v3.25.3
Fair Value Measurements - Financial Assets and Liabilities Carried at Fair Value, Including Disposal Groups (Details) - Recurring
$ in Millions
Dec. 31, 2024
USD ($)
Financial assets at fair value:  
Debt Securities, including held for sale assets $ 9,423
Quoted Prices in Active Markets for Identical Assets (Level 1)  
Financial assets at fair value:  
Debt Securities, including held for sale assets 165
Significant Other Observable Inputs (Level 2)  
Financial assets at fair value:  
Debt Securities, including held for sale assets 8,841
Significant Unobservable Inputs (Level 3)  
Financial assets at fair value:  
Debt Securities, including held for sale assets 417
Federal government and agency  
Financial assets at fair value:  
Debt Securities, including held for sale assets 281
Federal government and agency | Quoted Prices in Active Markets for Identical Assets (Level 1)  
Financial assets at fair value:  
Debt Securities, including held for sale assets 165
Federal government and agency | Significant Other Observable Inputs (Level 2)  
Financial assets at fair value:  
Debt Securities, including held for sale assets 116
Federal government and agency | Significant Unobservable Inputs (Level 3)  
Financial assets at fair value:  
Debt Securities, including held for sale assets 0
State and local government  
Financial assets at fair value:  
Debt Securities, including held for sale assets 37
State and local government | Quoted Prices in Active Markets for Identical Assets (Level 1)  
Financial assets at fair value:  
Debt Securities, including held for sale assets 0
State and local government | Significant Other Observable Inputs (Level 2)  
Financial assets at fair value:  
Debt Securities, including held for sale assets 37
State and local government | Significant Unobservable Inputs (Level 3)  
Financial assets at fair value:  
Debt Securities, including held for sale assets 0
Foreign government  
Financial assets at fair value:  
Debt Securities, including held for sale assets 344
Foreign government | Quoted Prices in Active Markets for Identical Assets (Level 1)  
Financial assets at fair value:  
Debt Securities, including held for sale assets 0
Foreign government | Significant Other Observable Inputs (Level 2)  
Financial assets at fair value:  
Debt Securities, including held for sale assets 344
Foreign government | Significant Unobservable Inputs (Level 3)  
Financial assets at fair value:  
Debt Securities, including held for sale assets 0
Corporate  
Financial assets at fair value:  
Debt Securities, including held for sale assets 8,423
Corporate | Quoted Prices in Active Markets for Identical Assets (Level 1)  
Financial assets at fair value:  
Debt Securities, including held for sale assets 0
Corporate | Significant Other Observable Inputs (Level 2)  
Financial assets at fair value:  
Debt Securities, including held for sale assets 8,049
Corporate | Significant Unobservable Inputs (Level 3)  
Financial assets at fair value:  
Debt Securities, including held for sale assets 374
Mortgage and other asset-backed  
Financial assets at fair value:  
Debt Securities, including held for sale assets 338
Mortgage and other asset-backed | Quoted Prices in Active Markets for Identical Assets (Level 1)  
Financial assets at fair value:  
Debt Securities, including held for sale assets 0
Mortgage and other asset-backed | Significant Other Observable Inputs (Level 2)  
Financial assets at fair value:  
Debt Securities, including held for sale assets 295
Mortgage and other asset-backed | Significant Unobservable Inputs (Level 3)  
Financial assets at fair value:  
Debt Securities, including held for sale assets $ 43