GOODWILL, INTANGIBLE ASSETS, NET, AND DIGITAL ASSETS HELD - Intangible assets by segment (Details) - USD ($) $ in Millions	3 Months Ended		12 Months Ended
	Dec. 31, 2025	Jun. 30, 2024	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Intangible Assets
Balance at beginning of the period			$ 1,376.9	$ 1,561.5
Additions				1.2
Sales			(0.7)	(0.1)
Amortization			(70.2)	(88.7)	$ (116.6)
Changes in foreign currency exchange rates			27.8	(16.0)
Impairment			(36.6)	(81.0)
Balance at end of the period	$ 1,297.2		1,297.2	1,376.9	1,561.5
Options
Intangible Assets
Balance at beginning of the period			126.4	134.1
Additions				0.0
Sales			0.0	0.0
Amortization			(6.5)	(7.7)
Changes in foreign currency exchange rates			0.0	0.0
Impairment			0.0	0.0
Balance at end of the period	119.9		119.9	126.4	134.1
North American Equities
Intangible Assets
Balance at beginning of the period			879.6	935.3
Additions				1.2
Sales			(0.7)	0.0
Amortization			(39.9)	(50.6)
Changes in foreign currency exchange rates			3.3	(6.3)
Impairment	(17.7)		(17.7)	0.0
Balance at end of the period	824.6		824.6	879.6	935.3
Europe and Asia Pacific
Intangible Assets
Balance at beginning of the period			326.7	352.5
Additions				0.0
Sales			0.0	0.0
Amortization			(14.2)	(16.1)
Changes in foreign currency exchange rates			24.5	(9.7)
Impairment			(18.9)	0.0
Balance at end of the period	318.1		318.1	326.7	352.5
Global FX
Intangible Assets
Balance at beginning of the period			44.2	56.2
Additions				0.0
Sales			0.0	0.0
Amortization			(9.6)	(12.0)
Changes in foreign currency exchange rates			0.0	0.0
Impairment			0.0	0.0
Balance at end of the period	34.6		34.6	44.2	56.2
Digital
Intangible Assets
Balance at beginning of the period			0.0	83.4
Additions				0.0
Sales			0.0	(0.1)
Amortization			0.0	(2.3)
Changes in foreign currency exchange rates			0.0	0.0
Impairment		$ (81.0)	0.0	(81.0)
Balance at end of the period	$ 0.0		$ 0.0	$ 0.0	$ 83.4