Financial Instruments - Derivative Instruments Notional Amount Outstanding (Detail) - USD ($) $ in Millions	Sep. 30, 2021	Dec. 31, 2020
Forward Contracts
Schedule Of Information By Major Category Of Credit Derivatives Contracts [Line Items]
Derivative instruments outstanding	$ 53	$ 221
Currency Swap
Schedule Of Information By Major Category Of Credit Derivatives Contracts [Line Items]
Derivative instruments outstanding	300	300
Commodity Contract
Schedule Of Information By Major Category Of Credit Derivatives Contracts [Line Items]
Derivative instruments outstanding	$ 23	$ 0