Income Taxes (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2018	Dec. 31, 2017
Tax Credit Carryforward [Line Items]
Income tax (recovery) expense	27.00%	27.00%
Unclaimed Tax Deductions Related To Scientific Research And Experimental Development Expenditures	$ 98,412	$ 92,799
Non-capital losses carried forward for tax purposes	$ 81,611	50,536
Tax Credit Carry forward, Expiration Date	Dec. 31, 2038
Unrecognized tax benefits of uncertain tax positions	$ 6,350	6,350
Canada Revenue Agency [Member] \| Latest Tax Year [Member]
Tax Credit Carryforward [Line Items]
Tax year open for income tax examination	2002
Canada Revenue Agency [Member] \| Earliest Tax Year [Member]
Tax Credit Carryforward [Line Items]
Tax year open for income tax examination	2017
Investment Tax credit [Member]
Tax Credit Carryforward [Line Items]
Tax credit available to offset federal taxes payable	$ 22,253	21,066
Provincial Tax Credit [Member]
Tax Credit Carryforward [Line Items]
Tax credit available to offset federal taxes payable	$ 7,640	$ 7,560

Percentage of domestic federal statutory tax rate applicable to pretax income (loss).

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