v3.25.2
Financial Instruments - Schedule of Fair Value Hierarchy of Assets and Liabilities Measured At Fair Value On a Recurring Basis (Details) - USD ($)
Mar. 31, 2025
Mar. 31, 2024
Disclosure Of Fair Value Measurement Of Assets And Liabilities [Line Items]    
Financial assets $ 11,333,000,000 $ 10,215,000,000
Financial liabilities 3,468,000,000 3,439,000,000
Financial Liability Under Option Arrangements    
Disclosure Of Fair Value Measurement Of Assets And Liabilities [Line Items]    
Financial liabilities 77,000,000 72,000,000
Other Liabilities Including Contingent Consideration    
Disclosure Of Fair Value Measurement Of Assets And Liabilities [Line Items]    
Financial liabilities 3,000,000  
Derivative Financial Instruments    
Disclosure Of Fair Value Measurement Of Assets And Liabilities [Line Items]    
Financial liabilities 7,000,000 4,000,000
Liquid Mutual Funds    
Disclosure Of Fair Value Measurement Of Assets And Liabilities [Line Items]    
Financial assets 229,000,000 313,000,000
Liquid Mutual Funds | Investments    
Disclosure Of Fair Value Measurement Of Assets And Liabilities [Line Items]    
Financial assets 229,000,000 313,000,000
Target Maturity Fund Units    
Disclosure Of Fair Value Measurement Of Assets And Liabilities [Line Items]    
Financial assets 54,000,000 51,000,000
Target Maturity Fund Units | Investments    
Disclosure Of Fair Value Measurement Of Assets And Liabilities [Line Items]    
Financial assets 54,000,000 51,000,000
Quoted Debt Securities    
Disclosure Of Fair Value Measurement Of Assets And Liabilities [Line Items]    
Financial assets 1,602,000,000 1,620,000,000
Quoted Debt Securities | Investments    
Disclosure Of Fair Value Measurement Of Assets And Liabilities [Line Items]    
Financial assets 1,602,000,000 [1] 1,620,000,000 [2]
Certificates of Deposit    
Disclosure Of Fair Value Measurement Of Assets And Liabilities [Line Items]    
Financial assets 410,000,000 365,000,000
Certificates of Deposit | Investments    
Disclosure Of Fair Value Measurement Of Assets And Liabilities [Line Items]    
Financial assets 410,000,000 365,000,000
commercial paper    
Disclosure Of Fair Value Measurement Of Assets And Liabilities [Line Items]    
Financial assets 426,000,000 579,000,000
commercial paper | Investments    
Disclosure Of Fair Value Measurement Of Assets And Liabilities [Line Items]    
Financial assets 426,000,000 579,000,000
Unquoted Investments Others    
Disclosure Of Fair Value Measurement Of Assets And Liabilities [Line Items]    
Financial assets 23,000,000 24,000,000
Unquoted Investments Others | Investments    
Disclosure Of Fair Value Measurement Of Assets And Liabilities [Line Items]    
Financial assets 23,000,000 24,000,000
Unquoted Equity and Preference Securities    
Disclosure Of Fair Value Measurement Of Assets And Liabilities [Line Items]    
Financial assets 23,000,000 11,000,000
Unquoted Equity and Preference Securities | Investments    
Disclosure Of Fair Value Measurement Of Assets And Liabilities [Line Items]    
Financial assets 23,000,000 11,000,000
Quoted Equity Securities    
Disclosure Of Fair Value Measurement Of Assets And Liabilities [Line Items]    
Financial assets 7,000,000 14,000,000
Quoted Equity Securities | Investments    
Disclosure Of Fair Value Measurement Of Assets And Liabilities [Line Items]    
Financial assets 7,000,000 14,000,000
Derivative Financial Instruments    
Disclosure Of Fair Value Measurement Of Assets And Liabilities [Line Items]    
Financial assets 23,000,000 10,000,000
Level 1 | Liquid Mutual Funds    
Disclosure Of Fair Value Measurement Of Assets And Liabilities [Line Items]    
Financial assets 229,000,000 313,000,000
Level 1 | Target Maturity Fund Units    
Disclosure Of Fair Value Measurement Of Assets And Liabilities [Line Items]    
Financial assets 54,000,000 51,000,000
Level 1 | Quoted Debt Securities    
Disclosure Of Fair Value Measurement Of Assets And Liabilities [Line Items]    
Financial assets 1,533,000,000 1,580,000,000
Level 1 | Quoted Equity Securities    
Disclosure Of Fair Value Measurement Of Assets And Liabilities [Line Items]    
Financial assets 7,000,000 14,000,000
Level 2 | Derivative Financial Instruments    
Disclosure Of Fair Value Measurement Of Assets And Liabilities [Line Items]    
Financial liabilities 7,000,000 4,000,000
Level 2 | Quoted Debt Securities    
Disclosure Of Fair Value Measurement Of Assets And Liabilities [Line Items]    
Financial assets 69,000,000 40,000,000
Level 2 | Certificates of Deposit    
Disclosure Of Fair Value Measurement Of Assets And Liabilities [Line Items]    
Financial assets 410,000,000 365,000,000
Level 2 | commercial paper    
Disclosure Of Fair Value Measurement Of Assets And Liabilities [Line Items]    
Financial assets 426,000,000 579,000,000
Level 2 | Derivative Financial Instruments    
Disclosure Of Fair Value Measurement Of Assets And Liabilities [Line Items]    
Financial assets 23,000,000 10,000,000
Level 3 | Financial Liability Under Option Arrangements    
Disclosure Of Fair Value Measurement Of Assets And Liabilities [Line Items]    
Financial liabilities 77,000,000 72,000,000
Level 3 | Other Liabilities Including Contingent Consideration    
Disclosure Of Fair Value Measurement Of Assets And Liabilities [Line Items]    
Financial liabilities 3,000,000  
Level 3 | Unquoted Investments Others    
Disclosure Of Fair Value Measurement Of Assets And Liabilities [Line Items]    
Financial assets 23,000,000 24,000,000
Level 3 | Unquoted Equity and Preference Securities    
Disclosure Of Fair Value Measurement Of Assets And Liabilities [Line Items]    
Financial assets $ 23,000,000 $ 11,000,000
[1] On account of fair value changes including interest accrued
[2] On account of fair value changes including interest accrued