Derivatives and Other Financial Instruments - Schedule of Carrying Values and Fair Values of Other Financial Instruments (Detail) - USD ($) $ in Millions	Jun. 30, 2020	Dec. 31, 2019
Carrying Value [Member]
Derivative [Line Items]
Cash and cash equivalents	$ 965	$ 879
Restricted cash	3	4
Long-term debt due within one year	1	1
Long-term debt, less amount due within one year	1,800	1,799
Fair Value [Member]
Derivative [Line Items]
Cash and cash equivalents	965	879
Restricted cash	3	4
Long-term debt due within one year	1	1
Long-term debt, less amount due within one year	$ 1,896	$ 1,961