XML 139 R109.htm IDEA: XBRL DOCUMENT v3.21.1
INCOME TAX EXPENSE - Reconciliation of tax rate (Details)
 12 Months Ended
Dec. 31, 2020
Dec. 31, 2019
Reconciliation of average effective tax rate and applicable tax rate    
Combined statutory income tax rate (as a percent) 26.50% 26.50%
Increase (decrease) resulting from:    
Mining taxes 1.70% 1.20%
Percentage of depletion (0.90%) (1.40%)
Difference in foreign tax rates and foreign exchange on deferred income taxes within income tax expense (as a percent) 5.50% 4.50%
Change in unrecognized deferred tax assets (as a percent) (0.40%) (4.10%)
Over provided in prior periods (as a percent)   (0.40%)
Income not subject to tax (as a percent) (0.70%) (0.70%)
Effect of non-taxable impairment reversals (as a percent) (6.90%) (4.20%)
Accounting expenses disallowed for tax (as a percent) 1.70% 2.30%
Taxes on repatriation of foreign earnings (as a percent) 0.10% 0.50%
Impact of CARES Act (1.40%)  
AMT credit receivable due to U.S.Tax Reform (as a percent)   (0.50%)
Other (as a percent) (0.70%) 1.90%
Effective tax rate (as a percent) 24.50% 25.60%