CONSOLIDATED STATEMENTS OF INCOME - USD ($) shares in Millions, $ in Millions	3 Months Ended
	Mar. 31, 2026	Mar. 31, 2025
Income Statement [Abstract]
Consolidated revenue	$ 544.9	$ 496.6
Consolidated expenses:
Compensation and related expenses	287.1	230.3
Selling, general and administrative	107.4	94.7
Intangible amortization and impairments	49.2	83.3
Interest expense	38.4	34.1
Depreciation and other amortization	2.5	2.8
Other expenses (net)	21.3	11.7
Total consolidated expenses	505.9	456.9
Equity method income (net)	147.4	75.3
Investment and other income	6.5	11.6
Income before income taxes	192.9	126.6
Income tax expense	46.5	27.4
Net income	146.4	99.2
Net income (non-controlling interests)	(36.0)	(26.8)
Net income (controlling interest)	$ 110.4	$ 72.4
Average shares outstanding (basic) (in shares)	26.8	29.2
Average shares outstanding (diluted) (in shares)	27.5	32.6
Earnings per share (basic) (in dollars per share)	$ 4.12	$ 2.48
Earnings per share (diluted) (in dollars per share)	$ 3.84	$ 2.20