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SIGNIFICANT JUDGMENTS, ESTIMATES AND ASSUMPTIONS (Details)
 12 Months Ended
Dec. 31, 2019
$ / oz
$ / bbl
Dec. 31, 2018
$ / oz
$ / bbl
Estimated short-term and long-term prices of gold | $ / oz 1,400 1,300
Estimated short-term and long-term prices of silver | $ / oz 17.50 18.00
Estimated short-term and long-term oil prices 60  
Estimated short-term oil price   65
Estimated long-term oil price   55
Minimum    
Cash flow projection, term 3 years  
Minimum | CGU    
Real discount rate 3.33% 4.86%
NAV multiples observed 0.80% 0.90%
Maximum    
Cash flow projection, term 18 years  
Maximum | CGU    
Real discount rate 6.97% 7.12%
NAV multiples observed 1.70% 1.40%