v3.26.1
Fair value of financial instruments - Disclosure of significant observable inputs used in fair value measurement (Details) - USD ($)
$ in Thousands
Dec. 31, 2025
Dec. 31, 2024
Disclosure of fair value measurement of assets [line items]    
Total financial assets $ 175,118 $ 61,861
Warrants on equity securities and convertible notes [Member] | Publicly traded mining companies, Precious metals [Member]    
Disclosure of fair value measurement of assets [line items]    
Financial assets at fair value through profit or loss 12,275 6,534
Warrants on equity securities and convertible notes [Member] | Publicly traded mining companies, Other minerals [Member]    
Disclosure of fair value measurement of assets [line items]    
Financial assets at fair value through profit or loss   14
Equity securities [Member] | Publicly traded royalty and streaming companies [Member]    
Disclosure of fair value measurement of assets [line items]    
Financial assets at fair value through other comprehensive (loss) income 22,145  
Equity securities [Member] | Publicly traded mining companies, Precious metals [Member]    
Disclosure of fair value measurement of assets [line items]    
Financial assets at fair value through other comprehensive (loss) income 118,354 1,822
Equity securities [Member] | Publicly traded mining companies, Other minerals [Member]    
Disclosure of fair value measurement of assets [line items]    
Financial assets at fair value through other comprehensive (loss) income 21,753 53,353
Equity securities [Member] | Private mining companies [Member]    
Disclosure of fair value measurement of assets [line items]    
Financial assets at fair value through other comprehensive (loss) income 591 138
Level 1 [Member]    
Disclosure of fair value measurement of assets [line items]    
Total financial assets 162,252 55,186
Level 1 [Member] | Warrants on equity securities and convertible notes [Member] | Publicly traded mining companies, Precious metals [Member]    
Disclosure of fair value measurement of assets [line items]    
Financial assets at fair value through profit or loss 0 0
Level 1 [Member] | Warrants on equity securities and convertible notes [Member] | Publicly traded mining companies, Other minerals [Member]    
Disclosure of fair value measurement of assets [line items]    
Financial assets at fair value through profit or loss   11
Level 1 [Member] | Equity securities [Member] | Publicly traded royalty and streaming companies [Member]    
Disclosure of fair value measurement of assets [line items]    
Financial assets at fair value through other comprehensive (loss) income 22,145  
Level 1 [Member] | Equity securities [Member] | Publicly traded mining companies, Precious metals [Member]    
Disclosure of fair value measurement of assets [line items]    
Financial assets at fair value through other comprehensive (loss) income 118,354 1,822
Level 1 [Member] | Equity securities [Member] | Publicly traded mining companies, Other minerals [Member]    
Disclosure of fair value measurement of assets [line items]    
Financial assets at fair value through other comprehensive (loss) income 21,753 53,353
Level 1 [Member] | Equity securities [Member] | Private mining companies [Member]    
Disclosure of fair value measurement of assets [line items]    
Financial assets at fair value through other comprehensive (loss) income 0 0
Level 2 [Member]    
Disclosure of fair value measurement of assets [line items]    
Total financial assets 0 0
Level 2 [Member] | Warrants on equity securities and convertible notes [Member] | Publicly traded mining companies, Precious metals [Member]    
Disclosure of fair value measurement of assets [line items]    
Financial assets at fair value through profit or loss 0 0
Level 2 [Member] | Warrants on equity securities and convertible notes [Member] | Publicly traded mining companies, Other minerals [Member]    
Disclosure of fair value measurement of assets [line items]    
Financial assets at fair value through profit or loss   0
Level 2 [Member] | Equity securities [Member] | Publicly traded royalty and streaming companies [Member]    
Disclosure of fair value measurement of assets [line items]    
Financial assets at fair value through other comprehensive (loss) income 0  
Level 2 [Member] | Equity securities [Member] | Publicly traded mining companies, Precious metals [Member]    
Disclosure of fair value measurement of assets [line items]    
Financial assets at fair value through other comprehensive (loss) income 0 0
Level 2 [Member] | Equity securities [Member] | Publicly traded mining companies, Other minerals [Member]    
Disclosure of fair value measurement of assets [line items]    
Financial assets at fair value through other comprehensive (loss) income 0 0
Level 2 [Member] | Equity securities [Member] | Private mining companies [Member]    
Disclosure of fair value measurement of assets [line items]    
Financial assets at fair value through other comprehensive (loss) income 0 0
Level 3 [Member]    
Disclosure of fair value measurement of assets [line items]    
Total financial assets 12,866 6,675
Level 3 [Member] | Warrants on equity securities and convertible notes [Member] | Publicly traded mining companies, Precious metals [Member]    
Disclosure of fair value measurement of assets [line items]    
Financial assets at fair value through profit or loss 12,275 6,534
Level 3 [Member] | Warrants on equity securities and convertible notes [Member] | Publicly traded mining companies, Other minerals [Member]    
Disclosure of fair value measurement of assets [line items]    
Financial assets at fair value through profit or loss   3
Level 3 [Member] | Equity securities [Member] | Publicly traded royalty and streaming companies [Member]    
Disclosure of fair value measurement of assets [line items]    
Financial assets at fair value through other comprehensive (loss) income 0  
Level 3 [Member] | Equity securities [Member] | Publicly traded mining companies, Precious metals [Member]    
Disclosure of fair value measurement of assets [line items]    
Financial assets at fair value through other comprehensive (loss) income 0 0
Level 3 [Member] | Equity securities [Member] | Publicly traded mining companies, Other minerals [Member]    
Disclosure of fair value measurement of assets [line items]    
Financial assets at fair value through other comprehensive (loss) income 0 0
Level 3 [Member] | Equity securities [Member] | Private mining companies [Member]    
Disclosure of fair value measurement of assets [line items]    
Financial assets at fair value through other comprehensive (loss) income $ 591 $ 138