Fair Value Measurements - Narrative (Details) - USD ($) $ in Millions	6 Months Ended
Jun. 30, 2021	Jun. 30, 2020	Dec. 31, 2020
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash flow hedge gain (loss)	$ 1	$ (5)
Derivative instruments	10		$ 11
Designated as Hedging Instrument \| Cash Flow Hedging \| Interest Rate Swap
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Notional amount	81		85
Other Liabilities \| Designated as Hedging Instrument \| Cash Flow Hedging
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative instruments	$ 7		$ 9

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, before tax and reclassification, of gain (loss) from derivative instrument designated and qualifying cash flow hedge included in assessment of hedge effectiveness.

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