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Financial Instruments and Fair Value - Fair Value Measurements (Details) - USD ($) $ in Millions | Sep. 30, 2025 | Dec. 31, 2024
--- | --- | ---
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Fair Value | $ 1,318.7 | $ 1,126.4
Marketable equity securities | 98.1 | 64.2
Fair Value | 1,416.8 | 1,190.6
Certificates of deposit and term deposits |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Fair Value | 102.3 | 61.8
U.S. government and agency securities |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Fair Value | 560.5 | 469.5
Commercial paper |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Fair Value | 370.5 | 428.7
Corporate debt securities |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Fair Value | 285.4 | 166.4
Recurring Basis | Fair Value |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Total | 1,625.8 | 1,546.4
Recurring Basis | Fair Value | Cash equivalents |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Fair Value | 209.0 | 355.8
Recurring Basis | Fair Value | Short term investments |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Fair Value | 1,127.7 | 1,190.6
Recurring Basis | Fair Value | Long-term investments |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Fair Value | 289.1 | 0.0
Recurring Basis | Fair Value | Level 1 |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Total | 819.0 | 824.8
Recurring Basis | Fair Value | Level 1 | Cash equivalents |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Fair Value | 170.5 | 296.1
Recurring Basis | Fair Value | Level 1 | Short term investments |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Fair Value | 535.2 | 528.7
Recurring Basis | Fair Value | Level 1 | Long-term investments |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Fair Value | 113.3 | 0.0
Recurring Basis | Fair Value | Level 2 |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Total | 806.8 | 721.6
Recurring Basis | Fair Value | Level 2 | Cash equivalents |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Fair Value | 38.5 | 59.7
Recurring Basis | Fair Value | Level 2 | Short term investments |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Fair Value | 592.5 | 661.9
Recurring Basis | Fair Value | Level 2 | Long-term investments |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Fair Value | 175.8 | 0.0
Recurring Basis | Fair Value | Level 3 |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Total | 0.0 | 0.0
Recurring Basis | Fair Value | Level 3 | Cash equivalents |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Fair Value | 0.0 | 0.0
Recurring Basis | Fair Value | Level 3 | Short term investments |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Fair Value | 0.0 | 0.0
Recurring Basis | Fair Value | Level 3 | Long-term investments |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Fair Value | 0.0 | 0.0
Recurring Basis | Fair Value | Money market funds | Cash equivalents |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Fair Value | 170.5 | 296.1
Recurring Basis | Fair Value | Money market funds | Level 1 | Cash equivalents |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Fair Value | 170.5 | 296.1
Recurring Basis | Fair Value | Money market funds | Level 2 | Cash equivalents |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Fair Value | 0.0 | 0.0
Recurring Basis | Fair Value | Money market funds | Level 3 | Cash equivalents |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Fair Value | 0.0 | 0.0
Recurring Basis | Fair Value | Commercial paper | Cash equivalents |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Fair Value | 34.0 | 59.7
Recurring Basis | Fair Value | Commercial paper | Level 1 | Cash equivalents |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Fair Value | 0.0 | 0.0
Recurring Basis | Fair Value | Commercial paper | Level 2 | Cash equivalents |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Fair Value | 34.0 | 59.7
Recurring Basis | Fair Value | Commercial paper | Level 3 | Cash equivalents |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Fair Value | 0.0 | 0.0
Recurring Basis | Fair Value | Certificates of deposit and term deposits | Cash equivalents |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Fair Value | 4.5 | 0.0
Recurring Basis | Fair Value | Certificates of deposit and term deposits | Short term investments |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Fair Value | 102.3 | 61.8
Recurring Basis | Fair Value | Certificates of deposit and term deposits | Level 1 | Cash equivalents |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Fair Value | 0.0 | 0.0
Recurring Basis | Fair Value | Certificates of deposit and term deposits | Level 1 | Short term investments |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Fair Value | 0.0 | 0.0
Recurring Basis | Fair Value | Certificates of deposit and term deposits | Level 2 | Cash equivalents |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Fair Value | 4.5 | 0.0
Recurring Basis | Fair Value | Certificates of deposit and term deposits | Level 2 | Short term investments |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Fair Value | 102.3 | 61.8
Recurring Basis | Fair Value | Certificates of deposit and term deposits | Level 3 | Cash equivalents |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Fair Value | 0.0 | 0.0
Recurring Basis | Fair Value | Certificates of deposit and term deposits | Level 3 | Short term investments |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Fair Value | 0.0 | 0.0
Recurring Basis | Fair Value | U.S. government and agency securities | Short term investments |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Fair Value | 437.1 | 469.5
Recurring Basis | Fair Value | U.S. government and agency securities | Long-term investments |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Fair Value | 123.4 | 0.0
Recurring Basis | Fair Value | U.S. government and agency securities | Level 1 | Short term investments |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Fair Value | 437.1 | 464.5
Recurring Basis | Fair Value | U.S. government and agency securities | Level 1 | Long-term investments |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Fair Value | 113.3 | 0.0
Recurring Basis | Fair Value | U.S. government and agency securities | Level 2 | Short term investments |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Fair Value | 0.0 | 5.0
Recurring Basis | Fair Value | U.S. government and agency securities | Level 2 | Long-term investments |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Fair Value | 10.1 | 0.0
Recurring Basis | Fair Value | U.S. government and agency securities | Level 3 | Short term investments |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Fair Value | 0.0 | 0.0
Recurring Basis | Fair Value | U.S. government and agency securities | Level 3 | Long-term investments |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Fair Value | 0.0 | 0.0
Recurring Basis | Fair Value | Commercial paper | Short term investments |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Fair Value | 370.5 | 428.7
Recurring Basis | Fair Value | Commercial paper | Level 1 | Short term investments |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Fair Value | 0.0 | 0.0
Recurring Basis | Fair Value | Commercial paper | Level 2 | Short term investments |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Fair Value | 370.5 | 428.7
Recurring Basis | Fair Value | Commercial paper | Level 3 | Short term investments |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Fair Value | 0.0 | 0.0
Recurring Basis | Fair Value | Corporate debt securities | Short term investments |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Fair Value | 119.7 | 166.4
Recurring Basis | Fair Value | Corporate debt securities | Long-term investments |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Fair Value | 165.7 | 0.0
Recurring Basis | Fair Value | Corporate debt securities | Level 1 | Short term investments |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Fair Value | 0.0 | 0.0
Recurring Basis | Fair Value | Corporate debt securities | Level 1 | Long-term investments |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Fair Value | 0.0 | 0.0
Recurring Basis | Fair Value | Corporate debt securities | Level 2 | Short term investments |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Fair Value | 119.7 | 166.4
Recurring Basis | Fair Value | Corporate debt securities | Level 2 | Long-term investments |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Fair Value | 165.7 | 0.0
Recurring Basis | Fair Value | Corporate debt securities | Level 3 | Short term investments |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Fair Value | 0.0 | 0.0
Recurring Basis | Fair Value | Corporate debt securities | Level 3 | Long-term investments |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Fair Value | 0.0 | 0.0
Recurring Basis | Fair Value | Marketable equity securities | Short term investments |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Marketable equity securities | 98.1 | 64.2
Recurring Basis | Fair Value | Marketable equity securities | Level 1 | Short term investments |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Marketable equity securities | 98.1 | 64.2
Recurring Basis | Fair Value | Marketable equity securities | Level 2 | Short term investments |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Marketable equity securities | 0.0 | 0.0
Recurring Basis | Fair Value | Marketable equity securities | Level 3 | Short term investments |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Marketable equity securities | $ 0.0 | $ 0.0

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