Condensed Consolidated Statements of Cash Flow (Unaudited) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Research and Development Expense [Member]
Items not involving cash:
Stock-based compensation	$ 1,377,000	$ 792,000	$ 2,705,000	$ 1,640,000
General and Administrative Expense [Member]
Items not involving cash:
Stock-based compensation	4,046,000	289,000	4,525,000	629,000
Net loss for the period	(14,886,000)	(6,081,000)	(26,875,000)	(24,065,000)
Depreciation of property and equipment	147,000	149,000	267,000	283,000
Unrealized foreign exchange (gains) losses	2,639,000	1,391,000	(4,418,000)	1,332,000
Change in fair value of warrant liability	(2,024,000)	(5,813,000)	(801,000)	7,803,000
Net change in non-cash operating items:
Accounts receivable	(1,738,000)	1,231,000	(4,624,000)	(178,000)
Accrued revenue	$ 1,304,000	220,000	$ 178,000	12,000
Deferred expenses		57,000		112,000
Prepaid expenses and other assets	$ (519,000)	243,000	$ (298,000)	725,000
Accounts payable and accrued liabilities	(7,351,000)	(943,000)	(5,343,000)	108,000
Deferred revenue	334,000	455,000	(957,000)	12,744,000
Net cash provided by (used in) operating activities	(16,671,000)	(8,010,000)	(35,641,000)	1,145,000
INVESTING ACTIVITIES
Disposition (acquisition) of short and long-term investments	$ (9,944,000)	$ (42,992,000)	27,419,000	$ (42,992,000)
Cash acquired through acquisition (note 3)			324,000
Acquisition of property and equipment	$ (383,000)	$ (246,000)	(524,000)	$ (581,000)
Net cash provided by (used) in investing activities	(10,327,000)	$ (43,238,000)	27,219,000	(43,573,000)
FINANCING ACTIVITIES
Proceeds from issuance of common shares, net of issuance costs	2,000		142,177,000	56,477,000
Issuance of common shares pursuant to exercise of options	939,000	$ 148,000	1,559,000	2,072,000
Issuance of common shares pursuant to exercise of warrants	19,000	86,000	44,000	974,000
Net cash provided by financing activities	960,000	234,000	143,780,000	59,523,000
Effect of foreign exchange rate changes on cash and cash equivalents	967,000	1,924,000	(340,000)	(545,000)
Increase in cash and cash equivalents	(25,071,000)	(49,090,000)	135,018,000	16,550,000
Cash and cash equivalents, beginning of period	232,276,000	134,357,000	72,187,000	68,717,000
Cash and cash equivalents, end of period	$ 207,205,000	85,267,000	$ 207,205,000	85,267,000
Non-cash transactions:
Fair value of warrants exercised on a cashless basis		$ (116,000)		$ (116,000)
Investment tax credits received	$ 25,000		$ 25,000
Acquisition of Arbutus Inc. excluding cash acquired			$ 381,618,000