v3.26.3
Financial Instruments and Risk Management (Financial Assets and Liabilities Carried at Fair Value) (Details) - USD ($)
$ in Millions
Sep. 30, 2026
Dec. 31, 2025
Sep. 30, 2025
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]      
Equity securities $ 69.9 $ 65.7  
Available-for-sale fixed income investments      
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]      
Available-for-sale securities 40.0 40.7  
Level 1      
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]      
Cash equivalents 1,370.6 982.2  
Equity securities 69.9 65.7  
Total assets at recurring fair value measurement 1,440.5 1,047.9  
Level 1 | Money market funds      
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]      
Cash equivalents 1,370.6 982.2  
Level 1 | Exchange traded funds      
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]      
Equity securities 66.5 62.3  
Level 1 | Marketable securities      
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]      
Equity securities 3.4 3.4  
Level 2      
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]      
Total assets at recurring fair value measurement 147.2 939.9  
Financial and Nonfinancial Liabilities, Fair Value Disclosure 96.3 169.3  
Level 2 | Foreign currency forward contracts      
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]      
Foreign exchange derivative assets 107.2 84.2  
Foreign exchange derivative liabilities 96.3 119.2  
Level 2 | Available-for-sale fixed income investments      
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]      
Available-for-sale securities 40.0 40.7  
Level 2 | Corporate bonds      
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]      
Available-for-sale securities 13.5 14.1  
Level 2 | U.S. Treasuries      
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]      
Available-for-sale securities 20.9 20.2  
Level 2 | Agency mortgage-backed securities      
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]      
Available-for-sale securities 1.9 2.3  
Level 2 | Asset-backed Securities      
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]      
Available-for-sale securities 3.4 3.8  
Level 2 | Other      
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]      
Available-for-sale securities 0.3 0.3  
Level 2 | Convertible Preferred Stock      
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]      
Equity Securities, FV-NI   (815.0)  
Level 3      
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]      
Total assets at recurring fair value measurement   0.0 $ 0.0
Financial and Nonfinancial Liabilities, Fair Value Disclosure 440.8 $ 371.6  
Level 3 | Contingent consideration      
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]      
Other Liabilities, Fair Value Disclosure $ 440.8