Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Operating activities:
Net income (loss)	$ (15,752)	$ 13,018	$ 12,032
Items not involving cash:
Depreciation and amortization	1,038	738	705
Gain on write-off of assets			(11)
Stock-based compensation	3,729	760	575
Non-cash compensation on issuance of subscription rights			73
Deferred tenant inducements	(63)	(66)	(115)
Unrealized foreign exchange loss	6,902	72	94
Changes in operating assets and liabilities:
Accounts receivable	(107)	209	(76)
Prepaid expenses, and other current assets	(1,214)	(573)	(14)
Prepaid expenses, long term	(1,094)
Accounts payable and accrued expenses	80	518	(228)
Deferred revenue	(11,622)	(14,410)	(16,357)
Net cash provided by (used in) operating activities	(18,103)	266	(3,322)
Investing activities:
Purchases of property, plant and equipment	(551)	(1,529)	(156)
Sale of property, plant and equipment			10
Purchase of marketable securities		(15,254)	(17,876)
Proceeds from marketable securities	10,745	13,539	6,550
Net cash provided by (used in) investing activities	10,194	(3,244)	(11,472)
Financing activities:
Note payable			(1,701)
Deferred financing fees		(1,533)	(2,739)
Proceeds from issuance of common shares	278	42,657	49
Net cash provided by (used in) financing activities	278	41,124	(4,391)
Effect of exchange rate changes on cash and cash equivalents	(5,744)	(4,070)	(3,027)
Increase (decrease) in cash and cash equivalents	(13,375)	34,076	(22,212)
Cash and cash equivalents, beginning of year	72,026	37,950	60,162
Cash and cash equivalents, end of year	58,651	72,026	37,950
Supplemental disclosures:
Interest paid			201
Interest received	659	574	279
Supplemental disclosures of non-cash transactions:
Issuance of common shares on conversion of subscription rights		124	$ 45
Financing fees included in accounts payable and accrued liabilities		39
Fair value of options exercised on a cashless basis	$ 744
Conversion of convertible preferred shares into common shares		$ 102,488