REVENUES - Schedule of Revenue Disaggregated by Revenue Source (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Disaggregation of Revenue [Line Items]
Interest expenses related to credit facilities	$ (6)	$ (5)	$ (12)	$ (11)
Total net interest revenues	285	234	539	442
Total net revenues	682	486	1,300	927
Transaction-based revenues
Disaggregation of Revenue [Line Items]
Total transaction-based revenues	327	193	656	400
Options
Disaggregation of Revenue [Line Items]
Total transaction-based revenues	182	127	336	260
Cryptocurrencies
Disaggregation of Revenue [Line Items]
Total transaction-based revenues	81	31	207	69
Equities
Disaggregation of Revenue [Line Items]
Total transaction-based revenues	40	25	79	52
Other
Disaggregation of Revenue [Line Items]
Total transaction-based revenues	24	10	34	19
Margin interest
Disaggregation of Revenue [Line Items]
Net interest revenues	73	57	145	110
Interest on corporate cash and investments
Disaggregation of Revenue [Line Items]
Net interest revenues	66	74	136	142
Interest on segregated cash, securities, and deposits
Disaggregation of Revenue [Line Items]
Net interest revenues	68	52	126	97
Cash Sweep
Disaggregation of Revenue [Line Items]
Net interest revenues	44	29	83	51
Securities lending, net
Disaggregation of Revenue [Line Items]
Net interest revenues	34	27	49	53
Credit card, net
Disaggregation of Revenue [Line Items]
Net interest revenues	6	0	12	0
Other revenues
Disaggregation of Revenue [Line Items]
Total transaction-based revenues	70	59	105	85
Gold subscription revenues
Disaggregation of Revenue [Line Items]
Total transaction-based revenues	26	18	49	35
Proxy revenues
Disaggregation of Revenue [Line Items]
Total transaction-based revenues	38	38	45	45
Other
Disaggregation of Revenue [Line Items]
Total transaction-based revenues	$ 6	$ 3	$ 11	$ 5