v3.26.1
License and Research Agreements - Share of Collaboration and Royalty Revenue Related to Crysvita (Details) - USD ($)
$ in Millions
3 Months Ended 6 Months Ended
Jun. 30, 2026
Jun. 30, 2025
Jun. 30, 2026
Jun. 30, 2025
Disaggregation Of Revenue [Line Items]        
Collaboration and license revenue $ 214 $ 167 $ 350 $ 306
Royalty revenue        
Disaggregation Of Revenue [Line Items]        
Collaboration and license revenue 102 86 149 134
Royalty revenue | Kyowa Kirin Collaboration | Royalty Revenue in North American Territory        
Disaggregation Of Revenue [Line Items]        
Collaboration and license revenue 67 55 94 84
Non-cash royalty revenue | Kyowa Kirin Collaboration | Royalty Revenue in North American Territory        
Disaggregation Of Revenue [Line Items]        
Collaboration and license revenue 27 24 39 36
Non-cash royalty revenue | Kyowa Kirin Collaboration | Royalty Revenue in European Territory        
Disaggregation Of Revenue [Line Items]        
Collaboration and license revenue 8 7 16 14
Collaboration and Royalty | Kyowa Kirin Collaboration        
Disaggregation Of Revenue [Line Items]        
Collaboration and license revenue 156 121 249 224
Collaboration and Royalty | Kyowa Kirin Collaboration | Royalty Revenue in North American Territory        
Disaggregation Of Revenue [Line Items]        
Collaboration and license revenue 94 79 133 120
Product sales        
Disaggregation Of Revenue [Line Items]        
Collaboration and license revenue 112 81 201 172
Product sales | Kyowa Kirin Collaboration        
Disaggregation Of Revenue [Line Items]        
Collaboration and license revenue $ 54 $ 35 $ 100 $ 90