FAIR VALUE OF FINANCIAL INSTRUMENTS Estimated Fair Values and Carrying Values of Long-Term Debt (Detail) - USD ($) $ in Millions	Sep. 30, 2019	Dec. 31, 2018
FAIR VALUE OF FINANCIAL INSTRUMENTS
Long-term debt (including current maturities) and line of credit, carrying value	$ 6,590	$ 6,344
Long-term debt (including current maturities) and line of credit, fair value (Level 2)	7,706	6,995
Fixed interest rate
FAIR VALUE OF FINANCIAL INSTRUMENTS
Long-term debt (including current maturities) and line of credit, carrying value	5,925	5,694
Long-term debt (including current maturities) and line of credit, fair value (Level 2)	7,041	6,345
Variable interest rate
FAIR VALUE OF FINANCIAL INSTRUMENTS
Long-term debt (including current maturities) and line of credit, carrying value	665	650
Long-term debt (including current maturities) and line of credit, fair value (Level 2)	$ 665	$ 650