Schedule I (Details) $ in Millions	Dec. 31, 2022 USD ($)
SEC Schedule, 12-15, Insurance Companies, Summary of Investments, Other than Investments in Related Parties [Line Items]
Cost	$ 340,287
Fair value	306,066
Amount at which shown in the Balance sheet	309,664
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	7,094
Fair value	6,619
Amount at which shown in the Balance sheet	6,619
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	13,306
Fair value	12,210
Amount at which shown in the Balance sheet	12,210
Non-U.S. governments
SEC Schedule, 12-15, Insurance Companies, Summary of Investments, Other than Investments in Related Parties [Line Items]
Cost	15,199
Fair value	13,551
Amount at which shown in the Balance sheet	13,551
Public utilities
SEC Schedule, 12-15, Insurance Companies, Summary of Investments, Other than Investments in Related Parties [Line Items]
Cost	23,095
Fair value	19,190
Amount at which shown in the Balance sheet	19,190
All other corporate debt securities
SEC Schedule, 12-15, Insurance Companies, Summary of Investments, Other than Investments in Related Parties [Line Items]
Cost	139,538
Fair value	121,041
Amount at which shown in the Balance sheet	121,041
Mortgage-backed, asset-backed and collateralized
SEC Schedule, 12-15, Insurance Companies, Summary of Investments, Other than Investments in Related Parties [Line Items]
Cost	62,246
Fair value	58,030
Amount at which shown in the Balance sheet	58,030
Fixed maturity securities
SEC Schedule, 12-15, Insurance Companies, Summary of Investments, Other than Investments in Related Parties [Line Items]
Cost	260,478
Fair value	230,641
Amount at which shown in the Balance sheet	230,641
Public utilities
SEC Schedule, 12-15, Insurance Companies, Summary of Investments, Other than Investments in Related Parties [Line Items]
Cost	1
Fair value	1
Amount at which shown in the Balance sheet	1
Banks, trust and insurance companies
SEC Schedule, 12-15, Insurance Companies, Summary of Investments, Other than Investments in Related Parties [Line Items]
Cost	155
Fair value	155
Amount at which shown in the Balance sheet	155
Industrial, miscellaneous and all other
SEC Schedule, 12-15, Insurance Companies, Summary of Investments, Other than Investments in Related Parties [Line Items]
Cost	172
Fair value	172
Amount at which shown in the Balance sheet	172
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	328
Fair value	328
Amount at which shown in the Balance sheet	328
Preferred stock
SEC Schedule, 12-15, Insurance Companies, Summary of Investments, Other than Investments in Related Parties [Line Items]
Cost	32
Fair value	32
Amount at which shown in the Balance sheet	32
Mutual funds
SEC Schedule, 12-15, Insurance Companies, Summary of Investments, Other than Investments in Related Parties [Line Items]
Cost	215
Fair value	215
Amount at which shown in the Balance sheet	215
Equity Securities And Mutual Funds
SEC Schedule, 12-15, Insurance Companies, Summary of Investments, Other than Investments in Related Parties [Line Items]
Cost	575
Fair value	575
Amount at which shown in the Balance sheet	575
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	49,605
Fair value	46,007
Amount at which shown in the Balance sheet	49,605
Other invested assets
SEC Schedule, 12-15, Insurance Companies, Summary of Investments, Other than Investments in Related Parties [Line Items]
Cost	16,739
Fair value	15,953
Amount at which shown in the Balance sheet	15,953
Short-term investments, at cost (approximates fair value)
SEC Schedule, 12-15, Insurance Companies, Summary of Investments, Other than Investments in Related Parties [Line Items]
Cost	12,376
Fair value	12,376
Amount at which shown in the Balance sheet	12,376
Derivative assets
SEC Schedule, 12-15, Insurance Companies, Summary of Investments, Other than Investments in Related Parties [Line Items]
Cost	514
Fair value	514
Amount at which shown in the Balance sheet	$ 514