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Fair Value Measurements (Tables) | 6 Months Ended
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Jun. 30, 2025
Fair Value Disclosures [Abstract] |
Schedule of Fair Value of Assets and Liabilities Measured on a Recurring Basis | The following tables summarize financial assets and liabilities that are measured at fair value on a recurring basis:
|  |  | Fair Value Measurements
| December 31, 2024 |
|  | Quoted Prices in Active Markets for Identical Assets (Level 1) |  | Significant Other Observable Inputs (Level 2) |  | Significant Unobservable Inputs (Level 3)
Financial Assets |  |  |  |  |  |  |
Investments in equity securities(1) | $32.3 |  | $32.3 |  | $— |  | $—
Investments in debt securities(1) | 24.3 |  | — |  | 24.3 |  | —
Financial Liabilities(2) |  |  |  |  |  |  |
Contingent payment obligations | $5.7 |  | $— |  | $— |  | $5.7
Affiliate equity purchase obligations | 54.8 |  | — |  | — |  | 54.8
|  |  | Fair Value Measurements
| June 30, 2025 |
|  | Quoted Prices in Active Markets for Identical Assets (Level 1) |  | Significant Other Observable Inputs (Level 2) |  | Significant Unobservable Inputs (Level 3)
Financial Assets |  |  |  |  |  |  |
Investments in equity securities(1) | $51.3 |  | $51.3 |  | $— |  | $—
Investments in debt securities(1) | 26.7 |  | — |  | 26.7 |  | —
Financial Liabilities(2) |  |  |  |  |  |  |
Contingent payment obligations | $0.0 |  | $— |  | $— |  | $0.0
Affiliate equity purchase obligations | 117.9 |  | — |  | — |  | 117.9
___________________________ (1)Amounts are recorded in Investments on the Consolidated Balance Sheets. (2)Amounts are recorded in Other liabilities on the Consolidated Balance Sheets.
Schedule of Changes in Level 3 Assets and Liabilities for Affiliate Equity Repurchase Obligation | The following tables present the changes in Level 3 liabilities:
|  | For the Three Months Ended June 30,
|  | 2024 |  | 2025
|  | Contingent Payment Obligations |  | Affiliate Equity Purchase Obligations |  | Contingent Payment Obligations |  | Affiliate Equity Purchase Obligations
Balance, beginning of period |  | $9.6 |  | $37.7 |  | $5.6 |  | $48.4
Purchases and issuances(1) |  | — |  | 31.3 |  | — |  | 71.1
Settlements and reductions |  | — |  | (16.6) |  | (4.9) |  | (13.7)
Net realized and unrealized (gains) losses(2) |  | (1.7) |  | 1.5 |  | (0.7) |  | 12.1
Balance, end of period |  | $7.9 |  | $53.9 |  | $0.0 |  | $117.9
Net change in unrealized (gains) losses relating to instruments still held at the reporting date(1) |  | $(1.7) |  | $1.5 |  | $— |  | $13.1
|  | For the Six Months Ended June 30,
|  | 2024 |  | 2025
|  | Contingent Payment Obligations |  | Affiliate Equity Purchase Obligations |  | Contingent Payment Obligations |  | Affiliate Equity Purchase Obligations
Balance, beginning of period |  | $14.7 |  | $53.9 |  | $5.7 |  | $54.8
Purchases and issuances(1) |  | — |  | 56.2 |  | — |  | 93.1
Settlements and reductions |  | — |  | (57.1) |  | (4.9) |  | (43.4)
Net realized and unrealized (gains) losses(2) |  | (6.8) |  | 0.9 |  | (0.8) |  | 13.4
Balance, end of period |  | $7.9 |  | $53.9 |  | $0.0 |  | $117.9
Net change in unrealized (gains) losses relating to instruments still held at the reporting date(1) |  | $(6.8) |  | $0.9 |  | $(0.1) |  | $14.4
___________________________ (1)Affiliate equity purchase obligation activity includes transfers from Redeemable non-controlling interests. (2)Gains and losses resulting from changes to expected payments related to contingent payment obligations and the accretion of these o bligations are included in Other expenses (net) and included in Interest expense, respectively, in the Consolidated Statements of Income. Changes to the redemption value of Affiliate equity purchase obligations are included in Compensation and related expenses in the Consolidated Statements of Income.
Schedule of Quantitative Information used in Valuing Level 3 Liabilities | The following table presents certain quantitative information about the significant unobservable inputs used in valuing the Company’s Level 3 fair value measurements:
| Quantitative Information about Level 3 Fair Value Measurements
|  |  |  |  | December 31, 2024 |  | June 30, 2025
| Valuation Techniques |  | Unobservable Input |  | Fair Value |  | Range |  | Weighted Average(1) |  | Fair Value |  | Range |  | Weighted Average(1)
Contingent payment obligations | Monte Carlo Simulation |  | Volatility |  | $5.7 |  | 18% |  | 18% |  | $0.0 |  | 20% |  | 20%
|  |  | Discount rates |  |  |  | 4% |  | 4% |  |  |  | 5% |  | 5%
Affiliate equity purchase obligations | Discounted cash flow |  | Growth rates(2) |  | $54.8 |  | (4)% - 9% |  | 1% |  | $117.9 |  | (4)% - 9% |  | 6%
|  |  | Discount rates |  |  |  | 12% - 19% |  | 14% |  |  |  | 12% - 19% |  | 15%
___________________________ (1)Calculated by comparing the relative fair value of an obligation to its respective total. (2)Represents growth rates of asset- and performance-based fees.
Schedule of Other Financial Assets and Liabilities Not Carried at Fair Value | The following table summarizes the Company’s other financial liabilities not carried at fair value:
| December 31, 2024 |  | June 30, 2025 |  |
| Carrying Value |  | Fair Value |  | Carrying Value |  | Fair Value |  | Fair Value Hierarchy
Senior notes | $1,097.4 |  | $1,062.9 |  | $1,097.6 |  | $1,078.5 |  | Level 2
Junior subordinated notes | 1,216.0 |  | 1,035.6 |  | 1,216.1 |  | 969.7 |  | Level 2
Junior convertible securities | 341.7 |  | 372.2 |  | 341.7 |  | 390.6 |  | Level 2

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- Definition Tabular disclosure of input and valuation technique used to measure fair value and change in valuation approach and technique for each separate class of asset and liability measured on recurring and nonrecurring basis. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 820 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Subparagraph (bbb)(1) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482106/820-10-50-2 Reference 2: http://www.xbrl.org/2003/role/exampleRef -Topic 820 -SubTopic 10 -Name Accounting Standards Codification -Section 55 -Paragraph 103 -Publisher FASB -URI https://asc.fasb.org/1943274/2147482078/820-10-55-103 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Topic 820 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Subparagraph (bbb)(2) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482106/820-10-50-2 + Details
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- Definition Tabular disclosure of the fair value measurement of liabilities using significant unobservable inputs (Level 3), a reconciliation of the beginning and ending balances, separately presenting changes attributable to the following: (1) total gains or losses for the period (realized and unrealized), segregating those gains or losses included in earnings (or changes in net assets), and gains or losses recognized in other comprehensive income (loss) and a description of where those gains or losses included in earnings (or changes in net assets) are reported in the statement of income (or activities); (2) purchases, sales, issues, and settlements (each type disclosed separately); and (3) transfers in and transfers out of Level 3 (for example, transfers due to changes in the observability of significant inputs) by class of liability. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 820 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 3 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482106/820-10-50-3 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 820 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Subparagraph (d) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482106/820-10-50-2 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Topic 820 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Subparagraph (c) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482106/820-10-50-2 + Details
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- Definition Tabular disclosure of assets and liabilities, including [financial] instruments measured at fair value that are classified in stockholders' equity, if any, that are measured at fair value on a recurring basis. The disclosures contemplated herein include the fair value measurements at the reporting date by the level within the fair value hierarchy in which the fair value measurements in their entirety fall, segregating fair value measurements using quoted prices in active markets for identical assets (Level 1), significant other observable inputs (Level 2), and significant unobservable inputs (Level 3). + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 820 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482106/820-10-50-2 Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 820 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482106/820-10-50-2 + Details
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