v3.21.1
SHARE CAPITAL - Post Qualifying Transaction (Details) - shares
 12 Months Ended 18 Months Ended
Dec. 23, 2020
Dec. 08, 2020
Nov. 30, 2020
Nov. 18, 2020
May 18, 2020
Nov. 20, 2019
Oct. 01, 2019
Jul. 26, 2019
Dec. 31, 2020
Dec. 31, 2019
Dec. 31, 2020
Dec. 31, 2018
Disclosure of classes of share capital [line items]                        
Number of warrants outstanding                 10,486,412 16,060,858 10,486,412 16,359,058
Subordinate Voting Shares                        
Disclosure of classes of share capital [line items]                        
Exercise of Warrants, shares   3,000,001 3,000,001         298,200     5,872,646  
Exercise of Rights, shares                 1,235,325 1,235,325    
Stock repurchase program maximum repurchase as a percentage to total issued and outstanding shares             5.00%          
Stock repurchase program period of repurchase for calculating repurchased shares             12 months          
Repurchase of Subordinate Voting Shares repurchased and cancelled, shares                 7,400   7,400  
Repurchase of Subordinate Voting Shares repurchased and held in treasury, shares                 63,800   63,800  
Share issuance - combinations and acquisitions, shares       128,265                
Exchangeable Shares                        
Disclosure of classes of share capital [line items]                        
Share issuance - make-whole, shares         614,515 389,905            
Conversion of Exchangeable Shares, shares                 8,170,805 8,170,805    
Share issuance - combinations and acquisitions, shares 1,310,041                      
Rights                        
Disclosure of classes of share capital [line items]                        
Number of Rights converted                 12,353,250 12,353,250    
Number of warrants outstanding                 1,383,938   1,383,938  
Rights redeemed during period                 1,756,400      
Rights | Subordinate Voting Shares                        
Disclosure of classes of share capital [line items]                        
Number of securities into which each right may be redeemed                 0.1   0.1