XML 109 R66.htm IDEA: XBRL DOCUMENT v3.20.1
Fair value measurements (Details)
12 Months Ended
Dec. 31, 2019
USD ($)
EquityInstruments
Dec. 31, 2018
USD ($)
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  
Assets $ 5,280,600,000 $ 4,931,800,000
Number of investments with no quoted market price in an active market | EquityInstruments 1  
Recurring Basis    
Fair value measurements    
Financial assets, at fair value $ 165,000,000 145,900,000
Recurring Basis | Level 1    
Fair value measurements    
Financial assets, at fair value 141,700,000 132,800,000
Recurring Basis | Level 2    
Fair value measurements    
Financial assets, at fair value 19,400,000 9,200,000
Recurring Basis | Level 3    
Fair value measurements    
Financial assets, at fair value 3,900,000 3,900,000
Non recurring Basis    
Fair value measurements    
Financial assets, at fair value   14,600,000
Non recurring Basis | Level 3    
Fair value measurements    
Financial assets, at fair value   14,600,000
Receivables from provisional concentrate sales | Recurring Basis    
Fair value measurements    
Financial assets, at fair value 16,400,000 8,500,000
Receivables from provisional concentrate sales | Recurring Basis | Level 2    
Fair value measurements    
Financial assets, at fair value 16,400,000 8,500,000
Equity investments | Recurring Basis    
Fair value measurements    
Financial assets, at fair value 145,600,000 136,700,000
Equity investments | Recurring Basis | Level 1    
Fair value measurements    
Financial assets, at fair value 141,700,000 132,800,000
Equity investments | Recurring Basis | Level 3    
Fair value measurements    
Financial assets, at fair value 3,900,000 3,900,000
Warrants | Recurring Basis    
Fair value measurements    
Financial assets, at fair value 3,000,000 700,000
Warrants | Recurring Basis | Level 2    
Fair value measurements    
Financial assets, at fair value $ 3,000,000 700,000
Royalty stream and working interests | Non recurring Basis    
Fair value measurements    
Financial assets, at fair value   14,600,000
Royalty stream and working interests | Non recurring Basis | Level 3    
Fair value measurements    
Financial assets, at fair value   $ 14,600,000