Insurance and Contractholder Liabilities - Net Amount of Risk and Average Age of Contractholders (Details) - Variable Annuity - USD ($) $ in Millions	9 Months Ended
Sep. 30, 2024	Sep. 30, 2023
Net Amount at Risk by Product and Guarantee [Line Items]
Net amount at risk	$ 1,361	$ 1,986
Average attained age of contractholders (weighted by exposure)	77 years 7 months 6 days	75 years 10 months 24 days

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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Net amount at risk, representing the guaranteed benefit in excess of the current account balance corresponding to the specified product, guarantee type and subset of the guarantee.

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Weighted average attained age of policyholders or contract holders in the specified guarantee type and subset of guarantee class, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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