Investments (Equity Securities) (Details) - USD ($) $ in Millions	Jun. 30, 2025	Dec. 31, 2024
Debt and Equity Securities, FV-NI [Line Items]
Equity Securities, FV-NI, Unrealized Gains (Losses)	$ 2,695	$ 2,388
Equity securities	790	712
Common Stock
Debt and Equity Securities, FV-NI [Line Items]
Equity Securities, FV-NI, Cost	411	451
Equity Securities, FV-NI, Unrealized Gains (Losses)	250	167
Equity securities	661	618
Non-redeemable preferred Stock
Debt and Equity Securities, FV-NI [Line Items]
Equity Securities, FV-NI, Cost	130	93
Equity Securities, FV-NI, Unrealized Gains (Losses)	(1)	1
Equity securities	129	94
Equity Securities
Debt and Equity Securities, FV-NI [Line Items]
Equity Securities, FV-NI, Cost	541	544
Equity Securities, FV-NI, Unrealized Gains (Losses)	249	168
Equity securities	$ 790	$ 712