Investments (Equity Securities) (Details) - USD ($) $ in Millions	Jun. 30, 2023	Dec. 31, 2022
Debt and Equity Securities, FV-NI [Line Items]
Equity Securities, FV-NI, Unrealized Gains (Losses)	$ 1,123	$ 562
Equity securities	769	1,684
Common Stock
Debt and Equity Securities, FV-NI [Line Items]
Equity Securities, FV-NI, Cost	421	1,347
Equity Securities, FV-NI, Unrealized Gains (Losses)	238	195
Equity securities	659	1,542
Non-redeemable Preferred Stock
Debt and Equity Securities, FV-NI [Line Items]
Equity Securities, FV-NI, Cost	111	148
Equity Securities, FV-NI, Unrealized Gains (Losses)	(1)	(6)
Equity securities	110	142
Equity Securities
Debt and Equity Securities, FV-NI [Line Items]
Equity Securities, FV-NI, Cost	532	1,495
Equity Securities, FV-NI, Unrealized Gains (Losses)	237	189
Equity securities	$ 769	$ 1,684