v3.25.4
Equity-based compensation - Narrative (Details)
$ / shares in Units, $ / shares in Units, $ in Millions, $ in Millions
12 Months Ended
Dec. 31, 2025
USD ($)
shares
$ / shares
Dec. 31, 2025
USD ($)
shares
$ / shares
Dec. 31, 2024
USD ($)
shares
$ / shares
Dec. 31, 2024
USD ($)
shares
$ / shares
Dec. 31, 2025
CAD ($)
shares
Dec. 31, 2024
CAD ($)
shares
Disclosure of range of exercise prices of outstanding share options [line items]            
Expense from equity-settled share-based payment transactions | $     $ 14      
Equity-based compensation | $ $ (14)   14      
Exercised (in CAD per share) | $ / shares   $ 65.01   $ 69.42    
Ordinary shares            
Disclosure of range of exercise prices of outstanding share options [line items]            
Number of shares authorised | shares 1,242,895 1,242,895     1,242,895  
Number of share options available remaining for issuance | shares 561,925          
Equity-based compensation | $ $ (13)   6      
Share-based payment arrangements, vesting rate 20.00%          
Share-based payment arrangements, vesting period 10 years          
Exercised (in CAD per share) | $ / shares   $ 111.47   $ 123.05    
Liabilities from share-based payment transactions | $ $ 7 $ 7 $ 21 $ 21    
Weighted average share price, share options granted | (per share) $ 10.43 $ 14.30 $ 30.04 $ 43.23    
Intrinsic value of liabilities from share-based payment transactions for which counterparty's right to cash or other assets vested $ 2 $ 2 $ 10 $ 10 $ 3 $ 14
Number of shares outstanding | shares 680,970 680,970     680,970  
Ordinary shares | Norbord Option Plan            
Disclosure of range of exercise prices of outstanding share options [line items]            
Number of shares outstanding | shares 33,612 33,612     33,612  
Phantom Share Unit            
Disclosure of range of exercise prices of outstanding share options [line items]            
Equity-based compensation | $ $ 1   $ 7      
Share-based payment arrangements, vesting period 3 years          
Performance Share Units            
Disclosure of range of exercise prices of outstanding share options [line items]            
Number of other equity instruments outstanding in share-based payment arrangement | shares 193,290 193,290 168,775 168,775 193,290 168,775
Deferred Share Unit            
Disclosure of range of exercise prices of outstanding share options [line items]            
Equity-based compensation | $     $ 2      
Recovery of expense from share-based payment transactions | $ $ (2)          
Number of other equity instruments outstanding in share-based payment arrangement | shares 103,318 103,318 91,450 91,450 103,318 91,450
Restricted Share Units            
Disclosure of range of exercise prices of outstanding share options [line items]            
Number of other equity instruments outstanding in share-based payment arrangement | shares 27,625 27,625 0 0 27,625 0