v3.25.2
Investments (Details) - USD ($)
$ in Millions
3 Months Ended 6 Months Ended
Jun. 30, 2025
Jun. 30, 2024
Jun. 30, 2025
Jun. 30, 2024
Dec. 31, 2024
Investments          
Investments $ 597.8   $ 597.8   $ 325.5
Equity method investments 590.4   590.4   324.8
Equity investments          
Investments          
Investments 590.4   590.4   324.8
Cost of equity investments disposed of 8.9 $ 0.7 14.6 $ 12.3  
Gross proceeds from disposal 15.8 1.1 25.5 8.5  
Unrealized gains (loss) on available-for-sale investments          
Net gain on changes in the fair value of equity investments at FVTOCI 35.9 17.8 207.4 19.8  
Income tax expense in other comprehensive (loss) income (4.7) (2.4) (27.4) (2.6)  
Gain on changes in the fair value of equity investments at FVTOCI, net of income tax 31.2 $ 15.4 180.0 $ 17.2  
G Mining Ventures Corp.          
Investments          
Equity method investments 232.3   232.3   133.8
Discovery Silver Corp.          
Investments          
Equity method investments 172.2   172.2    
Labrador Iron Ore Royalty Corporation          
Investments          
Equity method investments 131.7   131.7   127.3
Other          
Investments          
Equity method investments 54.2   54.2   63.7
Warrants          
Investments          
Investments $ 7.4   $ 7.4   $ 0.7