INCOME TAXES - Deferred Income Taxes (Benefits) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Income Tax Disclosure [Abstract]
Property, equipment and software	$ 149.8	$ (60.3)	$ (43.2)
Accrued, deferred, and long-term incentive compensation	(20.0)	(14.2)	(28.6)
Operating lease assets	33.9	(1.7)	(6.3)
Operating lease liabilities	(41.7)	5.0	3.8
Acquisition-related liabilities	(13.5)	(9.8)	0.6
Acquired investments	(5.3)	(27.9)	(19.5)
Unrealized gains (losses) recognized in non-operating income	16.6	16.8	43.8
Net operating losses	(15.8)	(11.2)	(31.5)
Change in valuation allowances	11.2	16.1	86.4
Other	(18.4)	(0.8)	3.1
Total net deferred income taxes (benefits)	$ 96.8	$ (88.0)	$ 8.6