Investments - Net appreciation (decline) recognized in net income (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Debt and Equity Securities, FV-NI [Line Items]
Total	$ 36	$ (54)
Equity securities
Debt and Equity Securities, FV-NI [Line Items]
Total	20	(92)
Limited partnership interests carried at fair value
Debt and Equity Securities, FV-NI [Line Items]
Total	$ 16	$ 38