XML 370 R112.htm IDEA: XBRL DOCUMENT v3.23.1
Impairment, Net of Reversal of Impairment of Investments and Assets - Summary of Impairment, Net of Reversal of Impairment of Investments and Assets (Detail) - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2022
Dec. 31, 2021
Dec. 31, 2020
Disclosures of impairment of investments and assets [line items]      
Investments $ 113.6 $ 30.8 $ (62.3)
Impairment loss recognised in profit or loss, property, plant and equipment 391.4 11.6 11.7
Impairment, net of reversal of impairment of investments and assets (505.0) (42.4) 50.6
Total equity accounted investees $ 84.9 178.8  
Lepanto Consolidated Mining Company      
Disclosures of impairment of investments and assets [line items]      
Interest in subsidiary 60.00%    
Far Southeast Gold Resources Incorporated ("FSE")      
Disclosures of impairment of investments and assets [line items]      
Total equity accounted investees $ 0.0    
Peru cash-generating unit      
Disclosures of impairment of investments and assets [line items]      
Impairment loss recognised in profit or loss, property, plant and equipment $ 63.1 $ 0.0 0.0
Discount rate applied to cash flow projections 8.10% 4.80%  
Recoverable amount of asset or cash-generating unit $ 477.1    
Tarkwa cash-generating unit      
Disclosures of impairment of investments and assets [line items]      
Impairment loss recognised in profit or loss, property, plant and equipment $ 325.2 $ 0.0 0.0
Discount rate applied to cash flow projections 15.90% 8.30%  
Recoverable amount of asset or cash-generating unit $ 812.4    
Impairment of property, plant and equipment - other      
Disclosures of impairment of investments and assets [line items]      
Impairment loss recognised in profit or loss, property, plant and equipment 3.1 $ 11.6 11.7
Capitalised exploration costs      
Disclosures of impairment of investments and assets [line items]      
Impairment loss recognised in profit or loss, property, plant and equipment 0.0 10.0 0.0
Drilling costs | Damang      
Disclosures of impairment of investments and assets [line items]      
Impairment loss recognised in profit or loss, property, plant and equipment 0.0 0.0 9.8
Redundant assets in Peru      
Disclosures of impairment of investments and assets [line items]      
Impairment loss recognised in profit or loss, property, plant and equipment 2.5 1.6 1.9
Redundant Assets In Chile      
Disclosures of impairment of investments and assets [line items]      
Impairment loss recognised in profit or loss, property, plant and equipment 0.6 0.0 0.0
Far Southeast Gold Resources Incorporated (FSE)      
Disclosures of impairment of investments and assets [line items]      
Investments $ 113.6 $ 30.8 $ (62.3)
Far Southeast Gold Resources Incorporated (FSE) | Lepanto Consolidated Mining Company      
Disclosures of impairment of investments and assets [line items]      
Interest in subsidiary   60.00%