v3.26.1
Product Sales - Schedule of Net Product Sales (Details) - USD ($)
$ in Millions
 3 Months Ended
Mar. 31, 2026
Mar. 31, 2025
Disaggregation of Revenue [Line Items]    
Revenues $ 3,605.4 $ 3,028.7
Net product sales    
Disaggregation of Revenue [Line Items]    
Revenues 1,534.5 1,415.6
Libtayo    
Disaggregation of Revenue [Line Items]    
Revenues 438.2 285.1
Other products    
Disaggregation of Revenue [Line Items]    
Revenues 31.3 0.0
Lynozyfic    
Disaggregation of Revenue [Line Items]    
Revenues 11.2 0.0
U.S. | EYLEA HD And EYLEA    
Disaggregation of Revenue [Line Items]    
Revenues 941.5 1,042.8
U.S. | EYLEA HD    
Disaggregation of Revenue [Line Items]    
Revenues 468.4 306.8
U.S. | EYLEA    
Disaggregation of Revenue [Line Items]    
Revenues 473.1 736.0
U.S. | Libtayo    
Disaggregation of Revenue [Line Items]    
Revenues 286.1 192.5
U.S. | Praluent    
Disaggregation of Revenue [Line Items]    
Revenues 66.6 56.8
U.S. | Evkeeza    
Disaggregation of Revenue [Line Items]    
Revenues 45.7 30.9
Rest Of World | Libtayo    
Disaggregation of Revenue [Line Items]    
Revenues $ 152.1 $ 92.6