v3.26.1
Fair Values of Assets and Liabilities - Assets and Liabilities Measured at Fair Value on a Recurring Basis (Details) - USD ($)
$ in Millions
Jun. 30, 2026
Dec. 31, 2025
Fair Value, Assets Measured on Recurring and Nonrecurring Basis [Line Items]    
Cash equivalents: $ 18,504 $ 15,936
Investments segregated and on deposit for regulatory purposes: 17,827 23,555
Fair Value 62,467 62,357
Other assets: 3,738 3,163
Total assets 102,536 105,011
Total accrued expenses and other liabilities 3,318 2,845
Total liabilities 3,318 2,845
Money market funds    
Fair Value, Assets Measured on Recurring and Nonrecurring Basis [Line Items]    
Cash equivalents: 18,504 13,947
U.S. Treasury securities    
Fair Value, Assets Measured on Recurring and Nonrecurring Basis [Line Items]    
Cash equivalents:   1,989
Fair Value 11,951 11,364
U.S. government securities    
Fair Value, Assets Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments segregated and on deposit for regulatory purposes: 17,827 23,555
Other assets: 16 15
U.S. agency mortgage-backed securities    
Fair Value, Assets Measured on Recurring and Nonrecurring Basis [Line Items]    
Fair Value 37,741 41,434
Corporate debt securities    
Fair Value, Assets Measured on Recurring and Nonrecurring Basis [Line Items]    
Fair Value 5,017 4,667
Asset-backed securities    
Fair Value, Assets Measured on Recurring and Nonrecurring Basis [Line Items]    
Fair Value 7,204 4,199
U.S. state and municipal securities    
Fair Value, Assets Measured on Recurring and Nonrecurring Basis [Line Items]    
Fair Value 424 561
Non-agency commercial mortgage-backed securities    
Fair Value, Assets Measured on Recurring and Nonrecurring Basis [Line Items]    
Fair Value 112 113
Other    
Fair Value, Assets Measured on Recurring and Nonrecurring Basis [Line Items]    
Fair Value 18 19
Total other securities owned    
Fair Value, Assets Measured on Recurring and Nonrecurring Basis [Line Items]    
Other assets: 3,738 3,162
Equity, corporate debt, and other securities    
Fair Value, Assets Measured on Recurring and Nonrecurring Basis [Line Items]    
Other assets: 2,141 1,788
Mutual funds and ETFs    
Fair Value, Assets Measured on Recurring and Nonrecurring Basis [Line Items]    
Other assets: 1,533 1,314
State and municipal debt obligations    
Fair Value, Assets Measured on Recurring and Nonrecurring Basis [Line Items]    
Other assets: 48 45
Interest rate swaps    
Fair Value, Assets Measured on Recurring and Nonrecurring Basis [Line Items]    
Other assets:   1
Total accrued expenses and other liabilities 2 1
Other    
Fair Value, Assets Measured on Recurring and Nonrecurring Basis [Line Items]    
Total accrued expenses and other liabilities 3,316 2,844
Level 1    
Fair Value, Assets Measured on Recurring and Nonrecurring Basis [Line Items]    
Cash equivalents: 18,504 13,947
Investments segregated and on deposit for regulatory purposes: 0 0
Fair Value 0 0
Other assets: 3,561 3,018
Total assets 22,065 16,965
Total accrued expenses and other liabilities 3,263 2,804
Total liabilities 3,263 2,804
Level 1 | Money market funds    
Fair Value, Assets Measured on Recurring and Nonrecurring Basis [Line Items]    
Cash equivalents: 18,504 13,947
Level 1 | U.S. Treasury securities    
Fair Value, Assets Measured on Recurring and Nonrecurring Basis [Line Items]    
Cash equivalents:   0
Fair Value 0 0
Level 1 | U.S. government securities    
Fair Value, Assets Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments segregated and on deposit for regulatory purposes: 0 0
Other assets: 0 0
Level 1 | U.S. agency mortgage-backed securities    
Fair Value, Assets Measured on Recurring and Nonrecurring Basis [Line Items]    
Fair Value 0 0
Level 1 | Corporate debt securities    
Fair Value, Assets Measured on Recurring and Nonrecurring Basis [Line Items]    
Fair Value 0 0
Level 1 | Asset-backed securities    
Fair Value, Assets Measured on Recurring and Nonrecurring Basis [Line Items]    
Fair Value 0 0
Level 1 | U.S. state and municipal securities    
Fair Value, Assets Measured on Recurring and Nonrecurring Basis [Line Items]    
Fair Value 0 0
Level 1 | Non-agency commercial mortgage-backed securities    
Fair Value, Assets Measured on Recurring and Nonrecurring Basis [Line Items]    
Fair Value 0 0
Level 1 | Other    
Fair Value, Assets Measured on Recurring and Nonrecurring Basis [Line Items]    
Fair Value 0 0
Level 1 | Total other securities owned    
Fair Value, Assets Measured on Recurring and Nonrecurring Basis [Line Items]    
Other assets: 3,561 3,018
Level 1 | Equity, corporate debt, and other securities    
Fair Value, Assets Measured on Recurring and Nonrecurring Basis [Line Items]    
Other assets: 2,028 1,704
Level 1 | Mutual funds and ETFs    
Fair Value, Assets Measured on Recurring and Nonrecurring Basis [Line Items]    
Other assets: 1,533 1,314
Level 1 | State and municipal debt obligations    
Fair Value, Assets Measured on Recurring and Nonrecurring Basis [Line Items]    
Other assets: 0 0
Level 1 | Interest rate swaps    
Fair Value, Assets Measured on Recurring and Nonrecurring Basis [Line Items]    
Other assets:   0
Total accrued expenses and other liabilities 0 0
Level 1 | Other    
Fair Value, Assets Measured on Recurring and Nonrecurring Basis [Line Items]    
Total accrued expenses and other liabilities 3,263 2,804
Level 2    
Fair Value, Assets Measured on Recurring and Nonrecurring Basis [Line Items]    
Cash equivalents: 0 1,989
Investments segregated and on deposit for regulatory purposes: 17,827 23,555
Fair Value 62,467 62,357
Other assets: 177 145
Total assets 80,471 88,046
Total accrued expenses and other liabilities 55 41
Total liabilities 55 41
Level 2 | Money market funds    
Fair Value, Assets Measured on Recurring and Nonrecurring Basis [Line Items]    
Cash equivalents: 0 0
Level 2 | U.S. Treasury securities    
Fair Value, Assets Measured on Recurring and Nonrecurring Basis [Line Items]    
Cash equivalents:   1,989
Fair Value 11,951 11,364
Level 2 | U.S. government securities    
Fair Value, Assets Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments segregated and on deposit for regulatory purposes: 17,827 23,555
Other assets: 16 15
Level 2 | U.S. agency mortgage-backed securities    
Fair Value, Assets Measured on Recurring and Nonrecurring Basis [Line Items]    
Fair Value 37,741 41,434
Level 2 | Corporate debt securities    
Fair Value, Assets Measured on Recurring and Nonrecurring Basis [Line Items]    
Fair Value 5,017 4,667
Level 2 | Asset-backed securities    
Fair Value, Assets Measured on Recurring and Nonrecurring Basis [Line Items]    
Fair Value 7,204 4,199
Level 2 | U.S. state and municipal securities    
Fair Value, Assets Measured on Recurring and Nonrecurring Basis [Line Items]    
Fair Value 424 561
Level 2 | Non-agency commercial mortgage-backed securities    
Fair Value, Assets Measured on Recurring and Nonrecurring Basis [Line Items]    
Fair Value 112 113
Level 2 | Other    
Fair Value, Assets Measured on Recurring and Nonrecurring Basis [Line Items]    
Fair Value 18 19
Level 2 | Total other securities owned    
Fair Value, Assets Measured on Recurring and Nonrecurring Basis [Line Items]    
Other assets: 177 144
Level 2 | Equity, corporate debt, and other securities    
Fair Value, Assets Measured on Recurring and Nonrecurring Basis [Line Items]    
Other assets: 113 84
Level 2 | Mutual funds and ETFs    
Fair Value, Assets Measured on Recurring and Nonrecurring Basis [Line Items]    
Other assets: 0 0
Level 2 | State and municipal debt obligations    
Fair Value, Assets Measured on Recurring and Nonrecurring Basis [Line Items]    
Other assets: 48 45
Level 2 | Interest rate swaps    
Fair Value, Assets Measured on Recurring and Nonrecurring Basis [Line Items]    
Other assets:   1
Total accrued expenses and other liabilities 2 1
Level 2 | Other    
Fair Value, Assets Measured on Recurring and Nonrecurring Basis [Line Items]    
Total accrued expenses and other liabilities 53 40
Level 3    
Fair Value, Assets Measured on Recurring and Nonrecurring Basis [Line Items]    
Cash equivalents: 0 0
Investments segregated and on deposit for regulatory purposes: 0 0
Fair Value 0 0
Other assets: 0 0
Total assets 0 0
Total accrued expenses and other liabilities 0 0
Total liabilities 0 0
Level 3 | Money market funds    
Fair Value, Assets Measured on Recurring and Nonrecurring Basis [Line Items]    
Cash equivalents: 0 0
Level 3 | U.S. Treasury securities    
Fair Value, Assets Measured on Recurring and Nonrecurring Basis [Line Items]    
Cash equivalents:   0
Fair Value 0 0
Level 3 | U.S. government securities    
Fair Value, Assets Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments segregated and on deposit for regulatory purposes: 0 0
Other assets: 0 0
Level 3 | U.S. agency mortgage-backed securities    
Fair Value, Assets Measured on Recurring and Nonrecurring Basis [Line Items]    
Fair Value 0 0
Level 3 | Corporate debt securities    
Fair Value, Assets Measured on Recurring and Nonrecurring Basis [Line Items]    
Fair Value 0 0
Level 3 | Asset-backed securities    
Fair Value, Assets Measured on Recurring and Nonrecurring Basis [Line Items]    
Fair Value 0 0
Level 3 | U.S. state and municipal securities    
Fair Value, Assets Measured on Recurring and Nonrecurring Basis [Line Items]    
Fair Value 0 0
Level 3 | Non-agency commercial mortgage-backed securities    
Fair Value, Assets Measured on Recurring and Nonrecurring Basis [Line Items]    
Fair Value 0 0
Level 3 | Other    
Fair Value, Assets Measured on Recurring and Nonrecurring Basis [Line Items]    
Fair Value 0 0
Level 3 | Total other securities owned    
Fair Value, Assets Measured on Recurring and Nonrecurring Basis [Line Items]    
Other assets: 0 0
Level 3 | Equity, corporate debt, and other securities    
Fair Value, Assets Measured on Recurring and Nonrecurring Basis [Line Items]    
Other assets: 0 0
Level 3 | Mutual funds and ETFs    
Fair Value, Assets Measured on Recurring and Nonrecurring Basis [Line Items]    
Other assets: 0 0
Level 3 | State and municipal debt obligations    
Fair Value, Assets Measured on Recurring and Nonrecurring Basis [Line Items]    
Other assets: 0 0
Level 3 | Interest rate swaps    
Fair Value, Assets Measured on Recurring and Nonrecurring Basis [Line Items]    
Other assets:   0
Total accrued expenses and other liabilities 0 0
Level 3 | Other    
Fair Value, Assets Measured on Recurring and Nonrecurring Basis [Line Items]    
Total accrued expenses and other liabilities $ 0 $ 0