Investments - Schedule of Net Appreciation (Decline) Recognized in Net Income (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Debt and Equity Securities, FV-NI [Line Items]
Total	$ 35	$ 51	$ 125	$ 114
Equity securities
Debt and Equity Securities, FV-NI [Line Items]
Total	18	19	78	66
Limited partnership interests carried at fair value
Debt and Equity Securities, FV-NI [Line Items]
Total	$ 17	$ 32	$ 47	$ 48