v3.26.1
Financial Instruments - Summary of Movement In Credit Allowance On Customer Balance (Details) - USD ($)
$ in Millions
12 Months Ended
Mar. 31, 2026
Mar. 31, 2025
Mar. 31, 2024
Disclosure Of Financial Instruments [Line Items]      
Balance at the beginning $ (11,322)    
Impairment loss recognized / (reversed), net (9) $ (13) $ (11)
Balance at the end (10,357) (11,322)  
Accumulated Impairment | Customer Balance      
Disclosure Of Financial Instruments [Line Items]      
Balance at the beginning 114 114 117
Translation differences   (2) (2)
Impairment loss recognized / (reversed), net 9 13 11
Amounts written off (30) (11) (12)
Balance at the end $ 93 $ 114 $ 114