v3.26.1
Revenue From Contracts With Customers (Disaggregation of Revenue ) (Details) - USD ($)
$ in Millions
 3 Months Ended 6 Months Ended
Jun. 30, 2026
Jun. 30, 2025
Jun. 30, 2026
Jun. 30, 2025
Disaggregation of Revenue [Line Items]        
Revenue from Contract with Customer, Excluding Assessed Tax [1] $ 760 $ 578 $ 1,459 $ 1,170
United States [Member]        
Disaggregation of Revenue [Line Items]        
Revenue from Contract with Customer, Excluding Assessed Tax [1] 457 351 870 713
International [Member]        
Disaggregation of Revenue [Line Items]        
Revenue from Contract with Customer, Excluding Assessed Tax [1] 303 227 589 457
Commissions [Member]        
Disaggregation of Revenue [Line Items]        
Revenue from Contract with Customer, Excluding Assessed Tax 673 516 1,286 1,030
Market Data Fees [Member]        
Disaggregation of Revenue [Line Items]        
Revenue from Contract with Customer, Excluding Assessed Tax [2] 23 20 44 39
Risk Exposure Fees [Member]        
Disaggregation of Revenue [Line Items]        
Revenue from Contract with Customer, Excluding Assessed Tax [2] 25 17 51 45
Payments For Order Flow [Member]        
Disaggregation of Revenue [Line Items]        
Revenue from Contract with Customer, Excluding Assessed Tax [2] 18 9 33 22
FDIC Sweep Fees [Member]        
Disaggregation of Revenue [Line Items]        
Revenue from Contract with Customer, Excluding Assessed Tax [2] 10 9 20 17
Others [Member]        
Disaggregation of Revenue [Line Items]        
Revenue from Contract with Customer, Excluding Assessed Tax [2] $ 11 $ 7 $ 25 $ 17
[1] Based on the location of the subsidiaries in which the revenues are recorded.
[2] Reported in “Other fees and services” in the condensed consolidated statements of comprehensive income.