v3.26.1
Fair Value Measurements - Narrative (Details) - USD ($)
$ in Millions
3 Months Ended
Mar. 31, 2026
Mar. 31, 2025
Dec. 31, 2025
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]      
Securities owned not readily marketable $ 571.6   $ 334.0
Net unrealized gains (losses) recognized on investments still held as of period end date 24.0 $ 139.7  
Long-term debt 1,986.2   1,985.9
Level 2      
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]      
Long-term debt, fair value 1,564.0   1,576.0
Level 3      
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]      
Equity investments $ 169.9   $ 147.5