Post employment benefits - Duration of benefit obligations (Details)	12 Months Ended
Mar. 31, 2026	Mar. 31, 2025
Post employment benefits
Weighted average duration of defined benefit obligation	12 years	13 years

The weighted average duration of a defined benefit obligation. [Refer: Weighted average [member]]

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 19
-IssueDate 2025-01-01
-Paragraph 147
-Subparagraph c
-URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=19&code=ifrs-tx-2025-en-r&anchor=para_147_c&doctype=Standard
-URIDate 2025-03-27

Name:	ifrs-full_WeightedAverageDurationOfDefinedBenefitObligation2019
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration