Taxes - Significant Components of Future Income Tax Assets and Liabilities (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013
Income Tax Disclosure [Abstract]
Tax loss carryforwards	$ 29,731	$ 32,981
Scientific research and experimental development ("SR&ED") carryforwards	5,251	5,345
Share issue costs	213us-gaap_DeferredTaxAssetsOther	497us-gaap_DeferredTaxAssetsOther
Investment tax credits	4,571us-gaap_InvestmentTaxCredit	4,571us-gaap_InvestmentTaxCredit
Accounts payable and accrued liabilities	2,559	3,102
Difference between tax and book value of finance obligations	(693)	(985)
Difference between tax and book value of capital and intangible assets	(6,758)	(7,694)
Difference between tax and book value of loan receivable	36us-gaap_DeferredTaxLiabilitiesOther	42us-gaap_DeferredTaxLiabilitiesOther
Total future income tax asset	34,910us-gaap_DeferredTaxAssetsGross	37,859us-gaap_DeferredTaxAssetsGross
Valuation allowance	(14,323)	(10,983)
Net future income tax asset	$ 20,587us-gaap_DeferredTaxAssetsLiabilitiesNet	$ 26,876us-gaap_DeferredTaxAssetsLiabilitiesNet

Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences and carryforwards.

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-Publisher FASB

-Name Accounting Standards Codification

-Topic 740

-SubTopic 10

-Section 50

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Amount after allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences and carryforwards, net of deferred tax liability attributable to taxable temporary differences.

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Amount before allocation of valuation allowances of deferred tax asset attributable to deductible operating loss carryforwards that are subject to expiration dates.

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Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences not separately disclosed.

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Amount before allocation of valuation allowances of deferred tax asset attributable to deductible research tax credit carryforwards.

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Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences from other reserves and accruals not separately disclosed.

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Amount of deferred tax assets for which it is more likely than not that a tax benefit will not be realized.

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Amount of deferred tax liability attributable to taxable temporary differences from financing arrangements.

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Amount of deferred tax liability attributable to taxable temporary differences not separately disclosed.

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Amount of deferred tax liability attributable to taxable temporary differences from property, plant, and equipment.

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The amount deducted from an entities' taxes, reflecting a percentage of an amount invested in certain assets spread over the useful life of those assets; includes deferred investment tax credits.

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