v3.26.1
Research Collaboration and License Agreements - Additional Information (Details)
$ / shares in Units, $ in Millions
 1 Months Ended 3 Months Ended 6 Months Ended 12 Months Ended
May 11, 2026
USD ($)
May 31, 2026
USD ($)
Nov. 30, 2017
USD ($)
Jun. 30, 2026
USD ($)
$ / shares
Jun. 30, 2025
USD ($)
$ / shares
Jun. 30, 2026
USD ($)
$ / shares
Jun. 30, 2025
USD ($)
$ / shares
Dec. 31, 2018
USD ($)
Dec. 31, 2015
USD ($)
Dec. 31, 2025
USD ($)
Dec. 31, 2024
USD ($)
May 31, 2024
USD ($)
Jul. 31, 2021
USD ($)
Dec. 31, 2017
USD ($)
Research Collaboration And License Agreements [Line Items]                            
Revenue       $ 249.7 $ 22.4 $ 265.3 $ 211.2              
Contract revenue receivable if milestones achieved       26.8 0.0 26.8 0.0     $ 0.0 $ 0.0      
Contract and other assets       10.6   10.6       3.8        
General and administrative       24.0 25.3 43.0 51.9              
Revenue recognized           152.9 211.2              
Collaboration settlement liability       52.7 0.0 52.7 0.0     0.0 0.0      
Contract with customer, liability       0.0 237.0 0.0 237.0     $ 205.6 $ 448.2      
Operating expenses       85.6 93.9 165.0 211.3              
Net income       $ 169.4 $ (61.2) $ 111.8 $ 21.7              
Net loss per common share, basic (in dollars per share) | $ / shares       $ 2.61 $ (0.84) $ 1.74 $ 0.30              
Net loss per common share, diluted (in dollars per share) | $ / shares       $ 2.58 $ (0.84) $ 1.70 $ 0.30              
Removal of Combination Trials                            
Research Collaboration And License Agreements [Line Items]                            
Revenue             $ 150.2              
Operating expenses             2.6              
Net income             $ 147.6              
Net loss per common share, basic (in dollars per share) | $ / shares             $ 2.04              
Net loss per common share, diluted (in dollars per share) | $ / shares             $ 2.03              
Updated Research Timelines                            
Research Collaboration And License Agreements [Line Items]                            
Revenue             $ (2.5)              
Net income             $ (2.5)              
Net loss per common share, basic (in dollars per share) | $ / shares             $ 0.03              
Net loss per common share, diluted (in dollars per share) | $ / shares             $ 0.03              
Rigel Pharmaceuticals, Inc. | License revenue                            
Research Collaboration And License Agreements [Line Items]                            
Development activities $ 40.0                          
Revenue 42.5     $ 62.5 $ 0.0 $ 62.5 $ 0.0              
Upfront license payment 70.0                          
Contract revenue receivable if milestones achieved 15.0                          
Consideration payable 42.5                          
Rigel Pharmaceuticals, Inc. | License revenue | Maximum                            
Research Collaboration And License Agreements [Line Items]                            
Contingent payments $ 320.0                          
Rigel Pharmaceuticals, Inc. | License Agreement, Sublicense Revenue                            
Research Collaboration And License Agreements [Line Items]                            
Development activities, percentage to refund 0.50                          
Revenue $ 20.0         20.0                
Pfizer, Inc.                            
Research Collaboration And License Agreements [Line Items]                            
Payments received               $ 28.0            
Pfizer, Inc. | Collaboration Agreement                            
Research Collaboration And License Agreements [Line Items]                            
Revenue       126.4                    
Contract revenue receivable if milestones achieved                         $ 650.0  
Collaboration agreement direct and incremental costs incurred           12.9                
Contract and other assets       12.9   12.9                
General and administrative       3.1                    
Revenue recognized   $ 179.1   7.3   21.7                
Collaboration settlement liability   $ 52.7                        
Pfizer, Inc. | Regulatory Milestone Related to Marketing Approvals                            
Research Collaboration And License Agreements [Line Items]                            
Contract revenue receivable if milestones achieved                         400.0  
Pfizer, Inc. | Sales-Based Milestones                            
Research Collaboration And License Agreements [Line Items]                            
Contract revenue receivable if milestones achieved                         1,000.0  
Pfizer, Inc. | Pfizer Collaboration Agreement                            
Research Collaboration And License Agreements [Line Items]                            
Revenue recognized       3.5                    
Pfizer, Inc. | Maximum | Regulatory and Sales-Based Milestones                            
Research Collaboration And License Agreements [Line Items]                            
Contract revenue receivable if milestones achieved                         $ 1,400.0  
Pfizer, Inc. | Maximum | Option Payments To License Agreement                            
Research Collaboration And License Agreements [Line Items]                            
Contract revenue receivable if milestones achieved                           $ 3.8
Pfizer, Inc. | Maximum | Development Milestone Payments                            
Research Collaboration And License Agreements [Line Items]                            
Contract revenue receivable if milestones achieved                           225.0
Pfizer, Inc. | Maximum | Sales Based Milestone Payments                            
Research Collaboration And License Agreements [Line Items]                            
Contract revenue receivable if milestones achieved                           $ 550.0
Vepdegestrant | Milestone Revenue                            
Research Collaboration And License Agreements [Line Items]                            
Revenue       $ 50.0 $ 0.0 $ 50.0 $ 0.0              
Novartis Pharma AG | License revenue                            
Research Collaboration And License Agreements [Line Items]                            
Contract with customer, liability                       $ 150.0    
Contingent payments                       $ 1,010.0    
Genentech                            
Research Collaboration And License Agreements [Line Items]                            
Payments received     $ 34.5           $ 11.0          
Genentech | Regulatory Milestone Related to Marketing Approvals                            
Research Collaboration And License Agreements [Line Items]                            
Contract revenue receivable if milestones achieved     52.5                      
Genentech | Commercial Milestones                            
Research Collaboration And License Agreements [Line Items]                            
Contract revenue receivable if milestones achieved     60.0                      
Genentech | Maximum | Development Milestone Payments                            
Research Collaboration And License Agreements [Line Items]                            
Contract revenue receivable if milestones achieved     $ 44.0