Quarterly report [Sections 13 or 15(d)]

CAPITAL STOCK - Narrative (Details)

v3.25.2
CAPITAL STOCK - Narrative (Details)
$ / shares in Units, $ in Millions
 3 Months Ended 6 Months Ended
Nov. 01, 2024
USD ($)
shares
Jun. 30, 2025
USD ($)
shares
Jun. 30, 2024
USD ($)
shares
Mar. 31, 2024
shares
Jun. 30, 2025
USD ($)
shares
Jun. 30, 2024
USD ($)
shares
Nov. 01, 2024
$ / shares
Nov. 01, 2024
$ / shares
Apr. 22, 2024
USD ($)
Feb. 10, 2022
USD ($)
Class of Stock [Line Items]                    
Authorized amount of stock repurchase | $                 $ 1,500 $ 1,000
Repurchase of common shares | $         $ 0 $ 733        
Remaining authorized amount of stock repurchase | $   $ 1,400     $ 1,400          
Stelco Holdings Inc                    
Class of Stock [Line Items]                    
Price per share (in dollars per share) | (per share)             $ 60.00 $ 13.27    
Business Acquisition, Shares Exchange Ratio 0.454                  
Stock Issued During Period, Shares, Acquisitions 25,900,000                  
Stock Issued During Period, Value, Acquisitions | $ $ 343                  
Common Stock                    
Class of Stock [Line Items]                    
Common stock repurchases (shares)   0 7,500,000 30,400,000 0 37,900,000        
Common Shares in Treasury                    
Class of Stock [Line Items]                    
Repurchase of common shares | $     $ 124     $ 733        
Series A Preferred Stock                    
Class of Stock [Line Items]                    
Preferred stock authorized (in shares)   3,000,000     3,000,000          
Preferred stock outstanding (in shares)   0     0          
Preferred stock issued (in shares)   0     0          
Series B Preferred Stock                    
Class of Stock [Line Items]                    
Preferred stock authorized (in shares)   4,000,000     4,000,000          
Preferred stock outstanding (in shares)   0     0          
Preferred stock issued (in shares)   0     0