Concentrations of Market Risk (Details) CAD in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2017 USD ($)	Dec. 31, 2017 CAD	Dec. 31, 2016 USD ($)	Dec. 31, 2016 CAD
Concentration Risk [Line Items]
Total outstanding loan balance, due within 12 months	$ 700
Interest Rate Risk [Member]
Concentration Risk [Line Items]
Cash and cash equivalents and marketable securities	$ 43,667
Interest rate risk, description	The Company does not enter into investments for trading or speculative purposes and has not used any derivative financial instruments to manage interest rate exposure. A 10% change in interest rates during any of the periods presented would not have had a material impact on the Company’s consolidated financial statements.
Total outstanding loan balance	$ 7,000
Total outstanding loan balance, due within 12 months	$ 700
Interest Rate Risk [Member] | Prime Rate [Member] | Loan Agreement [Member] | Bank [Member]
Concentration Risk [Line Items]
Percentage of floating rate above prime rate	0.50%
Foreign Currency Exchange Risk [Member]
Concentration Risk [Line Items]
Cash and cash equivalents and marketable securities	$ 28,028	CAD 19,619	$ 35,859	CAD 37,980