v3.26.1
Significant transactions (Details) - USD ($)
$ in Millions
6 Months Ended
Sep. 02, 2025
Mar. 24, 2025
Mar. 23, 2025
Jan. 16, 2025
Jan. 15, 2025
Jun. 30, 2026
Jun. 30, 2025
Dec. 31, 2025
Disclosure of detailed information about business combination [line items]                
Goodwill           $ 9,259   $ 9,256
Acquisitions of businesses, net of cash acquired           $ 0 $ (568)  
Investment ownership percentage           21.40%    
LumiThera, Inc                
Disclosure of detailed information about business combination [line items]                
Ownership percentage in subsidiary 100.00%              
Aurion Biotech, Inc.                
Disclosure of detailed information about business combination [line items]                
Ownership percentage in subsidiary   99.00%            
Investment ownership percentage     40.30%          
Cylite Pty Ltd.                
Disclosure of detailed information about business combination [line items]                
Ownership percentage in subsidiary       100.00%        
Investment ownership percentage         8.80%      
LumiThera, Inc                
Disclosure of detailed information about business combination [line items]                
Goodwill $ 38              
Acquisitions of businesses, net of cash acquired $ (124)              
Aurion Biotech, Inc.                
Disclosure of detailed information about business combination [line items]                
Goodwill   $ 175            
Acquisitions of businesses, net of cash acquired   $ (496)            
Percentage of outstanding shares acquired   58.70%            
Total acquisition date fair value of consideration   $ 486            
Previously-held commercialization rights in intangible assets   36            
Cash paid at closing   $ 522            
Cylite Pty Ltd.                
Disclosure of detailed information about business combination [line items]                
Goodwill       $ 90       90
Acquisitions of businesses, net of cash acquired       $ (72)        
Percentage of outstanding shares acquired       91.20%        
Total acquisition date fair value of consideration               123
Cash paid at closing               $ 78