v3.26.1
Financial Assets And Financial Liabilities (Fair Value Table) (Details) - USD ($)
$ in Millions
Jun. 30, 2026
Dec. 31, 2025
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Securities segregated for regulatory purposes $ 8,026 $ 6,097
Financial instruments owned, at fair value 3,317 4,982
Other assets 621 516
Total financial assets at fair value 11,964 11,595
Financial instruments sold, but not yet purchased, at fair value 509 740
Accounts payable, accrued expenses and other liabilities 582 428
Total Financial Liabilities at Fair Value 1,091 1,168
Municipal Securities [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Securities segregated for regulatory purposes   66
Financial instruments owned, at fair value 131  
Common Stock [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Financial instruments owned, at fair value 3,008 4,780
Financial instruments sold, but not yet purchased, at fair value 254 199
Options Owned [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Financial instruments owned, at fair value 140 72
Financial instruments sold, but not yet purchased, at fair value 207 498
U.S. And Foreign Government Securities [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Securities segregated for regulatory purposes 7,895 6,031
Financial instruments owned, at fair value 85 63
Customer-Held Fractional Shares [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Other assets 582 428
Other Investments In Equity Securities [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Other assets 39 88
Precious Metals [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Financial instruments owned, at fair value 48 50
Financial instruments sold, but not yet purchased, at fair value 42 42
Currency Forward Contracts [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Financial instruments owned, at fair value 36 17
Financial instruments sold, but not yet purchased, at fair value 6 1
Level 1 [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Securities segregated for regulatory purposes 7,895 6,031
Financial instruments owned, at fair value 3,165 4,866
Other assets 621 516
Total financial assets at fair value 11,681 11,413
Financial instruments sold, but not yet purchased, at fair value 298 214
Accounts payable, accrued expenses and other liabilities 582 428
Total Financial Liabilities at Fair Value 880 642
Level 1 [Member] | Common Stock [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Financial instruments owned, at fair value 3,008 4,780
Financial instruments sold, but not yet purchased, at fair value 254 199
Level 1 [Member] | Options Owned [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Financial instruments owned, at fair value 72 23
Financial instruments sold, but not yet purchased, at fair value 44 15
Level 1 [Member] | U.S. And Foreign Government Securities [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Securities segregated for regulatory purposes 7,895 6,031
Financial instruments owned, at fair value 85 63
Level 1 [Member] | Customer-Held Fractional Shares [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Other assets 582 428
Level 1 [Member] | Other Investments In Equity Securities [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Other assets 39 88
Level 2 [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Securities segregated for regulatory purposes 131 66
Financial instruments owned, at fair value 152 116
Total financial assets at fair value 283 182
Financial instruments sold, but not yet purchased, at fair value 211 526
Total Financial Liabilities at Fair Value 211 526
Level 2 [Member] | Municipal Securities [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Securities segregated for regulatory purposes   66
Financial instruments owned, at fair value 131  
Level 2 [Member] | Options Owned [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Financial instruments owned, at fair value 68 49
Financial instruments sold, but not yet purchased, at fair value 163 483
Level 2 [Member] | Precious Metals [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Financial instruments owned, at fair value 48 50
Financial instruments sold, but not yet purchased, at fair value 42 42
Level 2 [Member] | Currency Forward Contracts [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Financial instruments owned, at fair value 36 17
Financial instruments sold, but not yet purchased, at fair value $ 6 $ 1