Investments - Schedule of Net Appreciation (Decline) Recognized in Net Income (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
Sep. 30, 2026	Sep. 30, 2025	Sep. 30, 2026	Sep. 30, 2025
Debt and Equity Securities, FV-NI [Line Items]
Total	$ (31)	$ 194	$ 621	$ 278
Equity securities
Debt and Equity Securities, FV-NI [Line Items]
Total	(46)	178	614	291
Limited partnership interests carried at fair value
Debt and Equity Securities, FV-NI [Line Items]
Total	$ 15	$ 16	$ 7	$ (13)

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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+ Details