v3.26.1
Investments (Securities Lending and Repurchase Agreements) (Details) - USD ($)
$ in Millions
Mar. 31, 2026
Dec. 31, 2025
Securities Financing Transaction [Line Items]    
Cash collateral on deposit from counterparties $ 7,421 $ 7,043
Securities Lending Reinvestment Portfolio Estimated Fair Value 7,344 6,979
Repurchase Agreements    
Securities Financing Transaction [Line Items]    
Cash collateral on deposit from counterparties 3,075 2,975
Securities Lending Reinvestment Portfolio Estimated Fair Value 3,043 2,948
Estimated fair value    
Securities Financing Transaction [Line Items]    
Securities loaned 7,151 6,840
Securities Sold under Agreements to Repurchase $ 3,124 $ 3,002