v3.25.2
Cash, Cash Equivalents and Short-Term Investments - Schedule of Amortized Cost, Unrealized Gains and Losses and Estimated Fair Value of Cash, Cash Equivalents and Short-Term Investments (Details) - USD ($)
$ in Millions
Jun. 30, 2025
Dec. 31, 2024
Jun. 30, 2024
Cash and Cash Equivalents [Line Items]      
Cash and cash equivalents, amortized cost $ 736.3 $ 1,328.3 $ 515.1
Cash and cash equivalents, estimated fair value 736.3 1,328.3  
Short-term investments, amortized cost 221.7 272.9  
Short-term investments, unrealized gain 0.2 0.2  
Short-term investments, unrealized loss (3.5) (7.2)  
Short-term investments, estimated fair value 218.4 265.9  
Total cash, cash equivalents, and short term investments, before unrealized gains (losses) on investments 958.0 1,601.2  
Total cash, cash equivalents, and short term investments 954.7 1,594.2  
Corporate notes and obligations      
Cash and Cash Equivalents [Line Items]      
Short-term investments, amortized cost 101.4 133.1  
Short-term investments, unrealized gain 0.1 0.2  
Short-term investments, unrealized loss (1.6) (3.3)  
Short-term investments, estimated fair value 99.9 130.0  
U.S. Treasury securities      
Cash and Cash Equivalents [Line Items]      
Short-term investments, amortized cost 85.0 85.0  
Short-term investments, unrealized gain 0.1 0.0  
Short-term investments, unrealized loss (1.3) (2.6)  
Short-term investments, estimated fair value 83.8 82.4  
Municipal securities      
Cash and Cash Equivalents [Line Items]      
Short-term investments, amortized cost 21.1 30.0  
Short-term investments, unrealized gain 0.0 0.0  
Short-term investments, unrealized loss (0.3) (0.7)  
Short-term investments, estimated fair value 20.8 29.3  
Asset backed securities      
Cash and Cash Equivalents [Line Items]      
Short-term investments, amortized cost 8.6 19.2  
Short-term investments, unrealized gain 0.0 0.0  
Short-term investments, unrealized loss (0.2) (0.3)  
Short-term investments, estimated fair value 8.4 18.9  
U.S. agency obligations      
Cash and Cash Equivalents [Line Items]      
Short-term investments, amortized cost 3.8 3.8  
Short-term investments, unrealized gain 0.0 0.0  
Short-term investments, unrealized loss (0.1) (0.2)  
Short-term investments, estimated fair value 3.7 3.6  
Supranational securities      
Cash and Cash Equivalents [Line Items]      
Short-term investments, amortized cost 1.8 1.8  
Short-term investments, unrealized gain 0.0 0.0  
Short-term investments, unrealized loss 0.0 (0.1)  
Short-term investments, estimated fair value 1.8 1.7  
Cash      
Cash and Cash Equivalents [Line Items]      
Cash and cash equivalents, amortized cost 110.6 98.3  
Cash and cash equivalents, estimated fair value 110.6 98.3  
Money market funds      
Cash and Cash Equivalents [Line Items]      
Cash and cash equivalents, amortized cost 625.7 1,230.0  
Cash and cash equivalents, estimated fair value $ 625.7 $ 1,230.0