XML 146 R45.htm IDEA: XBRL DOCUMENT v3.25.0.1
Fair Value Measurements - Financial Assets Measured at Fair Value on Recurring Basis (Details) - USD ($)
$ in Millions
Dec. 31, 2024
Dec. 31, 2023
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fair Value $ 1,940.4 $ 1,881.0
Cash and cash equivalents    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fair Value 233.0 251.1
Available-for-sale debt securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fair Value 1,582.6 1,468.0
Equity investments    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fair Value 124.8 161.9
Fair Value Measurements Recurring | Level 1    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fair value of assets on recurring basis 357.8 413.0
Fair Value Measurements Recurring | Level 2    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fair value of assets on recurring basis 1,582.6 1,468.0
Fair Value Measurements Recurring | Cash and cash equivalents | Level 1    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fair value of assets on recurring basis 233.0 251.1
Fair Value Measurements Recurring | Cash and cash equivalents | Level 2    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fair value of assets on recurring basis 0.0 0.0
Fair Value Measurements Recurring | Available-for-sale debt securities | Level 1    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fair value of assets on recurring basis 0.0 0.0
Fair Value Measurements Recurring | Available-for-sale debt securities | Level 2    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fair value of assets on recurring basis 1,582.6 1,468.0
Fair Value Measurements Recurring | Equity investments | Level 1    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fair value of assets on recurring basis 124.8 161.9
Fair Value Measurements Recurring | Equity investments | Level 2    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fair value of assets on recurring basis $ 0.0 $ 0.0