Schedule I (Details) $ in Millions	Dec. 31, 2025 USD ($)
SEC Schedule, 12-15, Insurance Companies, Summary of Investments, Other than Investments in Related Parties [Line Items]
Cost	$ 93,882
Fair value	92,951
Amount at which shown in the Balance sheet	93,004
U.S. government and government sponsored entities
SEC Schedule, 12-15, Insurance Companies, Summary of Investments, Other than Investments in Related Parties [Line Items]
Cost	3,353
Fair value	3,298
Amount at which shown in the Balance sheet	3,298
Obligations of states, municipalities and political subdivisions
SEC Schedule, 12-15, Insurance Companies, Summary of Investments, Other than Investments in Related Parties [Line Items]
Cost	2,808
Fair value	2,826
Amount at which shown in the Balance sheet	2,826
Non-U.S. governments
SEC Schedule, 12-15, Insurance Companies, Summary of Investments, Other than Investments in Related Parties [Line Items]
Cost	6,822
Fair value	6,539
Amount at which shown in the Balance sheet	6,539
Public utilities
SEC Schedule, 12-15, Insurance Companies, Summary of Investments, Other than Investments in Related Parties [Line Items]
Cost	3,689
Fair value	3,601
Amount at which shown in the Balance sheet	3,601
All other corporate debt securities
SEC Schedule, 12-15, Insurance Companies, Summary of Investments, Other than Investments in Related Parties [Line Items]
Cost	34,331
Fair value	33,908
Amount at which shown in the Balance sheet	33,908
Mortgage-backed, asset-backed and collateralized
SEC Schedule, 12-15, Insurance Companies, Summary of Investments, Other than Investments in Related Parties [Line Items]
Cost	21,510
Fair value	21,601
Amount at which shown in the Balance sheet	21,601
Fixed maturity securities
SEC Schedule, 12-15, Insurance Companies, Summary of Investments, Other than Investments in Related Parties [Line Items]
Cost	72,513
Fair value	71,773
Amount at which shown in the Balance sheet	71,773
Banks, trust and insurance companies
SEC Schedule, 12-15, Insurance Companies, Summary of Investments, Other than Investments in Related Parties [Line Items]
Cost	206
Fair value	206
Amount at which shown in the Balance sheet	206
Industrial, miscellaneous and all other
SEC Schedule, 12-15, Insurance Companies, Summary of Investments, Other than Investments in Related Parties [Line Items]
Cost	73
Fair value	73
Amount at which shown in the Balance sheet	73
Common Stock, Par Value $2.50 Per Share
SEC Schedule, 12-15, Insurance Companies, Summary of Investments, Other than Investments in Related Parties [Line Items]
Cost	279
Fair value	279
Amount at which shown in the Balance sheet	279
Mutual funds
SEC Schedule, 12-15, Insurance Companies, Summary of Investments, Other than Investments in Related Parties [Line Items]
Cost	223
Fair value	223
Amount at which shown in the Balance sheet	223
Equity Securities And Mutual Funds
SEC Schedule, 12-15, Insurance Companies, Summary of Investments, Other than Investments in Related Parties [Line Items]
Cost	502
Fair value	502
Amount at which shown in the Balance sheet	502
Mortgage and other loans receivable, net of allowance
SEC Schedule, 12-15, Insurance Companies, Summary of Investments, Other than Investments in Related Parties [Line Items]
Cost	2,887
Fair value	2,834
Amount at which shown in the Balance sheet	2,887
Other invested assets
SEC Schedule, 12-15, Insurance Companies, Summary of Investments, Other than Investments in Related Parties [Line Items]
Cost	6,834
Fair value	6,696
Amount at which shown in the Balance sheet	6,696
Short-term investments
SEC Schedule, 12-15, Insurance Companies, Summary of Investments, Other than Investments in Related Parties [Line Items]
Cost	11,141
Fair value	11,141
Amount at which shown in the Balance sheet	11,141
Derivative assets
SEC Schedule, 12-15, Insurance Companies, Summary of Investments, Other than Investments in Related Parties [Line Items]
Cost	5
Fair value	5
Amount at which shown in the Balance sheet	$ 5