v3.26.1
Financial Instruments - Schedule of Fair Value Hierarchy of Assets and Liabilities Measured At Fair Value On a Recurring Basis (Details) - USD ($)
$ in Millions
Mar. 31, 2026
Mar. 31, 2025
Mar. 31, 2024
Mar. 31, 2023
Disclosure Of Fair Value Measurement Of Assets And Liabilities [Line Items]        
Financial assets $ 10,357 $ 11,333    
Financial liabilities 3,570 3,468    
Financial Liability Under Option Arrangements        
Disclosure Of Fair Value Measurement Of Assets And Liabilities [Line Items]        
Financial liabilities 93 77    
Other Liabilities Including Contingent Consideration        
Disclosure Of Fair Value Measurement Of Assets And Liabilities [Line Items]        
Financial liabilities 11 3    
Derivative Financial Instruments        
Disclosure Of Fair Value Measurement Of Assets And Liabilities [Line Items]        
Financial liabilities 63 7    
Mutual Fund Units        
Disclosure Of Fair Value Measurement Of Assets And Liabilities [Line Items]        
Financial assets 251 229    
Mutual Fund Units | Investments        
Disclosure Of Fair Value Measurement Of Assets And Liabilities [Line Items]        
Financial assets 251 229    
Target Maturity Fund Units        
Disclosure Of Fair Value Measurement Of Assets And Liabilities [Line Items]        
Financial assets   54    
Target Maturity Fund Units | Investments        
Disclosure Of Fair Value Measurement Of Assets And Liabilities [Line Items]        
Financial assets   54    
Quoted Debt Securities        
Disclosure Of Fair Value Measurement Of Assets And Liabilities [Line Items]        
Financial assets 981 1,602    
Quoted Debt Securities | Investments        
Disclosure Of Fair Value Measurement Of Assets And Liabilities [Line Items]        
Financial assets 981 [1] 1,602 [2]    
Certificates of Deposit        
Disclosure Of Fair Value Measurement Of Assets And Liabilities [Line Items]        
Financial assets 844 410    
Certificates of Deposit | Investments        
Disclosure Of Fair Value Measurement Of Assets And Liabilities [Line Items]        
Financial assets 844 410    
commercial paper        
Disclosure Of Fair Value Measurement Of Assets And Liabilities [Line Items]        
Financial assets 127 426    
commercial paper | Investments        
Disclosure Of Fair Value Measurement Of Assets And Liabilities [Line Items]        
Financial assets 127 426    
Unquoted Investments Others        
Disclosure Of Fair Value Measurement Of Assets And Liabilities [Line Items]        
Financial assets 28 23    
Unquoted Investments Others | Investments        
Disclosure Of Fair Value Measurement Of Assets And Liabilities [Line Items]        
Financial assets 28 23    
Unquoted Equity and Preference Securities        
Disclosure Of Fair Value Measurement Of Assets And Liabilities [Line Items]        
Financial assets 72 23    
Unquoted Equity and Preference Securities | Investments        
Disclosure Of Fair Value Measurement Of Assets And Liabilities [Line Items]        
Financial assets 72 23    
Quoted Equity Securities        
Disclosure Of Fair Value Measurement Of Assets And Liabilities [Line Items]        
Financial assets 6 7    
Quoted Equity Securities | Investments        
Disclosure Of Fair Value Measurement Of Assets And Liabilities [Line Items]        
Financial assets 6 7    
Derivative Financial Instruments        
Disclosure Of Fair Value Measurement Of Assets And Liabilities [Line Items]        
Financial assets 9 23    
Level 1 | Mutual Fund Units        
Disclosure Of Fair Value Measurement Of Assets And Liabilities [Line Items]        
Financial assets 251 229    
Level 1 | Target Maturity Fund Units        
Disclosure Of Fair Value Measurement Of Assets And Liabilities [Line Items]        
Financial assets   54    
Level 1 | Quoted Debt Securities        
Disclosure Of Fair Value Measurement Of Assets And Liabilities [Line Items]        
Financial assets 898 1,533    
Level 1 | Quoted Equity Securities        
Disclosure Of Fair Value Measurement Of Assets And Liabilities [Line Items]        
Financial assets 6 7    
Level 2 | Derivative Financial Instruments        
Disclosure Of Fair Value Measurement Of Assets And Liabilities [Line Items]        
Financial liabilities 63 7    
Level 2 | Quoted Debt Securities        
Disclosure Of Fair Value Measurement Of Assets And Liabilities [Line Items]        
Financial assets 83 69    
Level 2 | Certificates of Deposit        
Disclosure Of Fair Value Measurement Of Assets And Liabilities [Line Items]        
Financial assets 844 410    
Level 2 | commercial paper        
Disclosure Of Fair Value Measurement Of Assets And Liabilities [Line Items]        
Financial assets 127 426    
Level 2 | Derivative Financial Instruments        
Disclosure Of Fair Value Measurement Of Assets And Liabilities [Line Items]        
Financial assets 9 23    
Level 3 | Financial Liability Under Option Arrangements        
Disclosure Of Fair Value Measurement Of Assets And Liabilities [Line Items]        
Financial liabilities 93 77 $ 72 $ 73
Level 3 | Other Liabilities Including Contingent Consideration        
Disclosure Of Fair Value Measurement Of Assets And Liabilities [Line Items]        
Financial liabilities 11 3    
Level 3 | Unquoted Investments Others        
Disclosure Of Fair Value Measurement Of Assets And Liabilities [Line Items]        
Financial assets 28 23    
Level 3 | Unquoted Equity and Preference Securities        
Disclosure Of Fair Value Measurement Of Assets And Liabilities [Line Items]        
Financial assets $ 72 $ 23 $ 11 $ 24
[1] On account of fair value changes including interest accrued
[2] On account of fair value changes including interest accrued