GOODWILL, INTANGIBLE ASSETS, NET, AND DIGITAL ASSETS HELD - Intangible assets by segment (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Intangible Assets
Balance at beginning of the period			$ 1,668.6
Additions			226.0
Amortization	$ (30.6)	$ (31.8)	(91.0)	$ (95.3)
Changes in foreign currency exchange rates			(76.5)
Balance at end of the period	1,666.1		1,666.1
Options
Intangible Assets
Balance at beginning of the period			159.1
Amortization			(9.8)
Balance at end of the period	149.3		149.3
North American Equities
Intangible Assets
Balance at beginning of the period			991.4
Additions			130.1
Amortization			(44.6)
Changes in foreign currency exchange rates			(6.9)
Balance at end of the period	1,009.0		1,009.0
Europe and Asia Pacific
Intangible Assets
Balance at beginning of the period			426.4
Amortization			(19.3)
Changes in foreign currency exchange rates			(69.6)
Balance at end of the period	337.5		337.5
Global FX
Intangible Assets
Balance at beginning of the period			91.7
Amortization			(14.3)
Balance at end of the period	77.4		77.4
Digital
Intangible Assets
Additions			95.9
Amortization			(3.0)
Balance at end of the period	$ 92.9		$ 92.9