v3.25.2
Financial Assets And Financial Liabilities (Fair Value Table) (Details) - USD ($)
$ in Millions
Jun. 30, 2025
Dec. 31, 2024
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Securities segregated for regulatory purposes $ 6,020 $ 6,493
Total financial instruments owned, at fair value 3,856 1,924
Other assets 382 292
Total financial assets at fair value 10,258 8,709
Financial instruments sold, not yet purchased, at fair value 494 293
Accounts payable, accrued expenses and other liabilities 334 260
Total Financial Liabilities at Fair Value 828 553
US And Foreign Government Securities [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Securities segregated for regulatory purposes 5,956 6,460
Municipal Securities [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Securities segregated for regulatory purposes 64 33
Common Stock [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Total financial instruments owned, at fair value 2,990 1,763
Financial instruments sold, not yet purchased, at fair value 132 116
Options Owned [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Total financial instruments owned, at fair value 55 84
Financial instruments sold, not yet purchased, at fair value 332 96
U.S. And Foreign Government Securities [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Total financial instruments owned, at fair value 644 54
Customer-Held Fractional Shares [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Other assets 334 260
Other Investments In Equity Securities [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Other assets 48 32
Fractional Shares Repurchase Obligation [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Accounts payable, accrued expenses and other liabilities 334 260
Mutual Funds [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Total financial instruments owned, at fair value   2
Precious Metals [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Total financial instruments owned, at fair value 33 21
Financial instruments sold, not yet purchased, at fair value 29 18
Currency Forward Contracts [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Total financial instruments owned, at fair value 134  
Financial instruments sold, not yet purchased, at fair value 1 63
Level 1 [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Securities segregated for regulatory purposes 5,956 6,460
Total financial instruments owned, at fair value 3,665 1,903
Other assets 382 292
Total financial assets at fair value 10,003 8,655
Financial instruments sold, not yet purchased, at fair value 150 212
Accounts payable, accrued expenses and other liabilities 334 260
Total Financial Liabilities at Fair Value 484 472
Level 1 [Member] | US And Foreign Government Securities [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Securities segregated for regulatory purposes 5,956 6,460
Level 1 [Member] | Common Stock [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Total financial instruments owned, at fair value 2,990 1,763
Financial instruments sold, not yet purchased, at fair value 132 116
Level 1 [Member] | Options Owned [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Total financial instruments owned, at fair value 31 84
Financial instruments sold, not yet purchased, at fair value 18 96
Level 1 [Member] | U.S. And Foreign Government Securities [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Total financial instruments owned, at fair value 644 54
Level 1 [Member] | Customer-Held Fractional Shares [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Other assets 334 260
Level 1 [Member] | Other Investments In Equity Securities [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Other assets 48 32
Level 1 [Member] | Fractional Shares Repurchase Obligation [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Accounts payable, accrued expenses and other liabilities 334 260
Level 1 [Member] | Mutual Funds [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Total financial instruments owned, at fair value   2
Level 2 [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Securities segregated for regulatory purposes 64 33
Total financial instruments owned, at fair value 191 21
Total financial assets at fair value 255 54
Financial instruments sold, not yet purchased, at fair value 344 81
Total Financial Liabilities at Fair Value 344 81
Level 2 [Member] | Municipal Securities [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Securities segregated for regulatory purposes 64 33
Level 2 [Member] | Options Owned [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Total financial instruments owned, at fair value 24  
Financial instruments sold, not yet purchased, at fair value 314  
Level 2 [Member] | Precious Metals [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Total financial instruments owned, at fair value 33 21
Financial instruments sold, not yet purchased, at fair value 29 18
Level 2 [Member] | Currency Forward Contracts [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Total financial instruments owned, at fair value 134  
Financial instruments sold, not yet purchased, at fair value $ 1 $ 63