Insurance services - Summary of Effect of Reinsurance (Detail) ₨ in Millions, $ in Millions	12 Months Ended
Mar. 31, 2025 INR (₨)	Mar. 31, 2025 USD ($)	Mar. 31, 2024 INR (₨)
Premium and other operating income from insurance business:
Direct	₨ 510,646.9	$ 5,977.4	₨ 389,925.5
Assumed	2,581.4	30.2	1,588.5
Ceded	(14,963.1)	(175.2)	(9,634.5)
Total	498,265.2	5,832.4	381,879.5
Claims and benefits paid pertaining to insurance business:
Direct	537,887.7	6,296.3	383,194.5
Assumed	1,558.9	18.2	1,029.4
Ceded	(6,579.5)	(77.0)	(2,258.1)
Total	₨ 532,867.1	$ 6,237.5	₨ 381,965.8

Amount of earned premiums assumed from other entities.

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Amount of earned premiums ceded to other entities.

+ References

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Amount, before premiums ceded to other entities and premiums assumed by the entity, of premiums earned.

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Amount, before effect of policies assumed or ceded, of expense related to provision for policy benefits and costs incurred.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 944
-SubTopic 220
-Name Accounting Standards Codification
-Section S99
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-Publisher FASB
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Amount, after effects of policies assumed or ceded, of expense related to the provision for policy benefits and costs incurred.

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Amount, after premiums ceded to other entities and premiums assumed by the entity, of premiums earned.

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Amount of policy benefits and costs incurred for policies assumed.

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Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 944
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-URI https://asc.fasb.org/1943274/2147479838/944-20-50-3

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Amount of reduction of provision for policy benefits and costs incurred for policies ceded.

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