Investments - Investment Gains (Losses) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Investment Gains (Losses) [Abstract]
Investment losses	$ (81)	$ (81)	$ (53)
Nonredeemable Preferred Stock
Investment Gains (Losses) [Abstract]
Investment losses	7	19	14
Fixed maturity securities
Investment Gains (Losses) [Abstract]
Gross gains	42	48	75
Gross losses	(125)	(150)	(166)
Investment losses	(83)	(102)	(91)
Equity securities
Investment Gains (Losses) [Abstract]
Investment losses	7	21	4
Derivative instruments
Investment Gains (Losses) [Abstract]
Investment losses			(1)
Short-term investments and other
Investment Gains (Losses) [Abstract]
Investment losses	(5)		(11)
Gain on acquisition of a joint venture
Investment Gains (Losses) [Abstract]
Investment losses			$ 46