Fair Value of Financial Instruments - Schedule of Interest Rate Swaps Outstanding (Detail) - Interest Rate Swaps [Member] - USD ($) $ in Millions	3 Months Ended	6 Months Ended
Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020	Dec. 31, 2020
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Aggregate Notional Amount	$ 317		$ 317		$ 554
Gross Asset at Fair Value	0		0		0
Gross Liability at Fair Value	37		37		$ 58
Gross losses	9	$ 3	9	$ 42
Gross gains	$ 0	$ 0	$ 20	$ 0

Fair value, before effects of master netting arrangements, of a financial liability or contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes liabilities elected not to be offset. Excludes liabilities not subject to a master netting arrangement.

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Amount of increase in the fair value of derivatives recognized in the income statement.

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Fair value of asset associated with financial liability or contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset.

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Amount of decrease in the fair value of derivatives recognized in the income statement.

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Nominal or face amount used to calculate payment on derivative.

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