Income Taxes - Statutory Income Tax Rates and Effective Income Tax Rates (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Income Tax Disclosure [Abstract]
Loss from continuing operations before income taxes	$ (25,239)	$ (46,164)	$ (30,178)
Canadian statutory tax rates	25.75%	25.00%	26.50%
Expected income tax recovery	6,499	11,541	7,997
Net increase in valuation allowance	(6,717)	(10,127)	(12,509)
Non-taxable portion of capital gains	608	1,083	1,401
Tax recovery of undistributed earnings of affiliates		2
Foreign tax rate differences		(16)	(31)
Investment tax credits	990	2,249	3,245
Stock-based compensation	(154)	(794)	(564)
Changes in tax rates	145	1	(583)
Non-deductible expenditures	(1,828)
Other	(142)	(39)	(157)
(Provision for) recovery of income taxes	$ (599)	$ 3,900	$ (1,201)