v3.26.1
Accumulated other comprehensive income (loss) (Details) - USD ($)
$ in Millions
 3 Months Ended 6 Months Ended
Jun. 30, 2026
Mar. 31, 2026
Jun. 30, 2025
Mar. 31, 2025
Jun. 30, 2026
Jun. 30, 2025
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]            
Balance at beginning of period $ 9,055 $ 9,236 $ 9,605 $ 9,651 $ 9,236 $ 9,651
Foreign currency translation adjustments (25) (28) 170 47    
Balance at end of period 8,874 9,055 9,659 9,605 8,874 9,659
Accumulated other comprehensive income (loss)            
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]            
Balance at beginning of period (122) (97) (231) (273) (97) (273)
Foreign currency translation adjustments (22) (25) 152 42    
Balance at end of period (144) (122) (79) (231) (144) (79)
Foreign currency translation adjustments            
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]            
Balance at beginning of period (128) (99) (272) (330) (99) (330)
Foreign currency translation adjustments (31)   184   (64) 248
Amounts allocated to Noncontrolling interests and Redeemable noncontrolling interests 3   (20)   7 (26)
Balance at end of period (156) (128) (108) (272) (156) (108)
Derivatives            
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]            
Balance at beginning of period 6 2 41 57 2 57
Unrealized gain (loss) on interest rate hedges and foreign currency hedges 9   3   16 3
Net amount reclassified from AOCI to net income (loss) (2)   (19)   (4) (38)
Tax effect (1)   2   (1) 3
Amounts allocated to Noncontrolling interests and Redeemable noncontrolling interests 0   2   (1) 4
Balance at end of period $ 12 $ 6 $ 29 $ 41 $ 12 $ 29