Investments (Components of Net Investment Gains (Losses)) (Details) - USD ($) $ in Millions	1 Months Ended	3 Months Ended		9 Months Ended
	Jul. 31, 2025	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2025	Sep. 30, 2024
Net Investment Gains (Losses) [Line Items]
Net investment gains (losses)		$ 44	$ (62)	$ (79)	$ (225)
Fixed maturity securities
Net Investment Gains (Losses) [Line Items]
Net investment gains (losses)		(12)	(48)	(69)	(181)
Equity securities
Net Investment Gains (Losses) [Line Items]
Net investment gains (losses)		0	(1)	(2)	(4)
Mortgage loans
Net Investment Gains (Losses) [Line Items]
Net investment gains (losses)		(9)	(15)	(76)	(42)
Limited partnerships and LLCs
Net Investment Gains (Losses) [Line Items]
Net investment gains (losses)		0	0	0	(1)
Other
Net Investment Gains (Losses) [Line Items]
Net investment gains (losses)	$ 66	$ 65	$ 2	$ 68	$ 3