Derivative Financial Instruments - Fair Value of Derivatives (Details) - USD ($) $ in Millions	Jun. 30, 2021	Dec. 31, 2020
Cash Flow Hedging \| Interest Rate Swap \| Designated as Hedging Instrument
Derivatives, Fair Value [Line Items]
Fair Value	$ 67	$ 107

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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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant