REVENUES - Schedule of Revenue Disaggregated by Revenue Source (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Disaggregation of Revenue [Line Items]
Interest expenses related to credit facilities	$ (6)	$ (6)
Total net interest revenues	254	208
Total net revenues	618	441
Transaction-based revenues
Disaggregation of Revenue [Line Items]
Total transaction-based revenues	329	207
Options
Disaggregation of Revenue [Line Items]
Total transaction-based revenues	154	133
Cryptocurrencies
Disaggregation of Revenue [Line Items]
Total transaction-based revenues	126	38
Equities
Disaggregation of Revenue [Line Items]
Total transaction-based revenues	39	27
Other
Disaggregation of Revenue [Line Items]
Total transaction-based revenues	10	9
Margin interest
Disaggregation of Revenue [Line Items]
Net interest revenues	72	53
Interest on corporate cash and investments
Disaggregation of Revenue [Line Items]
Net interest revenues	70	68
Interest on segregated cash, securities, and deposits
Disaggregation of Revenue [Line Items]
Net interest revenues	58	45
Cash Sweep
Disaggregation of Revenue [Line Items]
Net interest revenues	39	22
Securities lending, net
Disaggregation of Revenue [Line Items]
Net interest revenues	15	26
Credit card, net
Disaggregation of Revenue [Line Items]
Net interest revenues	6	0
Other revenues
Disaggregation of Revenue [Line Items]
Total transaction-based revenues	$ 35	$ 26