Financial Instruments - Currency risk sensitivity analysis (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2019 CAD ($)
Financial Instruments
Increase in Loss from continuing operations if U.S. dollar currency weakened 10% against functional currencies	$ 653
Decrease in Loss from continuing operations if U.S. dollar currency strengthened 10% against functional currencies	(619)
Decrease in Loss from continuing operations if Euro weakened 10% against functional currencies	7,554
Increase in Loss from continuing operations if Euro strengthened 10% against functional currencies	7,554
Decrease in Loss from continuing operations if Canadian dollar weakened 10% against functional currencies	35
Increase in Loss from continuing operations if Canadian dollar strengthened 10% against functional currencies	$ 35