Investments - Investment Gains (Losses) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Investment Gains (Losses) [Abstract]
Investment losses recognized due to the change in fair value of non-redeemable preferred stock held as of March 31, 2023 and 2022	$ (35)	$ (11)
Nonredeemable Preferred Stock
Investment Gains (Losses) [Abstract]
Investment losses recognized due to the change in fair value of non-redeemable preferred stock held as of March 31, 2023 and 2022	(2)	(38)
Fixed maturity securities
Investment Gains (Losses) [Abstract]
Gross gains	35	26
Gross losses	(57)	(28)
Investment losses recognized due to the change in fair value of non-redeemable preferred stock held as of March 31, 2023 and 2022	(22)	(2)
Equity securities
Investment Gains (Losses) [Abstract]
Investment losses recognized due to the change in fair value of non-redeemable preferred stock held as of March 31, 2023 and 2022	(14)	(38)
Derivative instruments
Investment Gains (Losses) [Abstract]
Investment losses recognized due to the change in fair value of non-redeemable preferred stock held as of March 31, 2023 and 2022		29
Short term investments and other
Investment Gains (Losses) [Abstract]
Investment losses recognized due to the change in fair value of non-redeemable preferred stock held as of March 31, 2023 and 2022	$ 1