Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Operating activities:
Net loss	$ (3,263)	$ (9,156)
Items not involving cash:
Depreciation and amortization	282	207
Stock-based compensation	592	5,219
Deferred tenant inducements	(16)	(16)
Unrealized foreign exchange (gain) loss	(2,260)	3,140
Changes in operating assets and liabilities:
Accounts receivable	(60)	(996)
Prepaid expenses, and other current assets	82	220
Accounts payable and accrued expenses	(144)	(1,110)
Deferred revenue	(157)	(3,055)
Net cash used in operating activities	(4,944)	(5,547)
Investing activities:
Purchases of property, plant and equipment	(83)	(84)
Proceeds from marketable securities		1,575
Net cash provided by (used in) investing activities	(83)	1,491
Financing activities:
Proceeds from issuance of common shares	44	127
Net cash provided by financing activities	44	127
Effect of exchange rate changes on cash and cash equivalents	2,396	(2,180)
Decrease in cash and cash equivalents	(2,587)	(6,109)
Cash and cash equivalents, beginning of period	58,651	72,026
Cash and cash equivalents, end of period	56,064	65,917
Supplemental disclosures:
Interest received	$ 112	121
Supplemental disclosures of non-cash transactions:
Fair value of options exercised on a cashless basis		$ 69