v3.25.4
Fair Values of Assets and Liabilities - Assets and Liabilities Measured at Fair Value on a Recurring Basis (Details) - USD ($)
$ in Millions
Dec. 31, 2025
Dec. 31, 2024
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Total available for sale securities $ 62,357 $ 82,994
U.S. agency mortgage-backed securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Total available for sale securities 41,434 51,833
U.S. Treasury securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Total available for sale securities 11,364 14,469
Corporate debt securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Total available for sale securities 4,667 9,579
Asset-backed securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Total available for sale securities 4,199 5,910
U.S. state and municipal securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Total available for sale securities 561 549
Foreign government agency securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Total available for sale securities   527
Non-agency commercial mortgage-backed securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Total available for sale securities 113 109
Other    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Total available for sale securities 19 18
Fair Value, Recurring    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Total cash equivalents 15,936 11,005
Total investments segregated and on deposit for regulatory purposes 23,555 25,740
Total available for sale securities 62,357 82,994
Total other assets 3,163 2,543
Total assets 105,011 122,282
Total accrued expenses and other liabilities 2,845 2,198
Total liabilities 2,845 2,198
Fair Value, Recurring | Money market funds    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Total cash equivalents 13,947 11,005
Fair Value, Recurring | U.S. government securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Total investments segregated and on deposit for regulatory purposes 23,555 25,740
Total other assets 15 18
Fair Value, Recurring | U.S. agency mortgage-backed securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Total available for sale securities 41,434 51,833
Fair Value, Recurring | U.S. Treasury securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Total cash equivalents 1,989  
Total available for sale securities 11,364 14,469
Fair Value, Recurring | Corporate debt securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Total available for sale securities 4,667 9,579
Fair Value, Recurring | Asset-backed securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Total available for sale securities 4,199 5,910
Fair Value, Recurring | U.S. state and municipal securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Total available for sale securities 561 549
Fair Value, Recurring | Foreign government agency securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Total available for sale securities   527
Fair Value, Recurring | Non-agency commercial mortgage-backed securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Total available for sale securities 113 109
Fair Value, Recurring | Other    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Total available for sale securities 19 18
Fair Value, Recurring | Total other securities owned    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Total other assets 3,162 2,543
Fair Value, Recurring | Equity, corporate debt, and other securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Total other assets 1,788 1,468
Fair Value, Recurring | Mutual funds and ETFs    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Total other assets 1,314 1,019
Fair Value, Recurring | State and municipal debt obligations    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Total other assets 45 38
Fair Value, Recurring | Interest rate swaps    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Total other assets 1  
Total accrued expenses and other liabilities 1  
Fair Value, Recurring | Other    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Total accrued expenses and other liabilities 2,844 2,198
Fair Value, Recurring | Level 1    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Total cash equivalents 13,947 11,005
Total investments segregated and on deposit for regulatory purposes 0 0
Total available for sale securities 0 0
Total other assets 3,018 2,414
Total assets 16,965 13,419
Total accrued expenses and other liabilities 2,804 2,161
Total liabilities 2,804 2,161
Fair Value, Recurring | Level 1 | Money market funds    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Total cash equivalents 13,947 11,005
Fair Value, Recurring | Level 1 | U.S. government securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Total investments segregated and on deposit for regulatory purposes 0 0
Total other assets 0 0
Fair Value, Recurring | Level 1 | U.S. agency mortgage-backed securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Total available for sale securities 0 0
Fair Value, Recurring | Level 1 | U.S. Treasury securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Total cash equivalents 0  
Total available for sale securities 0 0
Fair Value, Recurring | Level 1 | Corporate debt securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Total available for sale securities 0 0
Fair Value, Recurring | Level 1 | Asset-backed securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Total available for sale securities 0 0
Fair Value, Recurring | Level 1 | U.S. state and municipal securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Total available for sale securities 0 0
Fair Value, Recurring | Level 1 | Foreign government agency securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Total available for sale securities   0
Fair Value, Recurring | Level 1 | Non-agency commercial mortgage-backed securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Total available for sale securities 0 0
Fair Value, Recurring | Level 1 | Other    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Total available for sale securities 0 0
Fair Value, Recurring | Level 1 | Total other securities owned    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Total other assets 3,018 2,414
Fair Value, Recurring | Level 1 | Equity, corporate debt, and other securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Total other assets 1,704 1,395
Fair Value, Recurring | Level 1 | Mutual funds and ETFs    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Total other assets 1,314 1,019
Fair Value, Recurring | Level 1 | State and municipal debt obligations    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Total other assets 0 0
Fair Value, Recurring | Level 1 | Interest rate swaps    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Total other assets 0  
Total accrued expenses and other liabilities 0  
Fair Value, Recurring | Level 1 | Other    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Total accrued expenses and other liabilities 2,804 2,161
Fair Value, Recurring | Level 2    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Total cash equivalents 1,989 0
Total investments segregated and on deposit for regulatory purposes 23,555 25,740
Total available for sale securities 62,357 82,994
Total other assets 145 129
Total assets 88,046 108,863
Total accrued expenses and other liabilities 41 37
Total liabilities 41 37
Fair Value, Recurring | Level 2 | Money market funds    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Total cash equivalents 0 0
Fair Value, Recurring | Level 2 | U.S. government securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Total investments segregated and on deposit for regulatory purposes 23,555 25,740
Total other assets 15 18
Fair Value, Recurring | Level 2 | U.S. agency mortgage-backed securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Total available for sale securities 41,434 51,833
Fair Value, Recurring | Level 2 | U.S. Treasury securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Total cash equivalents 1,989  
Total available for sale securities 11,364 14,469
Fair Value, Recurring | Level 2 | Corporate debt securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Total available for sale securities 4,667 9,579
Fair Value, Recurring | Level 2 | Asset-backed securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Total available for sale securities 4,199 5,910
Fair Value, Recurring | Level 2 | U.S. state and municipal securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Total available for sale securities 561 549
Fair Value, Recurring | Level 2 | Foreign government agency securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Total available for sale securities   527
Fair Value, Recurring | Level 2 | Non-agency commercial mortgage-backed securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Total available for sale securities 113 109
Fair Value, Recurring | Level 2 | Other    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Total available for sale securities 19 18
Fair Value, Recurring | Level 2 | Total other securities owned    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Total other assets 144 129
Fair Value, Recurring | Level 2 | Equity, corporate debt, and other securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Total other assets 84 73
Fair Value, Recurring | Level 2 | Mutual funds and ETFs    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Total other assets 0 0
Fair Value, Recurring | Level 2 | State and municipal debt obligations    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Total other assets 45 38
Fair Value, Recurring | Level 2 | Interest rate swaps    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Total other assets 1  
Total accrued expenses and other liabilities 1  
Fair Value, Recurring | Level 2 | Other    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Total accrued expenses and other liabilities 40 37
Fair Value, Recurring | Level 3    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Total cash equivalents 0 0
Total investments segregated and on deposit for regulatory purposes 0 0
Total available for sale securities 0 0
Total other assets 0 0
Total assets 0 0
Total accrued expenses and other liabilities 0 0
Total liabilities 0 0
Fair Value, Recurring | Level 3 | Money market funds    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Total cash equivalents 0 0
Fair Value, Recurring | Level 3 | U.S. government securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Total investments segregated and on deposit for regulatory purposes 0 0
Total other assets 0 0
Fair Value, Recurring | Level 3 | U.S. agency mortgage-backed securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Total available for sale securities 0 0
Fair Value, Recurring | Level 3 | U.S. Treasury securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Total cash equivalents 0  
Total available for sale securities 0 0
Fair Value, Recurring | Level 3 | Corporate debt securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Total available for sale securities 0 0
Fair Value, Recurring | Level 3 | Asset-backed securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Total available for sale securities 0 0
Fair Value, Recurring | Level 3 | U.S. state and municipal securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Total available for sale securities 0 0
Fair Value, Recurring | Level 3 | Foreign government agency securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Total available for sale securities   0
Fair Value, Recurring | Level 3 | Non-agency commercial mortgage-backed securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Total available for sale securities 0 0
Fair Value, Recurring | Level 3 | Other    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Total available for sale securities 0 0
Fair Value, Recurring | Level 3 | Total other securities owned    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Total other assets 0 0
Fair Value, Recurring | Level 3 | Equity, corporate debt, and other securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Total other assets 0 0
Fair Value, Recurring | Level 3 | Mutual funds and ETFs    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Total other assets 0 0
Fair Value, Recurring | Level 3 | State and municipal debt obligations    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Total other assets 0 0
Fair Value, Recurring | Level 3 | Interest rate swaps    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Total other assets 0  
Total accrued expenses and other liabilities 0  
Fair Value, Recurring | Level 3 | Other    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Total accrued expenses and other liabilities $ 0 $ 0