Stock-based Payments - Summary of Outstanding and Exercisable Options (Detail)
12 Months Ended
Dec. 31, 2017
CAD ($)
yr
Dec. 31, 2016
CAD ($)
Dec. 31, 2015
Disclosure of terms and conditions of share-based payment arrangement [line items]      
Number of options 11,603,750 6,177,594 1,610,003
Number of options, Exercisable 2,744,387    
Weighted average exercise price | $ $ 2.05 $ 1.10  
Weighted average exercise price, Exercisable | $ $ 1.71 $ 1.09  
Weighted average remaining contractual life (years) | yr 4.05    
Weighted average remaining contractual life (years), Exercisable | yr 3.57    
August 2016 [member]      
Disclosure of terms and conditions of share-based payment arrangement [line items]      
Vested terms of options Evenly over 48 months    
Number of options 1,141,666    
Weighted average exercise price | $ $ 0.50    
Weighted average remaining contractual life (years) | yr 3.60    
October 2016 [member]      
Disclosure of terms and conditions of share-based payment arrangement [line items]      
Vested terms of options Evenly over 48 months    
Number of options 3,578,084    
Weighted average exercise price | $ $ 1.23    
Weighted average remaining contractual life (years) | yr 3.77    
November 2016 [member]      
Disclosure of terms and conditions of share-based payment arrangement [line items]      
Vested terms of options On May 15, 2017    
Number of options 300,000    
Weighted average exercise price | $ $ 1.50    
Weighted average remaining contractual life (years) | yr 0.37    
November 2016 [member]      
Disclosure of terms and conditions of share-based payment arrangement [line items]      
Vested terms of options Evenly over 48 months    
Number of options 182,000    
Weighted average exercise price | $ $ 1.84    
Weighted average remaining contractual life (years) | yr 3.88    
April 2017 [member]      
Disclosure of terms and conditions of share-based payment arrangement [line items]      
Vested terms of options Evenly over 48 months    
Number of options 3,299,000    
Weighted average exercise price | $ $ 3.14    
Weighted average remaining contractual life (years) | yr 4.28    
August 2017 [member]      
Disclosure of terms and conditions of share-based payment arrangement [line items]      
Vested terms of options Evenly over 48 months    
Number of options 2,903,000    
Weighted average exercise price | $ $ 2.42    
Weighted average remaining contractual life (years) | yr 4.65    
November 2017 [member]      
Disclosure of terms and conditions of share-based payment arrangement [line items]      
Vested terms of options Evenly over 48 months    
Number of options 200,000    
Weighted average exercise price | $ $ 3.32    
Weighted average remaining contractual life (years) | yr 4.86