v3.25.2
Investments (Repurchase Agreements and Securities Lending Transactions) (Details) - USD ($)
$ in Millions
Jun. 30, 2025
Dec. 31, 2024
Transfer Of Certain Financial Assets Accounted For As Secured Borrowings [Line Items]    
Total securities sold under agreements to repurchase $ 8,205 $ 6,796
Total cash collateral for loaned securities 9,167 9,621
Overnight & Continuous    
Transfer Of Certain Financial Assets Accounted For As Secured Borrowings [Line Items]    
Total securities sold under agreements to repurchase 7,715 6,450
Total cash collateral for loaned securities 8,784 9,094
Up to 30 Days    
Transfer Of Certain Financial Assets Accounted For As Secured Borrowings [Line Items]    
Total securities sold under agreements to repurchase 490 346
Total cash collateral for loaned securities 383 527
30 to 90 Days    
Transfer Of Certain Financial Assets Accounted For As Secured Borrowings [Line Items]    
Total securities sold under agreements to repurchase 0 0
Total cash collateral for loaned securities 0 0
U.S. Treasury securities and obligations of U.S. government authorities and agencies    
Transfer Of Certain Financial Assets Accounted For As Secured Borrowings [Line Items]    
Total securities sold under agreements to repurchase 7,715 6,450
Total cash collateral for loaned securities 0 1
U.S. Treasury securities and obligations of U.S. government authorities and agencies | Overnight & Continuous    
Transfer Of Certain Financial Assets Accounted For As Secured Borrowings [Line Items]    
Total securities sold under agreements to repurchase 7,715 6,450
Total cash collateral for loaned securities 0 1
U.S. Treasury securities and obligations of U.S. government authorities and agencies | Up to 30 Days    
Transfer Of Certain Financial Assets Accounted For As Secured Borrowings [Line Items]    
Total securities sold under agreements to repurchase 0 0
Total cash collateral for loaned securities 0 0
U.S. Treasury securities and obligations of U.S. government authorities and agencies | 30 to 90 Days    
Transfer Of Certain Financial Assets Accounted For As Secured Borrowings [Line Items]    
Total securities sold under agreements to repurchase 0 0
Obligations of U.S. states and their political subdivisions    
Transfer Of Certain Financial Assets Accounted For As Secured Borrowings [Line Items]    
Total cash collateral for loaned securities 38 46
Obligations of U.S. states and their political subdivisions | Overnight & Continuous    
Transfer Of Certain Financial Assets Accounted For As Secured Borrowings [Line Items]    
Total cash collateral for loaned securities 38 46
Obligations of U.S. states and their political subdivisions | Up to 30 Days    
Transfer Of Certain Financial Assets Accounted For As Secured Borrowings [Line Items]    
Total cash collateral for loaned securities 0 0
Foreign government securities    
Transfer Of Certain Financial Assets Accounted For As Secured Borrowings [Line Items]    
Total cash collateral for loaned securities 222 128
Foreign government securities | Overnight & Continuous    
Transfer Of Certain Financial Assets Accounted For As Secured Borrowings [Line Items]    
Total cash collateral for loaned securities 222 122
Foreign government securities | Up to 30 Days    
Transfer Of Certain Financial Assets Accounted For As Secured Borrowings [Line Items]    
Total cash collateral for loaned securities 0 6
U.S. public corporate securities    
Transfer Of Certain Financial Assets Accounted For As Secured Borrowings [Line Items]    
Total securities sold under agreements to repurchase 470 327
Total cash collateral for loaned securities 7,451 7,909
U.S. public corporate securities | Overnight & Continuous    
Transfer Of Certain Financial Assets Accounted For As Secured Borrowings [Line Items]    
Total securities sold under agreements to repurchase 0 0
Total cash collateral for loaned securities 7,133 7,506
U.S. public corporate securities | Up to 30 Days    
Transfer Of Certain Financial Assets Accounted For As Secured Borrowings [Line Items]    
Total securities sold under agreements to repurchase 470 327
Total cash collateral for loaned securities 318 403
U.S. public corporate securities | 30 to 90 Days    
Transfer Of Certain Financial Assets Accounted For As Secured Borrowings [Line Items]    
Total securities sold under agreements to repurchase 0 0
Foreign public corporate securities    
Transfer Of Certain Financial Assets Accounted For As Secured Borrowings [Line Items]    
Total securities sold under agreements to repurchase 20 19
Total cash collateral for loaned securities 1,183 1,299
Foreign public corporate securities | Overnight & Continuous    
Transfer Of Certain Financial Assets Accounted For As Secured Borrowings [Line Items]    
Total securities sold under agreements to repurchase 0 0
Total cash collateral for loaned securities 1,118 1,181
Foreign public corporate securities | Up to 30 Days    
Transfer Of Certain Financial Assets Accounted For As Secured Borrowings [Line Items]    
Total securities sold under agreements to repurchase 20 19
Total cash collateral for loaned securities 65 118
Foreign public corporate securities | 30 to 90 Days    
Transfer Of Certain Financial Assets Accounted For As Secured Borrowings [Line Items]    
Total securities sold under agreements to repurchase 0 0
Commercial mortgage-backed securities    
Transfer Of Certain Financial Assets Accounted For As Secured Borrowings [Line Items]    
Total securities sold under agreements to repurchase 0 0
Commercial mortgage-backed securities | Overnight & Continuous    
Transfer Of Certain Financial Assets Accounted For As Secured Borrowings [Line Items]    
Total securities sold under agreements to repurchase 0 0
Commercial mortgage-backed securities | Up to 30 Days    
Transfer Of Certain Financial Assets Accounted For As Secured Borrowings [Line Items]    
Total securities sold under agreements to repurchase 0 0
Commercial mortgage-backed securities | 30 to 90 Days    
Transfer Of Certain Financial Assets Accounted For As Secured Borrowings [Line Items]    
Total securities sold under agreements to repurchase 0 0
Equity securities    
Transfer Of Certain Financial Assets Accounted For As Secured Borrowings [Line Items]    
Total cash collateral for loaned securities 273 238
Equity securities | Overnight & Continuous    
Transfer Of Certain Financial Assets Accounted For As Secured Borrowings [Line Items]    
Total cash collateral for loaned securities 273 238
Equity securities | Up to 30 Days    
Transfer Of Certain Financial Assets Accounted For As Secured Borrowings [Line Items]    
Total cash collateral for loaned securities $ 0 $ 0