INVESTMENTS (Details) - USD ($) $ in Millions	3 Months Ended
	Sep. 30, 2024	Jun. 30, 2024	Dec. 31, 2023
Schedule of Cost and Equity Method Investments
Total equity method investments	$ 321.1		$ 292.0
Total other equity investments	37.0		53.3
Total investments	358.1		345.3
Investment in 7Ridge Investments 3 LP
Schedule of Cost and Equity Method Investments
Total equity method investments	321.1		292.0
Investment in Eris Innovations Holdings, LLC
Schedule of Cost and Equity Method Investments
Total other equity investments	20.0		20.0
Investment in Globacap Technology Limited
Schedule of Cost and Equity Method Investments
Total other equity investments	0.0		16.0
Investment in CSD Br
Schedule of Cost and Equity Method Investments
Total other equity investments	5.9		5.9
Investment in Coin Metrics Inc.
Schedule of Cost and Equity Method Investments
Total other equity investments	5.0		5.0
Investment in Cboe Vest Financial Group, Inc.
Schedule of Cost and Equity Method Investments
Total other equity investments	2.9		2.9
Investment in OCC
Schedule of Cost and Equity Method Investments
Total other equity investments	0.3		0.3
Other equity investments
Schedule of Cost and Equity Method Investments
Total other equity investments	2.9		$ 3.2
Globacap Technology Limited
Schedule of Cost and Equity Method Investments
Impairment charge		$ 16.0
StratiFi Technologies Inc.
Schedule of Cost and Equity Method Investments
Impairment charge	$ 1.2