v3.26.1
Investments (Securities Lending Remaining Tenor) (Details) - USD ($)
$ in Millions
Jun. 30, 2026
Dec. 31, 2025
Securities Financing Transaction [Line Items]    
Cash collateral received from counterparties $ 3,323 $ 3,225
Remaining Tenor of Securities Lending Agreements: Open    
Securities Financing Transaction [Line Items]    
Cash collateral received from counterparties 561 480
Remaining Tenor of Securities Lending Agreements: 1 Month or Less    
Securities Financing Transaction [Line Items]    
Cash collateral received from counterparties 1,016 968
Remaining Tenor of Securities Lending Agreements: 1 to 6 Months    
Securities Financing Transaction [Line Items]    
Cash collateral received from counterparties 1,746 1,777
U.S. government and agency    
Securities Financing Transaction [Line Items]    
Cash collateral received from counterparties 2,963 2,857
U.S. government and agency | Remaining Tenor of Securities Lending Agreements: Open    
Securities Financing Transaction [Line Items]    
Cash collateral received from counterparties 557 417
U.S. government and agency | Remaining Tenor of Securities Lending Agreements: 1 Month or Less    
Securities Financing Transaction [Line Items]    
Cash collateral received from counterparties 973 663
U.S. government and agency | Remaining Tenor of Securities Lending Agreements: 1 to 6 Months    
Securities Financing Transaction [Line Items]    
Cash collateral received from counterparties 1,433 1,777
U.S. corporate    
Securities Financing Transaction [Line Items]    
Cash collateral received from counterparties 300 304
U.S. corporate | Remaining Tenor of Securities Lending Agreements: Open    
Securities Financing Transaction [Line Items]    
Cash collateral received from counterparties 4 48
U.S. corporate | Remaining Tenor of Securities Lending Agreements: 1 Month or Less    
Securities Financing Transaction [Line Items]    
Cash collateral received from counterparties 38 256
U.S. corporate | Remaining Tenor of Securities Lending Agreements: 1 to 6 Months    
Securities Financing Transaction [Line Items]    
Cash collateral received from counterparties 258 0
Foreign corporate    
Securities Financing Transaction [Line Items]    
Cash collateral received from counterparties 43 62
Foreign corporate | Remaining Tenor of Securities Lending Agreements: Open    
Securities Financing Transaction [Line Items]    
Cash collateral received from counterparties 0 15
Foreign corporate | Remaining Tenor of Securities Lending Agreements: 1 Month or Less    
Securities Financing Transaction [Line Items]    
Cash collateral received from counterparties 1 47
Foreign corporate | Remaining Tenor of Securities Lending Agreements: 1 to 6 Months    
Securities Financing Transaction [Line Items]    
Cash collateral received from counterparties 42 0
Foreign government    
Securities Financing Transaction [Line Items]    
Cash collateral received from counterparties 17 2
Foreign government | Remaining Tenor of Securities Lending Agreements: Open    
Securities Financing Transaction [Line Items]    
Cash collateral received from counterparties 0 0
Foreign government | Remaining Tenor of Securities Lending Agreements: 1 Month or Less    
Securities Financing Transaction [Line Items]    
Cash collateral received from counterparties 4 2
Foreign government | Remaining Tenor of Securities Lending Agreements: 1 to 6 Months    
Securities Financing Transaction [Line Items]    
Cash collateral received from counterparties $ 13 $ 0