Investments - Schedule of Net Appreciation (Decline) Recognized in Net Income (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Debt and Equity Securities, FV-NI [Line Items]
Total	$ (13)	$ (245)	$ 98	$ (763)
Equity securities
Debt and Equity Securities, FV-NI [Line Items]
Total	(32)	(209)	31	(771)
Limited partnership interests carried at fair value
Debt and Equity Securities, FV-NI [Line Items]
Total	$ 19	$ (36)	$ 67	$ 8