v3.26.3
Fair Value Measurements - Summary of Assets and Liabilities Recorded at Fair Value (Details) - USD ($)
$ in Millions
Sep. 30, 2026
Dec. 31, 2025
Assets:    
Cash equivalents $ 628.1 $ 2,233.2
Marketable debt securities:   1,239.1
Marketable equity securities 97.1 118.1
Other current assets:    
Derivative contracts 32.6 10.0
Other non-current assets:    
Convertible notes 35.0 35.0
Plan assets for deferred compensation 62.1 52.2
Derivative contracts 6.4 0.4
Total 861.3 3,688.0
Other current liabilities:    
Derivative contracts 26.9 56.7
Contingent consideration obligations 152.4  
Other non-current liabilities:    
Derivative contracts   2.2
Contingent consideration obligations 121.5 246.4
Total 300.8 305.3
City Therapeutics, Inc. | Collaborative Arrangement, Transaction with Party to Collaborative Arrangement    
Other non-current liabilities:    
Collaborative arrangements, investments in counterparty   30.0
Neela Therapeutics, Inc | Collaborative Arrangement, Transaction with Party to Collaborative Arrangement    
Other non-current liabilities:    
Collaborative arrangements, investments in counterparty   5.0
Corporate debt securities    
Assets:    
Marketable debt securities:   537.6
Government securities    
Assets:    
Marketable debt securities:   648.8
Mortgage and other asset backed securities    
Assets:    
Marketable debt securities:   52.7
Quoted Prices in Active Markets (Level 1)    
Assets:    
Cash equivalents 0.0 0.0
Marketable equity securities 97.1 118.1
Other current assets:    
Derivative contracts 0.0 0.0
Other non-current assets:    
Convertible notes 0.0 0.0
Plan assets for deferred compensation 0.0 0.0
Derivative contracts 0.0 0.0
Total 97.1 118.1
Other current liabilities:    
Derivative contracts 0.0 0.0
Contingent consideration obligations 0.0  
Other non-current liabilities:    
Derivative contracts   0.0
Contingent consideration obligations 0.0 0.0
Total 0.0 0.0
Quoted Prices in Active Markets (Level 1) | Corporate debt securities    
Assets:    
Marketable debt securities:   0.0
Quoted Prices in Active Markets (Level 1) | Government securities    
Assets:    
Marketable debt securities:   0.0
Quoted Prices in Active Markets (Level 1) | Mortgage and other asset backed securities    
Assets:    
Marketable debt securities:   0.0
Significant Other Observable Inputs (Level 2)    
Assets:    
Cash equivalents 628.1 2,233.2
Marketable equity securities 0.0 0.0
Other current assets:    
Derivative contracts 32.6 10.0
Other non-current assets:    
Convertible notes 0.0 0.0
Plan assets for deferred compensation 62.1 52.2
Derivative contracts 6.4 0.4
Total 729.2 3,534.9
Other current liabilities:    
Derivative contracts 26.9 56.7
Contingent consideration obligations 0.0  
Other non-current liabilities:    
Derivative contracts   2.2
Contingent consideration obligations 0.0 0.0
Total 26.9 58.9
Significant Other Observable Inputs (Level 2) | Corporate debt securities    
Assets:    
Marketable debt securities:   537.6
Significant Other Observable Inputs (Level 2) | Government securities    
Assets:    
Marketable debt securities:   648.8
Significant Other Observable Inputs (Level 2) | Mortgage and other asset backed securities    
Assets:    
Marketable debt securities:   52.7
Significant Unobservable Inputs (Level 3)    
Assets:    
Cash equivalents 0.0 0.0
Marketable equity securities 0.0 0.0
Other current assets:    
Derivative contracts 0.0 0.0
Other non-current assets:    
Convertible notes 35.0 35.0
Plan assets for deferred compensation 0.0 0.0
Derivative contracts 0.0 0.0
Total 35.0 35.0
Other current liabilities:    
Derivative contracts 0.0 0.0
Contingent consideration obligations 152.4  
Other non-current liabilities:    
Derivative contracts   0.0
Contingent consideration obligations 121.5 246.4
Total $ 273.9 246.4
Significant Unobservable Inputs (Level 3) | Corporate debt securities    
Assets:    
Marketable debt securities:   0.0
Significant Unobservable Inputs (Level 3) | Government securities    
Assets:    
Marketable debt securities:   0.0
Significant Unobservable Inputs (Level 3) | Mortgage and other asset backed securities    
Assets:    
Marketable debt securities:   $ 0.0