Derivative Financial Instruments - Narrative (Details) $ in Millions	12 Months Ended
Dec. 31, 2023 USD ($) contract	Dec. 31, 2022 USD ($) contract
All Counterparties Except Merrill Lynch
Derivative [Line Items]
Counterparties, collateral required threshold	0.00%
Embedded derivatives
Derivative [Line Items]
Term of contract, term one	1 year
Term of contract, term two	2 years
Term of contract, term three	3 years
Term of contract, term four	5 years
Call options \| Derivatives for Trading and Investment \| Not Designated as Hedging Instrument
Derivative [Line Items]
Collateral posted		$ 219
Maximum amount of loss due to credit risk	$ 39	33
Call options \| Cash and Cash Equivalents \| Not Designated as Hedging Instrument
Derivative [Line Items]
Collateral posted	$ 588	$ 178
Futures contracts
Derivative [Line Items]
Number of instruments held \| contract	439,000,000	409,000,000
Collateral held	$ 4	$ 3

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Derivative, Term of Contract, Term One

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Derivatives, Collateral, Net Exposure Threshold for Which Collateral Required

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The aggregate fair value of assets that are already posted, at the end of the reporting period, as collateral for derivative instruments with credit-risk-related contingent features.

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Amount of obligation to return cash collateral under master netting arrangements offset against derivative assets.

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Fair value, after effect of master netting arrangement and deduction of obligation to return financial collateral not offset and financial instrument subject to master netting arrangement not offset, of financial asset or other contract with one or more underlyings, notional amount or payment provision or both, and contract can be net settled by means outside contract or delivery of asset. Includes derivative not subject to master netting arrangement or similar agreement.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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The number of derivative instruments of a particular group held by the entity.

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