Investments - Schedule of Net Appreciation (Decline) Recognized in Net Income for Assets that are Still Held (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Debt and Equity Securities, FV-NI [Line Items]
Total	$ 113	$ 236	$ (471)
Equity securities
Debt and Equity Securities, FV-NI [Line Items]
Total	37	151	(466)
Limited partnership interests carried at fair value
Debt and Equity Securities, FV-NI [Line Items]
Total	$ 76	$ 85	$ (5)