Investments - Schedule of Net Appreciation (Decline) Recognized in Net Income (Details) - USD ($) $ in Millions	3 Months Ended
Mar. 31, 2025	Mar. 31, 2024
Debt and Equity Securities, FV-NI [Line Items]
Total	$ (112)	$ 91
Equity securities
Debt and Equity Securities, FV-NI [Line Items]
Total	(95)	61
Limited partnership interests carried at fair value
Debt and Equity Securities, FV-NI [Line Items]
Total	$ (17)	$ 30

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
-Topic 820
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 6B
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482106/820-10-50-6B

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