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FAIR VALUE OF FINANCIAL INSTRUMENTS (Debt Narrative) (Detail) - USD ($)
$ in Millions
Dec. 31, 2017
Dec. 31, 2016
Estimated Fair Value    
Debt Instrument [Line Items]    
Long-term Debt, Percentage Bearing Fixed Interest, Amount $ 822 $ 961
Carrying Value    
Debt Instrument [Line Items]    
Long-term Debt, Percentage Bearing Fixed Interest, Amount $ 799 $ 949