Investments (Equity Securities) (Details) - USD ($) $ in Millions	Jun. 30, 2024	Dec. 31, 2023
Debt and Equity Securities, FV-NI [Line Items]
Equity Securities, FV-NI, Unrealized Gains (Losses)	$ 2,093	$ 1,589
Equity securities	754	757
Common Stock
Debt and Equity Securities, FV-NI [Line Items]
Equity Securities, FV-NI, Cost	403	424
Equity Securities, FV-NI, Unrealized Gains (Losses)	242	239
Equity securities	645	663
Non-redeemable preferred Stock
Debt and Equity Securities, FV-NI [Line Items]
Equity Securities, FV-NI, Cost	110	90
Equity Securities, FV-NI, Unrealized Gains (Losses)	(1)	4
Equity securities	109	94
Equity Securities
Debt and Equity Securities, FV-NI [Line Items]
Equity Securities, FV-NI, Cost	513	514
Equity Securities, FV-NI, Unrealized Gains (Losses)	241	243
Equity securities	$ 754	$ 757