v3.26.1
Investments (Securities Lending and Repurchase Agreements Remaining Tenor) (Details) - USD ($)
$ in Millions
Mar. 31, 2026
Dec. 31, 2025
Securities Financing Transaction [Line Items]    
Cash collateral on deposit from counterparties $ 12,552 $ 12,198
U.S. government and agency    
Securities Financing Transaction [Line Items]    
Cash collateral on deposit from counterparties 11,246 10,777
Foreign government    
Securities Financing Transaction [Line Items]    
Cash collateral on deposit from counterparties 1,008 1,110
Agency RMBS    
Securities Financing Transaction [Line Items]    
Cash collateral on deposit from counterparties 298 311
Open (1)    
Securities Financing Transaction [Line Items]    
Cash collateral on deposit from counterparties 2,007 1,986
Open (1) | U.S. government and agency    
Securities Financing Transaction [Line Items]    
Cash collateral on deposit from counterparties 2,007 1,986
Open (1) | Foreign government    
Securities Financing Transaction [Line Items]    
Cash collateral on deposit from counterparties 0 0
Open (1) | Agency RMBS    
Securities Financing Transaction [Line Items]    
Cash collateral on deposit from counterparties 0 0
1 Month or Less    
Securities Financing Transaction [Line Items]    
Cash collateral on deposit from counterparties 5,724 4,977
1 Month or Less | U.S. government and agency    
Securities Financing Transaction [Line Items]    
Cash collateral on deposit from counterparties 4,852 3,911
1 Month or Less | Foreign government    
Securities Financing Transaction [Line Items]    
Cash collateral on deposit from counterparties 745 755
1 Month or Less | Agency RMBS    
Securities Financing Transaction [Line Items]    
Cash collateral on deposit from counterparties 127 311
Over 1 Month to 6 Months    
Securities Financing Transaction [Line Items]    
Cash collateral on deposit from counterparties 4,821 5,235
Over 1 Month to 6 Months | U.S. government and agency    
Securities Financing Transaction [Line Items]    
Cash collateral on deposit from counterparties 4,387 4,880
Over 1 Month to 6 Months | Foreign government    
Securities Financing Transaction [Line Items]    
Cash collateral on deposit from counterparties 263 355
Over 1 Month to 6 Months | Agency RMBS    
Securities Financing Transaction [Line Items]    
Cash collateral on deposit from counterparties 171 0
Over 6 Months to 1 Year    
Securities Financing Transaction [Line Items]    
Cash collateral on deposit from counterparties 0 0
Over 6 Months to 1 Year | U.S. government and agency    
Securities Financing Transaction [Line Items]    
Cash collateral on deposit from counterparties 0 0
Over 6 Months to 1 Year | Foreign government    
Securities Financing Transaction [Line Items]    
Cash collateral on deposit from counterparties 0 0
Over 6 Months to 1 Year | Agency RMBS    
Securities Financing Transaction [Line Items]    
Cash collateral on deposit from counterparties 0 0
Repurchase Agreements    
Securities Financing Transaction [Line Items]    
Cash collateral on deposit from counterparties 3,075 2,975
Repurchase Agreements | U.S. government and agency    
Securities Financing Transaction [Line Items]    
Cash collateral on deposit from counterparties 3,075 2,975
Repurchase Agreements | Open (1) | U.S. government and agency    
Securities Financing Transaction [Line Items]    
Cash collateral on deposit from counterparties 0 0
Repurchase Agreements | 1 Month or Less | U.S. government and agency    
Securities Financing Transaction [Line Items]    
Cash collateral on deposit from counterparties 3,075 2,975
Repurchase Agreements | Over 1 Month to 6 Months | U.S. government and agency    
Securities Financing Transaction [Line Items]    
Cash collateral on deposit from counterparties 0 0
Repurchase Agreements | Over 6 Months to 1 Year | U.S. government and agency    
Securities Financing Transaction [Line Items]    
Cash collateral on deposit from counterparties $ 0 $ 0