v3.26.1
Fair Value Measurement - Schedule of Assets and Liabilities Measured at Fair Value on Recurring Basis (Details) - USD ($)
$ in Millions
Jun. 30, 2026
Dec. 31, 2025
Assets    
Subtotal $ 13,774.6  
Investments measured at net asset value   $ 13,107.9
Liabilities    
Loans payable of Consolidated Funds 9,837.2 9,423.1
Total 9,839.5 9,427.5
Foreign currency forward contracts    
Liabilities    
Foreign currency forward contracts 2.3 4.4
Revolving Credit Facility    
Liabilities    
Loans payable of Consolidated Funds 41.5 63.0
Equity securities | Consolidated VIEs    
Assets    
Investments measured at net asset value 844.3 989.4
Investments In CLOs and other    
Assets    
Investments 444.7  
Fair Value, Inputs, Level 1, 2 and 3    
Assets    
Subtotal 11,741.3 11,767.3
Fair Value, Inputs, Level 1, 2 and 3 | Foreign currency forward contracts    
Assets    
Foreign currency forward contracts 1.4 4.8
Fair Value, Inputs, Level 1, 2 and 3 | Investments of Consolidated Funds    
Assets    
Investments 11,295.2 11,186.0
Fair Value, Inputs, Level 1, 2 and 3 | Equity securities    
Assets    
Investments 1,072.3 1,245.0
Fair Value, Inputs, Level 1, 2 and 3 | Bonds    
Assets    
Investments 720.7 691.2
Fair Value, Inputs, Level 1, 2 and 3 | Loans    
Assets    
Investments 9,502.2 9,249.8
Fair Value, Inputs, Level 1, 2 and 3 | Investments In CLOs and other    
Assets    
Investments   576.5
Fair Value, Inputs, Level 1, 2 and 3 | Investments in CLOs    
Assets    
Investments 321.0 349.0
Fair Value, Inputs, Level 1, 2 and 3 | Other investments    
Assets    
Investments 123.7 227.5
Level I    
Assets    
Subtotal 151.8 244.0
Liabilities    
Loans payable of Consolidated Funds 0.0 0.0
Total 0.0 0.0
Level I | Foreign currency forward contracts    
Assets    
Foreign currency forward contracts 0.0 0.0
Liabilities    
Foreign currency forward contracts 0.0 0.0
Level I | Investments of Consolidated Funds    
Assets    
Investments 68.3 132.0
Level I | Equity securities    
Assets    
Investments 68.3 132.0
Level I | Bonds    
Assets    
Investments 0.0 0.0
Level I | Loans    
Assets    
Investments 0.0 0.0
Level I | Investments In CLOs and other    
Assets    
Investments 83.5 112.0
Level I | Investments in CLOs    
Assets    
Investments 0.0 0.0
Level I | Other investments    
Assets    
Investments 83.5 112.0
Level II    
Assets    
Subtotal 43.8 43.9
Liabilities    
Loans payable of Consolidated Funds 0.0 0.0
Total 2.3 4.4
Level II | Foreign currency forward contracts    
Assets    
Foreign currency forward contracts 1.4 4.8
Liabilities    
Foreign currency forward contracts 2.3 4.4
Level II | Investments of Consolidated Funds    
Assets    
Investments 22.2 18.2
Level II | Equity securities    
Assets    
Investments 22.2 18.2
Level II | Bonds    
Assets    
Investments 0.0 0.0
Level II | Loans    
Assets    
Investments 0.0 0.0
Level II | Investments In CLOs and other    
Assets    
Investments 20.2 20.9
Level II | Investments in CLOs    
Assets    
Investments 0.0 0.0
Level II | Other investments    
Assets    
Investments 20.2 20.9
Level III    
Assets    
Subtotal 11,545.7 11,479.4
Liabilities    
Loans payable of Consolidated Funds 9,837.2 9,423.1
Total 9,837.2 9,423.1
Level III | Foreign currency forward contracts    
Assets    
Foreign currency forward contracts 0.0 0.0
Liabilities    
Foreign currency forward contracts 0.0 0.0
Level III | Investments of Consolidated Funds    
Assets    
Investments 11,204.7 11,035.8
Level III | Equity securities    
Assets    
Investments 981.8 1,094.8
Investments measured at net asset value 98.1 63.0
Level III | Bonds    
Assets    
Investments 720.7 691.2
Level III | Loans    
Assets    
Investments 9,502.2 9,249.8
Level III | Investments In CLOs and other    
Assets    
Investments 341.0 443.6
Level III | Investments in CLOs    
Assets    
Investments 321.0 349.0
Level III | Other investments    
Assets    
Investments 20.0 94.6
Fair Value Measured at NAV    
Assets    
Investments measured at net asset value 2,033.3 1,340.6
Fair Value Measured at NAV | Investments of Consolidated Funds    
Assets    
Investments $ 2,000.0 $ 1,300.0