Income Tax Expense (Detail) ₨ in Millions, $ in Millions	12 Months Ended
Mar. 31, 2023 INR (₨)	Mar. 31, 2023 USD ($)	Mar. 31, 2022 INR (₨)	Mar. 31, 2021 INR (₨)
Components of Income Tax Expense Benefit Abstract
Current tax expense	₨ 156,782.9	$ 1,907.6	₨ 142,446.5	₨ 122,087.4
Deferred tax expense/ (benefit)	12,280.9	149.4	(9,887.3)	(8,267.3)
Interest on income tax refund	(2,946.4)	(35.9)	0.0	0.0
Income tax expense	₨ 166,117.4	$ 2,021.1	₨ 132,559.2	₨ 113,820.1

Amount of deferred income tax expense (benefit) pertaining to income (loss) from continuing operations.

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Name:	us-gaap_DeferredIncomeTaxExpenseBenefit
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration