Investments (Equity Securities) (Details) - USD ($) $ in Millions	Dec. 31, 2024	Dec. 31, 2023
Debt and Equity Securities, FV-NI [Line Items]
Equity Securities, FV-NI, Unrealized Gains (Losses)	$ 2,388	$ 1,589
Equity securities	712	757
Common Stock
Debt and Equity Securities, FV-NI [Line Items]
Equity Securities, FV-NI, Cost	451	424
Equity Securities, FV-NI, Unrealized Gains (Losses)	167	239
Equity securities	618	663
Non-redeemable preferred Stock
Debt and Equity Securities, FV-NI [Line Items]
Equity Securities, FV-NI, Cost	93	90
Equity Securities, FV-NI, Unrealized Gains (Losses)	1	4
Equity securities	94	94
Equity Securities
Debt and Equity Securities, FV-NI [Line Items]
Equity Securities, FV-NI, Cost	544	514
Equity Securities, FV-NI, Unrealized Gains (Losses)	168	243
Equity securities	$ 712	$ 757