XML 154 R130.htm IDEA: XBRL DOCUMENT v3.24.0.1
FINANCIAL INSTRUMENTS - Cash Flow Hedge Fair Value Reserve (Details) - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2023
Dec. 31, 2022
Dec. 31, 2021
Gain (Loss) Recognized in Cash Flow Hedge [Abstract]      
Total cash flow hedge assets $ (1.9) $ 23.5 $ 64.0
Unrealized gain (loss) recognized in cash flow hedge reserve (1.4) 29.7  
Realized (gain) loss reclassified or adjusted from cash flow hedge reserve (16.4) (45.5)  
Unrealized (gain) loss reclassified or adjusted from cash flow hedge reserve due to hedge de-designation   (17.3)  
Unrealized (gain) loss reclassified or adjusted from cash flow hedge reserve due to hedge de-designation (0.2) (17.3)  
Time value excluded from hedge relationship (7.4) (7.4)  
Current portion of hedge asset 7.3    
Non-current portion of hedge asset 0.0    
Current portion of hedge liability (9.2)    
Non-current portion of hedge liability 0.0    
Hedging Instrument, assets (liabilities) (1.9)    
Canadian dollar contracts      
Gain (Loss) Recognized in Cash Flow Hedge [Abstract]      
Total cash flow hedge assets 1.6 3.2 24.5
Unrealized gain (loss) recognized in cash flow hedge reserve 2.9 (13.1)  
Realized (gain) loss reclassified or adjusted from cash flow hedge reserve (4.4) (7.2)  
Unrealized (gain) loss reclassified or adjusted from cash flow hedge reserve due to hedge de-designation   0.0  
Unrealized (gain) loss reclassified or adjusted from cash flow hedge reserve due to hedge de-designation 0.0    
Time value excluded from hedge relationship (0.1) (1.0)  
Current portion of hedge asset 1.6    
Non-current portion of hedge asset 0.0    
Current portion of hedge liability 0.0    
Non-current portion of hedge liability 0.0    
Hedging Instrument, assets (liabilities) 1.6    
Oil contracts      
Gain (Loss) Recognized in Cash Flow Hedge [Abstract]      
Total cash flow hedge assets 5.7 20.4 38.5
Unrealized gain (loss) recognized in cash flow hedge reserve (1.4) 41.4  
Realized (gain) loss reclassified or adjusted from cash flow hedge reserve (12.2) (37.5)  
Unrealized (gain) loss reclassified or adjusted from cash flow hedge reserve due to hedge de-designation   (17.3)  
Unrealized (gain) loss reclassified or adjusted from cash flow hedge reserve due to hedge de-designation (0.2)    
Time value excluded from hedge relationship (0.9) (4.7)  
Current portion of hedge asset 5.7    
Non-current portion of hedge asset 0.0    
Current portion of hedge liability 0.0    
Non-current portion of hedge liability 0.0    
Hedging Instrument, assets (liabilities) 5.7    
Gold price contracts      
Gain (Loss) Recognized in Cash Flow Hedge [Abstract]      
Total cash flow hedge assets (9.2) (0.1) $ 1.0
Unrealized gain (loss) recognized in cash flow hedge reserve (2.9) 1.4  
Realized (gain) loss reclassified or adjusted from cash flow hedge reserve 0.2 (0.8)  
Unrealized (gain) loss reclassified or adjusted from cash flow hedge reserve due to hedge de-designation   0.0  
Unrealized (gain) loss reclassified or adjusted from cash flow hedge reserve due to hedge de-designation 0.0    
Time value excluded from hedge relationship (6.4) $ (1.7)  
Current portion of hedge asset 0.0    
Non-current portion of hedge asset 0.0    
Current portion of hedge liability (9.2)    
Non-current portion of hedge liability 0.0    
Hedging Instrument, assets (liabilities) $ (9.2)