Annual report pursuant to Section 13 and 15(d)

DEBT AND CREDIT FACILITIES - Debt Issuances and Terms (Details)

v3.22.0.1
DEBT AND CREDIT FACILITIES - Debt Issuances and Terms (Details)
$ / shares in Units, $ in Millions
3 Months Ended 12 Months Ended
Oct. 15, 2021
USD ($)
Mar. 11, 2021
USD ($)
Apr. 24, 2020
USD ($)
Sep. 30, 2021
USD ($)
Jun. 30, 2021
USD ($)
Dec. 31, 2021
USD ($)
$ / shares
shares
Dec. 31, 2020
USD ($)
$ / shares
shares
Dec. 31, 2019
USD ($)
Feb. 17, 2021
USD ($)
Feb. 11, 2021
shares
Debt Instrument [Line Items]                    
Debt Extinguished     $ 736     $ 1,306 $ 1,513 $ 724    
Common shares, issued (in shares) | shares           506,832,537 506,832,537     20,000,000
Common shares, par value (in dollars per share) | $ / shares           $ 0.125 $ 0.125      
Total Principal Amount           $ 5,369        
AK Steel                    
Debt Instrument [Line Items]                    
Total Principal Amount           56        
9.875% 2025 Senior Secured Notes                    
Debt Instrument [Line Items]                    
Debt Extinguished   $ 322     $ 25 $ 347        
9.875% 2025 Senior Secured Notes | Cleveland-Cliffs Inc.                    
Debt Instrument [Line Items]                    
Repurchase price if triggering event occurs           101.00%        
Stated interest rate           9.875% 9.875%      
Total Principal Amount           $ 607 $ 955      
6.750% 2026 Senior Secured Notes | Cleveland-Cliffs Inc.                    
Debt Instrument [Line Items]                    
Stated interest rate           6.75% 6.75%      
Total Principal Amount           $ 845 $ 845      
4.625% 2029 Senior Notes | Cleveland-Cliffs Inc.                    
Debt Instrument [Line Items]                    
Repurchase price if triggering event occurs           101.00%        
Stated interest rate           4.625%        
Total Principal Amount           $ 500     $ 500  
4.875% 2031 Senior Notes | Cleveland-Cliffs Inc.                    
Debt Instrument [Line Items]                    
Repurchase price if triggering event occurs           101.00%        
Stated interest rate           4.875%        
Total Principal Amount           $ 500     $ 500  
1.500% 2025 Convertible Senior Notes                    
Debt Instrument [Line Items]                    
Redemption price, percentage           100.00%        
Debt Extinguished       $ 2   $ 2 $ 20      
Convertible debt, threshold percentage of stock price trigger, five-day trading           0.98        
Conversion ratio           129.2985   122.4365    
Convertible debt, initial conversion price (in dollars per share) | $ / shares           $ 8.17        
Convertible debt, equity component           $ 86        
1.500% 2025 Convertible Senior Notes | Minimum                    
Debt Instrument [Line Items]                    
Threshold percentage of stock price trigger           130.00%        
1.500% 2025 Convertible Senior Notes | Cleveland-Cliffs Inc.                    
Debt Instrument [Line Items]                    
Stated interest rate           1.50% 1.50%      
Total Principal Amount           $ 294 $ 296      
7.000% 2027 Senior Notes                    
Debt Instrument [Line Items]                    
Debt Extinguished             $ 262      
7.000% 2027 Senior Notes | Cleveland-Cliffs Inc.                    
Debt Instrument [Line Items]                    
Stated interest rate           7.00% 7.00%      
Total Principal Amount           $ 73 $ 73      
5.875% 2027 Senior Notes                    
Debt Instrument [Line Items]                    
Debt Extinguished             $ 195      
5.875% 2027 Senior Notes | Cleveland-Cliffs Inc.                    
Debt Instrument [Line Items]                    
Repurchase price if triggering event occurs           101.00%        
Stated interest rate           5.875% 5.875%      
Total Principal Amount           $ 556 $ 556 $ 750    
6.250% 2040 Senior Notes                    
Debt Instrument [Line Items]                    
Debt Extinguished             $ 36      
6.250% 2040 Senior Notes | Cleveland-Cliffs Inc.                    
Debt Instrument [Line Items]                    
Repurchase price if triggering event occurs           101.00%        
Stated interest rate           6.25% 6.25%      
Total Principal Amount           $ 263 $ 263      
4.875% 2021 Senior Notes                    
Debt Instrument [Line Items]                    
Debt Extinguished               124    
6.375% 2025 Senior Notes                    
Debt Instrument [Line Items]                    
Debt Extinguished           64 $ 168      
6.375% 2025 Senior Notes | Cleveland-Cliffs Inc.                    
Debt Instrument [Line Items]                    
Stated interest rate             6.375%      
Total Principal Amount             $ 64      
5.750% 2025 Senior Notes                    
Debt Instrument [Line Items]                    
Debt Extinguished         $ 396 $ 396 $ 77 $ 600    
5.750% 2025 Senior Notes | Cleveland-Cliffs Inc.                    
Debt Instrument [Line Items]                    
Repurchase price if triggering event occurs           101.00%        
Stated interest rate             5.75%      
Total Principal Amount             $ 396      
4.875% 2024 Senior Secured Notes                    
Debt Instrument [Line Items]                    
Debt Extinguished           $ 395 $ 6      
4.875% 2024 Senior Secured Notes | Cleveland-Cliffs Inc.                    
Debt Instrument [Line Items]                    
Stated interest rate             4.875%      
Total Principal Amount             $ 395      
Industrial Revenue Bonds                    
Debt Instrument [Line Items]                    
Debt Extinguished $ 26         26        
Industrial Revenue Bonds | AK Steel                    
Debt Instrument [Line Items]                    
Total Principal Amount           $ 66 $ 92      
Weighted average fixed rate           6.86%