v3.26.1
Investments (Repurchase Agreements and Securities Lending Transactions) (Details) - USD ($)
$ in Millions
Mar. 31, 2026
Dec. 31, 2025
Transfer Of Certain Financial Assets Accounted For As Secured Borrowings [Line Items]    
Total securities sold under agreements to repurchase $ 10,975 $ 9,598
Total cash collateral for loaned securities 8,905 8,700
Overnight & Continuous    
Transfer Of Certain Financial Assets Accounted For As Secured Borrowings [Line Items]    
Total securities sold under agreements to repurchase 10,427 7,352
Total cash collateral for loaned securities 8,831 8,532
Up to 30 Days    
Transfer Of Certain Financial Assets Accounted For As Secured Borrowings [Line Items]    
Total securities sold under agreements to repurchase 548 2,246
Total cash collateral for loaned securities 74 168
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 9,776 8,978
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 9,776 7,277
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 1,701
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 40 45
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 40 45
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 179 226
Foreign government securities | Overnight & Continuous    
Transfer Of Certain Financial Assets Accounted For As Secured Borrowings [Line Items]    
Total cash collateral for loaned securities 179 226
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 0
U.S. public corporate securities    
Transfer Of Certain Financial Assets Accounted For As Secured Borrowings [Line Items]    
Total securities sold under agreements to repurchase 530 527
Total cash collateral for loaned securities 6,395 7,220
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 6,331 7,068
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 530 527
Total cash collateral for loaned securities 64 152
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 18 18
Total cash collateral for loaned securities 1,069 1,173
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 1,065 1,157
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 18 18
Total cash collateral for loaned securities 4 16
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 651 75
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 651 75
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 1,222 36
Equity securities | Overnight & Continuous    
Transfer Of Certain Financial Assets Accounted For As Secured Borrowings [Line Items]    
Total cash collateral for loaned securities 1,216 36
Equity securities | Up to 30 Days    
Transfer Of Certain Financial Assets Accounted For As Secured Borrowings [Line Items]    
Total cash collateral for loaned securities $ 6 $ 0