v3.25.2
Fair Value Measurements (Details) - USD ($)
3 Months Ended 6 Months Ended
Jun. 30, 2025
Jun. 30, 2025
Dec. 31, 2024
Fair value measurements      
Transfer from Level 1 to 2 of financial assets $ 0 $ 0  
Transfer from Level 2 to 1 of financial assets 0 0  
Transfer from Level 1 to 2 of financial liabilities 0 0  
Transfer from Level 2 to 1 of financial liabilities 0 0  
Transfers Into Level 3 of financial assets 0 0  
Transfers Out of Level 3 of financial assets 0 0  
Transfers Into Level 3 of financial liabilities 0 0  
Transfers Out of Level 3 of financial liabilities 0 0  
Recurring Basis      
Fair value measurements      
Financial assets, at fair value 601,900,000 601,900,000 $ 328,100,000
Recurring Basis | Level 1      
Fair value measurements      
Financial assets, at fair value 581,600,000 581,600,000 316,800,000
Recurring Basis | Level 2      
Fair value measurements      
Financial assets, at fair value 11,500,000 11,500,000 3,300,000
Recurring Basis | Level 3      
Fair value measurements      
Financial assets, at fair value 8,800,000 8,800,000 8,000,000
Receivables from provisional concentrate sales | Recurring Basis      
Fair value measurements      
Financial assets, at fair value 4,100,000 4,100,000 2,600,000
Receivables from provisional concentrate sales | Recurring Basis | Level 2      
Fair value measurements      
Financial assets, at fair value 4,100,000 4,100,000 2,600,000
Equity investments | Recurring Basis      
Fair value measurements      
Financial assets, at fair value 590,400,000 590,400,000 324,800,000
Equity investments | Recurring Basis | Level 1      
Fair value measurements      
Financial assets, at fair value 581,600,000 581,600,000 316,800,000
Equity investments | Recurring Basis | Level 3      
Fair value measurements      
Financial assets, at fair value 8,800,000 8,800,000 8,000,000
Warrants | Recurring Basis      
Fair value measurements      
Financial assets, at fair value 7,400,000 7,400,000 700,000
Warrants | Recurring Basis | Level 2      
Fair value measurements      
Financial assets, at fair value $ 7,400,000 $ 7,400,000 $ 700,000