v3.26.3
Fair Value Measurements - Schedule of Fair Value Hierarchy for Financial Assets (Details) - USD ($)
$ in Millions
Sep. 30, 2026
Dec. 31, 2025
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Abstract]    
Total debt securities, available-for-sale $ 856.5 $ 1,081.0
Recurring    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Abstract]    
Cash equivalents 407.8 392.8
Total debt securities, available-for-sale 856.5 1,081.0
Convertible note investments 10.7 10.5
Deferred compensation plan assets 21.8 20.0
Total assets measured at fair value on a recurring basis 1,296.8 1,504.3
U.S. government agencies    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Abstract]    
Total debt securities, available-for-sale 336.0 357.3
U.S. government agencies | Recurring    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Abstract]    
Total debt securities, available-for-sale 336.0 357.3
Commercial paper    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Abstract]    
Total debt securities, available-for-sale 132.6 123.4
Commercial paper | Recurring    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Abstract]    
Total debt securities, available-for-sale 132.6 123.4
Corporate debt    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Abstract]    
Total debt securities, available-for-sale 387.9 600.3
Corporate debt | Recurring    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Abstract]    
Total debt securities, available-for-sale 387.9 600.3
Level 1 | Recurring    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Abstract]    
Cash equivalents 402.3 392.8
Total debt securities, available-for-sale 0.0 0.0
Convertible note investments 0.0 0.0
Deferred compensation plan assets 21.8 20.0
Total assets measured at fair value on a recurring basis 424.1 412.8
Level 1 | U.S. government agencies | Recurring    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Abstract]    
Total debt securities, available-for-sale 0.0 0.0
Level 1 | Commercial paper | Recurring    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Abstract]    
Total debt securities, available-for-sale 0.0 0.0
Level 1 | Corporate debt | Recurring    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Abstract]    
Total debt securities, available-for-sale 0.0 0.0
Level 2 | Recurring    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Abstract]    
Cash equivalents 5.5 0.0
Total debt securities, available-for-sale 856.5 1,081.0
Convertible note investments 0.0 0.0
Deferred compensation plan assets 0.0 0.0
Total assets measured at fair value on a recurring basis 862.0 1,081.0
Level 2 | U.S. government agencies | Recurring    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Abstract]    
Total debt securities, available-for-sale 336.0 357.3
Level 2 | Commercial paper | Recurring    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Abstract]    
Total debt securities, available-for-sale 132.6 123.4
Level 2 | Corporate debt | Recurring    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Abstract]    
Total debt securities, available-for-sale 387.9 600.3
Level 3 | Recurring    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Abstract]    
Cash equivalents 0.0 0.0
Total debt securities, available-for-sale 0.0 0.0
Convertible note investments 10.7 10.5
Deferred compensation plan assets 0.0 0.0
Total assets measured at fair value on a recurring basis 10.7 10.5
Level 3 | U.S. government agencies | Recurring    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Abstract]    
Total debt securities, available-for-sale 0.0 0.0
Level 3 | Commercial paper | Recurring    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Abstract]    
Total debt securities, available-for-sale 0.0 0.0
Level 3 | Corporate debt | Recurring    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Abstract]    
Total debt securities, available-for-sale $ 0.0 $ 0.0