GOODWILL, INTANGIBLE ASSETS, NET, AND DIGITAL ASSETS HELD - Goodwill by segment (Details) - USD ($) $ in Millions		3 Months Ended	6 Months Ended	9 Months Ended
	May 02, 2022	Sep. 30, 2022	Jun. 30, 2022	Sep. 30, 2022	Sep. 30, 2021	Dec. 31, 2021
Goodwill
Balance at beginning of the period			$ 3,025.4	$ 3,025.4
Adjustment				18.7
Additions				592.5
Impairment		$ (0.8)		(460.9)
Changes in foreign currency exchange rates				(61.8)
Balance at end of the period		3,113.9		3,113.9
Deferred tax benefit				146.8	$ (17.5)
Carrying value		253.6		253.6		$ 245.8
Cboe Digital
Goodwill
Adjustment				0.8
Additions	$ 460.9
Impairment		(0.8)
Options
Goodwill
Balance at beginning of the period			305.8	305.8
Balance at end of the period		305.8		305.8
North American Equities
Goodwill
Balance at beginning of the period			1,876.9	1,876.9
Adjustment				14.5
Additions				132.4
Changes in foreign currency exchange rates				(11.8)
Balance at end of the period		2,012.0		2,012.0
Europe and Asia Pacific
Goodwill
Balance at beginning of the period			575.5	575.5
Adjustment				3.4
Changes in foreign currency exchange rates				(50.0)
Balance at end of the period		528.9		528.9
Global FX
Goodwill
Balance at beginning of the period			267.2	267.2
Balance at end of the period		267.2		267.2
Digital
Goodwill
Adjustment				0.8
Additions				460.1
Impairment			460.1	(460.9)
Deferred tax benefit			116.2
Decrease in carrying value			343.9
Carrying value			$ 220.0
Intangible asset impairment				0.0
Futures
Goodwill
Balance at end of the period		$ 0.0		$ 0.0