Net Interest And Other Financial Costs (Detail) - USD ($) $ in Millions		3 Months Ended
		Mar. 31, 2020	Mar. 31, 2019
Other Income and Expenses [Abstract]
Interest income		$ (6)	$ (9)
Interest expense		357	340
Interest capitalized		(36)	(32)
Pension and other postretirement non-service credits	[1]	(3)	(3)
Other financial costs		26	10
Net interest and other financial costs		$ 338	$ 306

[1] See Note 21.