XML 116 R79.htm IDEA: XBRL DOCUMENT v3.19.1
PROVISIONS (Details) - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2018
Dec. 31, 2017
Provisions reconciliation    
Provisions at beginning of period $ 897.0  
Additions 65.9  
Reductions (36.9)  
Reclamation spending (58.1)  
Accretion 29.1  
Reclamation recovery (8.0)  
Provisions at end of period 889.0 $ 897.0
Current portion 72.6  
Non-current portion 816.4  
Reclamation and remediation obligations    
Provisions reconciliation    
Provisions at beginning of period 861.4  
Additions 53.7  
Reductions (24.0)  
Reclamation spending (58.1)  
Accretion 29.1  
Reclamation recovery (8.0)  
Provisions at end of period 854.1 861.4
Current portion 63.6  
Non-current portion 790.5  
Expense due to change in fair value 8.0 11.4
Letter of credit issued to various agencies 366.7 411.5
Surety bonds $ 264.4 $ 254.7
Reclamation and remediation obligations | Minimum    
Provisions reconciliation    
Discount rate used in estimating site restoration cost obligation (in percent) 2.50% 1.80%
Inflation rate used in estimating the site restoration cost obligation (in percent) 2.10% 1.80%
Reclamation and remediation obligations | Maximum    
Provisions reconciliation    
Discount rate used in estimating site restoration cost obligation (in percent) 12.30% 11.60%
Inflation rate used in estimating the site restoration cost obligation (in percent) 5.10% 5.00%
Other    
Provisions reconciliation    
Provisions at beginning of period $ 35.6  
Additions 12.2  
Reductions (12.9)  
Provisions at end of period 34.9 $ 35.6
Current portion 9.0  
Non-current portion $ 25.9