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

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 50
-Paragraph 12
-URI http://asc.fasb.org/extlink&oid=84230637&loc=d3e32687-109319

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SAB TOPIC 6.I)
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Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 50
-Paragraph 13
-URI http://asc.fasb.org/extlink&oid=84230637&loc=d3e32698-109319

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Amount of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations attributable to research tax credit.

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Tax year that remains open to examination under enacted tax laws, in CCYY format.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
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Amount of operating loss carryforward, before tax effects, available to reduce future taxable income under enacted tax laws.

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The amount of the tax credit carryforward, before tax effects, available to reduce future taxable income under enacted tax laws.

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Expiration date of the tax credit carryforward, in CCYY-MM-DD format.

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Amount of unrecognized tax benefits.

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Income Taxes (Details) - USD ($) $ in Thousands	12 Months Ended
Income Taxes (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Tax Credit Carryforward [Line Items]
Income tax (recovery) expense	26.00%	26.00%	26.00%
Unclaimed Tax Deductions Related To Scientific Research And Experimental Development Expenditures	$ 92,799	$ 87,781
Non-capital losses carried forward for tax purposes	$ 50,536	29,999
Tax Credit Carry forward, Expiration Date	Dec. 31, 2037
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	2016
Investment Tax credit [Member]
Tax Credit Carryforward [Line Items]
Tax credit available to offset federal taxes payable	$ 21,066	20,160
Provincial Tax Credit [Member]
Tax Credit Carryforward [Line Items]
Tax credit available to offset federal taxes payable	$ 7,560	$ 7,624