Employees' Stock Option Plans (ESOP) - Schedule of Break-up of Employee Stock Compensation Expense (Parentheticals) (Details) $ in Millions	12 Months Ended
Mar. 31, 2018 USD ($)
Former Chief Executive Officer and Managing Director
Disclosure Of Terms And Conditions Of Sharebased Payment Arrangement [Line Items]
Reversal of stock compensation cost toward forfeiture of stock incentives	$ 5

Line items represent concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes of the table.

No definition available.

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