Credit substitutes - Fair Value of Credit Substitutes for Non-Performing Credit Substitutes (Detail) ₨ in Millions, $ in Millions	12 Months Ended
Mar. 31, 2026 INR (₨)	Mar. 31, 2026 USD ($)	Mar. 31, 2025 INR (₨)	Mar. 31, 2026 USD ($)
Schedule of Available-for-sale Securities [Line Items]
Performing	₨ 273,023.1		₨ 161,179.6	$ 2,909.8
Non-performing—gross balance	0.0		0.0	0.0
Less: Non-performing losses	0.0		0.0	0.0
Non-performing credit substitutes, net	0.0		0.0	0.0
Total credit substitutes, net	273,023.1		161,179.6	2,909.8
Debt securities, other than asset and mortgage-backed securities
Schedule of Available-for-sale Securities [Line Items]
Average non-performing credit substitutes	0.0	$ 0.0	0.0
Interest income recognized on non-performing credit substitutes	0.0	$ 0.0	0.0
Debt securities, other than asset and mortgage-backed securities \| Credit Substitutes [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross non-performing credit substitutes	0.0		0.0	0.0
Debt securities, other than asset and mortgage-backed securities \| Credit Substitutes by Industry [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross non-performing credit substitutes	₨ 0.0		₨ 0.0	$ 0.0

This item represents the aggregate fair value of investments in Available for Sale Credit Substitute.

No definition available.

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- Definition

Average Gross amount during the period of credit substitute securities where cost exceeds fair value is not an other than temporary impairment (OTTI) and which is determined to be temporarily impaired.

+ References

No definition available.

+ Details

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- Definition

Credit Substitutes Performing in which payments are received or paid on a timely basis in accordance with the terms of the contract.

+ References

No definition available.

+ Details

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- Definition

Credit Substitutes Impaired Gross Amount where fair value is below cost and the decline is other than temporary.

+ References

No definition available.

+ Details

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Period Type:	instant

- Definition

Amount of interest income recognized on credit substitute securities classified as impaired during the period.

+ References

No definition available.

+ Details

Name:	hdb_ImpairedCreditSubstitutesInterestIncomeAccrualMethod
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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Amount of credit substitute net of expense on account of non-performing credit substitute.

+ References

No definition available.

+ Details

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- Definition

Gross amount of non-performing credit substitute.

+ References

No definition available.

+ Details

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- Definition

Amount of expense related to Credit substitutes based on assessment of uncollectability from the counterparty to reduce the account to their net realizable value.

+ References

No definition available.

+ Details

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- Definition

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

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 320
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-Topic 320
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- Details

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- Details

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- Details

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