Investments (Net realized investment gains (losses)) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022		Dec. 31, 2021
Fixed maturity securities:
Gross gains	$ 75	$ 120		$ 186
Gross losses	(166)	(261)		(90)
Net investment gains (losses) on fixed maturity securities	(91)	(141)		96
Equity securities	4	(116)		4
Derivatives	(1)	64		6
Mortgage loans	(11)	(8)		10
Short-term investments and other	0	2		4
Net investment gains (losses)	$ (99)	$ (199)	[1]	$ 120	[1]

[1] As of January 1, 2023, the Company adopted ASU 2018-12, Financial Services-Insurance (Topic 944): Targeted Improvements to the Accounting for Long-Duration Contracts (ASU 2018-12) using the modified retrospective method applied as of the transition date of January 1, 2021. Prior period amounts in the financial statements have been adjusted to reflect application of the new guidance. See Note A to the Consolidated Financial Statements for additional information.