Income Taxes (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2019	Dec. 31, 2018
Tax Credit Carryforward [Line Items]
Income tax (recovery) expense	27.00%	27.00%
Unclaimed Tax Deductions Related To Scientific Research And Experimental Development Expenditures	$ 101,965	$ 98,412
Non-capital losses carried forward for tax purposes	$ 87,417	81,611
Tax Credit Carry forward, Expiration Date	Dec. 31, 2039
Unrecognized tax benefits of uncertain tax positions	$ 10,850	6,350
Canada and United States Revenue Agency [Member] \| Latest Tax Year [Member]
Tax Credit Carryforward [Line Items]
Tax year open for income tax examination	2002
Canada and United States Revenue Agency [Member] \| Earliest Tax Year [Member]
Tax Credit Carryforward [Line Items]
Tax year open for income tax examination	2018
Investment Tax credit [Member]
Tax Credit Carryforward [Line Items]
Tax credit available to offset taxes payable	$ 22,992	22,253
Provincial Tax Credit [Member]
Tax Credit Carryforward [Line Items]
Tax credit available to offset taxes payable	$ 7,675	$ 7,640

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

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