v3.26.3
Acquisitions - Narrative (Details) - USD ($)
$ / shares in Units, $ in Millions
 1 Months Ended 3 Months Ended 9 Months Ended
May 14, 2026
Jul. 02, 2024
Jun. 30, 2026
Apr. 29, 2026
Jan. 31, 2026
Nov. 30, 2025
Sep. 30, 2026
Sep. 30, 2026
Sep. 30, 2025
Dec. 31, 2025
May 12, 2025
Business Combination [Line Items]                      
Goodwill*             $ 6,992.6 $ 6,992.6   $ 6,491.1  
Payments to acquire in process research and development               360.0 $ 0.0    
RayThera Inc.                      
Business Combination [Line Items]                      
Upfront and milestone paymentsmade to collaborative partner     $ 225.0                
TJ BIOPHARMA                      
Business Combination [Line Items]                      
Upfront and milestone paymentsmade to collaborative partner       $ 100.0              
Alcyone Therapeutics, Inc.                      
Business Combination [Line Items]                      
Payments to acquire productive assets   $ 85.0                  
Payments to acquire in process research and development         $ 35.0            
Asset acquisition, contingent consideration, range of outcomes, maximum, amount           $ 75.0          
Felzartamab | TJ BIOPHARMA | Milestone Payment, Commercial                      
Business Combination [Line Items]                      
Estimated additional payments upon achievement of development and commercial milestones       20.0              
Felzartamab | TJ BIOPHARMA | Milestone Payment, Sales-Based                      
Business Combination [Line Items]                      
Estimated additional payments upon achievement of development and commercial milestones       $ 730.0              
Felzartamab | TJ BIOPHARMA | Milestone Payment, Developmental                      
Business Combination [Line Items]                      
Estimated additional payments upon achievement of development and commercial milestones             275.0 275.0      
Felzartamab | TJ BIOPHARMA | Milestone Payment, Regulatory                      
Business Combination [Line Items]                      
Estimated additional payments upon achievement of development and commercial milestones             500.0 500.0      
Senior secured term loan                      
Business Combination [Line Items]                      
Debt instrument, face amount                     $ 1,750.0
Apellis Pharmaceuticals, Inc.                      
Business Combination [Line Items]                      
Price per share (in dollars per share) $ 41.00                    
Cash consideration paid to Apellis shareholders $ 5,406.0                    
Payment to shareholder (in dollars per share) $ 4.00                    
Outstanding unvested equity awards into cash retention awards $ 416.3                    
Pre-acquisition services 70.7                    
Contingent consideration 4.1                    
Share-based payment arrangement, expense 116.0                    
Inventory* $ 681.0                    
Weighted-average amortization period 3 years                    
Discount rate 13.25%                    
Goodwill* $ 503.5                    
Acquisition-related cost, expensed             $ 0.1 $ 30.9      
Business Combination, Separately Recognized Transaction, Acquisition-Related Cost, Expensed, Statement of Income or Comprehensive Income [Extensible Enumeration]             Selling, general and administrative Selling, general and administrative      
Apellis Pharmaceuticals, Inc. | Completed Technology                      
Business Combination [Line Items]                      
Intangible assets 4,630.0                    
Apellis Pharmaceuticals, Inc. | In-process research and development                      
Business Combination [Line Items]                      
Intangible assets 32.3           $ 32.3 $ 32.3      
Apellis Pharmaceuticals, Inc. | EMPAVELI | Completed Technology                      
Business Combination [Line Items]                      
Intangible assets 2,400.0                    
Apellis Pharmaceuticals, Inc. | SYFOVRE | Completed Technology                      
Business Combination [Line Items]                      
Intangible assets 1,900.0                    
Apellis Pharmaceuticals, Inc. | Sobi | Royalty and other revenue                      
Business Combination [Line Items]                      
Intangible assets 380.0                    
Apellis Pharmaceuticals, Inc. | Senior secured term loan                      
Business Combination [Line Items]                      
Debt instrument, face amount                     395.2
Apellis Pharmaceuticals, Inc. | Convertible note                      
Business Combination [Line Items]                      
Debt instrument, face amount                     $ 101.5
Apellis Pharmaceuticals, Inc. | Secured Debt | Line of Credit                      
Business Combination [Line Items]                      
Contingent consideration 2,000.0                    
Debt instrument, face amount 400.0                    
Apellis Pharmaceuticals, Inc. | Previously Reported                      
Business Combination [Line Items]                      
Cash consideration paid to Apellis shareholders 5,300.0                    
Outstanding compensation expense 345.6                    
Inventory* 712.0                    
Goodwill* 501.5                    
Apellis Pharmaceuticals, Inc. | Previously Reported | Completed Technology                      
Business Combination [Line Items]                      
Intangible assets 4,630.0                    
Apellis Pharmaceuticals, Inc. | Previously Reported | In-process research and development                      
Business Combination [Line Items]                      
Intangible assets $ 1.0