Employees' Stock Option Plans (ESOP) - Schedule of Break-up of Employee Stock Compensation Expense (Details) - USD ($) $ in Millions |
12 Months Ended | ||||
|---|---|---|---|---|---|
Mar. 31, 2024 |
Mar. 31, 2023 |
Mar. 31, 2022 |
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| Disclosure Of Terms And Conditions Of Sharebased Payment Arrangement [Line Items] | |||||
| Employee stock compensation expense | $ 79 | $ 64 | $ 56 | ||
| Employee stock compensation expense | 2 | 1 | 3 | ||
| KMP | |||||
| Disclosure Of Terms And Conditions Of Sharebased Payment Arrangement [Line Items] | |||||
| Employee stock compensation expense | [1] | 8 | 6 | 9 | |
| Employees Other Than KMP | |||||
| Disclosure Of Terms And Conditions Of Sharebased Payment Arrangement [Line Items] | |||||
| Employee stock compensation expense | $ 71 | $ 58 | $ 47 | ||
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