Investments - Investment Gains (Losses) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Investment Gains (Losses) [Abstract]
Investment losses	$ (81)	$ (53)	$ (199)
Net gain related to the expected novation of a coinsurance agreement			18
Gain (loss) on fixed maturity securities related to funds with held liability			62
Loss on embedded derivative			44
Nonredeemable Preferred Stock
Investment Gains (Losses) [Abstract]
Investment losses	19	14	(75)
Fixed maturity securities
Investment Gains (Losses) [Abstract]
Gross gains	48	75	120
Gross losses	(150)	(166)	(261)
Investment losses	(102)	(91)	(141)
Equity securities
Investment Gains (Losses) [Abstract]
Investment losses	21	4	(116)
Derivative instruments
Investment Gains (Losses) [Abstract]
Investment losses		(1)	64
Short-term investments and other
Investment Gains (Losses) [Abstract]
Investment losses		(11)	(6)
Joint venture
Investment Gains (Losses) [Abstract]
Investment losses		$ 46