Income Taxes - Net Deferred Income Tax Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Deferred income tax assets
Scientific research and experimental development pool	$ 22,823	$ 21,088
Investment tax credits	22,483	21,303
Non-capital losses	7,800	4,234
Depreciable assets	4,163	3,749
Deferred financing fees	1,020	959
Other	126	185
Less - valuation allowance	$ (58,415)	$ (51,518)

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Amount, before allocation of valuation allowance, of deferred tax asset attributable to deductible temporary differences, classified as other.

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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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