Investments - Funds Held by Reinsured Companies (Details) - USD ($) $ in Millions	3 Months Ended
Mar. 31, 2025	Dec. 31, 2024	Mar. 31, 2024	Dec. 31, 2023
Debt Securities, Available-for-sale [Line Items]
Funds held by reinsurance companies, at amortized cost	$ 2,315	$ 2,528
Funds held by reinsured companies	2,319	2,533
Funds held by reinsurance company, period decrease	(214)
Embedded derivatives
Debt Securities, Available-for-sale [Line Items]
Fair value of embedded derivative	$ 4	$ 5	$ 22	$ 40

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.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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Reference 2: http://www.xbrl.org/2003/role/disclosureRef
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Reference 3: http://www.xbrl.org/2003/role/disclosureRef
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+ Details