FAIR VALUE OF FINANCIAL INSTRUMENTS Estimated Fair Values and Carrying Values of Long-Term Debt (Detail) - USD ($) $ in Millions	Mar. 31, 2020	Dec. 31, 2019
FAIR VALUE OF FINANCIAL INSTRUMENTS
Long-term debt (including current maturities) and line of credit, carrying value	$ 7,426	$ 6,377
Long-term debt (including current maturities) and line of credit, fair value (Level 2)	8,008	7,441
Fixed interest rate
FAIR VALUE OF FINANCIAL INSTRUMENTS
Long-term debt (including current maturities) and line of credit, carrying value	6,651	5,922
Long-term debt (including current maturities) and line of credit, fair value (Level 2)	7,233	6,986
Variable interest rate
FAIR VALUE OF FINANCIAL INSTRUMENTS
Long-term debt (including current maturities) and line of credit, carrying value	775	455
Long-term debt (including current maturities) and line of credit, fair value (Level 2)	$ 775	$ 455