v3.26.1
Goodwill and Other Intangible Assets - Changes in Carrying Amount of Goodwill (Details) - USD ($)
$ in Millions
 3 Months Ended 6 Months Ended
Mar. 31, 2026
Mar. 31, 2026
Dec. 31, 2025
Goodwill [Line Items]      
Goodwill     $ 17,828
Accumulated impairment loss     (1,195)
Goodwill [Roll Forward]      
Balance at beginning of period $ 16,633 $ 16,633  
Foreign currency translation and other   (86)  
Balance at end of period 16,547 16,547  
Americas      
Goodwill [Line Items]      
Goodwill     14,092
Accumulated impairment loss     (918)
Goodwill [Roll Forward]      
Balance at beginning of period 13,174    
Foreign currency translation and other   (4)  
Balance at end of period 13,170 13,170  
EMEA      
Goodwill [Line Items]      
Goodwill     2,388
Accumulated impairment loss     (277)
Goodwill [Roll Forward]      
Balance at beginning of period 2,111    
Foreign currency translation and other   (78)  
Balance at end of period 2,033 2,033  
Allocation of goodwill from EMEA to held for sale assets 38    
APAC      
Goodwill [Line Items]      
Goodwill     1,348
Accumulated impairment loss     $ 0
Goodwill [Roll Forward]      
Balance at beginning of period 1,348    
Foreign currency translation and other   (4)  
Balance at end of period $ 1,344 $ 1,344