v3.26.1
Fair value measurement - Schedule of Fair Value of Financial Assets and Liabilities on Recurring Basis (Details) - USD ($)
$ in Millions
Jun. 30, 2026
Dec. 31, 2025
Assets:    
Available-for-sale securities: $ 13,415 $ 8,525
Equity securities 5,867 6,144
Derivatives:    
Total assets 19,595 14,913
Derivatives:    
Contingent consideration obligations 171 161
Total liabilities 937 988
Foreign currency forward contracts    
Derivatives:    
Derivative assets 306 196
Derivatives:    
Derivative liabilities 107 214
Interest rate swap contracts    
Derivatives:    
Derivative assets 7  
Derivatives:    
Interest rate swap contracts 330 293
Cross-currency swap contracts    
Derivatives:    
Derivative assets   48
Derivatives:    
Derivative liabilities 329 320
Quoted prices in active markets  for identical assets (Level 1)    
Assets:    
Equity securities 5,867 6,144
Derivatives:    
Total assets 16,660 13,539
Derivatives:    
Contingent consideration obligations 0 0
Total liabilities 0 0
Quoted prices in active markets  for identical assets (Level 1) | Foreign currency forward contracts    
Derivatives:    
Derivative assets 0 0
Derivatives:    
Derivative liabilities 0 0
Quoted prices in active markets  for identical assets (Level 1) | Interest rate swap contracts    
Derivatives:    
Derivative assets 0  
Derivatives:    
Interest rate swap contracts 0 0
Quoted prices in active markets  for identical assets (Level 1) | Cross-currency swap contracts    
Derivatives:    
Derivative assets   0
Derivatives:    
Derivative liabilities 0 0
Significant other observable inputs (Level 2)    
Assets:    
Equity securities 0 0
Derivatives:    
Total assets 2,935 1,374
Derivatives:    
Contingent consideration obligations 0 0
Total liabilities 766 827
Significant other observable inputs (Level 2) | Foreign currency forward contracts    
Derivatives:    
Derivative assets 306 196
Derivatives:    
Derivative liabilities 107 214
Significant other observable inputs (Level 2) | Interest rate swap contracts    
Derivatives:    
Derivative assets 7  
Derivatives:    
Interest rate swap contracts 330 293
Significant other observable inputs (Level 2) | Cross-currency swap contracts    
Derivatives:    
Derivative assets   48
Derivatives:    
Derivative liabilities 329 320
Significant unobservable inputs (Level 3)    
Assets:    
Equity securities 0 0
Derivatives:    
Total assets 0 0
Derivatives:    
Contingent consideration obligations 171 161
Total liabilities 171 161
Significant unobservable inputs (Level 3) | Foreign currency forward contracts    
Derivatives:    
Derivative assets 0 0
Derivatives:    
Derivative liabilities 0 0
Significant unobservable inputs (Level 3) | Interest rate swap contracts    
Derivatives:    
Derivative assets 0  
Derivatives:    
Interest rate swap contracts 0 0
Significant unobservable inputs (Level 3) | Cross-currency swap contracts    
Derivatives:    
Derivative assets   0
Derivatives:    
Derivative liabilities 0 0
U.S. Treasury bills    
Assets:    
Available-for-sale securities: 2,493 998
U.S. Treasury bills | Quoted prices in active markets  for identical assets (Level 1)    
Assets:    
Available-for-sale securities: 0 0
U.S. Treasury bills | Significant other observable inputs (Level 2)    
Assets:    
Available-for-sale securities: 2,493 998
U.S. Treasury bills | Significant unobservable inputs (Level 3)    
Assets:    
Available-for-sale securities: 0 0
Money market mutual funds    
Assets:    
Available-for-sale securities: 10,793 7,395
Money market mutual funds | Quoted prices in active markets  for identical assets (Level 1)    
Assets:    
Available-for-sale securities: 10,793 7,395
Money market mutual funds | Significant other observable inputs (Level 2)    
Assets:    
Available-for-sale securities: 0 0
Money market mutual funds | Significant unobservable inputs (Level 3)    
Assets:    
Available-for-sale securities: 0 0
Other short-term interest-bearing securities    
Assets:    
Available-for-sale securities: 129 132
Other short-term interest-bearing securities | Quoted prices in active markets  for identical assets (Level 1)    
Assets:    
Available-for-sale securities: 0 0
Other short-term interest-bearing securities | Significant other observable inputs (Level 2)    
Assets:    
Available-for-sale securities: 129 132
Other short-term interest-bearing securities | Significant unobservable inputs (Level 3)    
Assets:    
Available-for-sale securities: $ 0 $ 0