v3.25.4
Fair Value Measurements (Details)
12 Months Ended
Dec. 31, 2025
USD ($)
EquityInstruments
Dec. 31, 2024
USD ($)
Fair value measurements    
Transfer from Level 1 to 2 of financial assets $ 0  
Transfer from Level 2 to 1 of financial assets 0  
Transfer from Level 1 to 2 of financial liabilities 0  
Transfer from Level 2 to 1 of financial liabilities 0  
Transfers Into Level 3 of financial assets 0  
Transfers Out of Level 3 of financial assets 0  
Transfers Into Level 3 of financial liabilities 0  
Transfers Out of Level 3 of financial liabilities $ 0  
Number of investments with no quoted market price in an active market | EquityInstruments 2  
Recurring Basis    
Fair value measurements    
Financial assets, at fair value $ 1,147,900,000 $ 328,100,000
Recurring Basis | Level 1    
Fair value measurements    
Financial assets, at fair value 1,093,300,000 316,800,000
Recurring Basis | Level 2    
Fair value measurements    
Financial assets, at fair value 42,600,000 3,300,000
Recurring Basis | Level 3    
Fair value measurements    
Financial assets, at fair value 12,000,000 8,000,000
Receivables from provisional concentrate sales | Recurring Basis    
Fair value measurements    
Financial assets, at fair value 6,600,000 2,600,000
Receivables from provisional concentrate sales | Recurring Basis | Level 2    
Fair value measurements    
Financial assets, at fair value 6,600,000 2,600,000
Equity investments | Recurring Basis    
Fair value measurements    
Financial assets, at fair value 1,105,300,000 324,800,000
Equity investments | Recurring Basis | Level 1    
Fair value measurements    
Financial assets, at fair value 1,093,300,000 316,800,000
Equity investments | Recurring Basis | Level 3    
Fair value measurements    
Financial assets, at fair value 12,000,000 8,000,000
Warrants | Recurring Basis    
Fair value measurements    
Financial assets, at fair value 36,000,000 700,000
Warrants | Recurring Basis | Level 2    
Fair value measurements    
Financial assets, at fair value $ 36,000,000 $ 700,000