Insurance services - Summary of Balances of and Changes in Separate Account Liabilities (Detail) - 9 months ended Mar. 31, 2024 ₨ in Millions, $ in Millions	INR (₨)	USD ($)
Separate Account, Liability [Line Items]
Beginning Balance	₨ 857,528.7	$ 10,289.5
Premiums and deposits	116,856.2	1,402.1
Policy Charges	(14,111.7)	(169.3)
Surrenders and withdrawals	(119,417.6)	(1,432.9)
Benefit Payments	(40,431.7)	(485.1)
Investment Performance	158,152.0	1,897.7
Other Charges	(3,159.6)	(37.9)
Ending Balance	955,416.3	$ 11,464.1
Unit-Linked Life [Member]
Separate Account, Liability [Line Items]
Beginning Balance	709,215.4
Premiums and deposits	97,196.3
Policy Charges	(12,754.4)
Surrenders and withdrawals	(104,102.3)
Benefit Payments	(37,926.8)
Investment Performance	141,987.6
Other Charges	(2,904.3)
Ending Balance	790,711.5
Unit-Linked Pension [Member]
Separate Account, Liability [Line Items]
Beginning Balance	55,986.3
Premiums and deposits	3,556.3
Policy Charges	(594.4)
Surrenders and withdrawals	(8,432.7)
Benefit Payments	(2,504.9)
Investment Performance	7,709.9
Other Charges	(124.2)
Ending Balance	55,596.3
Group Linked [Member]
Separate Account, Liability [Line Items]
Beginning Balance	92,327.0
Premiums and deposits	16,103.6
Policy Charges	(762.9)
Surrenders and withdrawals	(6,882.6)
Benefit Payments	0.0
Investment Performance	8,454.5
Other Charges	(131.1)
Ending Balance	₨ 109,108.5

Amount of cash outflow to separate account policyholder from benefit payment.

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Amount of increase (decrease) in separate account liability from performance of investment.

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Amount increase (decrease) in separate account liability from change, classified as other.

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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.

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Amount of decrease in separate account liability from policy charge.

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- Definition

Amount of cash inflow to separate account liability from premium and deposit from cash received.

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Amount of decrease in separate account liability from contract redemption and withdrawal of funds.

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- Definition

Amount of liability for variable contract in which all or portion of contract holder's funds is allocated to specific separate account and supported by assets held in separate account.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 944
-SubTopic 80
-Name Accounting Standards Codification
-Section 55
-Paragraph 18
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480078/944-80-55-18

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Reference 4: http://www.xbrl.org/2003/role/disclosureRef
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