used in) operating activities	24,105	(11,958)
Investing activities
Purchases of property and equipment	(353)	(340)
Proceeds from disposal of fixed asset	0	29
Net cash used in investing activities	(353)	(311)
Financing activities
Post separation adjustments to the funding provided by Elan	0	(84)
Proceeds from issuance of ordinary shares upon exercise of stock options	390	0
Excess tax benefit from share-based award exercises	252	0
Proceeds from issuance of ordinary shares in public offering, net	102,780	0
Net cash provided by (used in) financing activities	103,422	(84)
Net increase (decrease) in cash and cash equivalents	127,174	(12,353)
Cash and cash equivalents, beginning of the year	176,677	124,860
Cash and cash equivalents, end of the period	303,851	112,507
Supplemental disclosures of cash flow information
Cash paid for income taxes, net of refunds	436	263
Supplemental disclosures of non-cash investing and financing activities
Accrued offering costs	$ 280	$ 0