CLEARING OPERATIONS - Clearing participant (Details) - USD ($) $ in Millions	Dec. 31, 2025	Dec. 31, 2024
Clearing Operations
Cboe Clear Europe central bank account	$ 1,156.5	$ 841.4
Cboe Clear Europe reverse repurchase and other	460.5
Cboe Clear U.S. customer bank deposits	1.2	4.1
Total cash margin deposits, clearing funds, and interoperability funds	1,618.2	845.5
Cboe Clear Europe non-cash contributions	$ 949.0	997.4
Minimum collateralization, as a percent	102.00%
Margin Deposits
Clearing Operations
Cboe Clear Europe central bank account	$ 755.3	378.4
Cboe Clear Europe reverse repurchase and other	137.1
Cboe Clear U.S. customer bank deposits	1.2	4.1
Total cash margin deposits, clearing funds, and interoperability funds	893.6	382.5
Cboe Clear Europe non-cash contributions	601.3	691.4
Clearing Funds
Clearing Operations
Cboe Clear Europe central bank account	146.8	173.7
Cboe Clear Europe reverse repurchase and other	135.2
Cboe Clear U.S. customer bank deposits	0.0	0.0
Total cash margin deposits, clearing funds, and interoperability funds	282.0	173.7
Cboe Clear Europe non-cash contributions	70.1	80.1
Interoperability Funds
Clearing Operations
Cboe Clear Europe central bank account	254.4	289.3
Cboe Clear Europe reverse repurchase and other	188.2
Cboe Clear U.S. customer bank deposits	0.0	0.0
Total cash margin deposits, clearing funds, and interoperability funds	442.6	289.3
Cboe Clear Europe non-cash contributions	$ 277.6	$ 225.9