Derivative Financial Instruments - Fair Value of Derivatives (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Cash Flow Hedging \| Interest rate swaps \| Designated as Hedging Instrument
Derivatives, Fair Value [Line Items]
Fair Value	$ 107	$ 51

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.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
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Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
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Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
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Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
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-URI http://asc.fasb.org/extlink&oid=99393222&loc=SL20226000-175313

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant