v3.26.1
FAIR VALUE MEASUREMENT: (Details) - USD ($)
$ in Millions
Jun. 30, 2026
Dec. 31, 2025
Short term investment:    
Trading securities $ 1,664.8 $ 604.5
Fair value measurements recurring | Quoted prices in active markets for identical assets (Level 1)    
Short term investment:    
Trading securities 1,664.8 604.5
Embedded derivatives-Not classified as hedges:    
Total assets, fair value 3,301.3 2,366.2
Fair value measurements recurring | Quoted prices in active markets for identical assets (Level 1) | Copper    
Embedded derivatives-Not classified as hedges:    
Provisionally priced sales 1,112.9 1,297.5
Fair value measurements recurring | Quoted prices in active markets for identical assets (Level 1) | Molybdenum    
Embedded derivatives-Not classified as hedges:    
Provisionally priced sales 442.6 383.8
Fair value measurements recurring | Quoted prices in active markets for identical assets (Level 1) | Zinc    
Embedded derivatives-Not classified as hedges:    
Provisionally priced sales 81.0 80.3
Fair value measurements recurring | Significant other observable inputs (Level 2)    
Embedded derivatives-Not classified as hedges:    
Total assets, fair value 0.1 0.1
Fair value measurements recurring | Significant other observable inputs (Level 2) | Mortgage backed securities    
Available-for-sale debt securities:    
Available-for-sale debt securities 0.1 0.1
Carrying Value    
Liabilities:    
Total long-term debt 7,994.4 6,750.7
Carrying Value | Quoted prices in active markets for identical assets (Level 1)    
Liabilities:    
Total long-term debt 7,943.3 6,699.5
Carrying Value | Significant other observable inputs (Level 2)    
Liabilities:    
Total long-term debt 51.2 51.2
Fair Value    
Liabilities:    
Total long-term debt 8,136.4 7,064.6
Fair Value | Quoted prices in active markets for identical assets (Level 1)    
Liabilities:    
Total long-term debt 8,083.2 7,009.5
Fair Value | Significant other observable inputs (Level 2)    
Liabilities:    
Total long-term debt 53.2 55.1
Fair Value | Fair value measurements recurring    
Short term investment:    
Trading securities 1,664.8 604.5
Embedded derivatives-Not classified as hedges:    
Total assets, fair value 3,301.4 2,366.3
Fair Value | Fair value measurements recurring | Copper    
Embedded derivatives-Not classified as hedges:    
Provisionally priced sales 1,112.9 1,297.5
Fair Value | Fair value measurements recurring | Molybdenum    
Embedded derivatives-Not classified as hedges:    
Provisionally priced sales 442.6 383.8
Fair Value | Fair value measurements recurring | Zinc    
Embedded derivatives-Not classified as hedges:    
Provisionally priced sales 81.0 80.3
Fair Value | Fair value measurements recurring | Mortgage backed securities    
Available-for-sale debt securities:    
Available-for-sale debt securities $ 0.1 $ 0.1