v3.24.3
Investments - Gross Unrealized Appreciation (Depreciation) on Debt Securities by Type of Issuer (Details) - USD ($)
$ in Millions
Sep. 30, 2024
Dec. 31, 2023
Debt Securities, Available-for-sale [Line Items]    
Amortized cost, including held for sale assets $ 10,273 $ 10,379
Allowance for Credit Loss, including held for sale assets (104) (33)
Unrealized Appreciation, including held for sale assets 242 195
Unrealized Depreciation, including held for sale assets (530) (686)
Fair Value, including held for sale assets 9,881 9,855
Federal government and agency    
Debt Securities, Available-for-sale [Line Items]    
Amortized cost, including held for sale assets 273 251
Allowance for Credit Loss, including held for sale assets 0 0
Unrealized Appreciation, including held for sale assets 21 24
Unrealized Depreciation, including held for sale assets (5) (8)
Fair Value, including held for sale assets 289 267
State and local government    
Debt Securities, Available-for-sale [Line Items]    
Amortized cost, including held for sale assets 37 37
Allowance for Credit Loss, including held for sale assets 0 0
Unrealized Appreciation, including held for sale assets 2 2
Unrealized Depreciation, including held for sale assets (1) (1)
Fair Value, including held for sale assets 38 38
Foreign government    
Debt Securities, Available-for-sale [Line Items]    
Amortized cost, including held for sale assets 373 355
Allowance for Credit Loss, including held for sale assets 0 0
Unrealized Appreciation, including held for sale assets 12 10
Unrealized Depreciation, including held for sale assets (9) (13)
Fair Value, including held for sale assets 376 352
Corporate    
Debt Securities, Available-for-sale [Line Items]    
Amortized cost, including held for sale assets 9,212 9,338
Allowance for Credit Loss, including held for sale assets (104) (33)
Unrealized Appreciation, including held for sale assets 204 158
Unrealized Depreciation, including held for sale assets (487) (630)
Fair Value, including held for sale assets 8,825 8,833
Mortgage and other asset-backed    
Debt Securities, Available-for-sale [Line Items]    
Amortized cost, including held for sale assets 378 398
Allowance for Credit Loss, including held for sale assets 0 0
Unrealized Appreciation, including held for sale assets 3 1
Unrealized Depreciation, including held for sale assets (28) (34)
Fair Value, including held for sale assets $ 353 $ 365