v3.26.1
Financial Instruments - Schedule of Carrying Value and Fair Value of Financial Instruments by Categories (Details) - USD ($)
$ in Millions
Mar. 31, 2026
Mar. 31, 2025
Disclosure Of Financial Instruments [Line Items]    
Financial assets amortised cost $ 8,098 $ 8,738
Financial assets at fair value through profit or loss designated upon initial recognition 6 3
Financial assets at fair value through profit or loss mandatory 282 326
Financial assets at fair value through OCI equity instruments designated upon initial recognition 72 27
Financial assets at fair value through OCI mandatory 1,899 2,228
Financial assets total carrying value 10,357 11,322
Financial assets total fair value 10,357 11,333
Financial liabilities amortised cost 3,403 3,381
Financial liabilities at fair value through profit or loss mandatory 161 83
Financial liabilities at fair value through OCI mandatory 6 4
Financial liabilities total carrying value 3,570 3,468
Financial liabilities total fair value 3,570 3,468
Trade Payables    
Disclosure Of Financial Instruments [Line Items]    
Financial liabilities amortised cost 500 487
Financial liabilities total carrying value 500 487
Financial liabilities total fair value 500 487
Lease liabilities    
Disclosure Of Financial Instruments [Line Items]    
Financial liabilities amortised cost 967 962
Financial liabilities total carrying value 967 962
Financial liabilities total fair value 967 962
Derivative Financial Instruments    
Disclosure Of Financial Instruments [Line Items]    
Financial liabilities at fair value through profit or loss mandatory 57 3
Financial liabilities at fair value through OCI mandatory 6 4
Financial liabilities total carrying value 63 7
Financial liabilities total fair value 63 7
Financial Liability Under Option Arrangements    
Disclosure Of Financial Instruments [Line Items]    
Financial liabilities at fair value through profit or loss mandatory 93 77
Financial liabilities total carrying value 93 77
Financial liabilities total fair value 93 77
Other Liabilities Including Contingent Consideration    
Disclosure Of Financial Instruments [Line Items]    
Financial liabilities amortised cost 1,936 1,932
Financial liabilities at fair value through profit or loss mandatory 11 3
Financial liabilities total carrying value 1,947 1,935
Financial liabilities total fair value 1,947 1,935
Contingent Consideration    
Disclosure Of Financial Instruments [Line Items]    
Financial liabilities total fair value 11 3
Cash and Cash Equivalents    
Disclosure Of Financial Instruments [Line Items]    
Financial assets amortised cost 2,341 2,861
Financial assets total carrying value 2,341 2,861
Financial assets total fair value 2,341 2,861
Mutual Funds    
Disclosure Of Financial Instruments [Line Items]    
Financial assets total fair value 251 229
Mutual Funds | Investments    
Disclosure Of Financial Instruments [Line Items]    
Financial assets at fair value through profit or loss mandatory 251 229
Financial assets total carrying value 251 229
Financial assets total fair value 251 229
Quoted Debt Securities    
Disclosure Of Financial Instruments [Line Items]    
Financial assets total fair value 981 1,602
Quoted Debt Securities | Investments    
Disclosure Of Financial Instruments [Line Items]    
Financial assets amortised cost 57 193
Financial assets at fair value through OCI mandatory 922 1,389
Financial assets total carrying value 979 1,582
Financial assets total fair value 981 [1] 1,602 [2]
Target Maturity Fund Units    
Disclosure Of Financial Instruments [Line Items]    
Financial assets total fair value   54
Target Maturity Fund Units | Investments    
Disclosure Of Financial Instruments [Line Items]    
Financial assets at fair value through profit or loss mandatory   54
Financial assets total carrying value   54
Financial assets total fair value   54
Certificates of Deposit    
Disclosure Of Financial Instruments [Line Items]    
Financial assets total fair value 844 410
Certificates of Deposit | Investments    
Disclosure Of Financial Instruments [Line Items]    
Financial assets at fair value through OCI mandatory 844 410
Financial assets total carrying value 844 410
Financial assets total fair value 844 410
Commercial Paper    
Disclosure Of Financial Instruments [Line Items]    
Financial assets total fair value 127 426
Commercial Paper | Investments    
Disclosure Of Financial Instruments [Line Items]    
Financial assets at fair value through OCI mandatory 127 426
Financial assets total carrying value 127 426
Financial assets total fair value 127 426
Quoted Equity Securities    
Disclosure Of Financial Instruments [Line Items]    
Financial assets total fair value 6 7
Quoted Equity Securities | Investments    
Disclosure Of Financial Instruments [Line Items]    
Financial assets at fair value through OCI equity instruments designated upon initial recognition 6 7
Financial assets total carrying value 6 7
Financial assets total fair value 6 7
Unquoted Equity and Preference Securities    
Disclosure Of Financial Instruments [Line Items]    
Financial assets total fair value 72 23
Unquoted Equity and Preference Securities | Investments    
Disclosure Of Financial Instruments [Line Items]    
Financial assets at fair value through profit or loss designated upon initial recognition 6 3
Financial assets at fair value through OCI equity instruments designated upon initial recognition 66 20
Financial assets total carrying value 72 23
Financial assets total fair value 72 23
Unquoted Investments Others    
Disclosure Of Financial Instruments [Line Items]    
Financial assets total fair value 28 23
Unquoted Investments Others | Investments    
Disclosure Of Financial Instruments [Line Items]    
Financial assets at fair value through profit or loss mandatory 28 23
Financial assets total carrying value 28 23
Financial assets total fair value 28 23
Trade Receivables    
Disclosure Of Financial Instruments [Line Items]    
Financial assets amortised cost 3,715 3,645
Financial assets total carrying value 3,715 3,645
Financial assets total fair value 3,715 3,645
Unbilled Revenue    
Disclosure Of Financial Instruments [Line Items]    
Financial assets amortised cost 1,211 [3] 1,195 [4]
Financial assets total carrying value 1,211 [3] 1,195 [4]
Financial assets total fair value 1,211 [3] 1,195 [4]
Prepayments and Other Assets    
Disclosure Of Financial Instruments [Line Items]    
Financial assets amortised cost 774 844
Financial assets total carrying value 774 844
Financial assets total fair value 772 [5] 835 [6]
Derivative Financial Instruments    
Disclosure Of Financial Instruments [Line Items]    
Financial assets at fair value through profit or loss mandatory 3 20
Financial assets at fair value through OCI mandatory 6 3
Financial assets total carrying value 9 23
Financial assets total fair value $ 9 $ 23
[1] On account of fair value changes including interest accrued
[2] On account of fair value changes including interest accrued
[3] Excludes unbilled revenue on contracts where the right to consideration is dependent on completion of contractual milestones
[4] Excludes unbilled revenue on contracts where the right to consideration is dependent on completion of contractual milestones
[5] Excludes interest accrued on quoted debt securities carried at amortized cost of $2 million
[6] Excludes interest accrued on quoted debt securities carried at amortized cost of $9 million