FAIR VALUE OF FINANCIAL INSTRUMENTS Estimated Fair Values and Carrying Values of Long-Term Debt (Detail) - USD ($) $ in Millions	Sep. 30, 2018	Dec. 31, 2017
FAIR VALUE OF FINANCIAL INSTRUMENTS [Line Items]
Long-term debt, including current maturities	$ 5,921	$ 5,992
Fair Value, Inputs, Level 2
FAIR VALUE OF FINANCIAL INSTRUMENTS [Line Items]
Long-term debt, fair value	6,603	7,048
Fixed interest rate
FAIR VALUE OF FINANCIAL INSTRUMENTS [Line Items]
Long-term debt, including current maturities	5,697	5,768
Fixed interest rate | Fair Value, Inputs, Level 2
FAIR VALUE OF FINANCIAL INSTRUMENTS [Line Items]
Long-term debt, fair value	6,378	6,823
Variable interest rate
FAIR VALUE OF FINANCIAL INSTRUMENTS [Line Items]
Long-term debt, including current maturities	224	224
Variable interest rate | Fair Value, Inputs, Level 2
FAIR VALUE OF FINANCIAL INSTRUMENTS [Line Items]
Long-term debt, fair value	$ 225	$ 225