XML 113 R82.htm IDEA: XBRL DOCUMENT v3.19.1
Impairment (Charges) Reversals and Goodwill - Key Assumptions and Sensitivity Analysis (Details)
 12 Months Ended
Dec. 31, 2018
$ / Ounce
$ / tonne
Dec. 31, 2017
$ / Ounce
$ / tonne
Disclosure of impairment loss and reversal of impairment loss [line items]    
Weighted average cost of capital, significant unobservable inputs, assets 5.30% 5.20%
Bottom of range [member]    
Disclosure of impairment loss and reversal of impairment loss [line items]    
Discount rate applied to cash flow projections 4.50% 4.00%
Top of range [member]    
Disclosure of impairment loss and reversal of impairment loss [line items]    
Discount rate applied to cash flow projections 9.80% 9.00%
Silver, Ounces    
Disclosure of impairment loss and reversal of impairment loss [line items]    
Metal prices used to calculate recoverable amounts | $ / Ounce 18.50 18.50
Silver, Ounces | Weighted average [member]    
Disclosure of impairment loss and reversal of impairment loss [line items]    
Metal prices used to calculate recoverable amounts | $ / Ounce 17.07 18.57
Gold, Ounces    
Disclosure of impairment loss and reversal of impairment loss [line items]    
Metal prices used to calculate recoverable amounts | $ / Ounce 1,300 1,300
Gold, Ounces | Weighted average [member]    
Disclosure of impairment loss and reversal of impairment loss [line items]    
Metal prices used to calculate recoverable amounts | $ / Ounce 1,300 1,307
Zinc [member]    
Disclosure of impairment loss and reversal of impairment loss [line items]    
Metal prices used to calculate recoverable amounts 2,400 2,600
Zinc [member] | Weighted average [member]    
Disclosure of impairment loss and reversal of impairment loss [line items]    
Metal prices used to calculate recoverable amounts 2,599 2,818
Copper [member]    
Disclosure of impairment loss and reversal of impairment loss [line items]    
Metal prices used to calculate recoverable amounts 6,000 5,500
Copper [member] | Weighted average [member]    
Disclosure of impairment loss and reversal of impairment loss [line items]    
Metal prices used to calculate recoverable amounts 6,975 6,742
Lead [member]    
Disclosure of impairment loss and reversal of impairment loss [line items]    
Metal prices used to calculate recoverable amounts 2,100 2,200
Lead [member] | Weighted average [member]    
Disclosure of impairment loss and reversal of impairment loss [line items]    
Metal prices used to calculate recoverable amounts 2,171 2,251