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IMPAIRMENT TESTING (Details) - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2019
Dec. 31, 2018
Dec. 31, 2017
IMPAIRMENT TESTING      
Projected cash flows calculation period 10 years    
Percentage of Inflation 2.00%    
Impairment charge arising in current year $ 71    
Discount rate used in calculation based on a Weighted Average Cost of Capital (WACC) 7.50% 8.30% 8.70%